MP3

[Belva]

Could i import video from Matrox G200 with mp3 audio coded ???
And if, how much i could earn in bytes ?!?
Thanx

[Dr Mordrid]

The Matrox RR-S, RR-G and Marvel cards encode 16 bit PCM at 11.025, 22.05 or 44.1 khz in their video files.

Few full-featured editing proggies can actually export MP3 audio in an *.avi. Even if one could the conversion should be done post-edit since recompressing MP3 on the timeline can cause audio artifacts that aren't very nice.

VirtualDUB can be used post-edit to convert the *.avi's PCM stream to MP3 and it's quite quick at doing this.

http://www186.pair.com/vdub/index.html

As far as how much you can save in file size, PCM audio is uncompressed so compressing it can make an *.avi quite a bit smaller. Example:

Test file:

"Karate" demo file from MSPro installation.
6.9 seconds, 320x240 Cinepak, 44.1khz 16 bit PCM stereo

Conversion in VirtualDUB:

Video setup: Direct stream copy.
Audio setup: MP3 transcoding at 24 khz, stereo, 56 kbps.

Original file size: 3.1 megs
File size with MP3: 1.9 megs

The trick is in keeping the audio and video in synch.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 17 January 2001).]