[FFmpeg-devel] [PATCH] avutil/imgutils: remove special case for aligning the palette

[Stefano Sabatini]

On date Sunday 2016-02-14 16:25:02 +0100, Michael Niedermayer encoded:
> This was suggested by wm4 and stefano.
> After this patch using align=1 the size used by various functions would not
> contain padding, while the palette would be aligned at align>1
> 
> This patch makes it required to use align>=4 if the palette is to be accessed
> as uint32
> 
> As a side-effect It fixes storing pal8 in nut with odd with&height
> 
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavutil/imgutils.c |   13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)

> 
> diff --git a/libavutil/imgutils.c b/libavutil/imgutils.c
> index adf6fdd..2f72ed7 100644
> --- a/libavutil/imgutils.c
> +++ b/libavutil/imgutils.c
> @@ -125,7 +125,6 @@ int av_image_fill_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt, int hei
>  
>      if (desc->flags & AV_PIX_FMT_FLAG_PAL ||
>          desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL) {
> -        size[0] = (size[0] + 3) & ~3;
>          data[1] = ptr + size[0]; /* palette is stored here as 256 32 bits words */
>          return size[0] + 256 * 4;
>      }
> @@ -216,8 +215,13 @@ int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
>          av_free(buf);
>          return ret;
>      }
> -    if (desc->flags & AV_PIX_FMT_FLAG_PAL || desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL)
> +    if (desc->flags & AV_PIX_FMT_FLAG_PAL || desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL) {
>          avpriv_set_systematic_pal2((uint32_t*)pointers[1], pix_fmt);
> +        if (align < 4) {
> +            av_log(NULL, AV_LOG_ERROR, "Formats with a palette require a minimum alignment of 4\n");
> +            return AVERROR(EINVAL);
> +        }
> +    }
>  
>      if ((desc->flags & AV_PIX_FMT_FLAG_PAL ||
>           desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL) &&
> @@ -409,10 +413,7 @@ int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
>      }
>  
>      if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
> -        uint32_t *d32 = (uint32_t *)(((size_t)dst + 3) & ~3);
> -
> -        if (dst_size - 1024 < (uint8_t*)d32 - orig_dst)
> -            d32 = (uint32_t *)dst;
> +        uint32_t *d32 = (uint32_t *)dst;
>  
>          for (i = 0; i<256; i++)
>              AV_WL32(d32 + i, AV_RN32(src_data[1] + 4*i));

I like it better than the other alternatives, also provides some bonus
simplifications.

LGTM if it LGTY.
-- 
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