[FFmpeg-devel] [PATCH 3/3] avcodec/libx264: Simplify copying packet data

[James Almer]

On 11/7/2021 11:36 AM, Andreas Rheinhardt wrote:
> x264.h: "the payloads of all output NALs are guaranteed to be
> sequential in memory." Therefore we can omit the loop.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>   libavcodec/libx264.c | 9 ++++-----
>   1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
> index 4fe02dd11c..5f62c7b1d8 100644
> --- a/libavcodec/libx264.c
> +++ b/libavcodec/libx264.c
> @@ -139,7 +139,6 @@ static int encode_nals(AVCodecContext *ctx, AVPacket *pkt,
>       X264Context *x4 = ctx->priv_data;
>       uint8_t *p;
>       uint64_t size = x4->sei_size;
> -    int i;
>       int ret;
>   
>       if (!nnal)
> @@ -165,14 +164,14 @@ static int encode_nals(AVCodecContext *ctx, AVPacket *pkt,
>       if (x4->sei_size > 0) {
>           memcpy(p, x4->sei, x4->sei_size);
>           p += x4->sei_size;
> +        size -= x4->sei_size;
>           x4->sei_size = 0;
>           av_freep(&x4->sei);
>       }
>   
> -    for (i = 0; i < nnal; i++){
> -        memcpy(p, nals[i].p_payload, nals[i].i_payload);
> -        p += nals[i].i_payload;
> -    }
> +    /* x264 guarantees the payloads of the NALs
> +     * to be sequential in memory. */
> +    memcpy(p, nals[0].p_payload, size);
>   
>       return 1;
>   }

LGTM.