Mysterious Mute MP3 Music

[volvoguy]

Sorry for the silly title, I'm getting a little loopy. I have a "mom thinks the computer is posessed" issue and since dbpoweramp converter is the only app that's giving me any information, I thought I'd pick the brains of you fine folks.

The issue started with, "I have some mp3's that won't play", and the number seemingly increased every day, with some other weird behavior thrown in for good measure.

Mom got an iPod, and has been ripping CDs and editing ID3 tags in iTunes like a madman (and doing some conversions with Music Converter). When I was finally able to sit down and look at these mp3's that won't play, I ran into something I've never seen before (maybe I'm just lucky). There are several dozen (out of several hundred) files that are the size they're supposed to be (comparing with mp3 backups on CD when available), but I can find no media player that will play them. The ID3 tag info is missing when viewed in Winamp, but dbpoweramp's little info popups (and file properties tab) show quite a bit of info (although still not the ID3 tags). The one I'm looking at now for instance shows:

Type: Winamp media file
Extension: .mp3
Length: 1:55
Size: 2262 KB
Uncompressed: 10853 KB
Comp. Ratio: 4 to 1 (20%)
Bitrate: 160
Frequency: 24000
Channels: 2 [Joint-Stereo (Intensity Sound)]
Level: MPEG 2 Layer II
Encoded by: QDesign (Guess)

Attempting to convert the file to WAV, a file is generated with the worst high-pitched, clipped sound you'd ever want to hear.

I'm not sure what other info might help diagnose the problem, but I'll get whatever is asked for. Ideally I'd like to know what might have happened to these seeming random files, how else to troubleshoot, how to fix and how to prevent. They're obviously corrupt somehow but Googling "corrupt mp3" leads to some shady looking freeware, so I'd rather get personal recommendations if possible. Knowing the end user, it could definitely be user error somehow, but I wouldn't even know how to mess up a file like this. Any thoughts or suggestions would be appreciated!

Aaron

P.S. - If the hydrogenaudio folks would be better to ask, let me know if there's any additional info that might help troubleshoot. Thanks!

[Deano]

Re: Mysterious Mute MP3 Music

Frequency: 24000
Channels: 2 [Joint-Stereo (Intensity Sound)]
Level: MPEG 2 Layer II

The above is likely to be showing where the symptoms are coming from. Mp3 is MPEG1 layer 3. CDs are also generally ripped at a frequency of 44100, not 24000. I think this explains why they won't play.

It does not quite explain how they got into this format in the first place though...

[xoas]

Re: Mysterious Mute MP3 Music

Are these 24 kHz (frequency=24000) files just scattered here and there amongst the files your mother has ripped or does it seems that some CD's are ripped at 24 kHz and some at 44.1 kHz? What have you tried to play them with?

As for playing these files you might try dBpowerAMP Audio Player (which uses the same MAD decoder as does dBpowerAMP Music Converter and which does a better job of reading non-standard MPEG files than most mp3 decoders). I believe the MAD decoder is available for WinAmp but I am not sure it is standard or not so you could try that also.

To convert these files to wave you could first try doing the conversion with dBpowerAMP Music Converter with Professional Frequency Conversion enabled. This is set through the dMC Configuration (Start>All Programs>dBpowerAMP Music Converter>Configuration>dBpowerAMP Music Converter Configuration). If that does not work, try converting first to wave at a frequency of 24 kHz (24000 Hz) and then to wave at 44.1 kHz. As an alternative, you might find it easier to convert to mp3 at standard (44.1) kHz frequency (still with Professional Frequency Conversion enabled).

If this won't convert to wave at 24 kHz, try a test conversion of one or more of these files. This is done the same way as a conversion to wave (or to standard mp3 for that matter) except that where you select wave or mp3 as your conversion format sselect "Test Conversion (No Write)". This will not create an output file but will quickly tell you if dMC thinks it can read the file.

Hope some of these ideas may prove useful. Please keep us posted on what you try and what your results are.

Best wishes,
Bill

[volvoguy]

Re: Mysterious Mute MP3 Music

Are these 24 kHz (frequency=24000) files just scattered here and there amongst the files your mother has ripped or does it seems that some CD's are ripped at 24 kHz and some at 44.1 kHz? What have you tried to play them with?

I should have been a bit more specific, but I was a little overwhelmed by the number of screwed up files. The dozens that aren't working have wildly different info in the file properties info. Some say zero length (time) and zero bitrate, while some display what you'd expect - 128 kbps, 44.1k sampling rate. They're totally random throughout the collection (one folder specifically, which mom just intuitively labeled "oldies") and not all of one specific album.

I've tried playing them with everything at hand - Winamp, Nero Showtime, Foobar2k, Musicmatch (yuck), Windows Media Player. The weird thing is that all these files worked at one time, and we have some of them backed up to verify that. The screwed up files show the same modified date as the rest in the album, so I can't imagine what happened to them between ripping and now. Oh, and here's a new discovery - several "oldies" files play, but play a song from a different album in a different directory. (another reason I kinda suspect user error)

As for playing these files you might try dBpowerAMP Music Converter (which uses the same MAD decoder as does dBpowerAMP Music Converter and which does a better job of reading non-standard MPEG files than most mp3 decoders). I believe the MAD decoder is available for WinAmp but I am not sure it is standard or not so you could try that also.

Do you mean the dbpoweramp audio player? I haven't tried that but I'll give it a go this afternoon and see what happens.

To convert these files to wave you could first try doing the conversion with dBpowerAMP Music Converter with Professional Frequency Conversion enabled. This is set through the dMC Configuration (Start>All Programs>dBpowerAMP Music Converter>Configuration>dBpowerAMP Music Converter Configuration). If that does not work, try converting first to wave at a frequency of 24 kHz (24000 Hz) and then to wave at 44.1 kHz. As an alternative, you might find it easier to convert to mp3 at standard (44.1) kHz frequency (still with Professional Frequency Conversion enabled).

If this won't convert to wave at 24 kHz, try a test conversion of one or more of these files. This is done the same way as a conversion to wave (or to standard mp3 for that matter) except that where you select wave or mp3 as your conversion format sselect "Test Conversion (No Write)". This will not create an output file but will quickly tell you if dMC thinks it can read the file.

I've tried converting the files to 16bit, 44.1k wave files as well as a few other sampling rates and get garbled output every time. When doing a test conversion, it gets about 3-5% through and just closes - so no meaningful output there (well, except that the files don't seem to be "convertable").

Even though these files don't have a newer modified date, could tag editing at some point have corrupted the files? If so, can that be fixed by any of the plethora of apps around that claim to do that task?

Thanks again!

Aaron

P.S. I can put one of the mp3's or resulting wave files online if someone wants to take a look at one. The bad files all seem to be a bit different so I'm not sure if that'd help, but it might be worth a try.

[xoas]

Re: Mysterious Mute MP3 Music

Yes, I meant dBpowerAMP Audio Player.

I suspect that there is no magic bullet that would apply to all of these files, since they do seem to have different properties. I strongly suspect that files with a file size of 0 kb, for example, cannot ever be made into anything (although I might right-click one or more of these files and click on Properties just to make sure that Windows also reports the file sizes as 0 kb.

I tend to doubt that the messed up file tag information would be a culprit but you could always try to convert in dMC unchecking the option to save tag information.

You have not specifically mentionned whether you have checked to make sure that Professional Frequency Conversion is enabled, although this would make a difference only where you convert from one frequency to another.

If you have do have a number of files with similar file information, it might make sense to have a look at a sample. But if there is no significant group of these files that have anything in common, then this might not be so useful.

I am not familiar with iTunes. Could your mother have asked iTunes to re-group or re-tag or re-organize your music files?

[volvoguy]

Re: Mysterious Mute MP3 Music

Yes, I meant dBpowerAMP Audio Player.

I suspect that there is no magic bullet that would apply to all of these files, since they do seem to have different properties. I strongly suspect that files with a file size of 0 kb, for example, cannot ever be made into anything (although I might right-click one or more of these files and click on Properties just to make sure that Windows also reports the file sizes as 0 kb.

Right. There are only a couple that Windows reports as 0kb, the rest are the file size the "should" be.

I tend to doubt that the messed up file tag information would be a culprit but you could always try to convert in dMC unchecking the option to save tag information.

I didn't think so, with nearly 10,000 songs in my own collection from a variety of sources, I've never had a file become corrupt - no matter how fragile the "mp3 fixer" software authors claim them to be.

You have not specifically mentionned whether you have checked to make sure that Professional Frequency Conversion is enabled, although this would make a difference only where you convert from one frequency to another.

Sorry. Yes, I always have it on.

If you have do have a number of files with similar file information, it might make sense to have a look at a sample. But if there is no significant group of these files that have anything in common, then this might not be so useful.

I haven't looked at all of them yet, but it doesn't seem like there's a pattern to the weirdness. That's why I was so frazzled. Though I know Windows modified timestamp isn't always correct, I thought it really strange that the messed up files don't *seem* to have been modified since they were created.

I am not familiar with iTunes. Could your mother have asked iTunes to re-group or re-tag or re-organize your music files?

Entirely possible, although she claims no. I asked about a few scenarios - selecting files and holding shift instead of control, using "select all" when she really shouldn't - that kinda thing. Even taking user error into account, I don't know how one would even accomplish the same results! I'm pretty confident that if you fine folks don't have a quick answer or suggestion, that there *isn't* a quick answer. Needless to say, once mom re-rips or re-purchases the bad files, we're doing a major backup this weekend! If only I could talk her into a few big hard drives for a RAID array. My hand-me-down server has made a great music server with a RAID 1 array on it.

Unless someone has a eureka moment regarding this weird issue, I think it's safe to call it closed. I appreciate all the replies!

Aaron

[ChristinaS]

Re: Mysterious Mute MP3 Music

What happens if you rename the first file you have at the top to .mp2 rather than .mp3 ?

[xoas]

Re: Mysterious Mute MP3 Music

I have 3 other ideas although none may be any good and you may have tried them all.

1. Try downloading and installing the dMC m4a/mp4 and aac codecs (if you have not already done so). This is based on the idea that iTunes'/iPod's default codec is .m4a (or so I believe). This contains aac audio in an mp4 container. Since AAC was introduced in mpeg 2.5 (if I recall correctly), perhaps the dMC MAD decoder is trying to read the .m4a files as mpeg 2, layer 2.

2. Use your Windows Search or Find functions to see if you can find working duplicates of your faulty files.

3. Try to make a complete inventory of your faulty files. Remove them from your system or leave them be. Take a 2 to 3 day break from any further ripping or converting of any audio files. Feel free to play audio files if you want. At the end of this period, see if you have any more faulty files. Here this idea is responding to your report that faulty files seemed to be sprining up from nowhere. If faulty files are indeed generating themselves, you could have a virus or other bug attacking your audio files. Then you may need to track down and eliminate the bug.

Keep us posted on how you make out.
Best wishes,
Bill