q->async_fifo grows too large when force idr, and few data written

[YaboWei]

OS: CentOS Linux release 7.2.1511 (Core) CPU: i7-6770HQ MSDK: 2017 repository: branch intel_plugins-3.3.1

I'm trying to follow the gop struct of the input, but few data written to output seconds later.

step 1: blew command works well: ./ffmpeg_g -i "http://192.168.86.26:9000/live/s1_720p.flv" -vcodec h264_qsv -vsync passthrough -b:v 2000k -g 500 -async_depth 4 -acodec copy -f flv -y ~/output.flv

step 2: modiry ffmpeg.c to keep picture type AV_PICTURE_TYPE_I --- a/ffmpeg.c +++ b/ffmpeg.c @@ -1236,6 +1236,8 @@ static void do_video_out(OutputFile *of, in_picture->quality = enc->global_quality; in_picture->pict_type = 0; ++ if (in_picture->key_frame) ++ in_picture->pict_type = AV_PICTURE_TYPE_I;

and force idr: ./ffmpeg_g -i "http://192.168.86.26:9000/live/s1_720p.flv" -vcodec h264_qsv -vsync passthrough -force_idr 1 -b:v 2000k -g 500 -async_depth 4 -acodec copy -f flv -y ~/output.flv after ffmpeg start a few seconds， output file ~/output.flv grows very slow.

do some work: 1, print q->async_fifo size：

q->async_fifo grows double in step 2：520,1040,2080,4160... ...,66560,133120,266240 only when q->async_fifo has no space, qsvenc read data from q->async_fifo and output them.

2, why q->async_fifo grows very quickly? modify code in libavutil/fifo.c: --- a/libavutil/fifo.c +++ b/libavutil/fifo.c @@ -113,7 +113,7 @@ int av_fifo_grow(AVFifoBuffer f, unsigned int size) size += av_fifo_size(f); if (old_size < size) -- return av_fifo_realloc2(f, FFMAX(size, 2old_size)); ++ return av_fifo_realloc2(f, FFMIN(size, 2*old_size)); return 0; }

q->async_fifo grows slowly, and in step 2, output file ~/output.flv grows normally.

3, if q->async_fifo has more than ASYNC_FIFO_ELEM_SIZE data, qsvenc read data from q->async_fifo modify libavcode/qsvenc.c @@ -1253,15 +1258,18 @@ int ff_qsv_encode(AVCodecContext avctx, QSVEncContext q, if (ret < 0) return ret; -- if (!av_fifo_space(q->async_fifo) || ++ if ((frame && ASYNC_FIFO_ELEM_SIZE < av_fifo_size(q->async_fifo)) || (!frame && av_fifo_size(q->async_fifo))) { AVPacket new_pkt; mfxBitstream bs; mfxSyncPoint sync;

in step 2, output file ~/output.flv grows normally, and q->async_fifo keep it's size.

questions: 1, why q->async_fifo always keep growing when force idr enabled? 2, why qsvenc read data from q->async_fifo only when q->async_fifo has no space?

[lizhong1008]

@YaboWei , testing it with another mp4 file, can't reproduce your issue. Haven't found the async_fifo size continually growing and the coded bitstream can be output. Maybe I need to reproduce it with your clip? Could you attach the "s1_720p.flv" file?

[YaboWei]

My test file: https://drive.google.com/open?id=1TRA46Qd-y-5oVT099HFk2z7XdwxQOXLI

[lizhong1008]

Add the code as below: diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c index 19ea703..3e31edd 100644 --- a/libavcodec/qsvenc.c +++ b/libavcodec/qsvenc.c @@ -1253,6 +1253,9 @@ int ff_qsv_encode(AVCodecContext avctx, QSVEncContext q, if (ret < 0) return ret;

• printf("fifo_space size is %d\n", av_fifo_space(q->async_fifo));
• printf("fifo size is %d\n", av_fifo_size(q->async_fifo));

diff --git a/ffmpeg.c b/ffmpeg.c index 2217fae..a8d8aba 100644 --- a/ffmpeg.c +++ b/ffmpeg.c @@ -1236,6 +1236,8 @@ static void do_video_out(OutputFile *of,

     in_picture->quality = enc->global_quality;
     in_picture->pict_type = 0;

• if (in_picture->key_frame)
• in_picture->pict_type = AV_PICTURE_TYPE_I;

Then ./ffmpeg_g -i s1_720p.flv -vcodec h264_qsv -vsync passthrough -force_idr 0 or 1 -b:v 2000k -g 500 -async_depth 4 -acodec copy -f flv -y ~/output.flv > log.txt Haven't seen any different output for the "fifo size" and "fifo space size" in the log.txt. Is there any thing wrong?

[YaboWei]

this is my output file: https://drive.google.com/file/d/1nZ7dV6OvBzQNJGeg61qMUqOXDgr1SVTw/view?usp=sharing

[lizhong1008]

@YaboWei , have you check the out put when force_idr is closed? See my output: https://drive.google.com/drive/folders/1P1Bvu7t98mVWZYSAe1nBo4q95Zxk68A-?usp=sharing , no matter force_idr is 0 or 1, the output of fifo size are same.

[YaboWei]

Recently，I use MediaServerStudioProfessionalEvaluation2017R3 do the same test, the problem is still in.