How to demux without reencode ?

[DaHuberHerbert]

I want to demux several Xvids to adjust their audio tracks, but I can't find any program that can demux the audio without reencoding it.

VirtualDub always encodes the audio to wav when demuxing, which takes time and is unnecessary.

I'd prefer if the track could be extracted without beeing changed in any way. This is no problem with mpg1+2 but surprisingly difficult with Xvid+Divx.

A second thing:
My DVD Player supports Divx Playback, but I often encounter problems playing Xvids. Sometimes I get a "codec not supported" message, but in most cases the audio troubles me by "stottering".
Is there any restriction regarding mp3 audio tracks in Xvid ???
The audio seems to be fine on PC.

Is their a tool to get more precise info about the video encoding options used? the "codec not supported" message resulted from some kind of "visual enhancement" with a four letter name something like "qslc". I would like to have an option to determine extraordinary encoding methodes like this BEFORE I burn it.

I'd be glad for help

[DaHuberHerbert]

One of the Xvid files just came up with "This file is not prepared for sequential reading ..." it said something about complete interleaving before burning. What the hell does this mean ???

[jon.schaffer]

Let's assume your soundtrack is MP3...
When you demux with VirtualDub, with DIRECT STREAM COPY in AUDIO menu, it creates a .WAV file which is indeed a MP3 files with a WAVE "envelope" (meaning with a WAVE-RIFF header and the .WAV extension), but the content has not been decoded nor transcoded. It's just that VDub does not deal with .MP3 files.

The MP3-WAVE file created can be remux then.

What do you want to adjust? Delay/synchronization?

Then do not demux. Just use the Audio->interleaving->delay option in VDub and re-save your AVI file with DIRECT STREAM COPY in both AUDIO and VIDEO...

Hope this helps

Jon

[yaz]

@DHH
pls, be a bit more specific about what do u want to do.
anyway, try avimuxgui. if i get u right, most of your problems can be solved with it simply by open&(re)save.

the bests
y

[HalfHuman]

vdub doesn't always reencode sound. like jon.schaffer said it just gives the soundtrack the wav extension. if you use direct stream copy the sound remains unchanged. meaning if it was mp3 it will stay mp3. same with ac3, ogg etc. you should know that how much you try you can't transcode ac3 using vdub or vdubmod.
be well

[jon.schaffer]

Originally posted by HalfHuman
same with ac3, ogg etc.

... for ogg, mp3-VBR, VirtualDubMod must be used (VDub doesn't deal with such formats)

can't transcode ac3 using vdub or vdubmod.
Yes, use BeSweet for this.

Jon

[stephanV]

you can transcode AC3 if you have ac3acm installed...

AVI doesnt deal wiht ogg anyway

[jon.schaffer]

Just one more point (I have just tested that):
if your soundtrack is MPEG-1 layer 2 (vs MPEG-1 layer 3 = MP3), VDub (and VDubMod) must decompress it. It cannont be demuxed (maybe that is your problem? - now, so is mine)

Has anyone an idea of a tool for demuxing MPEG-1 layer 2 audio (in AVI or MPG files)?

Jon

[HalfHuman]

@stephanV: where could i get the thing you mentioned?

@jon.schaffer: i only use vdubmod. didn't found a reason to use vdub for everyday use
i believe that vdubcan deal with mp3vbr and maybe also ogg???

[stephanV]

Originally posted by HalfHuman
@stephanV: where could i get the thing you mentioned?

www.google.com :p


[b]
i believe that vdubcan deal with mp3vbr and maybe also ogg???
VirtualDubMod (not VirtualDub) can handle with VBR MP3. It can also handle Ogg, but not in AVI (only for Matroska and OGM)

Originally posted by jon.schaffer
Just one more point (I have just tested that):
if your soundtrack is MPEG-1 layer 2 (vs MPEG-1 layer 3 = MP3), VDub (and VDubMod) must decompress it.

I think that is only valid for MPEG layer 2 in mpg, not in AVI.

Has anyone an idea of a tool for demuxing MPEG-1 layer 2 audio (in AVI or MPG files)?
AVI -> VirtualDubMod, AVImux GUI
MPG -> TPGMGEnc

[jon.schaffer]

Originally posted by stephanV

AVI -> VirtualDubMod, AVImux GUI
MPG -> TPGMGEnc

Thanks a lot!

[HalfHuman]

@stephanV: thanx a lot funny guy:angry: . i know how to use google. i thought you knew a good source for that. i'll check to see whether vdub can deal with vbrmp3 or not.

[stephanV]

now, now.. calm down... theres only one ac3acm out there :)

[DaHuberHerbert]

Most of the things I figured out, but I'm still looking for an option to determine the Xvid Codecs exact Version and the enhancements used.

I really hate the codec not supported message which I get about every second Xvid File I try on my DVD Player.

Sometimes they seems to be identical, same frame size, framerate, audio, codec, unfortunately only one of them works.

Have already updated the firmware, must be some difference with the Xvid coding used.