[FFmpeg-devel] Live streaming of VP8

[Michael Niedermayer]

On Sat, Jun 09, 2012 at 04:51:23PM +0200, Andy Bell wrote:
> Hi All,
> 
> I am streaming a VP8 stream over network and using the following code to
> encode:
> 
> _bitRate = 500 * 1000;
> _codecContext->bit_rate = _bitRate; // --target-bitrate=500
> _codecContext->rc_min_rate = _codecContext->rc_max_rate =
> _codecContext->bit_rate; // --end-usage=cbr
> 
> _codecContext->thread_count = 4;
> _codecContext->qmin = 4;
> _codecContext->qmax = 56;
> _codecContext->width = 800;
> _codecContext->height = 600;
> _codecContext->rc_buffer_aggressivity = 0.95;  // --undershoot-pct=95
> _codecContext->rc_buffer_size = _bitRate * 6; // --buz-sz=6000 ms
> _codecContext->rc_initial_buffer_occupancy = _bitRate * 4; //
> --buf-initial-sz=4000 ms
> _codecContext->profile = 3;
> _codecContext->time_base.num = 1;
> _codecContext->time_base.den = 25;
> _codecContext->gop_size = 999999; // --kf-max-dist
> 
> This works fine but when there is a huge scene change the codec generates a
> key frame which I am having trouble transmitting in realtime over the
> network due to the sudden jump in bitrate.

rc_buffer_size indicates a wanted max latency of 6 seconds
if you want it to be less you can use a smaller value
    
[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct awnser.
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