Need help to generate video with CBR (Constant BitRate)

[Maruti C]

Hi,

I have been able to build source and generate exe for encoding contents from YUV. However when I pass command argument for constant bitrate (cbr), it throws error. Is this configuration tested? if yes, please help. Generating CBR contents is important for me to test my player for adaptive streaming scenario.

[Sundar Govindarajan]

Please use a combination of ABR and VBV settings to mimic CBR. The VBV implementation is still evolving. However you can experiment and let us know what you see. For a CBR of 4000Kbps, try this CLI: --bitrate 4000 --vbv-maxrate 4000 --vbv-bufsize 2000.

[Ben Waggoner]

Having bitrate==vbv-maxrate IS a CBR encode as normally defined.

There really isn't such a thing as "pure" CBR with interframe codecs. There's always VBV/HRD to average out bitrate over multiple frames, unless it's some crazy low latency thing (and even then that's what vbv-bufsize is for). And unless you're using padding bits, bitrate will always drop down when the video is black or something.

[Steve Borho]

marking as closed since there is no planned change of behavior. we need to better document the various rate control modes we do support