[FFmpeg-devel] [PATCH v1 3/6] swscale: Add explicit rgb24->yv12 conversion

[Michael Niedermayer]

On Sun, Aug 20, 2023 at 03:10:19PM +0000, John Cox wrote:
> Add a rgb24->yuv420p conversion. Uses the same code as the existing
> bgr24->yuv converter but permutes the conversion array to swap R & B
> coefficients.
> 
> Signed-off-by: John Cox <jc at kynesim.co.uk>
> ---
>  libswscale/rgb2rgb.c          |  5 +++++
>  libswscale/rgb2rgb.h          |  7 +++++++
>  libswscale/rgb2rgb_template.c | 38 ++++++++++++++++++++++++++++++-----
>  libswscale/swscale_unscaled.c | 24 +++++++++++++++++++++-
>  4 files changed, 68 insertions(+), 6 deletions(-)
> 
> diff --git a/libswscale/rgb2rgb.c b/libswscale/rgb2rgb.c
> index 8707917800..de90e5193f 100644
> --- a/libswscale/rgb2rgb.c
> +++ b/libswscale/rgb2rgb.c
> @@ -83,6 +83,11 @@ void (*ff_bgr24toyv12)(const uint8_t *src, uint8_t *ydst,
>                         int width, int height,
>                         int lumStride, int chromStride, int srcStride,
>                         int32_t *rgb2yuv);
> +void (*ff_rgb24toyv12)(const uint8_t *src, uint8_t *ydst,
> +                       uint8_t *udst, uint8_t *vdst,
> +                       int width, int height,
> +                       int lumStride, int chromStride, int srcStride,
> +                       int32_t *rgb2yuv);
>  void (*planar2x)(const uint8_t *src, uint8_t *dst, int width, int height,
>                   int srcStride, int dstStride);
>  void (*interleaveBytes)(const uint8_t *src1, const uint8_t *src2, uint8_t *dst,
> diff --git a/libswscale/rgb2rgb.h b/libswscale/rgb2rgb.h
> index 305b830920..f7a76a92ba 100644
> --- a/libswscale/rgb2rgb.h
> +++ b/libswscale/rgb2rgb.h
> @@ -79,6 +79,9 @@ void    rgb12to15(const uint8_t *src, uint8_t *dst, int src_size);
>  void ff_bgr24toyv12_c(const uint8_t *src, uint8_t *ydst, uint8_t *udst,
>                        uint8_t *vdst, int width, int height, int lumStride,
>                        int chromStride, int srcStride, int32_t *rgb2yuv);
> +void ff_rgb24toyv12_c(const uint8_t *src, uint8_t *ydst, uint8_t *udst,
> +                      uint8_t *vdst, int width, int height, int lumStride,
> +                      int chromStride, int srcStride, int32_t *rgb2yuv);
>  
>  /**
>   * Height should be a multiple of 2 and width should be a multiple of 16.
> @@ -128,6 +131,10 @@ extern void (*ff_bgr24toyv12)(const uint8_t *src, uint8_t *ydst, uint8_t *udst,
>                                int width, int height,
>                                int lumStride, int chromStride, int srcStride,
>                                int32_t *rgb2yuv);
> +extern void (*ff_rgb24toyv12)(const uint8_t *src, uint8_t *ydst, uint8_t *udst, uint8_t *vdst,
> +                              int width, int height,
> +                              int lumStride, int chromStride, int srcStride,
> +                              int32_t *rgb2yuv);
>  extern void (*planar2x)(const uint8_t *src, uint8_t *dst, int width, int height,
>                          int srcStride, int dstStride);
>  
> diff --git a/libswscale/rgb2rgb_template.c b/libswscale/rgb2rgb_template.c
> index 8ef4a2cf5d..e57bfa6545 100644
> --- a/libswscale/rgb2rgb_template.c
> +++ b/libswscale/rgb2rgb_template.c


> @@ -646,13 +646,14 @@ static inline void uyvytoyv12_c(const uint8_t *src, uint8_t *ydst,
>   * others are ignored in the C version.
>   * FIXME: Write HQ version.
>   */
> -void ff_bgr24toyv12_c(const uint8_t *src, uint8_t *ydst, uint8_t *udst,
> +static void rgb24toyv12_x(const uint8_t *src, uint8_t *ydst, uint8_t *udst,

this probably should be inline

also i see now "FIXME: Write HQ version." above here. Do you really want to
add a low quality rgb24toyv12 ?
(it is vissible on the diagonal border (cyan / red )) in
 ./ffmpeg -f lavfi -i testsrc=size=5632x3168 -pix_fmt yuv420p -vframes 1 -qscale 1 -strict -1 new.jpg

 also on smaller sizes but for some reason its clearer on the big one zoomed in 400% with gimp
(the gimp test was done with the whole patchset not after this patch)


[...]
> diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c
> index 32e0d7f63c..751bdcb2e4 100644
> --- a/libswscale/swscale_unscaled.c
> +++ b/libswscale/swscale_unscaled.c
> @@ -1654,6 +1654,23 @@ static int bgr24ToYv12Wrapper(SwsContext *c, const uint8_t *src[],
>      return srcSliceH;
>  }
>  
> +static int rgb24ToYv12Wrapper(SwsContext *c, const uint8_t *src[],
> +                              int srcStride[], int srcSliceY, int srcSliceH,
> +                              uint8_t *dst[], int dstStride[])
> +{
> +    ff_rgb24toyv12(
> +        src[0],
> +        dst[0] +  srcSliceY       * dstStride[0],
> +        dst[1] + (srcSliceY >> 1) * dstStride[1],
> +        dst[2] + (srcSliceY >> 1) * dstStride[2],
> +        c->srcW, srcSliceH,
> +        dstStride[0], dstStride[1], srcStride[0],
> +        c->input_rgb2yuv_table);
> +    if (dst[3])
> +        fillPlane(dst[3], dstStride[3], c->srcW, srcSliceH, srcSliceY, 255);
> +    return srcSliceH;
> +}
> +
>  static int yvu9ToYv12Wrapper(SwsContext *c, const uint8_t *src[],
>                               int srcStride[], int srcSliceY, int srcSliceH,
>                               uint8_t *dst[], int dstStride[])

> @@ -2035,8 +2052,13 @@ void ff_get_unscaled_swscale(SwsContext *c)
>      /* bgr24toYV12 */
>      if (srcFormat == AV_PIX_FMT_BGR24 &&
>          (dstFormat == AV_PIX_FMT_YUV420P || dstFormat == AV_PIX_FMT_YUVA420P) &&
> -        !(flags & SWS_ACCURATE_RND) && !(dstW&1))
> +        !(flags & (SWS_ACCURATE_RND | SWS_BITEXACT)) && !(dstW&1))

this doesnt belong in this patch

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
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