sws: support xyz input

The implementation is heavily based on Matthias Buerchers and Nicolas Bertrands vf_xyz2rgb.c
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 65 insertions, 0 deletions

diff --git a/libswscale/swscale.c b/libswscale/swscale.c
index 0c20a71f71..190a7b98f4 100644
--- a/libswscale/swscale.c
+++ b/libswscale/swscale.c
@@ -791,6 +791,62 @@ static int check_image_pointers(const uint8_t * const data[4], enum AVPixelForma
     return 1;
 }
 
+static void xyz12Torgb48(struct SwsContext *c, uint16_t *dst,
+                         const uint16_t *src, int stride, int h)
+{
+    int xp,yp;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->srcFormat);
+
+    for (yp=0; yp<h; yp++) {
+        for (xp=0; xp+2<stride; xp+=3) {
+            int x, y, z, r, g, b;
+
+            if (desc->flags & PIX_FMT_BE) {
+                x = AV_RB16(src + xp + 0);
+                y = AV_RB16(src + xp + 1);
+                z = AV_RB16(src + xp + 2);
+            } else {
+                x = AV_RL16(src + xp + 0);
+                y = AV_RL16(src + xp + 1);
+                z = AV_RL16(src + xp + 2);
+            }
+
+            x = c->xyzgamma[x>>4];
+            y = c->xyzgamma[y>>4];
+            z = c->xyzgamma[z>>4];
+
+            // convert from XYZlinear to sRGBlinear
+            r = c->xyz2rgb_matrix[0][0] * x +
+                c->xyz2rgb_matrix[0][1] * y +
+                c->xyz2rgb_matrix[0][2] * z >> 12;
+            g = c->xyz2rgb_matrix[1][0] * x +
+                c->xyz2rgb_matrix[1][1] * y +
+                c->xyz2rgb_matrix[1][2] * z >> 12;
+            b = c->xyz2rgb_matrix[2][0] * x +
+                c->xyz2rgb_matrix[1][2] * y +
+                c->xyz2rgb_matrix[2][2] * z >> 12;
+
+            // limit values to 12-bit depth
+            r = av_clip_c(r,0,4095);
+            g = av_clip_c(g,0,4095);
+            b = av_clip_c(b,0,4095);
+
+            // convert from sRGBlinear to RGB and scale from 12bit to 16bit
+            if (desc->flags & PIX_FMT_BE) {
+                AV_WB16(dst + xp + 0, c->rgbgamma[r] << 4);
+                AV_WB16(dst + xp + 1, c->rgbgamma[g] << 4);
+                AV_WB16(dst + xp + 2, c->rgbgamma[b] << 4);
+            } else {
+                AV_WL16(dst + xp + 0, c->rgbgamma[r] << 4);
+                AV_WL16(dst + xp + 1, c->rgbgamma[g] << 4);
+                AV_WL16(dst + xp + 2, c->rgbgamma[b] << 4);
+            }
+        }
+        src += stride;
+        dst += stride;
+    }
+}
+
 /**
  * swscale wrapper, so we don't need to export the SwsContext.
  * Assumes planar YUV to be in YUV order instead of YVU.
@@ -922,6 +978,15 @@ int attribute_align_arg sws_scale(struct SwsContext *c,
         src2[0] = base;
     }
 
+    if (c->srcXYZ && !(c->dstXYZ && c->srcW==c->dstW && c->srcH==c->dstH)) {
+        uint8_t *base;
+        rgb0_tmp = av_malloc(FFABS(srcStride[0]) * srcSliceH + 32);
+        base = srcStride[0] < 0 ? rgb0_tmp - srcStride[0] * (srcSliceH-1) : rgb0_tmp;
+
+        xyz12Torgb48(c, base, src2[0], srcStride[0]/2, srcSliceH);
+        src2[0] = base;
+    }
+
     if (!srcSliceY && (c->flags & SWS_BITEXACT) && (c->flags & SWS_ERROR_DIFFUSION) && c->dither_error[0])
         for (i = 0; i < 4; i++)
             memset(c->dither_error[i], 0, sizeof(c->dither_error[0][0]) * (c->dstW+2));