[FFmpeg-devel] [PATCH] avcodec: fix setting GBR pixel format in AV1 decoders (PR #21306)

[James Almer via ffmpeg-devel <ffmpeg-devel@ffmpeg.org>]

PR #21306 opened by James Almer (jamrial)
URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21306
Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21306.patch

Fixes issue #21304


>From a8f1c2366e23ad35f34e2a9af0cd63f38e26fc00 Mon Sep 17 00:00:00 2001
From: James Almer <jamrial@gmail.com>
Date: Sun, 28 Dec 2025 15:21:06 -0300
Subject: [PATCH 1/2] avcodec/libaomdec: don't overwrite color information from
 the container if unset in the bitstream

Fixes part of #21304.

Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavcodec/libaomdec.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/libavcodec/libaomdec.c b/libavcodec/libaomdec.c
index 9e9c4d18c5..79b299bac8 100644
--- a/libavcodec/libaomdec.c
+++ b/libavcodec/libaomdec.c
@@ -71,9 +71,12 @@ static int set_pix_fmt(AVCodecContext *avctx, struct aom_image *img)
         AVCOL_RANGE_MPEG, AVCOL_RANGE_JPEG
     };
     avctx->color_range = color_ranges[img->range];
-    avctx->color_primaries = (enum AVColorPrimaries)img->cp;
-    avctx->colorspace  = (enum AVColorSpace)img->mc;
-    avctx->color_trc   = (enum AVColorTransferCharacteristic)img->tc;
+    if (img->cp != AOM_CICP_CP_UNSPECIFIED)
+        avctx->color_primaries = (enum AVColorPrimaries)img->cp;
+    if (img->mc != AOM_CICP_MC_UNSPECIFIED)
+        avctx->colorspace  = (enum AVColorSpace)img->mc;
+    if (img->tc != AOM_CICP_TC_UNSPECIFIED)
+        avctx->color_trc   = (enum AVColorTransferCharacteristic)img->tc;
 
     switch (img->fmt) {
     case AOM_IMG_FMT_I420:
-- 
2.49.1


>From fc5f45bd42c7f9cd203ca260765e549bd15ecaf2 Mon Sep 17 00:00:00 2001
From: James Almer <jamrial@gmail.com>
Date: Sun, 28 Dec 2025 15:20:03 -0300
Subject: [PATCH 2/2] avcodec/libdav1d: only consider colorspace when choosing
 between YUV and GBR

Several files use values for primaries and transfer characteristics other than
BT709 and IEC_61966 respectively, while still being GBR.
Also always set color_range while at it. It's always coded in the bistream.

Fixes part of #21304.

Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavcodec/libdav1d.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/libavcodec/libdav1d.c b/libavcodec/libdav1d.c
index 7f63bb1b15..14ec9842a0 100644
--- a/libavcodec/libdav1d.c
+++ b/libavcodec/libdav1d.c
@@ -147,13 +147,10 @@ static void libdav1d_init_params(AVCodecContext *c, const Dav1dSequenceHeader *s
         c->colorspace      = (enum AVColorSpace) seq->mtrx;
         c->color_primaries = (enum AVColorPrimaries) seq->pri;
         c->color_trc       = (enum AVColorTransferCharacteristic) seq->trc;
-        c->color_range     = seq->color_range ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
     }
+    c->color_range = seq->color_range ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
 
-    if (seq->layout == DAV1D_PIXEL_LAYOUT_I444 &&
-        c->colorspace      == AVCOL_SPC_RGB &&
-        c->color_primaries == AVCOL_PRI_BT709 &&
-        c->color_trc       == AVCOL_TRC_IEC61966_2_1)
+    if (seq->layout == DAV1D_PIXEL_LAYOUT_I444 && c->colorspace == AVCOL_SPC_RGB)
         c->pix_fmt = pix_fmt_rgb[seq->hbd];
     else
         c->pix_fmt = pix_fmt[seq->layout][seq->hbd];
-- 
2.49.1

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