Corrupted Audio Files

[Roxie2401]

Hi - maybe I'm doing something wrong but when I run the Batch Converter (changing from m4a to mp3) I will get a rather long list of failures. When I go back and check the original audio file it appears to be corrupted. It was playable before running the converter but after I will get a rather loud "pop" and then nothing.

I don't know that much about the format of the audio file but is there a "header" that contains the Tag information at the beginning? I wonder if this problem is caused by the Batch Converter trying to "read" the tag information......

What is really strange is if I restore from backup the "corrupted" files (m4a) and play them to check the tracks, running the converter again results in the same error and no audio on the original. It would appear "random" but the failures seem to be the same tracks on different albums - but not always.

If it weren't for the error report, when I play the album, the player just skips the back track and moves to the next one ----- only if I manually select the "bad" track will I hear the loud "pop."

More information -- the Tags are v2.3 and the reason for running the converter is that my car player likes mp3 files better. I also run MediaMonkey Player on the Desktop and it will tell me I have bad audio tracks - but they were OK before. And, I have even used dbpoweramp to rip the original CD to m4a and then run the converter and still get one or more bad tracks --- but not all of them.

Thoughts? Thanks!

[GBrown]

Re: Corrupted Audio Files

Hi - maybe I'm doing something wrong but when I run the Batch Converter (changing from m4a to mp3) I will get a rather long list of failures. When I go back and check the original audio file it appears to be corrupted. It was playable before running the converter but after I will get a rather loud "pop" and then nothing.

I don't know that much about the format of the audio file but is there a "header" that contains the Tag information at the beginning? I wonder if this problem is caused by the Batch Converter trying to "read" the tag information......

What is really strange is if I restore from backup the "corrupted" files (m4a) and play them to check the tracks, running the converter again results in the same error and no audio on the original. It would appear "random" but the failures seem to be the same tracks on different albums - but not always.

If it weren't for the error report, when I play the album, the player just skips the back track and moves to the next one ----- only if I manually select the "bad" track will I hear the loud "pop."

More information -- the Tags are v2.3 and the reason for running the converter is that my car player likes mp3 files better. I also run MediaMonkey Player on the Desktop and it will tell me I have bad audio tracks - but they were OK before. And, I have even used dbpoweramp to rip the original CD to m4a and then run the converter and still get one or more bad tracks --- but not all of them.

Thoughts? Thanks!

They may have played before, but that doesn't mean there isn't some corruption or header problems. There are some tools you can find online that can confirm this, depending on the type. Try mp3diags or mp3val as some suggestions.

[Roxie2401]

Re: Corrupted Audio Files

They may have played before, but that doesn't mean there isn't some corruption or header problems. There are some tools you can find online that can confirm this, depending on the type. Try mp3diags or mp3val as some suggestions.

Thanks for the suggestion. These are m4a files that were created with the dbpoweramp ripper from commercial CDs and have played well in the past. It was only after an attempt to convert them to mp3 that the originals no longer would play --- just a big "POP" at the beginning and the progress bar on the player would continue to move but no audio. It looks like something "clobber" data, maybe in the tag area.........I'll keep doing a "stare and compare" and try some things.

I've looked at the diagnostic tools you mentioned but its not the mp3 but the m4a that needs analysis after the corruption. Maybe there is a tool for those; I'll look around, thanks.

The reason for the conversion to mp3 is my car audio was doesn't want m4a files.....

I was just asking if anyone else had experienced something similar.

[Spoon]

Re: Corrupted Audio Files

Reading a file cannot corrupt it, only writing to the file. dBpoweramp would only read from the source files.

[Roxie2401]

Re: Corrupted Audio Files

Reading a file cannot corrupt it, only writing to the file. dBpoweramp would only read from the source files.

I totally agree. But when I run the batch converter (and the files were played just prior), the converter gives me a list of files it was unable to convert, and its strange that it may have converted some tracks on the album but failed on others, I go back and try to play that track, get one loud "pop" and nothing. Wonder if it happened on the attempt to "read" the tag?

The tracks the converter did convert both play in the m4a format and the mp3 --- just some tracks fail and then they don't play again and I reload from a backup; play all tracks, attempt to convert and the same track fails ---- any chance there is something in the existing tag data that the convert is trying to read/convert that works on the m4a but causes the failure?

Guess I'm sort of focused on something in the tag data that maybe seems "ok" for the m4a even if it shouldn't? Maybe my next test would be to clear all the tag data and attempt to convert the file.....

I'll look for a "tool" to check tag data on m4a ---- or rip the original CD to AAC and see what happens when trying to convert since the same tag data should be on the original.

Thanks

[Roxie2401]

Re: Corrupted Audio Files

I totally agree. But when I run the batch converter (and the files were played just prior), the converter gives me a list of files it was unable to convert, and its strange that it may have converted some tracks on the album but failed on others, I go back and try to play that track, get one loud "pop" and nothing. Wonder if it happened on the attempt to "read" the tag?

The tracks the converter did convert both play in the m4a format and the mp3 --- just some tracks fail and then they don't play again and I reload from a backup; play all tracks, attempt to convert and the same track fails ---- any chance there is something in the existing tag data that the convert is trying to read/convert that works on the m4a but causes the failure?

Guess I'm sort of focused on something in the tag data that maybe seems "ok" for the m4a even if it shouldn't? Maybe my next test would be to clear all the tag data and attempt to convert the file.....

I'll look for a "tool" to check tag data on m4a ---- or rip the original CD to AAC and see what happens when trying to convert since the same tag data should be on the original.

Thanks

Spoon, just a follow-up ----- do you know what you cause the converter to consider a file "unrecognizable file type" and show in the error report? Its strange that the converter will convert some tracks on an album but fail on others from the same folder, maybe one track is considered "unrecognizable" and then the original track (m4a) can't be played again. Strange. Just looking for more clues. Thanks

[mville]

Re: Corrupted Audio Files

What was the source of your original mp4 files that you have backed up?

Are you able to restore the original mp4 backup files to a new location and run Batch Converter > Test Conversion on them, and then report the results here?

[Spoon]

Re: Corrupted Audio Files

Unrecognizable file type for m4a would be the header corrupted which indicates which type of m4a file it is.

To see if anything has touched the files, right click on one >> Properties and look at the last modified date, if a long time ago then the disk drive itself is corrupting.

[simbun]

Re: Corrupted Audio Files

The most robust way to determine if the input files are being modified is to calculate the hash of the files before and after the conversion.

If you press the Windows key and type 'pwsh' it should open a powershell window, from there run the following code making sure to replace the path to your music files and of the output csv.

Get-ChildItem -Path '[B][I]D:\MUSIC\Artist\Album\CD01[/I][/B]' -include *.m4a -Recurse -File | 
    Get-FileHash -Algorithm MD5 | 
    Export-Csv -Path '[B][I]D:\FileHashes.csv[/I][/B]' -UseCulture -NoTypeInformation -Append