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Unofficial VirtualDub Support Forums > Testing / Bug Reports > Not Finding Ccitt U-law Audio Codec

Posted by: markchicobaby May 25 2007, 11:19 AM

Hi, really getting into Virtualdub, was hoping to compress and denoise some avi files captured with my trusty Richo digital camera. Unfortunately I get the following error when I hit play with the avi loaded:
"No audio decompressor could be found to decompress the source audio format. (source format tag: 0007)."

The video plays fine in Windows media player. I ran the video through AVIcodec to find out what audio codec is being used, it says " Audio : 0.0 B, 64 Kbps, 8000 Hz, 1 channels, 0x7 = CCITT u-Law, Supported". This is a standard packaged WinXP codec. I thought the codec might be corrupted so I tried following the instructions here:
http://www.free-codecs.com/guides/How_to_install_default_codecs_in_Windows_XP_2000.htm
to reinstall them. Codecs reinstalled OK but the problem has not been fixed, virtualdub still can't find the required codec.

I can edit and export the video in Windows Movie Maker, but the audio becomes very noisy and tinny. I suspect WMM is doing something weird to the audio, I'm hoping to get around this by using Virtualdub instead. I can also edit and save the file using Arcsoft Showbiz. I thought its worth mentioning as these two video editing programs seem to recognize the required codec OK, so I'm stumped as to why Virtualdub is having problems. Showbiz also recognises the same codec as AVIcodec (CCITT u-Law).

The other program that I've used that has had a similar problem with this video file is AutoGK. I've tried to use it to compress the video file, but it gives a similar error to Virtualdub, which may give a clue that the two programs are using similar methods to extract the audio, resulting in both having issues? The AutoGK log says:
[25/05/2007 8:59:06 PM] Demuxing audio.
*************************************
EXCEPTION: Unsupported audio type.
*************************************

The video file information is:
Video : 0.0 B, 0 Kbps, 14.999 fps, 320*240 (4:3), MJPG = Motion JPEG, Supported

One thought might be that the Richo is not tagging the codec correctly? Should I start up a HEX editor and plug away to force Virtualdub to use a certain codec (is this possible?). Also the audio is mono, could this be causing confusion?

Is there anyway to get Virtualdub to "skip" trying to translate the audio, and just copy it to the output avi as-is? The file works fine if I turn off the audio (Audio => No Audio), but of course I would like to have audio included!

Any help would be greatly appreciated! Thanks

Posted by: Placio74 May 25 2007, 02:10 PM

Try save video file with Direct stream copy for audio and video.
Open again.

Look at - File > File Information...

AVI information from VDM.

Before - Not decodable
http://img111.imageshack.us/my.php?image=mulaw3ht2.jpg

After - ACM Decodable
http://img412.imageshack.us/my.php?image=mulaw4uo5.jpg

Posted by: phaeron May 27 2007, 07:48 PM

The camera's probably writing out an AVI audio format header that's not quite correct for the format.

If anyone can send me by email the headers for the file that doesn't open (Tools > Create sparse AVI + zip), I could probably figure out workaround.

Posted by: Placio74 May 28 2007, 04:39 AM

QUOTE (phaeron @ May 27 2007, 07:48 PM)

http://kotuha.com/file/TNT9o-film.html

[EDIT]
I'm check and... still problem in VirtualDub - Unknown (tag 0007).
Bug?

But, it work for me in VirtualDubMod.
However... not always - sometime i'm must repeat loading file to VDM.

[EDIT]
I'm see below edited post phaeron. Thanks!

Posted by: markchicobaby May 28 2007, 01:53 PM

phaeron, thanks for your offer.

Here is a link to the headers as per your instructions:
http://www.dancebandit.com/R0012338_headers.zip

Here is a link to a simple video of a clock... just in case (2MB)
http://www.dancebandit.com/R0012338.AVI

Thanks for your help!
Mark

Posted by: phaeron May 28 2007, 07:29 PM

Yup, the camera's writing a bogus audio format. It's using a PCMWAVEFORMAT structure instead of WAVEFORMATEX, the former of which should never be used for a compressed format. My guess is that the codec may randomly work depending on what data happens to be after the struct in memory -- if it's a zero, it works, otherwise it fails.

I should be able to work around this -- I'll get back to you with a test version.

Update:
Try this version: http://www.virtualdub.org/beta/VirtualDub-1.7.3-test1.zip

Posted by: markchicobaby May 29 2007, 12:14 AM

Great! Works like a charm! Thanks phaeron! I checked for updated firmware for the camera too, but there's none that fixes this problem.

Thanks again!

Also thanks to Placio74 for digging around in Virtual Dub Mod!

Mark

Posted by: noobie Jul 3 2007, 05:34 PM

QUOTE (phaeron @ May 28 2007, 07:29 PM)

hi phaeron, I have a very similar problem with my camera, a Samsung D53, not being able to decode the audio. Due to some reason Media Player Classic can playback the sound, but not WMP nor VirtualDub/Mod. Unfortunately the test version of VirtualDub above does not work for me.

This is my header:
http://www3.telus.net/shawn2/d53sparse.zip
And the video clip:
http://www3.telus.net/shawn2/d53.avi

I'd be very grateful if you or someone here can point me to the right direction. Thanks!

Posted by: Placio74 Jul 4 2007, 06:12 AM

You can't hear sound or can't playback ("No audio decompressor...")?

What is File Information (compression for audio stream) in VirtualDub 1.7.3 test 1?
"Unknown (tag 0007)" or "CODEC Microsoft CCITT G.711 A-Law"?
http://img137.imageshack.us/my.php?image=g711ry8.jpg

Check render in http://www.videohelp.com/tools/GraphEdit.
http://img178.imageshack.us/my.php?image=ulawkj2.jpg

Please, check (maybe reinstall) Microsoft CCITT G.711 audio codec (default installed in WinXP).

Posted by: phaeron Jul 4 2007, 10:06 AM

Dunno what to say about this one. Everything seems to be going OK in VirtualDub, but I don't hear anything in the audio track -- in either VirtualDub or in Media Player Classic.

(Do any of these camera mfrs actually test their products??)

Posted by: noobie Jul 5 2007, 06:33 PM

QUOTE (Placio74 @ Jul 4 2007, 06:12 AM)

Ahh thanks! I just tried it again in VirtualDub 1.7.3 test 1 and it works now (a few reboots ago it would crash but not now, dunno why). Now the file info does say CODEC Microsoft CCITT G.711 A-Law instead of Unknown (Tag 0007) as in 1.6.19. (phaeron: there's audio in the clip but it's just background noise)

I assume there's something wrong with the way the camera records audio though since when opening the file VirtualDub 1.7.3 test 1 does report "AVI: Truncated or invalid compressed audio format detected (16 bytes, should be 18). Attempting to fix." But it does play the sound which is great!

Just curious, since version 1.6.19 does not recognize this type of audio, could the ability be added to future stable versions of VirtualDub? Thank you very much again.

Posted by: phaeron Jul 6 2007, 05:47 AM

I might backport it to 1.6.x, but only if there are other fixes waiting to go out, which currently there are none. I really need to get 1.7.x to stable state at some point.

Posted by: chrome Aug 5 2007, 11:37 AM

I had exactly same problem with Samsung Digimax S500 camera. With 1.7.3 test1 works great, thank you very much !

Btw. I also have the message "AVI: Truncated or invalid compressed audio format detected (16 bytes, should be 18). Attempting to fix." but it works anyway.