[FFmpeg-devel] [PATCH] avcodec/qpeg: speed-up copy of bytes

Anton Khirnov anton at khirnov.net
Tue Sep 1 14:17:09 EEST 2020


Quoting Paul B Mahol (2020-08-31 23:37:07)
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavcodec/qpeg.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/qpeg.c b/libavcodec/qpeg.c
> index 40931e3bdc..8bc710acfd 100644
> --- a/libavcodec/qpeg.c
> +++ b/libavcodec/qpeg.c
> @@ -101,8 +101,11 @@ static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
>          } else {
>              if (bytestream2_get_bytes_left(&qctx->buffer) < copy)
>                  copy = bytestream2_get_bytes_left(&qctx->buffer);
> -            for(i = 0; i < copy; i++) {
> -                dst[filled++] = bytestream2_get_byte(&qctx->buffer);
> +            while (copy > 0) {
> +                int step = FFMIN(copy, width - filled);
> +                bytestream2_get_bufferu(&qctx->buffer, dst + filled, step);
> +                filled += step;
> +                copy -= step;
>                  if (filled >= width) {
>                      filled = 0;
>                      dst -= stride;
> -- 
> 2.17.1

Looks ok.

-- 
Anton Khirnov


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