MP3 Compare

[Aaron]

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.

[Aaron]

Hello,

We are using a Windows API call for the playing of media, which is returning to us that it cannot. Windows Media Player (most recent) probably has been worked on (by Microsoft) to handle trouble or otherwise wider range of files. The older Windows Media Player 6.4 seems to be closer in consistancy with what this API call can also handle.

Investigating this is on our wishlist.

[RunnerBiker]

One additional clue is that the player controls are greyed out when the audio portion of an MP3 file begins after (or very nearly after) 128K into the mp3 file. (offset 20000 Hex)

This happens on my system (Win XP Media Center).
It happens on my wife's system (Win XP Home).
I believe Aaron told me it happens on his test system too.

What is special about the 20000Hex offset?

What Call did BC3 make to the Explorer shell to discover whether to enable the player controls, and what response code did BC3 get back that tells it to not enable the palyer controls.

When the BC3 player controls are not enabled, the MP3 file still plays successfully in Windows Media Player when you launch it from within BC3 (Alt+A X P) or by double clicking on it in the Windows Explorer. Why does BC3 think the mp3 is not playable?

Is there anyone else reading this who is running Windows XP Media Center who would like to try one of these "bad" MP3 files to see how your system responds to it?

[Tom]

Sounds pretty frustrating, RB. Still, you've ruled out any codec issues, so you & Aaron can look elsewhere.

[RunnerBiker]

Yes Tom, I rebooted after disabling all that stuff, and by the way, Sherlock doesn't report any problems either.

BC3 (and BC2) lock up when attempting to open an MP3 file that has the characteristics I described earlier in this thread.

Highlight one MP3 file.
Press ENTER to open it in MP3 Compare.

The cursor changes to an hourglass for a few seconds and then the screen flickers and the cursor returns to an hourglass. If you hover the cursor on the "Cancel" Red X in the top right corner, after the flicker, the cursor becomes an arrow.

After the cursor becomes an arrow, clicking on the Red X in the top right corner causes Windows to react to a Not Responding Application, and lets you cancel it.

[Tom]

Weird. What is it exactly that locks up BC3? Comparing 2 MP3s? I take it you rebooted after disabling all that stuff?

[RunnerBiker]

Yes, I saw the backup and restore functions, and I also saw the ability to create a TXT file with the details on all settings.

BAD NEWS -

Using the CodecTweakTool I disabled EVERYTHING.

Disabled ALL the filters
Disabled ALL the codecs
Disabled ALL the Direct Show objects
Disabled ALL DirectX Media Objects

I can not play an MP3, but I didn't expect to be able to.

BC3 still locks up. I have waited 30 minutes to see if maybe something was going to take a long time.

Is there anyone else out there with Windows XP Media Center Edition that can try one of these problem MP3 files?

[Tom]

I rebooted and can play MP3 files again. That is the good news.
BC3 locks up again, so I'll see what CodecTweakTool finds now.

Sorry to hear that it's turning out to be more of a challenge -- but it sounds like you're making progress! Don't forget that the tool has backup capabilities in case you need to undo any changes.

[RunnerBiker]

Tom! Woo Hoo!

You are my hero.

I ran the CodecTweakTool and it "fixed" 23 errors in the registry.

Now BC3 doesn't lock up for me any more.

It still disables the play controls, but that seems to be consistent across all other platforms.

If you are interested, I snapped screenshots of all the errors the CodecTweakTool fixed. I can post these, but I'm guessing you don't really care what was screwed up.

Thank you again.

RunnerBiker

UPDATE 1 ==================================================

While BC3 no longer locks up, I cannot play MP3 audio files any more. Windows Media Player displays this error:

Windows Media Player cannot play the file. The Player might not support the file type or might not support the codec that was used to compress the file.

I'll update this when I discover what needs to be put back.

UPDATE 2 ==================================================

I rebooted and can play MP3 files again. That is the good news.
BC3 locks up again, so I'll see what CodecTweakTool finds now.

[Tom]

That sounds very thorough, RunnerBiker! Here're a couple things that might help you track down squirrely codecs. Marc Liron, Microsoft MVP, created Sherlock, a software-based "Codec Detective". The app will point out the details of your codecs (audio & video separately) and highlight any problematic ones it finds, but doesn't offer any repair capability.

A good companion is the K-Lite Codec Tweak Tool. It seems to be a script-based approach created using Inno Setup and was just updated a couple of weeks ago.

[RunnerBiker]

Hi Tom,

I too have difficulty with some MP3 files. Here is a synopsis of what I found:

I am running Windows XP Media Center Edition (SP3 Beta) This system does not include WMP6.4, it uses MPlayer.exe (11.0.5721.5145 8/19/2004)

None of these lockup problems occur on my wife's computer. She is running Windows XP Home (SP3 Beta).

1) If the tag is large, the player controls are disabled (dimmed)
2) If the audio frames are preceeded by a LAME or XING or INFO frame, BC3 locks up and must be killed.

Notes about large tags. In my experimentation, I have altered an MP3 file by adding additional $00 pad bytes to the end of the TAG and preceeding the first audio frame. I have not found the "Exact" threshold where the problem occurs, but when the first music frame is at offset $1FF43 (Hex of course) the player controls are dimmed. (this also occurs on my wife's computer)

When the first audio frame is at offset $1F343, the player controls are enabled.

When the first audio frame is at offset $1F343 and it is preceeded by an INFO frame, BC3 works correctly, and enables the player controls.

When the first audio frame is at offset $1FF43 and it is preceeded by in INFO frame, BC3 locks up. (My wife's computer does not lock up, but the player controls are dimmed)

The audio frames in these test files are all identical.

All these test files play correctly when you launch them (Alt+A X P) from within BC3 or when you double click on them in the Windows Explorer.

All the symptoms are the same with BC2 and I have been working with Aaron since last fall on attempting to isolate the issue. Aaron believes (and he is probably right) that I have an errant codec installed that is causing the problem, but we haven't been able to isolate it yet.

Has anyone else with windows Media Center Edition experienced this type of lockup?

[Tom]

We have, though we can't implement just any open source project into our commercial product.

Understood -- I realize there are licensing issues to consider. Some do permit commercial use, or maybe you'd only need to release the modified source of the player (if any) and not BC itself.

Most of the issues we run into deal with malformed tags in the mp3 files that cause problems.

Hmm. Is there any straightforward way to diagnose the issue here locally? I ask because I've been reporting playback capability being completely disabled on and off since the turn of the century. Heh! It's definitely not something so simple as corrupted tags on my system -- I've even tried files with all tags removed, or after processing with an MP3 "cleanup" utility to make the files meet specific standards. Controls remained dimmed/disabled.

What would you think about a configurable way to hand off both files to a couple instances of a player of one's choice from within the comparison module? That might let you reuse code that's mostly in place already. I know there're overarching business considerations that affect development decisions, but maybe that'd eliminate the need for a complete redesign if it's going to remain a lower priority.

BC3 sure is lookin' good, though!

[Aaron]

We have, though we can't implement just any open source project into our commercial product. This kind of change is quite large and would be scheduled in the same way as 'better zip support.'

WMP6.4 is not exactly what we are currently calling, but seems to have similar limitations/error handling as the method we are using. Most of the issues we run into deal with malformed tags in the mp3 files that cause problems.

[Tom]

.

[Tom]

The problem is that we're asking Windows to play the file and it chooses to use an older player (Windows Media Player 6.4) which fails. We hope to have a fix in a future release.

Just checking back on the status of MP3 playback. Have you guys considered incorporating the open source MPLAYER.EXE? It seems to be very widely used.