How to fix corrupted voice memo (m4a) files.

Do you have broken voice memo files? You can fix those files by yourself. I will show you the steps in this article.

Voice memo files have the extension “m4a”. It is audio data encoded in the AAC format and encapsulated in MPEG4 file container. By following the instructions in this article, you can also repair files recorded by other apps like QuickVoice or recorded on Android phones, whose extensions may be “mp4” or “3gp”.

The m4a files get broken when some parts of header lost correct information.
For example, when the bytes indicating the length of the audio data become 0, the file can not be replayed any more on iPhone, iPad, Mac or Windows PC.

But, in some cases you can fix the broken header by yourself by extracting the audio data, encoding it, and putting it into the new file container.

Let’s do it together.

STEPS for Windows PC

1. Download faad.exe

Open http://rarewares.org/aac-decoders.php
Click “Download (225kB)” of “FAAD2v20100614 CVS snapshot for Win32“.
faad

Extract faad.exe from the downloaded zip file.
Place it in the “Downloads” folder, for example.

Be noted that the extracted file name is “faad.exe” although the downloaded file name is “faad2-20100614.zip”.

2. Download faac.exe

Open http://rarewares.org/aac-encoders.php
Click “Download (191kB)” for “FAACv1.28 Binary for Win32“.faac

Extract faac.exe from the downloaded zip file.
Place it in the same folder as above.

For example, you see faad.exe and faac.exe in the Downloads folder as below.
downloads

3. Download hex editor

You can choose any favorite hex editor.
If you don’t know well, I will recommend HxD.
Download a zip file from http://download.cnet.com/HxD-Hex-Editor/3000-2352_4-10891068.html or http://mh-nexus.de/en/downloads.php?product=HxD
Extract setup.exe and click it to install.

4. Place the file to the same directory.

Move your voice memo file from your iPhone to PC via iTunes. You can use other tools like iFunbox.

Please place the copied file to the same directory as where you placed the above faad.exe and faac.exe.
We call the file “20140615 163625.m4a”, for example.

5. Open the file with binary editor.

Please copy the broken m4a file to some folder for backup.
Start HxD or your binary editor program and open the broken m4a file.

Press F key with control key to open the Find box.
Type “mdat” and press the Find button.

Select from the beginning of the file to the “t” of “mdat” as shown below.

find_mdat

You have to select everything before the word “mdat” plus the word “mdat”.

Press Delete key to delete the selected area.
Press S key with control key to save.

6. Decode by faad.exe

Press R key with Windows key to open the dialog.
Type “cmd” and press OK button to open the Command Prompt.

In the command prompt window that was opened, type “cd Downloads” to move the Downloads folder.
Type faad.exe “20140615 163625.m4a” and press the Enter key.
In seconds or tens of seconds, you will find the decoded wave file named “20140615 163625.wav“.

Check if the command histories are like below.
cmd1

7. Encode by faac.exe

In the command prompt window, type faac.exe -b 160 -o repaired.m4a “20140615 163625.wav” and press the Enter key.

In seconds or minutes, you will find the encoded file named repaired.m4a.
Please replay the repaired.m4a to see the audio content is what you want.

Check if the command histories are like below.
cmd2

Did you succeed?
If you encounter any difficulties, please feel free to post a comment.

Repair Service

If you want us to repair your corrupted files, please send email to repair_m4a_service@sysfrontier.com

The price depends on the recording length recovered as shown below:

Length recoveredFee
0 – 15 minutes$10
15 – 60 minutes$20
1 – 2 hours$30
2 – 4 hours$40
4 – 8 hours$50
more than 8 hours$60

It usually takes one or two days to repair a file. If it is urgent, we can repair it within a few hours, but the additional fee, $20, is required.

You can pay the fee via PayPal.

If the file is very large, please upload it to Dropbox, Google Drive, or WeTransfer and send us the share link.

Donation

If you succeeded in repairing your files by following the methods described in this article, that is our pleasure. And if you have willingness to donate some to us, the pleasure will be doubled❗😃

Private Policy

We don’t disclose any information included email and audio files
without customer’s permission.

We will delete completely all the files, which are original corrupted files,
temporary files for repair work and repaired files, after we provided
the service or the customer canceled the service.

Company Information

SysFrontier Inc.
3-23-16, Ekoda, Aoba Ward, Yokohama, 225-0005, Japan.

See the company profile for more details.


Comments

380 responses to “How to fix corrupted voice memo (m4a) files.”

  1. I have a M4A file that I can’t open it shows zero duration and the size of the memo is around 80 MB and I use Mac how can I fix it?

    1. sysfrontier Avatar
      sysfrontier

      You can use 0xED editor http://www.suavetech.com/0xed/0xed.html to find a mdat area and extract it.
      But, then you should use m4a decoder and encoder running on Windows.

      1. Suman Kumar Avatar
        Suman Kumar

        Hi,
        By following your instructions, I have repaired the m4a file recorded on android phone by google recorder. But, there is one problem. The pitch of the sound has changed.
        The recording was of lectures & discussion of two male people but now it is sounds different like two females are discussing…
        Please help. Thank you.

      2. Johnson John Avatar
        Johnson John

        Kind of experiencing the same thing but with window 10 pro i opened with the extractor and all i are zeros any assistance to that please.

    2. I kind face the same situation i wish there is someone with the proper solution to it.

  2. Great info!

    Recovered two corrupted m4a from a BB10 device.

    Thanks

  3. I am getting stuck on step 6 with the decode. The command prompt says “Unable to find correct AAC sound track in the MP4 file”. Is there any way I can get some additional help?

    1. sysfrontier Avatar
      sysfrontier

      The file that you try to decode doesn’t seem to start with a correct byte of AAC sound data.
      Please extract another place from the original file, then try decoding.
      Keep doing so until you find the correct starting byte of audio data.

      1. JiniTwist Avatar
        JiniTwist

        Another place, such as where? I don’t understand hexidecimal, so I’m not clear what to remove or leave alone, to figure out how to make the right adjustments.

        1. It worked deleting all the zeroes up to the first non-zero (in my case it was an exclamation mark)

          1. Thsi worked for me, thanks!

          2. man you saved my life, thanks

      2. WOW!!!!! Awesome!!!! I had the same problem with “Unable to find correct AAC sound track in the M4a file” until I deleted the mdat data correctly. In my case I had to start at the beginning of the file up until the t in mdat which was pretty far from beginning to mdat line. Thank you so much!!!!!

  4. My m4a file cannot be recovered using the steps above, could you help to recover and then let me know?
    https://www.sendspace.com/file/XXXXXXX

    1. Gino Razionale Avatar
      Gino Razionale

      I’ve used this procedure to fix at least 5 files. I’m recording my band live with a Zoom Q3 HD recorder and if I don’t shut down properly I run into this problem. It happened again and I started the procedure but when I got to faad.exe “filename” it started to decode but stopped at 7% and I got an “ERROR: Maximum number of bitstream elements exceeded”. Not sure what to do at this point. Any suggestions? Thank you for such a wonderful procedure.

  5. You are a hero! Thanks…

  6. Someone very grateful Avatar
    Someone very grateful

    I never post online comments, but I will make an exception for this page. Your instructions helped me recover a corrupted iPhone recording I had thought to be lost, and what’s more, in a very simple, quick way (and without the high fees asked by recovery services). This made my day, and I thank you for that. Have a good one.

    1. Collins Avatar
      Collins

      I am with you on this one. I seldom post online but this page is a life saver! Awesomely great and easy to follow instructions? Check! Lost file recovered? Check! One happy human? Check check check!! My faith in Humanity is restored! Thank you Sys Frontier Inc!!!!!

      1. sysfrontier Avatar
        sysfrontier

        You saved your file. Great Job!

        1. Fawad khan Avatar
          Fawad khan

          Sir my name is fawad i have six iphone voice memos which is not working now i want you to fix it for me and i will pay my id is ******@****.com

      2. Hi, is it still possible to repair my file of ‘mdat’ can’t be found on hxd? Thanks in advance, Sarah.

  7. Hasitha Avatar
    Hasitha

    Dear sir, i want you to help me. I recorded a file which is related to university research purpose. now it is not working. it says that it is corrupted. I want you to help me. please please please…

    my email address is here. XXXXXXXX@yahoo.com

    please help me. I tried your method, i think i cannot do it because my english is poor. please help to fix this

  8. Oke, i can’t find mdat at step 5?

    1. sysfrontier Avatar
      sysfrontier

      Please try to find the beginning of the AAC audio data. Then, extract and decode it.

      1. saurabh chuahan Avatar
        saurabh chuahan

        how to identify beginning of aac data ? and what about size and number of sample

      2. Gursimar Avatar
        Gursimar

        Same here hex editor shows cant find mdat

  9. Your instructions are very good! thanks al lot!

    However I have a problem with the last step, when i run faad.exe , the cmd prompt says “unable to find correct AAC sound track in the MP4 file.” What did I did wrong?

    Thanks in advance!

  10. Not sure this information has been posted elsewhere – this is absolutely golden and allowed me to recover what I thought might be a lost voice recording on my blackberry which crashed whilst recording.

    Thank you very much for your help.

  11. Khai Tran Avatar
    Khai Tran

    Thank you for your instruction.

    I got stuck at step 6 with the error: Bitstream value not allowed by specification.

    Please guide me to fix this error.

    1. It’s explained here a little further.

      I got the same error but the generated .wav worked fine for me. It is normally audible and when I went forward with the last step, I also got a repaired .m4a file that worked also fine 🙂

      Thanks a lot to Sysfrontier.

  12. Filipe Carvalho Avatar
    Filipe Carvalho

    Hi! I cannot find ‘mdat’ and not sure how to solve it. Could I send you the file? Thank you very much!

  13. Hello how do I find the mdat area ? I found the mdat tag but how do i determen the end of the area. I assume that the meat tag is the start of the area. I am using the 0xED editor.

    thank you for your information

    1. mdat tag not meat tag, autocorrect grrr

    2. sysfrontier Avatar
      sysfrontier

      The 4 bytes before the mdat tag indicates the length of the mdat area. It might be in little endian byte order.

      1. There are 4 points in front of mdat. The 4 points are the eight zeros which are the four bytes ?

        00 00 00 00 6D 64 61 74 = ….mdat

        is this string of numbers what i need to delete including the mdat tag ?

        what length amounts 00 00 00 00 to ?

        I appreciate your answers greatly, I lack the common knowledge to translate the bytes into the length of the area. I have googled greatly but cannot find the “for dummies” version.

        1. sysfrontier Avatar
          sysfrontier

          Right, 8 zeros are the four bytes. But, these zeros should be replaced with correct length of mdat. It is impossible to do it by calculation because the file is not in the correct format. The only way I found is to decode and encode the remaining AAC audio data to regenerate the audio file again as I wrote in this article.

          1. WOOHOO it worked, i was thinking waaaaaaay too much. I thunk that an “area” in an hex editor must be something really complicated that would be something in the middle of the file that needed to be calculated………….

            Literally select from and including the first symbol in the left column of the hex editor to and including the letter “t” of “mdat” and delete the whole beginning area. Followed your steps and it just worked.

            Thank You Thank You Thank You

  14. I meant the right column in the hex editor where i found the mdat tag.

  15. When decoding i am facing below issue.

    recording162 file info:
    RAW

    Error: PCE shall be the first element in a frame
    0% decoding recording162.

    Plz help me.

  16. Hi, got stuck at Step 6. Seems m4a file went from nearly 90Mb to 20mb. Is it possible to email you the file directly for assistance? Thanks,

  17. HELLO I have a file I was hoping you could help me with. its about 29mb, I only have access to a mac

  18. Bob Jackson Avatar
    Bob Jackson

    Just used these instructions to salvage a corrupted 45 minute research interview. The decoding and encoding worked flawlessly.

    The repaired file is twice the size of the original — this because the original was mono and the recovered file is stero.

    In this case the “mdat” string was not found. So I found the beginning of what looked like data and deleted everything prior to it. It appears the absence of this string was what caused the corruption in the first place.

    Thank you for taking the time to describe this process and the available tools. This is a valuable and informative technique!

  19. Hello, thank you for your time and helpfulless! I am finally feeling hopeful but now that I’ve downloaded all the files and got iHex, I’m realizing I can’t open the faac file and that you clearly wrote STEPS for Windows PC!

    Do you know if there is another decoder for mac? And encoder? Maybe some more steps?! lol I’m willing to pay to get my m4a files fixed. I can’t open them in iTunes (no error, just won’t load) or QuickTime (gives an error that the file is either damaged or unsupported). I downloaded and deleted them from iTunes (as well as my iPhone) a few months ago so now all I have is the corrupted file :s

    Thank you!

  20. Freek Avatar
    Freek

    Hi, got stuck in step six. command prompt says error opening file.. Help please

  21. LBURNS Avatar
    LBURNS

    I have a file that is corrupt from an iPhone recording app.
    It contains evidence of a conversation with in a legal matter and the app crashed at some point, but not after it capture over 10MB of audio.

    I tried fixing it myself, but failed.

    Can you assist me?
    This is extremely important to me.

    How can I get this file to you?

  22. Tarak Patel Avatar
    Tarak Patel

    I have a very important file 12MB

    It is not working cause the phone crashed while it was recording. It’s m4a and I need it recovered fast.

    I will pay for service.

    Can you please help and tell me next steps?

  23. Works great!

    Was able to decode 72% of the file before the following error : ‘PCE shall be first element in a frame’

    A .wav file is still created but is missing the other 28% of the audio – Any suggestions?

  24. Matias Avatar
    Matias

    YOU SAVE MY LIFE! IT WORKS, IVE LOST 20 HOURS SEARCHING IN THE WEB, BECAUSE IT WAS A FILE FOR MY THESIS.

    THANKS MAN!

  25. Found your webpage a few days ago. Worked on following your instructions. I suspect it took me longer to get to a successful conclusion than most.

    Yesterday, I tried again. I finally figured out how much of the corrupted file to delete with the binary editor in Step 5; finally remembered to add the .m4a extension to Step 6 with faad.exe; finally was able to get to Step 7 and faac.exe; faac.exe started running and in no time I had a ‘repaired’ file; and, I opened the repaired file to hear the voices on the recording that I thought I had lost for good.

    Though I may have struggled more than most, the fact remains that you have provided us with such a really simple process that generates such an amazing result. Thank you so much.

  26. Oh my goodness! an amazing article dude. Thanks Nonetheless I am experiencing concern with ur rss . Don’t know why Unable to subscribe to it. Is there anybody getting identical rss drawback? Anybody who is aware of kindly respond. Thnkx

  27. could not locate the “mdat” using the Hex editor. Is my file a lost cause?

    1. sysfrontier Avatar
      sysfrontier

      You need to find the beginning byte of the raw audio data instead.

      1. i think this is the same problem as mine… how can i find the beginning byte? can you give me step by step instruction for this method. thanks

      2. Richard Avatar
        Richard

        This is also my problem. I’m excited to find this method of repairing m4a audio, and I was able to complete the directions using an m4a file that I knew was “good” but the file I’m trying to fix doesn’t have mdat. While searching online I found a website that will fix my file for $35 and they provided a sample, so I believe my file can be fixed, but I don’t have the needed mdat. I’m not tech savvy, but I am persistent and methodical. Can you give us more details about finding the beginning byte of raw audio? Could you recommend a link where we could learn more about that? We were to DELETE data before and including mdat, and save the remaining file. I’ve tried to DELETE starting at different points, but nothing has worked yet. In any case, what needs to be deleted would start at the beginning of the file in all cases. Is that a true statement? THANKS SO MUCH!

        1. sysfrontier Avatar
          sysfrontier

          Please skip thousands of zero-value bytes and specify the beginning of some non-zero values. Delete all the bytes before that specified point and decode the rest by faad.exe.

      3. Richard Avatar
        Richard

        Thank you for your encouragement! I have not given up;) I have tried deleting the block of zeros itself and I’ve tried deleting from the block of 0s to the beginning- no luck yet. I’ve tried deleting half the file. No luck. All those tries (plus 4 others) have produced “Error: Channel coupling no yet implemented.” However, when I deleted a little less that half of the data I got a different message. “Error: PCE shall be the first element in the frame.” I wanted to reiterate that I do think something can be retrieved because I heard a sample of it from a website that wanted $35 to fix the file. If I had not heard that sample I would never have thought some of the m4a audio could be retrieved. I appreciate your help. I will keep trying and follow up with what I find. Thank you!

        1. Richard Avatar
          Richard

          I see Wyatt wrote: “Was able to decode 72% of the file before the following error : ‘PCE shall be first element in a frame’” I felt I should clarify my last post to say I also got that message but it did not decode any of the file. 0%. No .wav file. Richard

  28. Knincas Avatar
    Knincas

    Hi! I try to recover a voice file broken but when I do the 6 step the command prompt window says “Error opening file” and anything happen…

    What I suppose to do?
    Thank you in advance.

  29. I cant search mdat when i open in binary editor as per step 5

  30. Hello. fantastic job. I did not anticipate this. This is a splendid story. Thanks!

  31. JiniTwist Avatar
    JiniTwist

    Figured it out! The wording on step 6 just confused me a bit; thought it meant the beginning of the word “mdat”, to the end of the t, not everything up until the last letter of “mdat”. I appreciate you making this available.

    And I’ve just this minute gotten the recovered version; the entire 1.15 hour lecture I recorded! I’m really happy for this, because it was the most important of the series, and I only expected about half that to be saved in there after seeing an expensive audio recovery service’s assessment. You’re a gentleman and a scholar and I wish you nothing but happiness and success in your endeavors. Have a great day!

  32. bharadwaj Avatar
    bharadwaj

    i have couple of .m4a files which are corrupted and need fixing. can u please help ?

  33. Hey, I tried this method, but still unsuccessful… can you help me out?

  34. ironmike Avatar
    ironmike

    Excellent advice. So nice to find a well written process, using good tools, from someone who understands the audio codecs and wrappers. I am very grateful to Sysfrontier and the author/s.

  35. Elliot Avatar
    Elliot

    I have a 25 minute file that was unfortunately corrupted. Any chance you have time to re-package for me? I’m on mac and not .root savvy. Thanks

  36. Peter Best Avatar
    Peter Best

    Excellent. Very clear instructions. Good result. Thank you.

  37. Jeremy Christie Avatar
    Jeremy Christie

    Please fix my voice memo file. I would be really grateful for your help.

  38. i have the file in a .m4a but file will not play back quicktime say it can not open itunes does do anything can not hear in preview area

    1. sysfrontier Avatar
      sysfrontier

      Does it have mdat tag? If so, you can recover the data by yourself.

  39. Katherin Avatar
    Katherin

    MAN! YOU REALLY DON’T KNOW HOW MUCH I’M LOVING YOU RIGHT NOW!!!

    i gave for lost my m4a file, and you really healp me 😀

    Thank you, seriouly!

  40. hi
    thank you for your information but when i go to the cmd and type faad filename.m4a it responses:
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    Unable to find correct AAC sound track in the MP4 file.

    1. sysfrontier Avatar
      sysfrontier

      It might be possible that you extracted the wrong place. Please follow the article’s instructions again.

  41. Awesome, you saved my butt. Thanks so much! This worked great for me.

  42. Could you please do this for me, I keep getting error, cannot open file “Voice 006.m4a” why is that?

  43. how do i fix “the error: Bitstream value not allowed by specification.”

    1. sysfrontier Avatar
      sysfrontier

      Did you find the mdat area? Please follow the article’s instructions exactly again.

      1. Yes i did

        1. sysfrontier Avatar
          sysfrontier

          The area that contains encoded audio data might be screwed up. I need to take a look at the file to know if I can repair it or not.

  44. You are awesome Avatar
    You are awesome

    Just recovered a very important file, thank you so much!

  45. help me out ,unable to resolve it .
    is there any way to recover..?

    Error opening file: 1.m4a

    C:\Documents and Settings\KINGU1\My Documents\Downloads\New Folder>faad.exe “1.m
    4a”
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    Error opening file: 1.m4a

  46. Am not at all tech savvy but really appreciating your clear instructions and am desperate to retrieve a recorded interview on voice memo. I think I’ve got the process up to step 6 but then I get this message “is not recognised as an internal or external command, operable programme or batch file.”

    Can you help?

    1. sysfrontier Avatar
      sysfrontier

      You may not be in the same folder as the folder that has faad.exe. Please put the faad.exe in the same folder.

      1. Definitely all in the same folder. File route is C:/Users/Sarah> into which I am putting faad.exe and the file name in double quotation marks. It can’t read it – I get the same error message. What am I doing wrong?

      2. Is there any way I can get you to have a look at this file for me?

        1. sysfrontier Avatar
          sysfrontier

          In the command prompt window, please type “cd C:/Users/Sarah” and “faad …”.
          Or, please move all files to the Downloads folder and follow the instructions on the article.

          1. Still struggling. I have tried deleting everything from mdat to the start with HxD and I’ve also tried deleting more but it seems to make no difference. The file – several versions of it – are in the downloads folder and so are faad and faac but I just cannot get it to work from the command prompt. I can see that there is 3.88MB in the file and I tried to look at in on a video recovery programme and can see that there is a recording there. Any other ideas?

          2. Same problem, Didi you fix it?

          3. sysfrontier Avatar
            sysfrontier

            Did you put all of faad.exe and your m4a files together into the same folder? In the command prompt, please type “dir” to make sure that you have faad.exe there.

  47. Hello, Im getting the error “faad.exe is not recognized as an internal or external commad, operable program or batch file” Any ideas? Im on 64win virtual machine…
    Thanks for the help

  48. Worked beautifully. A corrupted bb playbook voice memo mpa file recovered on windows 7 using Frhed as the editor. Stumbled over what was to be deleted at first but caught on at eventually: “Select from the beginning *of the file* to the “t” of “mdat”.

    This page absolutely deserves it’s spot at the top of the google search results. Great job and a great site, thank you!

    1. sysfrontier Avatar
      sysfrontier

      Thank you for improving the description! I updated.

  49. I recorded a short story for my granddaughter on voice memo but it is corrupted. I tried your well written instructions many times but am too much of an old timer. Can you fix the file for me if I send it to you?

    1. sysfrontier Avatar
      sysfrontier

      Yes, I can do it for you. I’ll send you email.

      1. Hi! Can you please help me with my corrupt file? I followed all the steps, yet I am still unable to play my voice memo. Your help will be much appreciated! This voice memo means a lot to me. Thank you so much. I look forward to hearing back from you soon.

  50. This worked very well. Thank you very much! It saved one of my children’s recordings.

  51. Thanks a lot for the explanation!

    It worked quite well but! after decoding it says:

    Error: Bitstream Value not allowed by specification

    I tried to encode – got the *.wav an die repaired one but all without playing. May I send you my file to have a closer look?

    Best wishes!

  52. as an addition: if there is an easy way to fix it I will try to do this on my own. It would be great if you just could help me. This is an important interview for my thesis! Would be more than great to have this problem solved!

    1. sysfrontier Avatar
      sysfrontier

      It is very difficult to know what really happens in your file. You may send it to me so that I can find the problem.

  53. You make my day! couple of hours spending on recover recorder from wedding. SUCCEED!

  54. neeljesse Avatar
    neeljesse

    May I please email you my file?
    ——@—-.com
    It’s less than ten minutes long and I’ve been trying to do this for over a week..the recording was on an iphone 6 on ‘voice recorder pro’ app, while recording I accidentally turned the phone off..it’s saved as an mp4 file with aac format..has about 5mb data and 00:00 duration..it literally does not have mdat anywhere in the binary editor, I’ve also compared it to several good versions to match it up.. heres the message im getting now, ive tried it as mp4 and m4a–
    **************************************************************************

    20150929-140454(2).m4a file info:
    RAW

    ———————
    | Config: 2 Ch |
    ———————
    | Ch | Position |
    ———————
    | 00 | Left front |
    | 01 | Right front |
    ———————

    Error: Bitstream value not allowed by specification

    C:\Users\TR_User\Downloads>

    I am hoping to hear from you via email so I may send you the clip, it’s very important and maybe you will be able to help others who have had this exact issue, it’s been almost impossible to find anyone else with this specific experience.

    Thank you so much!!

  55. Heya i am for the primary time here. I came across this board and I find It really useful & it helped me out much. I hope to provide something again and aid others like you helped me.

  56. Hasithaq says:
    March 29, 2015 at 12:28 AM
    it does not work for me. there is an error indicating “Error opening file “SoundFile-8.m4a”

    im stuck at step 6 like the guy above, anyone can help?

  57. imauricem Avatar
    imauricem

    Hi!
    Thanks for the very clear explanation… However…. There is no mdat to be found in the file. So I can’t make it work. I have tried to reverse engineer what else I can think of, by comparing in the hex editor the codes of a valid m4a file with my corrupted file. But nothing working yet.

    Could you please help me out? Hope to hear from you soon.

    Thanks!

  58. When I originally commented I clicked the “Notify me when new comments are added” checkbox and now each time a comment is added I get several emails with the same comment. Is there any way you can remove me from that service? Appreciate it!

  59. Hi

    I am getting the following error when using faad.exe:

    Error: Channel coupling not yet implemented

    Any chance you could assist or even take a look at the file.

    Thanks in advance.

  60. college bound Avatar
    college bound

    Hi Thank you for sharing your expertise, the universe is grateful!
    I am not that tech savvy and I’m sure you will make fun of me that i have a mac!
    could you please decode a voice recording that got corrupt when my battery died.
    please help my daughter needs it for a college essay.. her future rides on it (no just kidding, but it is important info!)

  61. Hello, I followed each step and it seems to work fine until step 6. Instead of giving me a .wav file it says “Error: Array index out of range”. I am attempting to fix a corrupted .m4a music file

  62. exelente informacion. Pude recuperar la informacion del audio, apesar que en el paso 6 salio el error “Error: Bitstream value not allowed by specification”.

    solo hay que continuar al paso 7 con el archivo wav generado en el paso 6.

    saludos gracias por compartir la informacion.

  63. Dear,
    I have read and tried to use your instructions to
    “How to fix corrupted voice memo (m4a) files”. I can successfully use the binary editor and delete the “mdat” data. But when I use the faad.exe software it does not produce a .wav file. Can you help? I am willing to email you the file and PAY YOU to repair It. Please respond ASAP. This is an extremely important file. So please respond
    Thank you,
    Al Internicola
    Canada

  64. ERROR BITSTREAM VALUE NOT ALLOWED BY ESPESCIFICATION

  65. I have to admit I haven’t tried this at all, but out of all the help out there this post addresses my problem exactly. I have file with 13 mb but 0 seconds. I am completely lost from direction one, it might as well be in Chinese. I will however pay you via paypal if you will do it for me. I know this was posted a whole ago, so you might have rescinded your offer for help. I am desperate. Oh, and I need it by today or its no help. =D! Pretty pretty pretty please!

  66. I kept failing and kept re reading your instructions. Thank you for saving this tutorial online. A must have !

    Next thing, change the Recording app! haha

  67. very much useful for me, but i stuck up @ 6% with the error “Maximum number of beatstream elements exceeded” how to overcome this ?

  68. Can you help me? Yesterday I recorded a voice memo, it took all day. I couldn’t get it right so I kept trying. Finally I got it and it’s 4 1/2 hours long. It worked fine and was all there. Right after I finished I chose a name and saved the file. The phone died moments later, it was out of battery. This morning, I cannot play the file on the phone. It’s visible, I can move the mark anywhere on the file and see the entire waveform. But when I hit play the pause symbol comes up, but it doesn’t move along the waveform, it doesn’t play. I backed up the phone to itunes, and it doesn’t show up in the voice memo or music folder with the other voice memos. So I opened the backup file with Dr. Fone for iOS by wondershare. With that program I can see the file, it’s 87.7mb. I don’t know if that’s big enough, I’m not sure of the bit depth or sample rate the voice memo app records at, so I can’t say how large it should be. I chose to extract the file and I placed in the folder with the faad etc. The name of the file is Mads Message.m4a (Mads is a person). After the first step with the faad.exe, it says this in the cmd window “Error opening file: Mads”
    I don’t know what to do. I tried so hard to record it, I don’t think I could do it again. It’s, very important. They’re the last things I want to say to someone, who was the most significant person to me in all my 35 years. It explains important things. I hope you can help.

    1. sysfrontier Avatar
      sysfrontier

      Thank you for contacting us.
      You are trying to fix the very important file.
      Can you check again that the m4a file and the faad.exe are in the same directory?
      If they are so, could you try to do the step 5 and 6 again?
      Please make sure that you delete the area from the beginning of the file to the “t” of “mdat”.

      1. Thanks for your reply. I tried again, and I made sure I had the .m4a file, faad.exe and faac.exe all in the downloads folder. I opened the file in the binary editor. Now when you said “Select from the beginning of the file to the “t” of “mdat”.”, I wasn’t sure if you meant through the T all the way to the period, or right before the T only highlighted through the A, so I tried it both ways. So then get to the CMD prompt and I get to “cd Downloads”, then I type “faad.exe Mads Message.m4a” (Mads Message.m4a is the name of the file). I tried using “Mads Message.m4a”, and “MadsMessage.m4a”, Both times it does give me the software information for the faad.exe program, and then right below that it will just say “error opening file”, followed by the file name. So I am unable to make it through step 6, I am unable to generate the wave file.
        I will say that after examining the file in the binary editor, and comparing it with other working voice memos from the same time period, recorded on the same iOS version, there appears to be no footer. I don’t believe there is a moov atom or I guess anything that would normally be after that, I’m not sure if that is correct though as this is all new to me as of yesterday. So I tried Deleting through the T of mdat on my corrupt file, and to the T. Then I took the moov atom and eveything after that including what I guess is the footer with the date, os version etc., I took all that after the moov atom from a working voice memo and placed it at the end of my corrupt file, and then tried step 6 again, same result. Any ideas?

        1. sysfrontier Avatar
          sysfrontier

          Can you try the same steps on a working file?
          I want to make sure that a wave file is generated for the working file.

  69. Thank you very much for this tutorial! Just helped me fix a client’s audio file which I would have been in trouble if I had lost it.

    Cheers!

  70. hi i have tried multiple times but keep getting error: bitstream value not allowed by specification 0% decoding i would be very grateful if i could send you the file to see if it is recoverable ? thank you in anticipation
    grant

  71. Hi.I have a problem.I could not able to done this process.would you mind do it for me?How to send my file to YOU?

  72. Hi Sysfrontier,

    I was very encouraged to see this thread as I am dealing with the same issue. I recorded an important interview using the Quick Voice app on an iPhone 5. After stopping the recording, the phone ran out of batteries. Upon reopening the app, the 45 minute interview still shows as being 8.5 MB but it has a length of 0:00. It is an m4a ACC file. I am working on a mac and am not able to use the encoding and decoding software nor am I savvy enough to edit the header.

    I have had a diagnostic test run on the corrupt file and I know it is fixable but the company who ran the test charges exorbitant prices.

    Is there ANY way you can repackage the file for me? I can share with you a m4a file of comparable length that is playable.

    I am desperate.

    Thanks.

  73. Julie Roulston Avatar
    Julie Roulston

    Good afternoon. I have a 12 minute VoiceMemo file which won’t play (it’s an interview) – could I possibly pay you to fix it for me? Thanks in advance and kindest regards
    Julie

  74. thank u very much…. my file got repaired

  75. You guys are the best! It worked perfectly where nothing else worked. Thanks!!

    1. could you please explain the step 6 and seven to my in a more simple way Iam stuck their. thanx

  76. Hi there.
    Thank you for the instructions.
    could you please clarify step 5 ?
    isom3gp4.Þªtmdat
    should i delete this whole section? 🙁 sorry to be thick.

    1. I was being thick sorry. I am now getting “error: array index out of range” any idea?
      x

    2. sysfrontier Avatar
      sysfrontier

      Yes, please delete the section including “mdat”. For the decoding error, I need to take a closer look at the file data.

      1. Thank you for the reply Sysfrontier! i have deleted alll of the characters in front of the Mdat section and FAAD came back with an error “error: array index out of range”. :\ im sure it is something i am doing wrong, but i cant seem to figure out what 🙁

        thanks once again.
        x

  77. I just wanted to thank you. Even though the file only kept the first 8 minutes of a 25 minute conversation….and i did lose the most important part, I have to thank you for this guide. Every little step is needed to fix the file. It just sucks I have to live with this loss…..

  78. Jennifer H Avatar
    Jennifer H

    Good morning! Thank you for your help! I’m eager to recover this file, I’m somewhat computer savvy. (or used to be 15 years ago anyway) honestly, i have tried many things but Im unable to do anything with this one. I was sick when it would’t play anymore after the first play, this one of the only files that truly has a significance in meaning to me.
    My only problem is I am unable to transfer or sync it from my phone to my iTunes, it is the only file I’m unable to do so. Do you have any suggestions on how I do this or software that I can crack my iPhone 6plus operating system to pull the file? Thank you so so much!

    1. sysfrontier Avatar
      sysfrontier

      Did you try iFunbox?

      1. Jennifer H Avatar
        Jennifer H

        No I did not! I will try it! Thank you so much!

  79. Hi! I am having problems on the 6 step. When I try to decode the file it says “Error opening the file:___” Please help!

    1. sysfrontier Avatar
      sysfrontier

      The file may be corrupted in other way than described in this article.

  80. Hi, I had mistakenly formatted my memory card of my android phone. Later on I recovered the files using an data recovery software. The most important files for me were a few voice records of my class lecture. But those files were recovered as .m4a files, & they were corrupted. Then I followed the methods described in this article. For the 1st one, I could recover about 60 min of the total 80 min file. But the rest of them I could only recover a very little part of the files. Could you please comment on this issue? & help me in recovering the full files?
    Thank you very much!

    1. sysfrontier Avatar
      sysfrontier

      I’m sorry, but the parts that were not recovered can be lost forever due to the corruption of the audio data when the card was formatted.

  81. Hello, I am not tech savvy at all. Really hopeful you can help. I have two recordings on my Samsung s5 phone which used to play fine. They both show the original file name, and it seems the correct byte size and duration too. I don’t recall treating them differently than my other recordings on my phone which still play fine. Maybe I’ve stopped playing them through to the end before either turning off my phone or going to another selection..? but the other files are still ok, and I imagine I did the same with them. I see the volume bars moving when I play these two, but there is no sound. Both recorded on same date — the dates are still there. In this case, could you please help me? I really hope so. Thank you!!

    1. sysfrontier Avatar
      sysfrontier

      Can you compare the file size of the corrupted one with the working one?
      The size has an linear relationship with the recording length.
      If the file still has enough size, there’s a probability to recover the file by fixing the header, which is used for application to know necessary parameters to decode the compressed audio data.

      1. Thank you for your quick reply! Gee… I don’t understand completely. It’s over my head. The corrupted files’ full lengths are still accurately indicated. One file is 50 seconds, and the other 1 minute and 35 seconds. May I send them to you to recover? They are short but every second precious to me and irreplaceable. (Recordings of my child’s voice.) I was devastated when I discovered they wouldn’t play sound any more. If so, thank you so, so much!!!

  82. ChristianG Avatar
    ChristianG

    Hi,

    First of all, I would like to thank the author of this article for the effort in helping those with corrupted mp4 files.

    I just want to seek your help in explaining the meaning of this error, after decoding:

    Error: PCE shall be the first element in a frame

    Thanks in advance for any explanation.

  83. Anton Pan Avatar
    Anton Pan

    It worked. Thank you very much.

  84. Hi, this is Sun who is lived in Korea.
    First of all, Thank you for your detailed explanation about how to repair my corrupted m4a file even if I haven’t succeed, yet.
    I followed your description but I have in trouble because “corrupted.wav“ file was not appeared.
    even though I typed faad.exe “corrupted.m4a” , “corrupted.wav“ file was not appeared like below figure.

    I send an email for more detail explanation.
    Thank you.

  85. Hi. I finally did it. I really thank you sincerely.

  86. I send an email to ask another case problem.
    Thank you.

  87. F1Sierra Avatar
    F1Sierra

    awesome!!!, it really fix it, i recorded a 13 hours voice memo with my iPhone s4, it was fine, but it crashed when I was plugin the head phones and by mistake I select the option to cut the audio, well since then it was´t able to play, even it wasn´t able to pass to the iTunes… This is the only solution I get in the whole web, and it fix my voice memo, now i can hear it, ATTENTION: IT ONLY FIX 4 HOURS, well is better something than nothing, i just follow the instruction, thanks,

  88. Thank you soooo much. Anybody having this problem, it works perfect. Thank you.

  89. UPENDRA Avatar
    UPENDRA

    Well SysFrontier, I am getting the “Error: Array index out of range” What does that mean? What should I do or not do?

  90. Jochem Avatar
    Jochem

    Fixed it!!! Great help!!! Thanks a lot for your information.

  91. Great, i can do it. Thank you a lot

    I have met all the errors that you guys listed above.
    The first time, i was not succesful because the of the long path road of the folder that contains all the files (Downloads\a\b\c\d…), you should put all in a folder in DESKTOP and simplify all the file names).

    My advice: Just create simple name for files and simple path road for the folder. It will work the second time

    Don’t give up

  92. alireza Avatar
    alireza

    Recoverd an important file a moment ago. Thanks alot man thanks alot!

  93. You, sir, are a friggin genius. That was crazy, and it worked.

  94. Dilara Avatar
    Dilara

    Hey, I am trying this.. 5 m4a files have been deleted ive saved them by using a program but the problem is saved files are corrupted!

    When I use this method only saves 2 seconds or so… I want full I need to learn where does it get broken!

    I have also used on a healthy m4a file.. 8 minutes .. only 2 minutes saved…

    Can I get over this?

    1. sysfrontier Avatar
      sysfrontier

      Haven’t you saved original files as backup?

  95. DAVID SILVA Avatar
    DAVID SILVA

    Hi, i have the same problem. I’ve been trying to find the bytes since my file doesn’t have the mdat string. After following the steps sometimes i get a tiny wav file, is it suposed to happen? Originaly, my recording is around 12min within a 6.1 MB file.

    1. sysfrontier Avatar
      sysfrontier

      It may be possible that the recording data was not saved to the file due to application crash.
      In this case, a shorter wav file is generated than expected.

  96. hadi207 Avatar
    hadi207

    thnks alot
    it worked for me

  97. Hi there. I followed the instruction closely but still got
    ***************************************
    Z.m4a file info:
    RAW

    Error: Bitstream value not allowed by specification
    0% decoding Z.m4a”
    ***************************************
    (Z is the file name)

    What to do in this situation?

  98. John Sanders Avatar
    John Sanders

    I have a question: when I look for the line “mdat in hxd editor, I see many instances. what instance should I delete?

  99. Hello, after following step no.6 I get this:
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    ice_video_20160612-123444.m4a file info:
    RAW

    Error: Bitstream value not allowed by specification
    0% decoding ice_video_20160612-123444.m4a.

    What might seem the problem?

  100. Gilberto Esparza Avatar
    Gilberto Esparza

    Hello, I’m leaving a comment because I really need this file fixed, I would do the work myself, and I have been, but I have not been able to find the correct “mdat” tag that is said to be found. So if its not too much to ask can you take a look at it and see if you can fix it? Thanks alot

  101. Hello! Thank you for your sulotion! I’ve got some problems:
    In the first try, I got “Error: Bitstream value not allowed by specification” after running faad in command line.
    I reopened the target m4a file and find a other “MDAT”. Than I tried deleting the contents from the beginning of the file to the “t” of “mdat” again.
    Reran faad, the same error showed again…..”Error: Bitstream value not allowed by specification”
    Do you have any suggestion about what could possibly lead to this error?

    BTW: May I have your authority to translate this article into Chinese and repost it to some social network?

    1. Addition:
      Even If i tried the samd steps using a correct/uncorrupted m4a file, the same error after faad still exist……..

  102. Vandini Bruno Avatar
    Vandini Bruno

    Hi !

    Hmmm thanks for the help but doesn’t work for me. Is it normal that the WAV file and repaired file are each both 1ko ?

    The last step doesn’t give the same command window as yours. I don’t have the columns frame; bitrates, elapse; playCPU,etc.

    Thx for help !

  103. MoeHac Avatar
    MoeHac

    If your file doesn’t contain “mdat”, delete from beginning of file till you hit “00 CC” in HEX or “.Ì” in text. Delete everything from start up UNTIL “00 CC”, DO NOT delete “00 CC”.

    Area to delete:
    https://gyazo.com/44b62490acf73b005a9101cb2f780f46

    I you have more zeroes than I have highlighted here, no biggie since I ad more as well, but deleted them in order to illustrate.

    Good luck!

    1. Thx for the reply ! I finally resolve my problem by another way. 🙂

  104. Enrique Avatar
    Enrique

    Hello.
    I have a m4a corrupted file and I’ve followed all steps above. In principle I found no errors, but no luck. The output from the faad command (the wav file) is much shorter than the original m4a file (the original is about 24 MB and the wav only 4 MB). If I look with HxD inside the wav, I find that the file has OxOO nearly all its bytes. The final file after faac is even smaller (less than 1 MB, although it have some non OxOO bytes). One more question: the original file has at the beginning the signature: ftypmp42 which corresponds with M4V MPEG-4 files. Is that normal?
    Thanks

  105. Vincenzo Avatar
    Vincenzo

    Hi, I have a fix corrupted m4a file and i would like recover it!
    The size of the corrupted file is about 110 MB. I followed all the steps but after FAAD command i had a file of 5 KB and after FAAC command i had a file of 1 KB.
    Can you help me please?

    Thanks

  106. step 6 command not recognized.Help plz

  107. I got error: PCE shall be the first element in a frame

    What can I do?

  108. I emailed you this morning. I would be much obliged if you responded as soon as possible. My email will explain why. Thank you

  109. Hello,

    I would be so so thankful if you could help me. I was recording a voicememo but then my phone ran out of battery so I guess it was not saved correctly. I cannot play the voicememo on my phone and neither can I download it to itunes. Is there anything I can do to recover it?

    Thank yo so much in advance.

  110. you saved me – thank you so much !

  111. You almost saved my life!!
    that .m4a file was so important to me.
    thank you!!

  112. Help please. when i put the M4a. file in the binary editor, it was all 00 00 00 00 00 till the end. i cant find the t to mdat. help please. why is it all 00 00 ?

    1. sysfrontier Avatar
      sysfrontier

      It means that it includes no valid audio data.
      It is impossible to restore the audio.

  113. Thanks a zillion!

  114. First of al my m4a file didn’t have the mdat, but I erased the ftypm4a section.

    and after I opened with faad.exe with cmd and I get

    audio.m4a file info:
    RAW

    Error: Maximum number of bitstream elements exceeded
    0% decoding audio.m4a.

    I’m using a virtual machine windows7 but I don’t think it’s the problem.
    The audio file is really long like 1.5 hour maybe it is?

    1. sysfrontier Avatar
      sysfrontier

      It may be possible that raw audio data gets corrupted.

      1. Can u please help me if I send the file to your email. Im struggling

        1. sysfrontier Avatar
          sysfrontier

          Yes, please send the file to repair_m4a@sysfrontier.com

  115. I love you, thanks <3 _ <3

  116. Hello,
    unfortunately I stuck at point 6 (decoding by faad.exe), getting a message “unable to find correct AAC sound track in the MP4 file”.

    Maybe I should upload the file and send you the link?

    Regards from Germany!
    Oliver

  117. goood thx

  118. THx I got it

  119. Thanks a lot, Sysfrontier. Your steps helped but my original file had a recording of 60 min yet the repaired file was only able to recover the first 9 minutes of it. Any ideas or suggestions? Thanks a lot

    1. Worth adding that I got this error during the decoding step – “Maximum number of bitstream elements exceeded”

    2. sysfrontier Avatar
      sysfrontier

      What is the size of the file? Is it same as the size of a working file with 60 min? It may be possible that the data after first 9 minutes has slipped off due to app crash.

  120. On step 6, I got “cd Downloads” and “faad.exe “20140615 163625.m4a” without problem, but when I pressed enter, I got an output saying “Error opening file ‘ 20140615 163625.m4a’” Any ideas? Thank you!

    This is the whole log:

    Microsoft Windows [Version 10.0.14393]
    (c) 2016 Microsoft Corporation. All rights reserved.

    C:\Users\seanc>cd Downloads

    C:\Users\seanc\Downloads>faad.exe “20140615 163625.m4a”
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    Error opening file: 20140615 163625.m4a

    C:\Users\seanc\Downloads>

  121. AMAZING! You just saved my girlfriends life!

    Had a HR dismisall interview recorded and needed to write it up but it got corrupt, ii tried loads but this worked!

  122. meliorit Avatar
    meliorit

    If you got: bitstream value not allowed by specification error, and near the beginning of your file, in the hex editor, you see that the file format is “ftypdash”, it means you should use ffmpeg to decode your file.

    Go grab the ffmpeg binaries and use this command from the binary directory:
    ffmpeg -i input.m4a -vn -acodec copy output.m4a

    source: https://www.mixxx.org/forums/viewtopic.php?f=3&t=6866

  123. Maxine Kaufman-Lacusta Avatar
    Maxine Kaufman-Lacusta

    p.s. I tried a second time, and I notice that the Error message I got after the Faad.exe “filename.m4a” was: Channel coupling not yet implemented.m4a
    Thanks for any feedback.

  124. Amazing. I just recovered some broken recording from BB10.
    I couldn’t fine mdat as well, so I just deleted few first zeros of file till first different symbol and it allowed me to decode file.

    Thank you!

    1. sysfrontier Avatar
      sysfrontier

      Cheers!

      1. joanna Avatar
        joanna

        Hi! I have a problem with faad.exe followed by file name, the response I get is “faad is not recognized as internal or external command, operable program or batch file”…. What I am doing wrong?

  125. I have one corrupted audio file, but I can’t recover it by this method, the problem is in faad.exe. when I try to call faad in command promt to decode audio file, the answer is:
    Error: Channel coupling not yet implemented
    0% decoding aaa.m4a
    Please help, what can I do to fix this ?

    1. sysfrontier Avatar
      sysfrontier

      We need to look into the file to see how the data gets corrupted.
      If you want us to do so, please send us via Dropbox or Google drive.

    2. Hi Stella did you get this resolved as I have the same issue??

  126. aasdsafd Avatar
    aasdsafd

    thank you so freakin’ much!

  127. Dear Sysfrontier!
    I had same problem as Sachin. 2 files went through this algorythm.
    1st file was about 14 min. – became 1min 36 sec, 2nd one 57 min. – became almost 15 min.
    And this error – “Maximum number of bitstream elements exceeded”, when using faad.exe.
    Answering to question about size – 1 file was 13,1 Mb – became 1,44 and 2nd one was 53,4 – became 12,1.
    I have to fix them up urgently,because my future job depends on these 2 files, so please , if you have any suggetions, tell!
    Thanx in advance.

  128. kootra Avatar
    kootra

    Hi, I had the same problem as joanna ” faad is not recognized as internal or external command, operable program or batch file”

    What did we do wrong ?

    1. sysfrontier Avatar
      sysfrontier

      Please make sure you have faad.exe and the m4a file in the same directory such as Downloads.
      You need to do “cd” to the directory in the command window.

  129. Kantong_kresek Avatar
    Kantong_kresek

    I just found this really useful guideline.. Thank you admin!
    During the repairing process, I experienced the ”faad is not recognized as internal or external command, operable program or batch file” problem, which turn out I was not using the right directory (I created 1 folder inside “Downloads” folder).
    I also experienced with “Maximum number of bitstream elements exceeded” problem, but in my case, the wav file was there, so I just tried to encode it using faac.exe.
    Then, the repaired.m4a file is a little bit smaller than original.m4a, but it is much better than not at all.
    Thank you again..

  130. Abimbola ASHAJU Avatar
    Abimbola ASHAJU

    You guys are a life-saver. I’ve tried every possible method using audacity and other softwares which didn’t work. I came here as a last resort and you saved my day. Thanks a million guyss

  131. woior Avatar
    woior

    hello i have been recording a voice clip for 45 minutes and sudenly my phone shut off
    when i did restard and i started to record again (a new 1 minute recording) and i noticed that the phone had mix the new file with the old one i was recording and had created a new recording file 45 mb. but when i play the file it just play me the last recording i made while the file has much more information.
    i cannot reach the raw m4a data that are still in the file and it just play me the last 1 minute recording i made. there are two audios merged in one file and i want to fix the first long recording data that there are inside

    1. woior Avatar
      woior

      i tried the methods for fixing the file that you explained above but still i cannot fix the file.
      i tried one webside that repair the file online and has also made a preview for me but it is expensive 70$. i also have link of the file -> https://drive.google.com/open?id=xxxxxxxxxxxxxxxxxxxx

      but if you could give some informations to recover it will be great. thanks

  132. This was really helpful (for someone who doesn’t use cmd very often, it was really informative and had every detail covered). Still, at first I encountered an error using faad: “channel coupling not yet implemented” and lost any hope – but then I tried to delete every bit one by one after the “mdat” in binary editor HxD and tried the new file with faad until it worked eventually (after five or six tries). I have to admit though the file seems to have lowered in pitch by a tiny bit – is it possible this has something to do with the sample rate? All in all, I’m very happy to have my recording back, so thanks!

  133. hi please help i followed the instructions but when i try step 6 on cmd
    it says
    error opening file:Audio_05_09_2017_16_44_26

    i dont know why if you could help me it would mean so much to me
    its a 8minute thing or something i put my heart and soul into it and i dont think ill ever feel the way i felt again to recreate it again

  134. Rushikesh Avatar
    Rushikesh

    I am getting message — “Unexpected channel configuration change” after 6 th step. And when I finish the process; I get the file name repaired.wav but of zero duration. CAn you please explain what can be the problem. My file is of 44.7 MB and if I am not wrong it should be of 35 min. length

    1. sysfrontier Avatar
      sysfrontier

      We need to look into your file to find the cause of the error.

      1. Rushikesh Avatar
        Rushikesh

        How can I post the voice clip?

        1. sysfrontier Avatar
          sysfrontier

          Please upload your file to Dropbox or Google Drive, etc.
          Get the link to the file.
          Send it to us by email to repair_m4a@sysfrontier.com

      2. Mounir Avatar
        Mounir

        Hello I’m having the same issue. Do you still repair those files?

        1. sysfrontier Avatar
          sysfrontier

          Yes, we do. Please contact us by repair_m4a@sysfrontier.com

  135. mounir Avatar
    mounir

    Hello, can you please tell me what to do since i am stuck in step 5. I couldn’t find “mdat”

    Please help, i need this m4a file.

    Thank you

  136. Joao Santos Avatar
    Joao Santos

    Oh guy you saved my work!!! Thank you so much!

  137. Thank you very much! I repaired a voice memo successfully. It was very important for me.
    I followed the exact description. The only thing what I didn’t understand was that ‘cd Downoads’ command, “to move” the Downloads folder, but after I just did what you say, it works fine and everything was a piece of cake.

    Great!!! Thnx!!!

  138. Clement Avatar
    Clement

    Hi there!
    I tried this way with a 20Mo file but I only get a 72Ko wav file.
    Can you help me with this issue ?

    1. sysfrontier Avatar
      sysfrontier

      The size implies that the audio data has been lost forever from the file.
      It is impossible to restore the original data from the 72KB file.

      1. Clement Avatar
        Clement

        That’s strange, because the Web app “Treasured” say it could recover at least 1/3 of the record. I think I’m doing the wrong thing with the “mdat” header … Can you take a look ?

  139. Bl4ck41 Avatar
    Bl4ck41

    Hey sysfrontier,

    thank you for your turtorial! I do it for my friend and it work in my case. But I have i think we lost a little bit records.
    The original file have 65,7 MB and the repaired file only 34,4 MB (37,36 min).
    The WAV file have 379 MB (37.36 min)

    The faad.exe only decode till 31%…
    Can we repaire more than this??

    Thank you for your Support!

  140. It’s just awesome! 😀
    I had recorded a call while talking with my girl but the recorder didn’t record it properly.. It created a corrupt .m4a file. I was so disappointed.. 🙁 But now I am happy to see it recovered after following above steps. Thanks Team..

    1. sysfrontier Avatar
      sysfrontier

      Great! It is glad to hear that.

  141. Hey there! Thanks a lot for such a helpful article. I have followed all the steps, but I just can’t find the mdat area and can’t recover the file. This is a very important recording for me, though. Could you please take a look at it? I’m gonna send it via email.

  142. its working 100%/ just do it step by step. THANKS

  143. Alexandre petit Avatar
    Alexandre petit

    Hy sysfrontier,

    My files m4a is corrupted due by end batterie of my phone.
    The file have 65Mb, so what could be the cost if you do the repair?

    thanks

    Alex

    1. sysfrontier Avatar
      sysfrontier

      How long is the recording?
      If it is less than 10 minutes in length, it costs $10.
      If its length is between 10 minutes and 60 minutes, it costs $20.
      If it is more than 60 minutes, it costs $30.
      Please contact us by sending email to repair_m4a_service@sysfrontier.com.

  144. I tried this fix on a 50 minute voice memo, but got the error “PCE shall be the first element in a frame” in FAAD, and the recovered .wav file is only 3 minutes long.
    Any suggestions?

    1. sysfrontier Avatar
      sysfrontier

      It may be possible that the data after 3 minutes got lost.

      1. The strange thing is, the file was working before, and the filesize is the same as other similar length .m4a (~50mb)
        Somehow the file just stopped working

  145. I recorded a voice memo on my iPhone and the battery shut down so I believe the recording did not save properly.

  146. Miguel Pérez Gómez Avatar
    Miguel Pérez Gómez

    Thank you Sysfrontier for this complete tutorial. I had one corrupted M4A file and thanks to your information I could restore this important file. I would recommend this post for anybody that have this kind of problems. I’m very happy because I found this post.

  147. Natalie Ford Avatar
    Natalie Ford

    AMAZING!!!! Thank you sooo much! Repaired 2 corrupted m4a’s using this guide. So grateful for your kindness and generosity in supplying this page.

  148. Hi! I was trying to recover 2 different MP4 files recorded by EasyVoiceRecorder on Android 2.3. They were recorded on different days and were both about the same length, 70 and 73 mb. (Almost 3 hours) Failed due to no space left. When removing the header and trying to decode with Fadd, both times the resulting file is a stereo WAV file of exactly 6.33 MB (6,647,852 bytes)

    So seems this is not a problem with the defective files but with the decoder. The data in the Hex editor HxD seems to all be there to the end. So I was thinking, it says it’s for Win32 but I’m using Windows 10 64 bit, does this break the decoder and I should try on a 32 bit OS? (FAAD2v20100614 CVS snapshot for Win32)

    Thanks,
    Jerry.

    1. No I just tried on a 32 bit XP and same exact file size results! BTW, the original files are supposed to 63 or 64 kbps, Mono, 44 kHz. These files do not show any details in Windows explorer though.

      1. Well, I tested a GOOD file. Same length, about 74 mb, length 2 hr 36m. faad wouldn’t decode it at all without removing the header. After removing the header it decoded it to a file size which was exactly the same length of 74 mb, but the resulting file is exactly 7 min 2 .208 seconds! It’s a Stereo file of 44,100 Hz, 32 bit float. It plays fine.

        So apparently faad is not compatible with this mp4 format. It can’t even decode a good file properly… Any other decoders I can try?

        Thanks!

  149. carly wills Avatar
    carly wills

    Hi, I have a corrupted file due to losing battery on my phone.

    The recording is quite large, 391mb.

    Just wondering if you can please provide some help for how to recover this file through my mac, alternatively are you able to fix this for me? And at what cost and how long would this take?

    Thank you 🙂

    1. sysfrontier Avatar
      sysfrontier

      We currently recommend to use Windows.
      Please send the file to repair_m4a_service@sysfrontier.com
      If it is less than two hours, it is $30.
      We will fix it as soon as possible.

  150. I just recoreded an 1,5 hour session with my mother talking about my late father’s youth when the battery of my phone died. I recovered the audiofile but couldn’t play it. The method you described worked perfectly, thanks!

  151. hi, thanks for all, but i need to ask why my 20 min corrupted m4a audio file when i follow ur steps goes to just 1 min ? also i get an msg “error channel coupling not yet implemented”
    tried with 2 files.

    1. sysfrontier Avatar
      sysfrontier

      I am sorry, but I think that the last 19 minutes got lost due to app crash.

  152. Raju Bhalerao Avatar
    Raju Bhalerao

    Trying to repair file .m4a with 27 mb with your instructions above.

    First, the file I opened with HxD, but could not find “mdat” but however I fould 2 lines as shown in figure above “M4A mp4” and deleted upto . . . and saved it.

    Also, I executed FAAD as said, but file just shows 1 KB.

    Please help.

  153. Jónás Tamás Avatar
    Jónás Tamás

    Thank you sooo much for your help! Repaired 1 corrupted m4a’s using this guide. So grateful for your kindness and generosity in supplying this page.

  154. Thanks so much! I was recording a class and dropped my phone so it turned off. When i tried to play the audio it didn’t let me until i did this. Thanks! You rock

  155. Just wanted to thank you for posting this …. these instructions helped me recover several interviews and voice recordings I had stored on my Android phone (Samsung Galaxy S6). The files were critical for a new story I was writing. I’m on Windows 10 in Winter of 2018. Thanks so much!!!

    Arigato gozaymusu!!

  156. Samitha Darshana Avatar
    Samitha Darshana

    Thank you sooo much for your help! Repaired 1 corrupted m4a’s using this guide. So grateful for your kindness and generosity in supplying this page.

  157. Thank you so much for these instructions, I didn’t bother with the re-encoding (faac) as that wasn’t important to me, but I recovered all but the last few words of an hour-long recording I was almost certain I had lost.

  158. thank you very very very much. I really needed my file…

  159. Fredrick Avatar
    Fredrick

    Thank You so much for your help. God Bless…

  160. My friend, can I fix corrupted m4a file through android phone?

    1. sysfrontier Avatar
      sysfrontier

      No, you need PC to apply the instructions in this article.

  161. James Smith Avatar
    James Smith

    Hi!

    Very useful information, indeed. I was able to save at least five corrupted files, hopefully!!

    But, the last file I tried to rescue is the most difficult. When I try this method, I get the error “Error: Gain control not yet implemented4a.”.

    Here is the information from a file recorded minutes earlier under the same setup (wich plays fine):

    General
    Format : MPEG-4
    Format profile : Base Media / Version 2
    Codec ID : mp42
    File size : 38.5 MiB
    Duration : 1h 23mn
    Overall bit rate mode : Constant
    Overall bit rate : 64.7 Kbps
    Encoded date : UTC 2018-02-20 09:15:47
    Tagged date : UTC 2018-02-20 09:15:47

    Audio
    ID : 1
    Format : AAC
    Format/Info : Advanced Audio Codec
    Format profile : HE-AAC / LC
    Codec ID : 40
    Duration : 1h 23mn
    Bit rate mode : Constant
    Bit rate : 64.0 Kbps
    Nominal bit rate : 96.0 Kbps
    Channel(s) : 1 channel
    Channel positions : Front: C
    Sampling rate : 44.1 KHz / 22.05 KHz
    Compression mode : Lossy
    Stream size : 38.1 MiB (99%)
    Title : SoundHandle
    Language : English
    Encoded date : UTC 2018-02-20 09:15:47
    Tagged date : UTC 2018-02-20 09:15:47

    I tried to decode with Nero and FFMpeg, no success. Maybe I’m not using the right commands.

    Any solution?

  162. Zeljko Zlatkovic Avatar
    Zeljko Zlatkovic

    THANK YOU SO MUCH !!!!

  163. Yaurelie Avatar
    Yaurelie

    Please, guy help me. I have an issue on the step 6 too. faad.exe”20180402.m4a” is not recognized as internal or external command, operable program or batch file. Please, help me on this issue.

    1. sysfrontier Avatar
      sysfrontier

      Please confirm that you are in the same directory as where faad.exe resides.
      Type “dir” to see if faad.exe exists.
      If not, please use “cd” to change the directory to where you have faad.exe.

      1. Yaurelie Avatar
        Yaurelie

        I downloaded the faad and faac softwares in the same folder “Downloads” as well as my audio file. It is a recorded file for a concert that we prepare. I need just to relisten to the music and voice to get prepare. And i had this issue. It was recorded on my Blackberry Z3 phone.

        I tried to change the folder and put the faad and faac.exe and the audio file on the desktop and try it again, but it doesnot work. Could you help me please? This file is so important. The other team member didn’t record our vocal sessions so I’m really lost. I spent already 5 hours to do it. Help me please. Should I send the file to you via a share link to see if you can fix it for me? Please…

        1. Yaurelie Avatar
          Yaurelie

          Otherwise, maybe it’s best for me to forego this project and go back to my Excel spreadsheets, waiting for another vocal session maybe….. I’m sad for not having succeeded while using your advice. Lost in encoding steps…

          1. sysfrontier Avatar
            sysfrontier

            Can you send us the file?
            Our address is repair_m4a_service@sysfrontier.com
            We will look into it to find if it is recoverable.

  164. Yaurelie Avatar
    Yaurelie

    Ooooh ok it’s well noted. I’ll send you a wetransfer link very very soon. Kind regards. I did many researches online, in french-speaking forums also. But, I found very limited options.

  165. Thanks a lot! I was able to repair two research interview recordings, so thank you very very very much!!!

  166. Deafinition Avatar
    Deafinition

    Holy shit, it works! Thank you so much!

  167. Amirhossein Avatar
    Amirhossein

    Dear sysfrontier,

    It’s a very great method. I am really able to retrieve the audio files, but in most cases the duration of the repaired file is too shorter than the first damaged file. So. I want to humbly request if you could please help me to be able to have complete files.

    Regards

    1. sysfrontier Avatar
      sysfrontier

      It is possible that some of the last part gets lost due to app crash. In such cases, it’s impossible to recover the lost data.

      1. jhon carter Avatar
        jhon carter

        Hi, please help i am getting error as Array index out of range at the stage of faad.exe “name.m4a”

  168. Rasino Avatar
    Rasino

    I’ve followed the steps.
    When I execute faad.exe, I obtain the message
    “RAW”
    “Channel coupling not yet implemented”
    0% done
    Have you an idea ?
    Thanks a lot !

    1. jhon carter Avatar
      jhon carter

      did you got this error two array index out of range

  169. jhon carter Avatar
    jhon carter

    i am getting this error “array index out of reach” at the step of faad.exe “name.m4a” please tell me how to fix it?

    1. jhon carter Avatar
      jhon carter

      array index out of range at faad.exe stage. tell me what is the problem i removed the mdat and till beginning

      1. jhon carter Avatar
        jhon carter

        Please answer ASAP

    2. sysfrontier Avatar
      sysfrontier

      It may be possible that not only the header part, but the data part is damaged. We are sorry, but it is impossible to restore the audio in such a case.

  170. joseph Avatar
    joseph

    When i do step 6, i have a file .wav of 33Kb (the original is of 58Mb).
    When i do step 7, i have a repaired file ok 1 Kb (the “repaired.m4a” is a file of 1Kb. it doesn’t work.)

    1. sysfrontier Avatar
      sysfrontier

      The data part might have been damaged.

      1. Nikki R. Raton Avatar
        Nikki R. Raton

        Hi! Am already on the last part as shown below:

        Microsoft Windows [Version 6.3.9600]
        (c) 2013 Microsoft Corporation. All rights reserved.

        C:\Users\Admin>cd downloads faad.exe”LUMBERA INCOM TAX 1ST PART 0012018072613271
        1_MyRecording.m4a”
        The system cannot find the path specified.

        C:\Users\Admin>cd downloads

        C:\Users\Admin\Downloads>faad.exe “LUMBERA INCOM TAX 1ST PART 00120180726132711_
        MyRecording.m4a”
        *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

        Build: Jun 14 2010
        Copyright 2002-2004: Ahead Software AG
        http://www.audiocoding.com
        Floating point version

        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License.

        **************************************************************************

        LUMBERA INCOM TAX 1ST PART 00120180726132711_MyRecording.m4a file info:
        RAW

        ———————
        | Config: 2 Ch |
        ———————
        | Ch | Position |
        ———————
        | 00 | Left front |
        | 01 | Right front |
        ———————

        Error: Bitstream value not allowed by specification32711_MyRecording.m4a.

        C:\Users\Admin\Downloads>faac.exe – b 160 – o repaired.m4a “LUMBERA INCOM TAX 1S
        T PART 00120180726132711_MyRecording.m4a”
        Freeware Advanced Audio Coder
        FAAC 1.28

        C:\Users\Admin\Downloads>faac.exe – b 160 – o repaired.m4a “LUMBERA INCOM TAX 1S
        T PART 00120180726132711_MyRecording.wav”
        Couldn’t open input file –

        C:\Users\Admin\Downloads>faac.exe – b 160 – o repaired.m4a “LUMBERA INCOM TAX 1S
        T PART 00120180726132711_MyRecording.m4a”
        Freeware Advanced Audio Coder
        FAAC 1.28
        ______________________________

        Am trying to recover a corrupted audio recording from quickvoice – a lecture from a tax professor to be used as review materials for the bar exam. This file is supposedly 80mb but I can;t open it when i am supposed to listen to it to check the quality. It shows zero duration. I recorded this for more than an hour. How long supposedly should I wait for the corrected file to appear? I kept on looking and following your instructions to the dot (to the point of trial and error just to make sure I follow exactly the same procedure). Hope to hear from you ASAP. Thank you.

  171. Is it really possible that the word mdat is there despite the fact that I typed the mdat word in the Find Box and it says that “cannot find mdat”? Do I really have to browse all these figures ? Please advise ASAP. Thank you.

  172. Is it really possible that the word mdat is there despite the fact that I typed the mdat word in the Find Box and it says that “cannot find mdat”? Do I really have to browse all these figures ? Please advise. Thank you.

  173. Nikki R. Raton Avatar
    Nikki R. Raton

    Hi! Am already on the last part as shown below:

    Microsoft Windows [Version 6.3.9600]
    (c) 2013 Microsoft Corporation. All rights reserved.

    C:\Users\Admin>cd downloads faad.exe”LUMBERA INCOM TAX 1ST PART 0012018072613271
    1_MyRecording.m4a”
    The system cannot find the path specified.

    C:\Users\Admin>cd downloads

    C:\Users\Admin\Downloads>faad.exe “LUMBERA INCOM TAX 1ST PART 00120180726132711_
    MyRecording.m4a”
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    LUMBERA INCOM TAX 1ST PART 00120180726132711_MyRecording.m4a file info:
    RAW

    ———————
    | Config: 2 Ch |
    ———————
    | Ch | Position |
    ———————
    | 00 | Left front |
    | 01 | Right front |
    ———————

    Error: Bitstream value not allowed by specification32711_MyRecording.m4a.

    C:\Users\Admin\Downloads>faac.exe – b 160 – o repaired.m4a “LUMBERA INCOM TAX 1S
    T PART 00120180726132711_MyRecording.m4a”
    Freeware Advanced Audio Coder
    FAAC 1.28

    C:\Users\Admin\Downloads>faac.exe – b 160 – o repaired.m4a “LUMBERA INCOM TAX 1S
    T PART 00120180726132711_MyRecording.wav”
    Couldn’t open input file –

    C:\Users\Admin\Downloads>faac.exe – b 160 – o repaired.m4a “LUMBERA INCOM TAX 1S
    T PART 00120180726132711_MyRecording.m4a”
    Freeware Advanced Audio Coder
    FAAC 1.28
    ______________________________

    Am trying to recover a corrupted audio recording from quickvoice – a lecture from a tax professor to be used as review materials for the bar exam. This file is supposedly 80mb but I can;t open it when i am supposed to listen to it to check the quality. It shows zero duration. I recorded this for more than an hour. How long supposedly should I wait for the corrected file to appear? I kept on looking and following your instructions to the dot (to the point of trial and error just to make sure I follow exactly the same procedure). Hope to hear from you ASAP. Thank you.

  174. Nikki R. Raton Avatar
    Nikki R. Raton

    Hi! Am already on the last part as shown below:
    —————————————-
    Microsoft Windows [Version 6.3.9600]
    (c) 2013 Microsoft Corporation. All rights reserved.

    C:\Users\Admin>cd Downloads

    C:\Users\Admin\Downloads>faad.exe “LUMBERA INCOM TAX 1ST PART 00120180726132711_
    MyRecording.m4a”
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    LUMBERA INCOM TAX 1ST PART 00120180726132711_MyRecording.m4a file info:
    RAW

    ———————
    | Config: 2 Ch |
    ———————
    | Ch | Position |
    ———————
    | 00 | Left front |
    | 01 | Right front |
    ———————

    Error: Bitstream value not allowed by specification32711_MyRecording.m4a.

    C:\Users\Admin\Downloads>
    C:\Users\Admin\Downloads>faac.exe – b 160 – 0 repaired.m4a “LUMBERA INCOM TAX 1S
    T PART 00120180726132711_MyRecording.wav”
    Freeware Advanced Audio Coder
    FAAC 1.28

    ————————————————-
    Am trying to recover a corrupted audio recording from quickvoice – a lecture from a tax professor to be used as review materials for the bar exam. This file is supposedly 80mb but I can;t open it when i am supposed to listen to it to check the quality. It shows zero duration. I recorded this for more than an hour. How long supposedly should I wait for the corrected file to appear? I kept on looking and following your instructions to the dot (to the point of trial and error just to make sure I follow exactly the same procedure). Hope to hear from you ASAP. Thank you.

    1. u need to type faad.exe, i think it’s a typo on his guide

  175. Thank you so much! I just recover 1 hour interview i tought i had lost forever! Infinite love <3

  176. oh my god.. you’re a GOD. You’re a MIDAS. Thank you so much. It really helped me : -3 It really works!!

  177. Thank you so much for posting this! Just saved an important recording for my band.

  178. krishna soni Avatar
    krishna soni

    i am getting very small .wav file and also it show error as “first SBC frame is not same as first AAC frame”

  179. krishna soni Avatar
    krishna soni

    i am getting very small .wav file and also it show error as “first SBC frame is not same as first AAC frame”
    please reply to this comment.

    1. sysfrontier Avatar
      sysfrontier

      We haven’t seen the “first SBC frame is not same as first AAC frame” error. Did you record it with Voice Memo app on iPhone?

  180. hey. i’m in step 7 but there’s might to be a problem. as soon as i run that last command, it shows me the inline below text:
    —————————————————
    C:\Users\Decio>faac.exe -b 160 -o repaired.m4a Recording_107.wav
    Freeware Advanced Audio Coder
    FAAC 1.28

    Average bitrate: 160 kbps
    Quantization quality: 100
    Bandwidth: 20000 Hz
    Object type: Low Complexity(MPEG-4) + M/S
    Container format: MPEG-4 File Format (MP4)
    Encoding Recording_107.wav to repaired.m4a
    frame | elapsed | play/CPU

    C:\Users\Decio>
    —————————————-
    there’s no update after 5 minutes already
    can you help me?
    this is probably the most important audio file of my life.
    i’ve been in the last 3 hours going through ffmpeg trying to get it right, but it was a dead end since it said that the moov atom was missing every time i tried to fix it in every single way.
    i’m desperate

  181. cheeseburger Avatar
    cheeseburger

    Hi, is normal that repaired file has only 12 minutes instead of 1 hour? Voice memos in iPhone shows the correct length even though I am not able to play it, but if I try to use faad and repair the file I get only 12 minutes 🙁

  182. Hi

    I have the exact same problem as cheeseburger posted above. My repaired file lost more than 20 minutes of the original length. Is there any way to repair a larger portion of the corrupted m4a file? I suppose the change in length has something to do with the deletion of lines in the binary editor?

    Any suggestions would be appreciated 🙂
    Bests,
    Jens

  183. Dafina Bogeska Avatar
    Dafina Bogeska

    I did all steps but where can I fined repaired file? in which folder

    1. sysfrontier Avatar
      sysfrontier

      It is in the same folder as faac.exe.

  184. I need help desperately. I am partially deaf and get accommodations at college to voice record lectures so I can listen to them later. Two of my M4A files from two full classes just won’t work/play all of a sudden! I keep following these instructions, and I cannot do it. I keep getting an error message about how it is not recognized. I do not know what I am doing wrong– they are all in the folder and everything.Will someone please please help me? Can I email it? Please

  185. Thank, it works for my corrupted iphone voice memo file. The original file was 51 mins, while using your methods, I recovered 19 mins. Any idea about how to recover the full length?

  186. hello,
    my file work now, but I have only 27 minutes for a record to 1 hours.
    How can I fix that.

    thank you for your help

  187. Marije Mobach Avatar
    Marije Mobach

    Hi,
    I’ve used your tips to restore a memo I recorded on my Iphone. I’ve recovered the first 7 minutes, but now the recording stops in the middle. The total recording is 16 minutes, so I still miss 9 minutes. When I typed “mdat” I deleted a very short part of the recording in the beginning.
    Is there a way to recover the last part of the recording?
    Thank you so much for your help, recovering the first 7 minutes was great!
    Kind regards,
    Marije Mobach
    The Netherlands

  188. F Scheltens Avatar
    F Scheltens

    Hi,
    I tried the steps above with an m4a file from a phone which had its battery die.
    When i try to decode the file with FAAD (unmodified) I get an error saying
    “Unable to find correct AAC sound track in the MP4 file”

    Now when i remove the header as per above instructions, i get :

    recording.m4a file info:
    RAW

    ———————
    | Config: 1 Ch |
    ———————
    | Ch | Position |
    ———————
    | 00 | Center front |
    ———————

    Error: Maximum number of scalefactor bands exceeded

    Can anyone help me sort this out? I have found a website called mp4repair which does seem to be able to recover the file, but I would rather not pay $149.

    Much obliged,
    Floor!

  189. I followed the steps but it only recovered 7 minutes of a 24 minute file. Is there any way of getting more of the recording back?

  190. Dear Sysfrontier, thanks a lot for sharing this!
    I have an issue, after step 6 I get – Error: Channel coupling not yet implemented. I get a file of 600 bytes compared with the original 80MBytes…

    I was only able to find one mdat in the binary data. The recording is of a lecture with no stops in the middle.

    Any idea why?

    Many thanks,

    Moty

  191. Ayn Bacon Avatar
    Ayn Bacon

    Hi! I followed the steps listed above but I encountered some errors through steps 5 and 6. I am extremely worried that my .m4a file is more than just corrupted. You see, I did an interview yesterday and I wasn’t able to save the audio file. My initial reaction was: “Fucking stupid me.” and then I checked my phone’s internal storage > Sounds folder > and there it was, my unsaved recording is there BUT I can’t play it on my phone. The error I get is: “File can’t be played”. So I Googled what the best solution could be to my problem and I stumbled upon this page. I transferred the file from my phone to PC through Google Drive, I followed the entire instructions listed above, but it still didn’t to work with my seemingly corrupted file. Please help. It will be greatly appreciated. The freaking audio file is an hour-long interview for my undergraduate thesis. It is utterly important. Thank you.

    1. you did type faad.exe during step 7 right, not faac like it says 😐

  192. Hello, I fixed “m4a” file which was around 10Mb and duration of 1 hour (it sounds weird but that was the real amount of when I was recording it from native iPhone app)
    The problem is that the output I was able to get at the end is 6 min… (4~5 mb) .. could you please advice me if this is reasonable …?

  193. Bulldoser Avatar
    Bulldoser

    Hi!
    I am actually at the end step 7, coding is running. But it did not stop at 100%… Now I am at 161% and it is still running.. I do not know where will be the end… Any experince about this issue? My file is very big, more than 2 gb.

  194. Bulldoser Avatar
    Bulldoser

    Hi!

    I am at the end of step 7, decoding is runing but it did not stop at 100%… It is still running and now it is actually at 206%… I do not know why and where the end is. Can you help me please? What could be wrong? My file is more than 2gb…
    Thanks

  195. cheers, worked great.
    Failed 1st time when in step 5. i just deleted the ‘mdat’ bit but then i tried again and selected all the bits with all those …’s (the light blue stuff) that were being selected and it let me repair it, / convert to a .wav file.

  196. Bulldoser Avatar
    Bulldoser

    Hi, I fixed it, thank you! It stopped at 355% 🙂
    Unfortunately I lost almost the half of the file but I have the important part.

    Thanks again!

  197. Hi. Just followed the guide as described. works very well.

    Thank you so much
    your a life saver.

    best regards
    Bernhard

  198. Hi,
    Thank, it works for my corrupted iphone voice memo file.
    This worked for me,
    Many thanks !

  199. Thank you so much!!!!!!!
    Perfect.

  200. Hi,
    I just want to tell you that this guide is amazing. It’s eazy to follow and you just saved me so much extra work with it. Thank you so much!
    Best regards

  201. Works perfect! Thank you! Saved me!

    1. It trimmed 1 hour 36 minutes to 7 minutes.

      1. sysfrontier Avatar
        sysfrontier

        The data after 7 min may have been lost forever due to app crash.
        I am sorry, but it may be impossible to recover any more data from your file.

        1. Fredrik Sjodin Avatar
          Fredrik Sjodin

          Hey sysfrontier,

          First of all – Thank YOU for a solution that finally worked for me.
          As the person mentioned above – I only restored about 4 minutes of the total 63 minutes.

          Any idea of why it shows as 1 hour 3 minutes in my voice memo app on my iPhone and it only saved 4 minutes. If the app crashed during the recording it shouldn’t show 1 hour 3 minutes…. right?

          Any suggestion would be appreciated.
          Thank you once again for an excellent guide.

          Regards,
          Fredrik

  202. Thanks for this. My wife does interviews for our community paper. First time voice memo has failed her. I was able to recover the first (important) half of the interview. ++thanks

  203. Chris J Avatar
    Chris J

    My 79 year old dad is a retired university music professor. Among the many things he does to keep himself busy is judging student honor bands. He uses his iPhone Voice Memo app to record his voice while the group is playing so the students can listen to his critiques along with their performance in the background. He just got a new iPhone Xs and was excited to use it at the most recent performance. It produced a corrupt file. He and the conductor were crestfallen when it wouldn’t open. I was able to follow the instructions in this tutorial and salvage the audio data from the file! My dad would like me to pass along his most sincere gratitude for making this information available. Thank you so very much!

  204. Yseult Avatar
    Yseult

    I only got 7 min of my 48 min recording. Do you know if I can still get the rest of it in any way ?
    Thank you

  205. cecilie Avatar
    cecilie

    THANK YOU!
    I have tried everything and every program or app! I had some problems with step 6, only because I only deleted the word mdat and nothing more. I then received the “Unable to find correct AAC sound track in the M4a file”, went back and looked again. You have to delete everything before the word mdat + the word mdat

    I can now listen to it, but since it apparently was an error in the voice memo app, I lost 10 minutes of it. I was aware of this since I did a diagnostic test.

    So happy with all the help, including the text, links, photos and comments!

  206. Hi, I’ve tried following your guide to the letter, but when I erase from the beginning to the “t” in “mbat” and do the next step, this is what happens in the cmd prompt:

    Microsoft Windows [Version 10.0.xxxxx.xxx]
    (c) 2018 Microsoft Corporation. All rights reserved.

    C:\Users\alex>cd desktop

    C:\Users\alex\Desktop>faad.exe “ARC.m4a”
    *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

    Build: Jun 14 2010
    Copyright 2002-2004: Ahead Software AG
    http://www.audiocoding.com
    Floating point version

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License.

    **************************************************************************

    ARC.m4a file info:
    RAW

    Error: Bitstream value not allowed by specification
    0% decoding ARC.m4a.
    C:\Users\alex\Desktop>

    After that, there is no .wav file anywhere, can you help?

    1. Sophia Ramirez Avatar
      Sophia Ramirez

      Did you ever find a solution to this? I’m having the same issue

  207. First of all, let me say this has been a great help and saved a lot of my research interview. Thank you very very very much for this tutorial.

    However, my file which was originally about 47m long is now only 23m20s and (as far as I remember) it does not start at the start and does not end at the end. When decoding, it usually gets stuck at 53% and after a while it shows that it’s completed without giving me an error or anything. Do you think there is a way to recover the other half of my interview or is it because the app (the native iPhone recorder) did not work the right way?

    Thanks for your help.

  208. Hi,

    I have a corrupted voice memo from an iPhone, that should be 1 hour and 40 minutes long, but when copied from the phone the file size is reduced from 80 to 26 MB and after using this method, I end up with only 16 and a half minute of the recording.

    Does anyone know if this issue is fixable?

  209. Thank you SOOOOOOOO much!! I was able to recover an important meeting recording that I thought was lost forever, and I no nothing about hexidecimal, mdat, faad and all the things in your article. Following your steps exactly (and reading the comments to see I didn’t to the mdat part correctly the first time) saved the day! Very grateful that people like you take the time to write these things up.

  210. Thank you for the instructions sysfrontier!

    I just wanted to shared that on OS X, you can use Homebrew (https://brew.sh) to install the 0xED hex editor (brew cask install 0xed) and the faad binaries (brew install faad2).

  211. Thank you thank you thank you! Saved a really important research interview and only lost 8 minutes at the end. I will be donating to say thank you 🙂

    A note for others: the FAAD program here did not run on my PC and I had to download FAAD2 from a different link. It extracted as FAAD.exe (not FAAD2.exe) so all the instructions here were identical otherwise. I have a Windows 10 64x PC – not sure if this was a factor. So if your command prompt says it can’t open the application, try this instead.

  212. Hi, I was able to recover 11:37min of a 24:22min voice memo following your steps exactly. Is there any way to recover the rest of the file?
    Thank you.

    1. sysfrontier Avatar
      sysfrontier

      The data after 11:37 till the end may have been lost forever due to app crash. We are sorry, but it is impossible to recover any more data from your file.

      1. I have the same problem. Is it possible that the app crashed without actually shutting down? Like silently crashing? Because i did stop the recording once the Meeting was done. From that Point on it was weird. The recording wasnt shown in the app after i stopped it. I closed and started the app again and than the recording was shown again but not playable. Does this Sound like my app silently crashed?

  213. Fantastic – saved my bacon

  214. Karen Cangialosi Avatar
    Karen Cangialosi

    I have an unplayable iphone voice memo that says it is 48 min long. I followed all of your instructions exactly and was thrilled when it worked! But the repaired file is only 16 min. Is there no possible way to get the rest of it?? If the application crashed, why does it say that it is 48 min on my phone. The file size of the original is 27,163 KB, but the repaired file is only 13,427 KB. Please help!

  215. Hi, SysFrontier, I’ve successfully gotten to Step 6, but when I try to decode, I get the following message:

    C:\Users\Barry\Downloads>faad Freetravel61118copy.m4a
    ‘faad’ is not recognized as an internal or external command,
    operable program or batch file.

    C:\Users\Barry\Downloads>faad “Freetravel61118copy.m4a”
    ‘faad’ is not recognized as an internal or external command,
    operable program or batch file.

    I’ve checked my directory, and all necessary files are in there. The file I am trying to repair is 179mb, and I am on Windows 10 64bit.

    What am I doing wrong?

    Thanks.

    1. sysfrontier Avatar
      sysfrontier

      By typing “dir”, please check if “faad.exe” really exists.

    2. Whaner Endo Avatar
      Whaner Endo

      Hey Barry,
      I got the same message… To fix it, i noticed that I wasn’t using the right directory. Just changed to the right one and worked.
      Best

      1. Barry Avatar
        Barry

        Thanks for your suggestion, but I don’t know what you mean . The necessary downloaded files are in the directory into which they get downloaded, and that’s the only directory they’re in, isn’t it? And my corrupted audio files are also only in one directory.

        So exactly what do you mean when you say that you just changed to the right directory? Specifically, which directory did you change from and which did you change into?

        Thanks.

  216. Thanks so much for your response.

    The following relevant section is what is in my directory:

    05/05/2018 08:48 AM 328,957 EN-Quick Guide-Lenovo Moto Mods DLP projektor Insta – share.pdf
    04/07/2019 10:35 PM 195,124 faac-1.28-mod.zip
    04/09/2019 07:50 AM faad.exe
    04/09/2019 07:41 AM 229,721 faad2-20100614.zip
    03/21/2018 11:31 AM 38,808,920 FileFormatConverters.exe
    11/27/2016 07:04 PM 552,500 Flash_Drive_Tester_v114.exe
    04/09/2019 08:23 AM 158,878,748 Freetravel61118copy.m4a
    04/08/2019 11:40 PM 187,784,333 Freetravel61118copy.m4a.bak

    I tried again this morning to no avail. I await your further ideas.

    Thanks.

  217. sysFrontier, I did respond to your comment a couple of days ago, and have not heard anything back from you. Please respond.

    Thanks.

  218. Hi, I found this thread and am (desperately) hoping someone here can help me – I have an audio file I recorded using Voice Memo on my iPhone 7. It seemed to be recording fine and when I go to play it back, it shows as being 52 min and when I upload to dropbox, it shows as being 38.2 MB, which seems just right. But I can’t play it anywhere, appears to be corrupted. It’s a really important interview for work – is there anything I can do on Mac? Or if I send you the link could you fix it on Windows?
    Thank you…
    CJ

  219. Could anyone here find a solution for “Array index out of range” Error?
    is it recoverable?

  220. Excelent help.! Was able to save 50 min of my 1h20 iphone 6s voice memo. Did not find any other info like yours on internet. Simple to apply. Thank you very much. Patricia

  221. Christian Avatar
    Christian

    Hi, i get under step 6 the following error message:

    Error opening file: file.m4a

    Can you help?

    Many thanks

  222. Dear friend,
    Thank you very much for the tutorial. It save my life… 😎
    God bless u, my friend.

    Whaner

  223. I used the samsung audio recording app for multiple interviews of 1 hour. When I play the files on my phone or on my computer the sounds drops after 1.02 minutes. However, in the app the frequency of our voices is still visible in the application.
    Is this able to be repaired with this tutorial?

    1. sysfrontier Avatar
      sysfrontier

      Well, please try it!

  224. hi, I got to step 6 but then when when I press Enter I get the following message:

    Error opening file: 20140615 163625.m4a

    What does this mean? Could you help me?

    Thanks

  225. Nikolay Avatar
    Nikolay

    i have a message “Unable to find correct AAC sound track in the MP4 file” ? but all files (faac, faad, HxD, m4a, m4a.bak) in the same folder “Downloads”…Whats wrong? pleaaase help.

    1. sysfrontier Avatar
      sysfrontier

      The file got corrupted in the way other than described in the article. Please contact us for our repair service.

  226. Pauline Avatar
    Pauline

    Hello,
    I have tried but it didn’t work.
    My file was recorded with Samsung S8 Voice recorder with the Interview setup. It lasts 40-ish minutes but after 3 minutes, the sound stops, though the soundwave continue to appear like it recorded something. After following all your steps it still does the same.
    What can I do ?
    Thanks in advance

  227. Yogesh Avatar
    Yogesh

    Hi I am trying to recover 6 corrupted M4A files. For all corrupted files I was able to recover 50% using your instructions. Can you please help me? Its for my book.

    1. sysfrontier Avatar
      sysfrontier

      We are sorry, but the last part after the 50% may have been lost forever due to app crash. It is impossible to recover that part.

  228. Stefanel Gheorghica Avatar
    Stefanel Gheorghica

    Hello,
    what can I do if my Windows is running on 64bits, not 32?

    Best regards,
    Stef

    1. sysfrontier Avatar
      sysfrontier

      The tools work on Windows 64 bits as well.

  229. Sylvia Avatar
    Sylvia

    Hi,

    At Step 6, I get the message – “Error opening file”

    Please help? Thank You!

    1. sysfrontier Avatar
      sysfrontier

      Are your faad and the audio file in the same directory?

  230. Mandy Lai Avatar
    Mandy Lai

    Thanks for the fixing article, it’s helps me a lot.
    2 questions about repair service
    1. Do you receive BTC or any kind of cryptocurrency?
    2. By following your tutorial, I have successfuly recover 48% of my recording file. Can your service get the rest of the recording?
    Thank You!

  231. Siddhi Patel Avatar
    Siddhi Patel

    Hi, I was only able to repair 4 minutes of a 57 minutes corrupted recording. What can I do to repair it fully?

  232. Hi,
    When I was using faad.exe to decode the m4a file, I got the message “Channel Coupling not implemented” at 17% progress.
    Could you help me ?
    Thank You!

  233. Hi. I have tried doing the steps mentioned above and I’m stuck at step 5. When I open the file at the binary editor, all I can see is 00 under the column 00-15 and —- under the decoded text column. That’s why I couldn’t see the “mdat”.

    What should I do to repair my file?
    I have recorded the voice file using Samsung j6.

    Any help, please. Thank you.

  234. Madhawa Perera Avatar
    Madhawa Perera

    SysFrontier Inc.,

    Thank you so much for this extremely useful information. This helps a lot and it worked to some extent. 😀

    This is a recording created using my iPhone. However, after the recording, it was not working for some reason. Could not even share it with another device. I duplicated the original recording and luckily the duplicated file could be shared.

    The corrupted recording file shows that it has 46 minutes. However, by using the suggested method above, I could only save 22 minutes. I do not know why the rest cannot be saved. At least the method helped me to saved 22 minutes. It’s better than nothing. 🙂

    Thanks again for the very useful information.

  235. Ries Rommens Avatar
    Ries Rommens

    SysFrontier Inc.,
    Many, many thanks from me and my daughter. She interviewed people in Africa during here apprenticeship. A two hours lasting interview was gone forever….
    Thanks to your information everything is solved, the interview is “alive and kicking”.

  236. Miranda C Avatar
    Miranda C

    It worked perfectly, though only 10 minutes of the 2 hours recording saved, I guess the app crashed very early in the process, after all the file was only around 20MB. Thank you very much!

  237. Hi
    I have a problem but I dont know if I use this method it will help or not.
    My problem is I have a voice memo with 52 Min duration but with Size 413 kb. The file play until 49 second then it stops. Is it possible to restore or repair my file?

  238. Jasper Avatar
    Jasper

    SysFrontier Inc.,

    You guys are lifesavers! My interview recording got corrupted somehow and thanks to this article I can finally listen to it again!

  239. Thank you so much! It worked! I’ve been delaying a youtube video that I was supposed to upload about 5 months ago because of not knowing what’s wrong with the audio. Thank you for the clear steps!

  240. somebody Avatar
    somebody

    Awesome, it worked perfectly, the whole file is restored. And I feel like an IT-nerd now (yay, can follow an instruction… :D)
    Thank you so much for the detailed manual!

  241. Megaman Avatar
    Megaman

    This is a HUGE contribution. I just recovered an insanely important audio file. I was looking at the file with an hex editor and didn’t know what to do. Following your instructions I repaired the file in 10 minutes, it worked flawlessly, beautifully well.
    Thanks a lot for sharing your knowledge! It’s particularly important for the people that can’t afford a repair fee.

  242. Hi – my file is is large 256MB – 8 hours.

    The conversion runs and stops with the message “”

    The system recovers the first 4 hours fine, but then stops the conversion saying “Array index out of range”.

    The wav file includes the first 4 hours. I need the final 4 hours.

    Is it possible to remove the first have of the audio and convert the rest?

    Does each audio segment have a start and finish code, so that I can remove without corrupting?

    Thanks

  243. Faisal Alshammari Avatar
    Faisal Alshammari

    When I type “faad.exe filename.m4a” then press enter it shows the following message:

    1.m4a file info:
    RAW

    Error: Array index out of range
    0% decoding 1.m4a.

    Any thoughts?!

  244. Ryan Z. Avatar
    Ryan Z.

    Desperately could use your help. Followed all of your instructions to a T – literally.

    And I get the error “error: bitstream value not allowed by specification 0% decoding”

    I could really use your help. Please let me know.

    Thanks,
    Z

  245. Alexis Smith Avatar
    Alexis Smith

    When I get to the cmd and type in faad.exe “20140615 163625.m4a”, it says error opening the file

  246. Kiprotich Brian Avatar
    Kiprotich Brian

    Invalid number of channels how do I fix this

    1. same problem. how do i fix this?

  247. Viktor Liashenk Avatar
    Viktor Liashenk

    Thank you for this tutorial. I’ve repaired my recording successfully.

  248. THANKS, someone posted your page I managed to fix it , have that file been broken for almost 3 years this was the 5 serious attempt , i was to give up, the .wav was enough

  249. Ekemini Avatar
    Ekemini

    Thanks so much. It worked for me. I was able to recover a 30 minutes recording from my android phone that couldn’t be played in any audio player including the recording app! Thanks so so much. Simple and straight forward process and within minutes I was able to recover the file.

  250. Lavaleur Avatar
    Lavaleur

    Hi,
    I have the same message : ” When I type “faad.exe filename.m4a” then press enter it shows the following message:

    1.m4a file info:
    RAW
    Error: Array index out of range
    0% decoding 1.m4a.
    Can you please help me.
    Thank in advance

    1. Hello Jello Avatar
      Hello Jello

      Send to me and I’ll send it fixed back. I had to deal with this a while back.

      hellojello936 at gmail

      1. Can you please help me with this same issue.
        error: bitstream value not allowed by specification
        0% decoding

  251. Tibebu Avatar
    Tibebu

    This was absolutely best thing, thank you a lot

  252. Johanna Avatar
    Johanna

    Hi,
    I have a problem with a coruppted voice memo (aac and m4a format). I can hear until Min 01:50 and afterwards it is just silence. The file has a size of 44,5 MB/ 23MB so I hope that we can fix it. I need this interview for my thesis!
    I followed all the metioned steps but the corruption is still present. I also got the Error: Invalid number of channelsck.m4a.

    I hope you can help me out!

  253. I got this error:
    “Invalid number of channels”
    How to fix it?

  254. Thank you SOOOO much!
    Thanks to Faad I’ve managed to recover my SUPER important recording (students performance) that was f**ked up by Zoom q4n.
    THANK YOU!!!!!!!!

  255. […] the repair method described in the previous post on the no longer […]

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