[FFmpeg-devel] [PATCH v5] avcodec/v210dec: add the frame and slice threading support

mypopy at gmail.com mypopy at gmail.com
Sat Oct 12 14:36:29 EEST 2019


On Sat, Oct 12, 2019 at 6:58 PM <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 | 132 +++++++++++++++++++++++++++----------------
>  libavcodec/v210dec.h |   1 +
>  2 files changed, 85 insertions(+), 48 deletions(-)
>
> diff --git a/libavcodec/v210dec.c b/libavcodec/v210dec.c
> index 5a33d8c089..c3ef8051e6 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;
> @@ -64,21 +71,87 @@ static av_cold int decode_init(AVCodecContext *avctx)
>      avctx->pix_fmt             = AV_PIX_FMT_YUV422P10;
>      avctx->bits_per_raw_sample = 10;
>
> +    s->thread_count  = av_clip(avctx->thread_count, 1, avctx->height/4);
>      s->aligned_input = 0;
>      ff_v210dec_init(s);
>
>      return 0;
>  }
>
> +static int v210_decode_slice(AVCodecContext *avctx, void *arg, int jobnr, int threadnr)
> +{
> +    V210DecContext *s = avctx->priv_data;
> +    int h, w;
> +    ThreadData *td = arg;
> +    AVFrame *frame = td->frame;
> +    int stride = td->stride;
> +    int slice_h = avctx->height / s->thread_count;
> +    int slice_m = avctx->height % s->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;
> +
> +    /* add the remaining slice for the last job */
> +    if (jobnr == s->thread_count - 1)
> +        slice_end += slice_m;
> +
> +    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;
> +
> +        w = (avctx->width / 12) * 12;
> +        s->unpack_frame(src, y, u, v, w);
> +
> +        y += w;
> +        u += w >> 1;
> +        v += w >> 1;
> +        src += (w << 1) / 3;
> +
> +        if (w < avctx->width - 5) {
> +            READ_PIXELS(u, y, v);
> +            READ_PIXELS(y, u, y);
> +            READ_PIXELS(v, y, u);
> +            READ_PIXELS(y, v, y);
> +            w += 6;
> +        }
> +
> +        if (w < avctx->width - 1) {
> +            READ_PIXELS(u, y, v);
> +
> +            val  = av_le2ne32(*src++);
> +            *y++ =  val & 0x3FF;
> +            if (w < avctx->width - 3) {
> +                *u++ = (val >> 10) & 0x3FF;
> +                *y++ = (val >> 20) & 0x3FF;
> +
> +                val  = av_le2ne32(*src++);
> +                *v++ =  val & 0x3FF;
> +                *y++ = (val >> 10) & 0x3FF;
> +            }
> +        }
> +
> +        psrc += stride;
> +        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;
> -
> -    int h, w, ret, stride, aligned_input;
> +    ThreadData td;
> +    int ret, stride, aligned_input;
> +    ThreadFrame frame = { .f = data };
>      AVFrame *pic = data;
>      const uint8_t *psrc = avpkt->data;
> -    uint16_t *y, *u, *v;
>
>      if (s->custom_stride )
>          stride = s->custom_stride;
> @@ -86,6 +159,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
>          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) {
> @@ -110,55 +184,15 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
>          ff_v210dec_init(s);
>      }
>
> -    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
> +    if ((ret = ff_thread_get_buffer(avctx, &frame, 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;
>
> -    for (h = 0; h < avctx->height; h++) {
> -        const uint32_t *src = (const uint32_t*)psrc;
> -        uint32_t val;
> -
> -        w = (avctx->width / 12) * 12;
> -        s->unpack_frame(src, y, u, v, w);
> -
> -        y += w;
> -        u += w >> 1;
> -        v += w >> 1;
> -        src += (w << 1) / 3;
> -
> -        if (w < avctx->width - 5) {
> -            READ_PIXELS(u, y, v);
> -            READ_PIXELS(y, u, y);
> -            READ_PIXELS(v, y, u);
> -            READ_PIXELS(y, v, y);
> -            w += 6;
> -        }
> -
> -        if (w < avctx->width - 1) {
> -            READ_PIXELS(u, y, v);
> -
> -            val  = av_le2ne32(*src++);
> -            *y++ =  val & 0x3FF;
> -            if (w < avctx->width - 3) {
> -                *u++ = (val >> 10) & 0x3FF;
> -                *y++ = (val >> 20) & 0x3FF;
> -
> -                val  = av_le2ne32(*src++);
> -                *v++ =  val & 0x3FF;
> -                *y++ = (val >> 10) & 0x3FF;
> -            }
> -        }
> -
> -        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;
> -    }
> +    td.buf = (uint8_t*)psrc;
> +    td.frame = pic;
> +    avctx->execute2(avctx, v210_decode_slice, &td, NULL, s->thread_count);
>
>      if (avctx->field_order > AV_FIELD_PROGRESSIVE) {
>          /* we have interlaced material flagged in container */
> @@ -194,6 +228,8 @@ 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,

I only saw the slice thread acceleration, did not see the frame thread
acceleration, is it something I missed?
>      .priv_class     = &v210dec_class,
>  };
> diff --git a/libavcodec/v210dec.h b/libavcodec/v210dec.h
> index cfdb29da09..662e266315 100644
> --- a/libavcodec/v210dec.h
> +++ b/libavcodec/v210dec.h
> @@ -27,6 +27,7 @@ typedef struct {
>      AVClass *av_class;
>      int custom_stride;
>      int aligned_input;
> +    int thread_count;
>      int stride_warning_shown;
>      void (*unpack_frame)(const uint32_t *src, uint16_t *y, uint16_t *u, uint16_t *v, int width);
>  } V210DecContext;
> --


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