What am I doing wrong in reencoding xvid to smaller filesize?

[Jeff D]

I'm trying to make a 700MB xvid file half the size (yet keep the AR and source sizing) to allow me to put all episodes of a show on a single DVD. All the other episodes have a file size of 350MB and this last one is at 700MB.

I've looked through here for information and followed the guides, yet my output files are all larger than my source.

I'm using the doom9 guide for converting dvd to xvid and just using the information on xvid encoding.

My source is 576x320 and has VBR mp3 audio (or at least that's what I can figure out as Vdub mod complains about VBR mp3 and gspot reports mp3 audio) I'm using vdub mod that comes with GK to open a simple avisynth file that has one avisource function and that's all.

This avisynth file is opened in vdub mod that comes with gordianknot, I configure the encoder for fast recompress and xvid compressor. The compressor has been tested with two different settings, one for avg bitrate of 516 and the other for a file size of 358400 (350MB in Kbytes) both tests have resulted in 1GB output files.

The settings for the encoder are taken from the xvid codec settings for 1.0 (as I'm running 1.0.3) and the guide matches the options I have available.

So, any idea what I'm doing wrong? And... is there a better way to do this than the method I'm trying?

Thanks

[manono]

Hi-

both tests have resulted in 1GB output files.

I suspect that you kept the audio in the .AVI, and used Full Processing to convert it to WAV, and that accounts for the overly large size. You can open the final 1 GB AVI in GSpot to confirm that the audio has been converted to WAV.

Here's how I would do it. First demux the MP3 Audio (ignoring that stupid message when you open the AVI in VDubMod). Then save the AVI, but without the audio. You'll then have 2 new files, the MP3 alone, and the AVI without audio. Then go find a bitrate calculator that will take into account the size of the MP3 and the overhead to give you a video-only bitrate or size (I would use GKnot). Then open your AviSynth script file and do it as you did before, but with the lower bitrate or filesize, and remux the MP3 when all done.

You could try and demux the MP3 from the original AVI and mux it into the final AVI which (maybe) has WAV audio, but I expect you'll be oversized by about the size of the MP3.

[Jeff D]

PCM audio!!! DoH! An hour of audio is about 600MB...

Thanks, I'll demux and play with those options.