[FFmpeg-devel] [RFC]Allow to change colour range with the scale filter

[Carl Eugen Hoyos]

Hi!

The scale filter currently skips scaling if width, height and pix_fmt do not 
change. I suspect it should scale if the user specified different colour 
ranges for input and output.
Attached patch is not sufficient, libswscale decides to use "simple copy" 
before srcRange and dstRange are set. I also failed to set them with the 
src_range and dst_range option from the command line: How can this be solved?

See also  
http://thread.gmane.org/gmane.comp.video.ffmpeg.user/57005/focus=57093

Carl Eugen
-------------- next part --------------
diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 2a3d008..7cc731c 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -344,6 +344,7 @@ static int config_props(AVFilterLink *outlink)
         sws_freeContext(scale->isws[1]);
     scale->isws[0] = scale->isws[1] = scale->sws = NULL;
     if (inlink->w == outlink->w && inlink->h == outlink->h &&
+        scale->in_range == scale->out_range &&
         inlink->format == outlink->format)
         ;
     else {
diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c
index b426fa1..baf21a0 100644
--- a/libswscale/swscale_unscaled.c
+++ b/libswscale/swscale_unscaled.c
@@ -1736,6 +1736,7 @@ void ff_get_unscaled_swscale(SwsContext *c)
 
 #define isPlanarGray(x) (isGray(x) && (x) != AV_PIX_FMT_YA8 && (x) != AV_PIX_FMT_YA16LE && (x) != AV_PIX_FMT_YA16BE)
     /* simple copy */
+    if (c->srcRange == c->dstRange)
     if ( srcFormat == dstFormat ||
         (srcFormat == AV_PIX_FMT_YUVA420P && dstFormat == AV_PIX_FMT_YUV420P) ||
         (srcFormat == AV_PIX_FMT_YUV420P && dstFormat == AV_PIX_FMT_YUVA420P) ||