[FFmpeg-devel] [PATCH] libavfilter: vf_scale: Properly take in->color_range into account

[Martin Storsjö]

While swscale can be reconfigured with sws_setColorspaceDetails,
the in/out ranges also need to be set before calling
sws_init_context, otherwise the initialization might choose
fastpaths that don't take the ranges into account.

Therefore, look at in->color_range too, when deciding on whether
the scaler needs to be reconfigured.

Add a new member variable for keeping track of this, for being
able to differentiate between whether the scale filter parameter
"in_range" has been set (which should override whatever the input
frame has set) or whether it has been configured based on the
latest frame (which should trigger reconfiguring the scaler if
the input frame ranges change).

Signed-off-by: Martin Storsjö <martin at martin.st>
---
To test this (without risking running many conflicting swscale
filters in one filter pipeline), we'd need to be able to tag
the incoming raw yuv data with colorspace and range without setting
the in_color_matrix and in_range options on the scale filter.

When using the rawvideo demuxer, the pixel format is set via the
ffmpeg -pix_fmt option, but there's no corresponding option for
setting color matrix or range for it.
---
 libavfilter/vf_scale.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 44f85cb019..996f7aaa5b 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -138,6 +138,7 @@ typedef struct ScaleContext {
     char *out_color_matrix;
 
     int in_range;
+    int in_frame_range;
     int out_range;
 
     int out_h_chr_pos;
@@ -322,6 +323,8 @@ static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
     scale->opts = *opts;
     *opts = NULL;
 
+    scale->in_frame_range = AVCOL_RANGE_UNSPECIFIED;
+
     return 0;
 }
 
@@ -544,6 +547,9 @@ static int config_props(AVFilterLink *outlink)
             if (scale->in_range != AVCOL_RANGE_UNSPECIFIED)
                 av_opt_set_int(s, "src_range",
                                scale->in_range == AVCOL_RANGE_JPEG, 0);
+            else if (scale->in_frame_range != AVCOL_RANGE_UNSPECIFIED)
+                av_opt_set_int(s, "src_range",
+                               scale->in_frame_range == AVCOL_RANGE_JPEG, 0);
             if (scale->out_range != AVCOL_RANGE_UNSPECIFIED)
                 av_opt_set_int(s, "dst_range",
                                scale->out_range == AVCOL_RANGE_JPEG, 0);
@@ -690,6 +696,13 @@ static int scale_frame(AVFilterLink *link, AVFrame *in, AVFrame **frame_out)
                     in->sample_aspect_ratio.den != link->sample_aspect_ratio.den ||
                     in->sample_aspect_ratio.num != link->sample_aspect_ratio.num;
 
+    if (in->color_range != AVCOL_RANGE_UNSPECIFIED &&
+        scale->in_range == AVCOL_RANGE_UNSPECIFIED &&
+        in->color_range != scale->in_frame_range) {
+        scale->in_frame_range = in->color_range;
+        frame_changed = 1;
+    }
+
     if (scale->eval_mode == EVAL_MODE_FRAME || frame_changed) {
         unsigned vars_w[VARS_NB] = { 0 }, vars_h[VARS_NB] = { 0 };
 
-- 
2.32.0 (Apple Git-132)