[FFmpeg-devel] [PATCH] swscale: Add support for unscaled 8-bit Packed RGB -> Planar RGB

[Michael Niedermayer]

On Sat, Feb 09, 2013 at 03:04:35PM -0500, Derek Buitenhuis wrote:
> Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
> ---
>  libswscale/swscale_unscaled.c |  119 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 119 insertions(+)
> 
> diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c
> index 55cda5d..7599779 100644
> --- a/libswscale/swscale_unscaled.c
> +++ b/libswscale/swscale_unscaled.c
> @@ -488,6 +488,122 @@ static int planarRgbToRgbWrapper(SwsContext *c, const uint8_t *src[],
>      return srcSliceH;
>  }
>  
> +static void packed24togbr24p(const uint8_t *src, int srcStride,
> +                             uint8_t *dst[], int dstStride[], int srcSliceH,
> +                             int width)
> +{
> +    uint8_t *dest[3];
> +    int x, h;
> +
> +    dest[0] = dst[0];
> +    dest[1] = dst[1];
> +    dest[2] = dst[2];
> +
> +    for (h = 0; h < srcSliceH; h++) {
> +        for (x = 0; x < width; x++) {
> +            dest[0][x] = *src++;
> +            dest[1][x] = *src++;
> +            dest[2][x] = *src++;
> +        }
> +        src     += srcStride - width * 3;
> +        dest[0] += dstStride[0];
> +        dest[1] += dstStride[1];
> +        dest[2] += dstStride[2];
> +    }
> +}
> +
> +static void packed32togbr24p(const uint8_t *src, int srcStride,
> +                             uint8_t *dst[], int dstStride[], int srcSliceH,
> +                             int alpha_first, int width)
> +{
> +    uint8_t *dest[4];
> +    int x, h;
> +
> +    dest[0] = dst[0];
> +    dest[1] = dst[1];
> +    dest[2] = dst[2];
> +
> +    if (alpha_first) {
> +        for (h = 0; h < srcSliceH; h++) {
> +            for (x = 0; x < width; x++) {
> +                src++;
> +                dest[0][x] = *src++;
> +                dest[1][x] = *src++;
> +                dest[2][x] = *src++;
> +            }
> +            src     += srcStride - width * 4;
> +            dest[0] += dstStride[0];
> +            dest[1] += dstStride[1];
> +            dest[2] += dstStride[2];
> +        }
> +    } else {
> +        for (h = 0; h < srcSliceH; h++) {
> +            for (x = 0; x < width; x++) {
> +                dest[0][x] = *src++;
> +                dest[1][x] = *src++;
> +                dest[2][x] = *src++;
> +                src++;
> +            }
> +            src     += srcStride - width * 4;
> +            dest[0] += dstStride[0];
> +            dest[1] += dstStride[1];
> +            dest[2] += dstStride[2];
> +        }
> +    }

that can be simplified with a
if(alpha_first)
    src++;
outside the loop, i think


> +}
> +
> +static int rgbToPlanarRgbWrapper(SwsContext *c, const uint8_t *src[],
> +                                 int srcStride[], int srcSliceY, int srcSliceH,
> +                                 uint8_t *dst[], int dstStride[])
> +{
> +    int alpha_first = 0;
> +    int stride102[] = { dstStride[1], dstStride[0], dstStride[2] };
> +    int stride201[] = { dstStride[2], dstStride[0], dstStride[1] };
> +    uint8_t *dst102[] = { dst[1] + srcSliceY * dstStride[1],
> +                          dst[0] + srcSliceY * dstStride[0],
> +                          dst[2] + srcSliceY * dstStride[2] };
> +    uint8_t *dst201[] = { dst[2] + srcSliceY * dstStride[2],
> +                          dst[0] + srcSliceY * dstStride[0],
> +                          dst[1] + srcSliceY * dstStride[1] };
> +
> +    if (c->dstFormat != PIX_FMT_GBRP) {
> +        av_log(c, AV_LOG_ERROR, "unsupported planar RGB conversion %s -> %s\n",
> +               av_get_pix_fmt_name(c->srcFormat),
> +               av_get_pix_fmt_name(c->dstFormat));
> +        return srcSliceH;
> +    }
> +
> +    switch (c->srcFormat) {
> +    case PIX_FMT_RGB24:
> +        packed24togbr24p((const uint8_t *) src[0], srcStride[0],
> +                         dst201, stride201, srcSliceH, c->srcW);
> +        break;
> +    case PIX_FMT_BGR24:
> +        packed24togbr24p((const uint8_t *) src[0], srcStride[0],
> +                         dst102, stride102, srcSliceH, c->srcW);

these 2 can be simplified with 2  FFSWAP
the advantage is smaller code size if the compiler chooses to inline
packed24togbr24p

otherwise patch LGTM

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I know you won't believe me, but the highest form of Human Excellence is
to question oneself and others. -- Socrates
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