[FFmpeg-devel] avcodec/qsvenc Question for Intel QSV low latency
n.kai.cj.github at gmail.com
Sun Nov 12 04:40:57 EET 2017
this is my first posting to ffmpeg-devel, and I believe my mail format is
I'm using ffmpeg for encoding video in real-time, so low encode delay is
Once I call "avcodec_send_frame(avctx, frame)", I'd like to get the encoded
data from "avcodec_receive_packet(avctx, avpkt)".
However I cannot do that in ffmpeg and Intel QSV (qsv),
"avcodec_receive_packet()" returns nothing when I input the first frame to
qsv encoder by calling "avcodec_send_frame()".
Of cource, after second frame inputs, qsv encoder returns valid data.
I'd like to get a valid data from first calling.
I've tried some cases and as a result, my requirement is satisfied when
avcodec/qsvenc.c will be fixed like below diff info.
Then I have a question.
Why q->async_fifo is set to be q->async_depth "+ 1"?
@@ -803,7 +803,7 @@
q->param.AsyncDepth = q->async_depth;
- q->async_fifo = av_fifo_alloc((1 + q->async_depth) *
+ q->async_fifo = av_fifo_alloc((q->async_depth) *
sizeof(mfxSyncPoint*) + sizeof(mfxBitstream*)));
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