[FFmpeg-devel] [PATCH v3 1/3] avutil/hwcontext_videotoolbox: Unset undefined values

[Marvin Scholz]

When mapping AVFrame properties to the CVBuffer attachments, it is
necessary to properly delete undefined attachments, else we can
leave incorrect values in there guessed from VideoToolbox for
example, leading to inconsistent results where the AVFrame and
CVBuffer differ in metadata.

Ref #10884
---
 libavutil/hwcontext_videotoolbox.c | 76 ++++++++++++++++--------------
 1 file changed, 41 insertions(+), 35 deletions(-)

diff --git a/libavutil/hwcontext_videotoolbox.c b/libavutil/hwcontext_videotoolbox.c
index 9f82b104c3..0af2ab822f 100644
--- a/libavutil/hwcontext_videotoolbox.c
+++ b/libavutil/hwcontext_videotoolbox.c
@@ -342,8 +342,10 @@ static int vt_pixbuf_set_par(void *log_ctx,
     CFNumberRef num = NULL, den = NULL;
     AVRational avpar = src->sample_aspect_ratio;
 
-    if (avpar.num == 0)
+    if (avpar.num == 0) {
+        CVBufferRemoveAttachment(pixbuf, kCVImageBufferPixelAspectRatioKey);
         return 0;
+    }
 
     av_reduce(&avpar.num, &avpar.den,
                 avpar.num, avpar.den,
@@ -423,7 +425,10 @@ static int vt_pixbuf_set_chromaloc(void *log_ctx,
             kCVImageBufferChromaLocationTopFieldKey,
             loc,
             kCVAttachmentMode_ShouldPropagate);
-    }
+    } else
+        CVBufferRemoveAttachment(
+            pixbuf,
+            kCVImageBufferChromaLocationTopFieldKey);
 
     return 0;
 }
@@ -534,52 +539,53 @@ static int vt_pixbuf_set_colorspace(void *log_ctx,
     Float32 gamma = 0;
 
     colormatrix = av_map_videotoolbox_color_matrix_from_av(src->colorspace);
-    if (!colormatrix && src->colorspace != AVCOL_SPC_UNSPECIFIED)
-        av_log(log_ctx, AV_LOG_WARNING, "Color space %s is not supported.\n", av_color_space_name(src->colorspace));
+    if (colormatrix)
+        CVBufferSetAttachment(pixbuf, kCVImageBufferYCbCrMatrixKey,
+            colormatrix, kCVAttachmentMode_ShouldPropagate);
+    else {
+        CVBufferRemoveAttachment(pixbuf, kCVImageBufferYCbCrMatrixKey);
+        if (src->colorspace != AVCOL_SPC_UNSPECIFIED)
+            av_log(log_ctx, AV_LOG_WARNING,
+                "Color space %s is not supported.\n",
+                av_color_space_name(src->colorspace));
+    }
 
     colorpri = av_map_videotoolbox_color_primaries_from_av(src->color_primaries);
-    if (!colorpri && src->color_primaries != AVCOL_PRI_UNSPECIFIED)
-        av_log(log_ctx, AV_LOG_WARNING, "Color primaries %s is not supported.\n", av_color_primaries_name(src->color_primaries));
+    if (colorpri)
+        CVBufferSetAttachment(pixbuf, kCVImageBufferColorPrimariesKey,
+            colorpri, kCVAttachmentMode_ShouldPropagate);
+    else {
+        CVBufferRemoveAttachment(pixbuf, kCVImageBufferColorPrimariesKey);
+        if (src->color_primaries != AVCOL_SPC_UNSPECIFIED)
+            av_log(log_ctx, AV_LOG_WARNING,
+                "Color primaries %s is not supported.\n",
+                av_color_primaries_name(src->color_primaries));
+    }
 
     colortrc = av_map_videotoolbox_color_trc_from_av(src->color_trc);
-    if (!colortrc && src->color_trc != AVCOL_TRC_UNSPECIFIED)
-        av_log(log_ctx, AV_LOG_WARNING, "Color transfer function %s is not supported.\n", av_color_transfer_name(src->color_trc));
+    if (colortrc)
+        CVBufferSetAttachment(pixbuf, kCVImageBufferTransferFunctionKey,
+            colorpri, kCVAttachmentMode_ShouldPropagate);
+    else {
+        CVBufferRemoveAttachment(pixbuf, kCVImageBufferTransferFunctionKey);
+        if (src->color_trc != AVCOL_TRC_UNSPECIFIED)
+            av_log(log_ctx, AV_LOG_WARNING,
+                "Color transfer function %s is not supported.\n",
+                av_color_transfer_name(src->color_trc));
+    }
 
     if (src->color_trc == AVCOL_TRC_GAMMA22)
         gamma = 2.2;
     else if (src->color_trc == AVCOL_TRC_GAMMA28)
         gamma = 2.8;
 
-    if (colormatrix) {
-        CVBufferSetAttachment(
-            pixbuf,
-            kCVImageBufferYCbCrMatrixKey,
-            colormatrix,
-            kCVAttachmentMode_ShouldPropagate);
-    }
-    if (colorpri) {
-        CVBufferSetAttachment(
-            pixbuf,
-            kCVImageBufferColorPrimariesKey,
-            colorpri,
-            kCVAttachmentMode_ShouldPropagate);
-    }
-    if (colortrc) {
-        CVBufferSetAttachment(
-            pixbuf,
-            kCVImageBufferTransferFunctionKey,
-            colortrc,
-            kCVAttachmentMode_ShouldPropagate);
-    }
     if (gamma != 0) {
         CFNumberRef gamma_level = CFNumberCreate(NULL, kCFNumberFloat32Type, &gamma);
-        CVBufferSetAttachment(
-            pixbuf,
-            kCVImageBufferGammaLevelKey,
-            gamma_level,
-            kCVAttachmentMode_ShouldPropagate);
+        CVBufferSetAttachment(pixbuf, kCVImageBufferGammaLevelKey,
+            gamma_level, kCVAttachmentMode_ShouldPropagate);
         CFRelease(gamma_level);
-    }
+    } else
+        CVBufferRemoveAttachment(pixbuf, kCVImageBufferGammaLevelKey);
 
     return 0;
 }

base-commit: fa3b153cb1eba0d68327c716842c9a38f95c1667
-- 
2.39.3 (Apple Git-146)