compressing Divx smaller

Bebop0083 · Post by **Bebop0083** » Sun Jun 29, 2003 11:34 pm

ok i got a Divx file thats like 95 MB and i want to compress it or make it smaller by making it at least 30 MB or less. how can i do that in virtual dub?

klinky · Post by **klinky** » Mon Jun 30, 2003 1:09 am

Video filesize is determined by bitrate.

The formula for finding the proper video bitrate is :

(desired_size * 8) * 1024 / length_of_video_in_seconds.

/ = divide.

So if you want 30MB, that's 30 * 8 = 240megabits, * 1024 = 245760kilobits / 180seconds = 1365kilobits_per_second.

So just adjust whatever codec you're using to use that bitrate. Also keep in mind that audio plays a part. MP3 128kbit audio takes about 1MB/min

klinky · Post by **klinky** » Mon Jun 30, 2003 1:11 am

Damnit...

'formula'

(desired_size * 8) * 1024 / length_of_video_in_seconds.

the Black Monarch · Post by **the Black Monarch** » Tue Jul 01, 2003 5:04 pm

Yeah dude, just lower the bitrate the first time you export.

paranoia · Post by **paranoia** » Fri Jul 04, 2003 4:00 pm

just watch out. From what I understand you are taking an already compressed file, and compressing it again to 2/3's of it's orginal compressed size. That could get really low quality of the final file.

But of course if that's okay, or if it turns out to not be to much of a loss, just do what the other people said and lower your bit rate.

FurryCurry · Post by **FurryCurry** » Fri Jul 04, 2003 9:05 pm

Please post what you originally compressed from (Premiere? vdub?), output size, and whether or not you compressed your audio, and at what bitrate.

That will help a lot in determining what's taking up so much space.

If you just forgot to compress your audio, for example, you can use direct stream copy for video, and compress just your audio, saving much time and trouble.

Farlo · Post by **Farlo** » Fri Jul 04, 2003 9:33 pm

compress the audio to mp3 format that helps a lot