[FFmpeg-user] use q:v and maxrate

[Carl Eugen Hoyos]

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.

[...]

> 1. for mpeg4 encoder, what qscale value is good enough 
> to keep same quality as input?

Old MEncoder documentation recommends a value of 2 but I 
don't think this is what you want.

> 2. if -q:v, -maxrate -bt are used together,  no matter 
> what qscale value specified, bitrate will be guaranteed 
> to be below maxrate?

I don't think so: It would mean that qscale gets ignored.

Please do not cross-post, it is considered rude 
everywhere.

Carl Eugen