2016-04-07 10:56 GMT+10:00 Carl Eugen Hoyos <ceho...@ag.or.at>: > YIRAN LI <mrfun.china <at> gmail.com> writes: > > > > > ffmpeg.exe -i a.mp4 -c:v mpeg4 -profile:v 15 -vtag DIVX > > > > -bufsize 3080000 -maxrate 8000000 -bt 8000000 -an a.avi > > > > (so that maxbitrate will be 8000kbps) > > > > > > You forgot to set the video bitrate. > > > > my target is to archieve good quality while keeping bitrate > > under a certain limit. I want to achieve best quality within > > this limit. > > > For this purpose, what combinations of options should I use? > > Set both video bitrate and maximum bitrate (or maximum and > minimum bitrate). >
Hi Carl, I'm using this in a program so input video can have any bitrate, unless I have an algorithm to estimate best target bitrate, I can't set a target bitrate that works good for all possible source videos. (if target bitrate is much higher than input, there must be some waste I think) For example: ffmpeg.exe -i big_buck_bunny.mp4 -c:v mpeg4 -profile:v 15 -vtag DIVX -bufsize 3080000 -maxrate 8000000 -bt 8000000 -minrate 0 -an a.avi ffmpeg.exe -i big_buck_bunny.mp4 -c:v mpeg4 -q:v 4 -profile:v 15 -vtag DIVX -bufsize 3080000 -maxrate 8000000 -bt 8000000 -minrate 0 -an a.avi First command generates a 262kbps one and second generates a better one with 1380kbps. > Carl Eugen > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user