[FFmpeg-devel] [PATCH 1/3] lavd/xv: speed up yuv420p write packet

[Stefano Sabatini]

On date Wednesday 2013-11-13 23:40:45 +0100, Lukasz Marek encoded:
> xv_write_packet do operations like multiplication that are not required.
> Small optimizations allows to make function up to 10% faster.
> 
> Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
> ---
>  libavdevice/xv.c |   31 +++++++++++++++++--------------
>  1 file changed, 17 insertions(+), 14 deletions(-)
> 
> diff --git a/libavdevice/xv.c b/libavdevice/xv.c
> index 50d72a5..fdc96c9 100644
> --- a/libavdevice/xv.c
> +++ b/libavdevice/xv.c
> @@ -141,6 +141,17 @@ static int xv_write_header(AVFormatContext *s)
>      return 0;
>  }
>  

> +static av_always_inline void xv_copy_line(int h, const char *src, char *dst,
> +                                          int src_linesize, int dst_linesize)
> +{
> +    int y, len = FFMIN(src_linesize, dst_linesize);
> +    for (y = 0; y < h; ++y) {
> +        memcpy(dst, src, len);
> +        src += src_linesize;
> +        dst += dst_linesize;
> +    }
> +}

av_image_copy_plane()?

> +
>  static int xv_write_packet(AVFormatContext *s, AVPacket *pkt)
>  {
>      XVContext *xv = s->priv_data;
> @@ -148,22 +159,14 @@ static int xv_write_packet(AVFormatContext *s, AVPacket *pkt)
>      XWindowAttributes window_attrs;
>      AVPicture pict;
>      AVCodecContext *ctx = s->streams[0]->codec;
> -    int y, h;
> -
> -    h = img->height / 2;
>  
>      avpicture_fill(&pict, pkt->data, ctx->pix_fmt, ctx->width, ctx->height);
> -    for (y = 0; y < img->height; y++) {
> -        memcpy(&img->data[img->offsets[0] + (y * img->pitches[0])],
> -               &pict.data[0][y * pict.linesize[0]], img->pitches[0]);
> -    }
> -
> -    for (y = 0; y < h; ++y) {
> -        memcpy(&img->data[img->offsets[1] + (y * img->pitches[1])],
> -               &pict.data[1][y * pict.linesize[1]], img->pitches[1]);
> -        memcpy(&img->data[img->offsets[2] + (y * img->pitches[2])],
> -               &pict.data[2][y * pict.linesize[2]], img->pitches[2]);
> -    }
> +    xv_copy_line(img->height, pict.data[0], &img->data[img->offsets[0]],
> +                 pict.linesize[0], img->pitches[0]);
> +    xv_copy_line(img->height / 2, pict.data[1], &img->data[img->offsets[1]],
> +                 pict.linesize[1], img->pitches[1]);
> +    xv_copy_line(img->height / 2, pict.data[2], &img->data[img->offsets[2]],
> +                 pict.linesize[2], img->pitches[2]);

av_image_copy()?
-- 
FFmpeg = Fierce and Forgiving MultiPurpose Enlightening Gnome