MP3 Compare

[Tom]

Of course you did. Sorry I didn't look back in the thread to verify the poster.

Heh! No harm done -- I'm just being difficult.

The player controls are not dimmed on her PC when analyzing the shenandoahlowres.mp3 file either.

By the way, the website kind of eats filenames apparently -- the original filename was "Shenandoah (low res).mp3". Oh well -- next time I'll try underscores or something.

I started collecting MP3 files that dim the player controls on my PC.

Well, everybody needs a hobby. No, seriously, you've been very thorough in your approach -- but I'm not sure what else can be done.

I tried to discover the author of the AAC_Parser.ax file but was unsuccessful. If that one was problematic, maybe another .ax file written by the same company is causing a problem too.

That makes sense -- but heck, not including the DLL cache in Windows, there're 186 .AX files on my system, so lotsa luck making sense out of that collection.

[RunnerBiker]

See it? I started it.

Of course you did. Sorry I didn't look back in the thread to verify the poster.

I did a trial install of BC3 (Beta 462) on my wife's computer (Win XP Home SP3). The player controls are not dimmed on her PC when analyzing the shenandoahlowres.mp3 file either.

I started collecting MP3 files that dim the player controls on my PC. I have about 25 right now. The unique thing about them is that the first audio frame is at offset 2,000(Hex) or higher into the file. If I remove the tag so the first audio frame is at offset 0 (Hex or Decimal), the player controls are not dimmed.

In three of the MP3 files, the first audio frame is past offset 2,000(Hex), yet the player controls are not dimmed. In fact one of those files has a huge APIC (picture) tag (1,393,575 bytes decimal). The first audio frame is at offset 15,453B(Hex) and the player controls are not dimmed.

On my wife's computer, all 25 files dim the player controls. The three that enable the player controls on my PC do not enable the player controls on her's. The player controls are enabled for the shenandoahlowres.mp3 file on her PC.

I tried to discover the author of the AAC_Parser.ax file but was unsuccessful. If that one was problematic, maybe another .ax file written by the same company is causing a problem too.

[Tom]

I have MP3/Tag Studio too. It does some things better than Tag&Rename, but in general I prefer Tag&Rename.

Fair enough.

I believe Windows Media Player or one if its addons is writing the PRIV tags into the MP3s. I wish I could figure out how to stop that.

Me too! I guess you could try locking the files, since you don't need to edit them very often (if ever). It's pretty arrogant for WMP to modify files just because it plays them. MS Office apps do the same thing -- modify files just because you opened them, even if you don't make any changes. Definitely annoying, if for nothing else than the senseless additional file & drive fragmentation over time.

Did you see the discussion about Sherlock and CodecTweakTool earlier in this thread? Have you run them to see what they have to say?

See it? I started it. They're not reporting any problems, and nothing else (I'm talking about over a dozen audio utils or players) has a problem with MP3s on my system. It's just that none of the others make it easy to do a side-by-side audio comparison.

[RunnerBiker]

I have MP3/Tag Studio too. It does some things better than Tag&Rename, but in general I prefer Tag&Rename. MP3/Tag Studio lets me scour all the files in a directory to remove undocumented frames like PRIV and NCON.

I believe Windows Media Player or one if its addons is writing the PRIV tags into the MP3s. I wish I could figure out how to stop that.

I downloaded your file. The player controls are enabled for me, and I confirmed that you removed the tag completely.

Did you see the discussion about Sherlock and CodecTweakTool earlier in this thread? Have you run them to see what they have to say?

[Tom]

Do you have an MP3 TAG Editor?

Yup -- I (mainly) use MP3/Tag Studio. The developer isn't much for keeping up with bug reports, but overall it's got a really good and versatile design. (BTW, I do love SoftPointer's AudioShell and use it all the time.)

Maybe you can post one of your MP3 files that has the player controls disabled, to see if they are disabled with my install.

Be glad to. I tried checking it with and without a tag, but there was no change. (Tag Studio offers a Shell Extension, so you can strip/copy/paste tags right from the Explorer context menu, among other things.) The one I'm posting is about a meg -- it's very low res, but it'll give you something to mess with.

The board won't let me upload it, but you can get it here.

[RunnerBiker]

Hi Tom,

Do you have an MP3 TAG Editor? Something like Tag&Rename? (http://www.softpointer.com/tr.htm)

Can you remove the tag from an MP3? If you remove the tag, are the player controls enabled?

Maybe you can post one of your MP3 files that has the player controls disabled, to see if they are disabled with my install.

[Tom]

But the controls are only greyed out for some MP3 files, not all of them.

Not here -- it's probably been years since I last saw an MP3 for which the play controls were active. Naturally, that's caused me to use BC a lot less for that file format, representing about a 35% reduction of use overall. Instead of fixing BC's plugin, it might only take someone knowledgable to post how to set the right codec to be prioritized (in Windows).

[RunnerBiker]

As we've mentioned before, the controls are grayed out because we're asking Windows if it can play the file and it tells us it can't because it wants to use an older player. It's on our wishlist to figure out how to get it to use a newer player.

Windows is probably consulting some codec (or another .ax file) to decide how to answer your query.

But the controls are only greyed out for some MP3 files, not all of them. I'm investigation for what is different about the MP3 files that it can't play. maybe there is a clue there.

Preliminary results show that the same files that locked me up before I discovered the aac_parser.ax connection are the ones that don't allow playback. The common feature of these files seems to be the first audio frame is at or after $2,000 hex. These files usually have a large picture (APIC frame) in the tag.

[Erik]

As we've mentioned before, the controls are grayed out because we're asking Windows if it can play the file and it tells us it can't because it wants to use an older player. It's on our wishlist to figure out how to get it to use a newer player.

[RunnerBiker]

The next challenge is to discover why sometimes the player controls are greyed out. The file is playable with Windows Media Player, but BC's player controls are greyed out.

[Chris]

RunnerBiker,

Thanks for posting the update. I'm glad you finally managed to solve the problem!

Also, thanks again for all the feedback you've given us on BC3. We really appreciate it.

[RunnerBiker]

Thanks Tom, This problem bothered me for quite a while.

Curiously, I had suspected Super from the start, since the behavior of the MP3 compare in BC changed for the worse when I installed an upgrade to Super.

Anyway - the problem seems to be gone now, I have used the MP3 Compare tool to analyze hundreds of MP3 files that would have caused me trouble and it has worked without any trouble.

[Tom]

Congrats, RB! Too bad it's not easier to troubleshoot that kind of stuff, but SysInternals really has done a lot to make it doable. The Win Driver Verifier (verifier.exe) is pretty good, too (although not designed for codecs, of course), but it's a pretty obscure tool and requires a lot of CPU. With all Microsoft's (and other people's) work on virtual machines, maybe there'll be a solution soon that'll create an automated, self-contained environment that would really stress-test these kinds of things without affecting the actual installed OS until you were ready to do some kind of repair.

You've really done quite a bit of detective work, sir!

[RunnerBiker]

aac_parser.ax causing lockups

I finally figured out what was causing BC to lock up on certain files.

I used SysInternals: FileMon to watch what files BC accessed when it locked up. The last file it opened was aac_parser.ax. Then it went into an infinite loop reading 9 bytes from the MP3 file at the offset of the first audio frame.

This frame was an INFO frame and didn't really have any audio in it. I suspect that is one factor. The INFO frame is a recent addition to the MP3 encoding. It is possible that aac_parser.ax was not written to handle INFO frames.

The first time I reported the lockups to Scooter in October/November 2007, I had just upgraded an audio conversion program that I use. It is called SUPER (http://www.erightsoft.net/home.html). The behavior of BC2 changed.

Before I upgraded SUPER, when I encountered a trouble file, BC2 would not complete an MP3 compare, but it would respond to the ESC key and regain control. After I upgraded SUPER, BC2 would not respond to the ESC key (locked up).

I uninstalled SUPER, rebooted, tested, installed the previous version, rebooted and tested again but the new behavior was stuck.

What I discovered yesterday was that SUPER installs aac_parser.ax but it doesn't uninstall it. I deleted it and scoured it from the registry.

Finally after months and months, I can use BC2/3 without worrying about getting locked up.

Thanks for Aaron and Chris and everyone else who worked on this with me.

aac_parser.ax details:

Comments: Allows playback of ADTS files (normal extension .aac) in DirectShow players.
File Version: 1.1.0.0
Language: English (United Kingdom)
File Size: 81,920 bytes

[RunnerBiker]

Are you still encountering any type of freezing? It sounds like from your later forum post that you managed to fix that and simply see the "button not enabled" which is the expected behavior.

YES, I'm still getting lockups.

For a moment after running Sherlock the first time, I could open MP3s that have the 20000Hex offset issue, but as soon as I rebooted the lockups returned. Running Sherlock again did not help.

Like I said in my post on "06-01-2008 05:57 PM" I'm still getting lockups.

Thanks for your perserverence.

I sure would like to see someone else volunteer to test one of these files on a Windows XP Media Center Edition.