To calculate video and audio bitrates when trying to fit material onto DVD, I created this _very simple_ script. Its input is the total number of seconds of footage. It prints out the video rates with several common audio bitrates. Note that you should go at least slightly under the rate shown, as you still have to account for the basic DVD structure. Don't forget to include the menu footage seconds too (if you have a menu)! A more complicated script is possible if you want to do different video bitrates for different parts of the DVD, etc. but since it's all just basic math I usually just do that by hand if I need to :-)
Also note that DVD MPEG2 video bitrate is technically max 9800 kbps and the total (including audio/subpicture) bitrate is max 10080 kbps: http://www.videohelp.com/dvd but ffmpeg and mpeg2enc might enforce lower maxes... #!/bin/bash SEC=$1 TOTAL_SPACE=4700000000 BYTES_PER_SEC=$[ $TOTAL_SPACE / $SEC ] BPS=$[ $BYTES_PER_SEC * 8 ] KBPS=$[ $BPS / 1024 ] echo $KBPS kbps total for n in 384 256 128 64 32 ; do echo $[ $KBPS - $n ] kbps video / $n kbps audio done On 8/7/06, Graham Evans <[EMAIL PROTECTED]> wrote:
jim scott wrote: > I think the spec is around 10000 for video + audio. If you're using > AC3 audio at 128 kbps, you should be able to go 9800 kbps for video. > > On 8/7/06, *Dimitrios * <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> > wrote: > > On Tue, 08 Aug 2006 00:17:46 +0800 Graham Evans < > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote: > > > 10000 fixed bitrate > > wasn't the maximum bitrate at 8000 (official dvd spec)? i could be > wrong... > ...All of which explains why 50 minutes of footage ended up only just fitting on a single layer dvd. My dvd player did play the footage but I obviously got lucky. I will tone down those settings - thanks for the info dimitrios and jim. Vaughan I have never had success with the YUV4MPEG pipe commands despite many months of wrestling with them and seeking assistance. Yet my system (Fc4_64 bit) seems to function well with all the other aspects of cinelerra cv. On the other hand MPEN2ENC works as described. Obviously most users here have lots of success with the pipe commands but I just thought I would let you know in case you suffer further problems... Graham _______________________________________________ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
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