Mpeg2 to xvid encoding results in extremely large file size convert, minutes, simple, source

andy

Hi all ... I'm just trying to convert an mpeg2 video to xvid mpeg4 using the VirtualDub mpeg2 source reader mod (VirtualDubMpeg2).  I'm just doing a simple resize from 720x576 to a native 16:9 aspect (video is recorded in 720x576 16:9) such as 1024x576 or 640x360 etc and using the xvid 1.1 codec to try and compress it down.

The native mpeg2 video file is 53 minutes in lengh and its size is just over 1 gig, and I'm trying to get it down to about a 350Mb divx file.  According to the bitrate calculator this should be fine using about a 780kbit bitrate.  I've set up the xvid encoder to try both 1/31 and 2/31 quants and tried a few other sizing tricks, such as varying overflow control.

However, every time I encode I end up with an output file of around 900mb, which is a long way off what I'm aiming for.  Even setting the bitrate down to around 150kbit still nets me a file of around 600mb of terrible quality video.  I appear to be doing something fundamentally wrong here, but so far all my searching has not netted me an answer, and my problem seems to be a long way off the usual xvid oversize problem of 50mb or so.

Thanks for any help, even if it's a slap in the head and pointing out the right guide/faq/whatever to read that I've missed in my searching...

Are you using any audio compression?

Please load the .stats file from the first pass into statsreader and tell us what first-pass filesize is displayed.



53 minutes of PCM audio at 48000Hz is exactly 600mb.

Also, 780kbps times 53 minutes is 300mb, and add up the 600mb for audio you get 900mb./me gives squid_80 a candy.


Originally Posted by sysKin

53 minutes of PCM audio at 48000Hz is exactly 600mb.

Also, 780kbps times 53 minutes is 300mb, and add up the 600mb for audio you get 900mb./me gives squid_80 a candy.Nice google

Awesome guys - spot on the money.  Uncompressed PCM audio.  Thanks for setting me straight