[FFmpeg-devel] [PATCH] pthread_frame: attempt to get frame to reduce latency

[Kieran Kunhya]

On Wed, 11 Mar 2020 at 02:29, Dai, Jianhui J <jianhui.j.dai at intel.com>
wrote:

> Thanks, I will update the commit message.
>
> I test it with FFmpeg native sw H264 decoder.
> In previous FF_THREAD_FRAME,  the latency is constant as N ( =
> thread_count - 1) frames.
> It won't sync thread state until no idle threads available, therefore N
> frames are cached internal, even some frames are ready for output.
> E.g. in RTSP 30fps streaming playback, 16 frame threads (default), the
> internal frame caching contributes 495ms(33ms x 15frame) latency.
> And the latency is the same, regardless the video resolution is 640x480 or
> 4320x2160.
>
> In this patch, I attempt to check thread state and try best output frame
> to reduce the constant frame caching latency.
>
> Thanks,
> Jianhui Dai
>

Unless I misunderstand, surely this outputs frames nondeterministically?
i.e you don't know that the thread which has finished is the next one that
is due

Not to mention the variable latency problems.

Kieran