[FFmpeg-devel] [PATCH] avfilter/vf_colorspace: use colorspace negotiation API

[Nicolas Gaullier]

Fixes a regression due to the fact that the colorspace filter does
not use the new API introduced by 8c7934f73ab6c568acaa.
The scale filter uses it since 45e09a30419cc2a7251e, and the setparams
filter since 3bf80df3ccd32aed23f0.

Example:
ffmpeg -f lavfi -i testsrc -vf setparams=color_primaries=bt470bg:
color_trc=smpte170m:colorspace=bt470bg,colorspace=bt709:range=tv,scale
,showinfo -f null -frames 1 -

Before:
  color_range:unknown color_space:unknown color_primaries:bt709 ...
After:
  color_range:tv color_space:bt709 color_primaries:bt709 ...

There is still an issue with the color_range when it is not specified:
the documentation states the output defaults to the same value as the
input, but it does not seem possible to implement currently.

Signed-off-by: Nicolas Gaullier <nicolas.gaullier at cji.paris>
---
 libavfilter/vf_colorspace.c | 62 +++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 26 deletions(-)

diff --git a/libavfilter/vf_colorspace.c b/libavfilter/vf_colorspace.c
index f367ce17c6..b1e1b9b719 100644
--- a/libavfilter/vf_colorspace.c
+++ b/libavfilter/vf_colorspace.c
@@ -432,8 +432,7 @@ static int create_filtergraph(AVFilterContext *ctx,
     if (out->color_trc       != s->out_trc) s->out_txchr     = NULL;
     if (in->colorspace       != s->in_csp ||
         in->color_range      != s->in_rng)  s->in_lumacoef   = NULL;
-    if (out->colorspace      != s->out_csp ||
-        out->color_range     != s->out_rng) s->out_lumacoef  = NULL;
+    if (out->color_range     != s->out_rng) s->rgb2yuv       = NULL;
 
     if (!s->out_primaries || !s->in_primaries) {
         s->in_prm = in->color_primaries;
@@ -562,26 +561,8 @@ static int create_filtergraph(AVFilterContext *ctx,
         redo_yuv2rgb = 1;
     }
 
-    if (!s->out_lumacoef) {
-        s->out_csp = out->colorspace;
+    if (!s->rgb2yuv) {
         s->out_rng = out->color_range;
-        s->out_lumacoef = av_csp_luma_coeffs_from_avcsp(s->out_csp);
-        if (!s->out_lumacoef) {
-            if (s->out_csp == AVCOL_SPC_UNSPECIFIED) {
-                if (s->user_all == CS_UNSPECIFIED) {
-                    av_log(ctx, AV_LOG_ERROR,
-                           "Please specify output colorspace\n");
-                } else {
-                    av_log(ctx, AV_LOG_ERROR,
-                           "Unsupported output color property %d\n", s->user_all);
-                }
-            } else {
-                av_log(ctx, AV_LOG_ERROR,
-                       "Unsupported output colorspace %d (%s)\n", s->out_csp,
-                       av_color_space_name(s->out_csp));
-            }
-            return AVERROR(EINVAL);
-        }
         redo_rgb2yuv = 1;
     }
 
@@ -686,6 +667,26 @@ static av_cold int init(AVFilterContext *ctx)
 {
     ColorSpaceContext *s = ctx->priv;
 
+    s->out_csp  = s->user_csp == AVCOL_SPC_UNSPECIFIED ?
+                  default_csp[FFMIN(s->user_all, CS_NB)] : s->user_csp;
+    s->out_lumacoef = av_csp_luma_coeffs_from_avcsp(s->out_csp);
+    if (!s->out_lumacoef) {
+        if (s->out_csp == AVCOL_SPC_UNSPECIFIED) {
+            if (s->user_all == CS_UNSPECIFIED) {
+                av_log(ctx, AV_LOG_ERROR,
+                       "Please specify output colorspace\n");
+            } else {
+                av_log(ctx, AV_LOG_ERROR,
+                       "Unsupported output color property %d\n", s->user_all);
+            }
+        } else {
+            av_log(ctx, AV_LOG_ERROR,
+                   "Unsupported output colorspace %d (%s)\n", s->out_csp,
+                   av_color_space_name(s->out_csp));
+        }
+        return AVERROR(EINVAL);
+    }
+
     ff_colorspacedsp_init(&s->dsp);
 
     return 0;
@@ -745,10 +746,10 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
     } else {
         out->color_trc   = s->user_trc;
     }
-    out->colorspace      = s->user_csp == AVCOL_SPC_UNSPECIFIED ?
-                           default_csp[FFMIN(s->user_all, CS_NB)] : s->user_csp;
-    out->color_range     = s->user_rng == AVCOL_RANGE_UNSPECIFIED ?
-                           in->color_range : s->user_rng;
+    // FIXME color_range must be set in query_formats for negotiation.
+    // The value updated here will not be propagated further in the graph.
+    if (s->user_rng == AVCOL_RANGE_UNSPECIFIED)
+        out->color_range = outlink->color_range = in->color_range;
     if (rgb_sz != s->rgb_sz) {
         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(out->format);
         int uvw = in->width >> desc->log2_chroma_w;
@@ -838,10 +839,19 @@ static int query_formats(AVFilterContext *ctx)
         AV_PIX_FMT_YUVJ420P,  AV_PIX_FMT_YUVJ422P,  AV_PIX_FMT_YUVJ444P,
         AV_PIX_FMT_NONE
     };
-    int res;
+    int res, ret;
     ColorSpaceContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
     AVFilterFormats *formats = ff_make_format_list(pix_fmts);
 
+    if (ret = ff_formats_ref(ff_make_formats_list_singleton(s->out_csp),
+                             &outlink->incfg.color_spaces) < 0)
+        return ret;
+    if (s->user_rng != AVCOL_RANGE_UNSPECIFIED
+        && (ret = ff_formats_ref(ff_make_formats_list_singleton(s->user_rng),
+                             &outlink->incfg.color_ranges) < 0))
+        return ret;
+
     if (!formats)
         return AVERROR(ENOMEM);
     if (s->user_format == AV_PIX_FMT_NONE)
-- 
2.30.2