[FFmpeg-devel] [PATCH 1/2] avcodec: add YUV color space metadata to AVCodec

[Niklas Haas]

From: Niklas Haas <git at haasn.dev>

This is motivated primarily by a desire for YUVJ removal, which will
require signalling the supported color ranges as part of the codec
capabilities. But since we're adding YUV range, we might as well add the
YUV color matrix as well - since some codecs (e.g. VP8, JPEG) only
support certain values.

I decided to preserve the ambiguous and misleading "color_spaces" name,
for symmetry with AVFrame.colorspace. (Though this would IMO be better
called "color_matrix" or "color_system")

I also decided to omit the other AVColor* fields for now, because
vf_scale cannot handle auto-conversion between primaries/transfer/etc.
There is little value in adding metadata we cannot do anything with, and
no harm in extending the API again in the future. In theory, vf_scale
can handle conversion between chroma locations, but also the signalling
for this is annoying, so I'll defer it to a future commit.
---
 doc/APIchanges       | 3 +++
 libavcodec/codec.h   | 6 ++++++
 libavcodec/version.h | 2 +-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index 1f5724324a..7849ce47d9 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09
 
 API changes, most recent first:
 
+2024-02-xx - xxxxxxxxxx - lavc 60.40.100 - avcodec.h
+  Add AVCodec.color_ranges and AVCodec.color_spaces.
+
 2024-02-04 - xxxxxxxxxx - lavc 60.39.100 - packet.h
   Add AV_PKT_DATA_AMBIENT_VIEWING_ENVIRONMENT.
 
diff --git a/libavcodec/codec.h b/libavcodec/codec.h
index 8034f1a53c..8bd678de7a 100644
--- a/libavcodec/codec.h
+++ b/libavcodec/codec.h
@@ -235,6 +235,12 @@ typedef struct AVCodec {
      * Array of supported channel layouts, terminated with a zeroed layout.
      */
     const AVChannelLayout *ch_layouts;
+
+    /**
+     * Array of supported YUV color formats. Ignored for RGB/Gray formats.
+     */
+    const enum AVColorRange *color_ranges; ///< terminated by AVCOL_RANGE_UNSPECIFIED
+    const enum AVColorSpace *color_spaces; ///< terminated by AVCOL_SPC_UNSPECIFIED
 } AVCodec;
 
 /**
diff --git a/libavcodec/version.h b/libavcodec/version.h
index f2f14eaed1..19f3f4a272 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
 
 #include "version_major.h"
 
-#define LIBAVCODEC_VERSION_MINOR  39
+#define LIBAVCODEC_VERSION_MINOR  40
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
-- 
2.43.0