No audio when decompressing a DivX Avi to VCD MPG

[chipzoller]

I used Gknot to encode my DivX video and I want to convert it to to VCD as a trial, but I seem to be falling short. I use standard VCD settings using both the wizard and manually and I'll start encoding and stop after a few seconds to check to progress, and the video stream is ok (just helluva macroblocks) but no audio. Is the audio done at the end? I know there are other ways around this, but it is time consuming and not necessary if this program can accomplish this.

I checked all the codecs out, to make sure that I still have PCM codec for .wav's installed, yes it's fine...I was wondering if the audio stream was available, just not playing. All of my sndvol32 settings are correct for this. I dont' know what else I should try. I should say that I haven't spent an enormous amount of time on this, because I could use VirtualDub to strip the sound away as a .wav and just multi-plex it back in once I have the VCD video stream.

Can anyone offer suggestions?

thanks,


chip

[mr.e]

...first i would suggest creating a small sample vid of your AVI to play with. maybe 10 megs or so.
i'm probably wrong in everything i say here, i'm in experimental stage myself, so please forgive me...
i believe that when you are transcoding an AVI to MPEG, TMPG first demuxes the stream, then encodes the video and audio in a seperate process, video first. if you are aborting the operation before any audio is (re)encoded, then TMPG has no useable audio stream to mux to the already (re)encoded .m1v file, therefore...no sound.
try a small test vid as i said above, and see what pops up. good luck!

[mordant]

I'm pretty sure TMPGenc does video and audio at the same time. I've stopped encodes at various points and the sound is there. Do you know the sound format for the Divx? AC3 sound requires a few extra steps. Extract with VirtualDub to fake WAV then convert that WAV to AC3.

For VBR MP3 - extract the sound to wav format with VirtualDub and use that wav file as audio source in TMPGenc. That solves most problems and actually speeds up the encoding process in TMPGenc.

You can also try changing the Direct Show Filter setting to a positive number in the enviormental settings - but extracting to wav first is really a better way to go.

[mr.e]

...AVI to MPG, TMPG de-compresses the AVI audio stream to a temp WAV, then re-compresses and muxes to the video, correct? unless you have stripped the WAV from your AVI and are planning to mux after the m1v stream is complete? either way, if you abort the operation before completing the video, there will be no mp1 layer II audio stream to mux, therefore, no audio?

also, now i'm confused...
your first post, you state "...and I'll start encoding and stop after a few seconds to check to progress, and the video stream is ok (just helluva macroblocks) but no audio.", and then go on to say in your reply that you've "..stopped encodes at various points and the sound is there." are you talking about using TMPG in conjunction with a frame server here, or what? if so, the audio (and video) stream has already been decompressed to WAV (and MPEG, respectivly) by the time it (they) has reached TMPG, who job now is only to use whatever filters you've got going, compress and mux. so, yes, you would have audio here.

as far as the sound format for DivX, it is what you make it. i've used just about all of them, including ac3 and wma. i generally use a VBR LAME encoding for my archives, and a CBR Fraunhofer IIS for posts(this avoids a few issues that you might encounter when splitting VBR encoded vids). and i prefer to do my audio compression in a seperate process, then interleave with NANDub.
also, as of late, i prefer to manually mux my AVI2MPG conversions. this seems to avoid alot of sync problems, especially when prepping for a VCD(which is the ONLY reason i would deal with creating MPG to begin with! lol!) i strip the WAV with VDub, and convert to 44.1kH/224kbps/mp1 layer II(2) with 'Steinberger WaveLab', where i also do my edits, mixes and clean-up, if nesessary.

i hope this makes some kind of sense, after reading it back to myself, it sounds like the rantings of a loon! lol!