color: Clarify default behaviors

media/filters/ffmpeg_video_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/ffmpeg_video_decoder.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 167 matching lines @@
   ColorSpace color_space = AVColorSpaceToColorSpace(codec_context->colorspace,
                                                     codec_context->color_range);
   if (color_space == COLOR_SPACE_UNSPECIFIED)
     color_space = config_.color_space();
   video_frame->metadata()->SetInteger(VideoFrameMetadata::COLOR_SPACE,
                                       color_space);
 
   if (codec_context->color_primaries != AVCOL_PRI_UNSPECIFIED ||
       codec_context->color_trc != AVCOL_TRC_UNSPECIFIED ||
       codec_context->colorspace != AVCOL_SPC_UNSPECIFIED) {
-    video_frame->set_color_space(
-        gfx::ColorSpace(codec_context->color_primaries,
-                        codec_context->color_trc, codec_context->colorspace,
-                        codec_context->color_range != AVCOL_RANGE_MPEG
-                            ? gfx::ColorSpace::RangeID::FULL
-                            : gfx::ColorSpace::RangeID::LIMITED));
+    video_frame->set_color_space(gfx::ColorSpace(
+        gfx::ColorSpace::PrimaryIDFromH264(codec_context->color_primaries),
+        gfx::ColorSpace::TransferIDFromH264(codec_context->color_trc),
+        gfx::ColorSpace::MatrixIDFromH264(codec_context->colorspace),
+        codec_context->color_range != AVCOL_RANGE_MPEG
+            ? gfx::ColorSpace::RangeID::FULL
+            : gfx::ColorSpace::RangeID::LIMITED));
   }
 
   for (size_t i = 0; i < VideoFrame::NumPlanes(video_frame->format()); i++) {
     frame->data[i] = video_frame->data(i);
     frame->linesize[i] = video_frame->stride(i);
   }
 
   frame->width = coded_size.width();
   frame->height = coded_size.height();
   frame->format = codec_context->pix_fmt;
@@ skipping 223 matching lines @@
   if (!codec || avcodec_open2(codec_context_.get(), codec, NULL) < 0) {
     ReleaseFFmpegResources();
     return false;
   }
 
   av_frame_.reset(av_frame_alloc());
   return true;
 }
 
 }  // namespace media