X-Git-Url: https://git.piment-noir.org/?p=deb_ffmpeg.git;a=blobdiff_plain;f=ffmpeg%2Flibavfilter%2Fvf_lut.c;h=0b7a2cac0256fa490841e9a89ffa7572159c9941;hp=fff5a2ba3179424abb52e956374c5265aeeccab9;hb=f6fa7814ccfe3e76514b36cf04f5cd3cb657c8cf;hpb=2ba45a602cbfa7b771effba9b11bb4245c21bc00

diff --git a/ffmpeg/libavfilter/vf_lut.c b/ffmpeg/libavfilter/vf_lut.c
index fff5a2b..0b7a2ca 100644
--- a/ffmpeg/libavfilter/vf_lut.c
+++ b/ffmpeg/libavfilter/vf_lut.c
@@ -161,15 +161,32 @@ static double compute_gammaval(void *opaque, double gamma)
     return pow((val-minval)/(maxval-minval), gamma) * (maxval-minval)+minval;
 }
 
+/**
+ * Compute Rec.709 gama correction of value val
+ */
+static double compute_gammaval709(void *opaque, double gamma)
+{
+    LutContext *s = opaque;
+    double val    = s->var_values[VAR_CLIPVAL];
+    double minval = s->var_values[VAR_MINVAL];
+    double maxval = s->var_values[VAR_MAXVAL];
+    double level = (val - minval) / (maxval - minval);
+    level = level < 0.018 ? 4.5 * level
+                          : 1.099 * pow(level, 1.0 / gamma) - 0.099;
+    return level * (maxval - minval) + minval;
+}
+
 static double (* const funcs1[])(void *, double) = {
     (void *)clip,
     (void *)compute_gammaval,
+    (void *)compute_gammaval709,
     NULL
 };
 
 static const char * const funcs1_names[] = {
     "clip",
     "gammaval",
+    "gammaval709",
     NULL
 };