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Posted by: HAHAHA Dec 18 2003, 02:41 PM

Hi~

I have a question about VDubMod. After cutting a .avi file by VDubMod and using NanDub to save WAV, the length of the total time of two files are different.

I have a .avi file that includes the VBR audio stream. The length of the total time is 01:49:46. I use NanDub(1.0rc2 build 1853) to save WAV. The length of the total time of this .wav file is also 01:49:46. Then I use VDubMod(1.5.10.1 build 2389) to open this .avi file(at that time, VDubMod popup a message box about VBR audio stream and I choose No). I cut a part of the .avi file(compression is Xivd MPEG4 Codec) and the length of the total time is 00:01:33. Next, I use NanDub to save WAV. The length of the total time of this .wav file is 00:01:26?!

Why?

I open this .wav file by Windows Media Player 6.4, the sound is correct and the length of the total time that I heard is about 00:01:33. I used TMPGEnc to make a .mpg file with above two files, then I got a .mpg file that has no sound after 00:01:26.

I don't know NanDub has a bug or VDubMod has a bug. Maybe my PC has a bug.

Thanks!

Posted by: Suiryc Dec 21 2003, 03:19 PM

"Save WAV" will save into a WAV file that (unlikely to AVI) can't give you a correct length for VBR streams. (in AVI a hack is used, but this hack uses things that aren't in a WAV file)
That's why you see a different length for the WAV file.
If you play this file without seeking you will hear sound for 00:01:33.
If you mux this WAV file into another container (AVI, MPEG, whatever) using inappropriate tools (i.e. tools that don't check if your MP3 stream is VBR or not inside your WAV file) the resulting file will also believe the length of the audio is 00:01:26. In the case of containers using timestamps such as MPEG, OGM or MKV it maybe result in problems when playing back (generally out-of-synch issues when seeking).

So none of the programs has bugs.
What I recommand you (if possible) is to "Demux" (using VirtualDubMod e.g.) the MP3 stream from your AVI file, and mux the resulting mp3 file in your MPEG file (if TMPGEnc allow that of course).

Posted by: HAHAHA Dec 22 2003, 02:06 AM

Thank you very much!

Posted by: phaeron Dec 22 2003, 02:27 AM

MPEG layer III audio in an interleaved MPEG-1 file is problematic. In particular, some versions of Windows Media Player will not be able to play MP3 audio in an MPEG-1 file. It sometimes can if you install some MPEG-2 playback filters, and I think some newer versions of DirectShow might be able to connect the MP3 decoder filter to the MPEG-1 demuxer, but be warned that MP3 in MPEG-1 is risky.

Posted by: HAHAHA Dec 22 2003, 01:26 PM

Thanks a lot!

--
I will try to solve it.