[Libav-user] avcodec_decode_video2 latency.

Jean-Yves Avenard jyavenard at gmail.com
Thu Nov 19 12:27:42 CET 2015


Never mind.

I quickly discovered CODEC_FLAG_LOW_DELAY

Anyone know if this can be used safely on any frames (a similar flag
on Windows WMF will cause h264 b-frame to not be decoded properly)

On 19 November 2015 at 22:22, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
> Hi
>
> Started to use FFmpeg/ffvp9 to decode VP9 streams in place of libvpx ;
> the gain in performance is very welcome.
>
> However, the major issue is the latency added by libavcodec ; when
> feeding avcodec_decode_video2 with samples, it won't return decoded
> frames until 16 frames have been buffered (this is the same with h264
> btw).
>
> That makes ffvp9 unusable for any real-time video conference (such as webrtc).
>
> libvpx will immediately output a decoded frame, with 0 latency.
>
> Is there a way to set to AVCodecContext so it outputs frame much quicker ?
>
> Thank you
> Jean-Yves


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