FFmpeg constant bitrate

Question

I want to convert some videos with FFmpeg to make them streamable. So I want to convert to a video format with a constant bitrate. Can anyone help me? I have tried a lot of options, like -maxrate, -minrate -bufsize, but none of them produced a video at a fixed bitrate.

Solution

From the FFmpeg documentation:

Set min video bitrate (in bit/s). Most useful in setting up a CBR encode:

ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v

So, set minrate, maxrate and bitrate to the same rate.

Note that x264 doesn't have a true constant bit rate mode, this will effectively emulate one for most purposes - the bit rate will still vary over lengths of time less than or equal to 1 second.

Comments

[Astad]

For example I tried the ffmpeg -y -i myVideo.avi -vcodec libx264 -vb 4000k -minrate 4000k -maxrate 4000k -s qvga -vpre normal -bufsize 1835k -acodec ac3 -ab 192k -ar 44100 -ac 2 ~/Desktop/test.mp4 but I get a VBR output, I have read the documentation of the ffmpeg but I did't have result, I'm still new to video compression and ffmpeg.So I need some help.

[Royi]

What about Constant Bit Rate for MPEG1 and MPEG2?