[FFmpeg-devel] [PATCH v4 2/2] avcodec/v210dec: add the frame and slice threading support

Limin Wang lance.lmwang at gmail.com
Fri Oct 11 03:59:18 EEST 2019



Michael, have updated the patch by your suggestion, please help to review the final version.


On Sun, Sep 22, 2019 at 11:55:49AM +0800, lance.lmwang at gmail.com wrote:
> From: Limin Wang <lance.lmwang at gmail.com>
> 
> The multithread is avoid one core cpu is full with other filter like scale etc.
> About the performance, the gain is very small, below is my testing for
> performance.
> In order to avoid the disk bottleneck, I'll use stream_loop mode for 10 frame
> only.
> 
> ./ffmpeg -y -i ~/Movies/4k_Rec709_ProResHQ.mov -c:v v210 -f rawvideo -frames 10
> ~/Movies/1.v210
> 
> master:
> ./ffmpeg -threads 1 -s 4096x3072 -stream_loop 100 -i ~/Movies/1.v210 -benchmark
> -f null -
> frame= 1010 fps= 42 q=-0.0 Lsize=N/A time=00:00:40.40 bitrate=N/A speed=1.69x
> video:529kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing
> overhead: unknown
> bench: utime=10.082s stime=13.784s rtime=23.889s
> bench: maxrss=147836928kB
> 
> patch applied:
> ./ffmpeg -threads 4 -thread_type frame+slice  -s 4096x3072 -stream_loop 100 -i
> ~/Movies/1.v210 -benchmark -f null -
> 
> frame= 1010 fps= 55 q=-0.0 Lsize=N/A time=00:00:40.40 bitrate=N/A speed=2.22x
> video:529kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing
> overhead: unknown
> bench: utime=11.407s stime=17.258s rtime=18.279s
> bench: maxrss=442884096kB
> 
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  libavcodec/v210dec.c | 131 ++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 83 insertions(+), 48 deletions(-)
> 
> diff --git a/libavcodec/v210dec.c b/libavcodec/v210dec.c
> index 6ce18aa..2e46342 100644
> --- a/libavcodec/v210dec.c
> +++ b/libavcodec/v210dec.c
> @@ -28,6 +28,7 @@
>  #include "libavutil/internal.h"
>  #include "libavutil/mem.h"
>  #include "libavutil/intreadwrite.h"
> +#include "thread.h"
>  
>  #define READ_PIXELS(a, b, c)         \
>      do {                             \
> @@ -37,6 +38,12 @@
>          *c++ = (val >> 20) & 0x3FF;  \
>      } while (0)
>  
> +typedef struct ThreadData {
> +    AVFrame *frame;
> +    uint8_t *buf;
> +    int stride;
> +} ThreadData;
> +
>  static void v210_planar_unpack_c(const uint32_t *src, uint16_t *y, uint16_t *u, uint16_t *v, int width)
>  {
>      uint32_t val;
> @@ -70,55 +77,28 @@ static av_cold int decode_init(AVCodecContext *avctx)
>      return 0;
>  }
>  
> -static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
> -                        AVPacket *avpkt)
> +static int v210_decode_slice(AVCodecContext *avctx, void *arg, int jobnr, int threadnr)
>  {
>      V210DecContext *s = avctx->priv_data;
> -
> -    int h, w, ret, stride, aligned_input;
> -    AVFrame *pic = data;
> -    const uint8_t *psrc = avpkt->data;
> +    int h, w;
> +    ThreadData *td = arg;
> +    AVFrame *frame = td->frame;
> +    int stride = td->stride;
> +    int slice_h = avctx->height / avctx->thread_count;
> +    int slice_m = avctx->height % avctx->thread_count;
> +    int slice_start = jobnr * slice_h;
> +    int slice_end = slice_start + slice_h;
> +    const uint8_t *psrc = td->buf + stride * slice_start;
>      uint16_t *y, *u, *v;
>  
> -    if (s->custom_stride )
> -        stride = s->custom_stride;
> -    else {
> -        int aligned_width = ((avctx->width + 47) / 48) * 48;
> -        stride = aligned_width * 8 / 3;
> -    }
> -
> -    if (avpkt->size < stride * avctx->height) {
> -        if ((((avctx->width + 23) / 24) * 24 * 8) / 3 * avctx->height == avpkt->size) {
> -            stride = avpkt->size / avctx->height;
> -            if (!s->stride_warning_shown)
> -                av_log(avctx, AV_LOG_WARNING, "Broken v210 with too small padding (64 byte) detected\n");
> -            s->stride_warning_shown = 1;
> -        } else {
> -            av_log(avctx, AV_LOG_ERROR, "packet too small\n");
> -            return AVERROR_INVALIDDATA;
> -        }
> -    }
> -    if (avctx->codec_tag == MKTAG('C', '2', '1', '0')
> -        && AV_RN32(psrc) == AV_RN32("INFO")
> -        && avpkt->size - 64 >= stride * avctx->height)
> -        psrc += 64;
> -
> -    aligned_input = !((uintptr_t)psrc & 0x1f) && !(stride & 0x1f);
> -    if (aligned_input != s->aligned_input) {
> -        s->aligned_input = aligned_input;
> -        ff_v210dec_init(s);
> -    }
> -
> -    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
> -        return ret;
> -
> -    y = (uint16_t*)pic->data[0];
> -    u = (uint16_t*)pic->data[1];
> -    v = (uint16_t*)pic->data[2];
> -    pic->pict_type = AV_PICTURE_TYPE_I;
> -    pic->key_frame = 1;
> +    /* add the remaining slice for the last job */
> +    if (jobnr == avctx->thread_count - 1)
> +        slice_end += slice_m;
>  
> -    for (h = 0; h < avctx->height; h++) {
> +    y = (uint16_t*)frame->data[0] + slice_start * frame->linesize[0] / 2;
> +    u = (uint16_t*)frame->data[1] + slice_start * frame->linesize[1] / 2;
> +    v = (uint16_t*)frame->data[2] + slice_start * frame->linesize[2] / 2;
> +    for (h = slice_start; h < slice_end; h++) {
>          const uint32_t *src = (const uint32_t*)psrc;
>          uint32_t val;
>  
> @@ -154,10 +134,63 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
>          }
>  
>          psrc += stride;
> -        y += pic->linesize[0] / 2 - avctx->width + (avctx->width & 1);
> -        u += pic->linesize[1] / 2 - avctx->width / 2;
> -        v += pic->linesize[2] / 2 - avctx->width / 2;
> +        y += frame->linesize[0] / 2 - avctx->width + (avctx->width & 1);
> +        u += frame->linesize[1] / 2 - avctx->width / 2;
> +        v += frame->linesize[2] / 2 - avctx->width / 2;
> +    }
> +
> +    return 0;
> +}
> +
> +static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
> +                        AVPacket *avpkt)
> +{
> +    V210DecContext *s = avctx->priv_data;
> +    ThreadData td;
> +    int ret, stride, aligned_input;
> +    ThreadFrame frame = { .f = data };
> +    AVFrame *pic = data;
> +    const uint8_t *psrc = avpkt->data;
> +
> +    if (s->custom_stride )
> +        stride = s->custom_stride;
> +    else {
> +        int aligned_width = ((avctx->width + 47) / 48) * 48;
> +        stride = aligned_width * 8 / 3;
> +    }
> +    td.stride = stride;
> +
> +    if (avpkt->size < stride * avctx->height) {
> +        if ((((avctx->width + 23) / 24) * 24 * 8) / 3 * avctx->height == avpkt->size) {
> +            stride = avpkt->size / avctx->height;
> +            if (!s->stride_warning_shown)
> +                av_log(avctx, AV_LOG_WARNING, "Broken v210 with too small padding (64 byte) detected\n");
> +            s->stride_warning_shown = 1;
> +        } else {
> +            av_log(avctx, AV_LOG_ERROR, "packet too small\n");
> +            return AVERROR_INVALIDDATA;
> +        }
>      }
> +    if (avctx->codec_tag == MKTAG('C', '2', '1', '0')
> +        && AV_RN32(psrc) == AV_RN32("INFO")
> +        && avpkt->size - 64 >= stride * avctx->height)
> +        psrc += 64;
> +
> +    aligned_input = !((uintptr_t)psrc & 0x1f) && !(stride & 0x1f);
> +    if (aligned_input != s->aligned_input) {
> +        s->aligned_input = aligned_input;
> +        ff_v210dec_init(s);
> +    }
> +
> +    if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
> +        return ret;
> +
> +    pic->pict_type = AV_PICTURE_TYPE_I;
> +    pic->key_frame = 1;
> +
> +    td.buf = (uint8_t*)psrc;
> +    td.frame = pic;
> +    avctx->execute2(avctx, v210_decode_slice, &td, NULL, avctx->thread_count);
>  
>      if (avctx->field_order > AV_FIELD_PROGRESSIVE) {
>          /* we have interlaced material flagged in container */
> @@ -193,6 +226,8 @@ AVCodec ff_v210_decoder = {
>      .priv_data_size = sizeof(V210DecContext),
>      .init           = decode_init,
>      .decode         = decode_frame,
> -    .capabilities   = AV_CODEC_CAP_DR1,
> +    .capabilities   = AV_CODEC_CAP_DR1 |
> +                      AV_CODEC_CAP_SLICE_THREADS |
> +                      AV_CODEC_CAP_FRAME_THREADS,
>      .priv_class     = &v210dec_class,
>  };
> -- 
> 2.6.4
> 


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