color: Clarify default behaviors

media/filters/h264_parser.cc

 // Copyright 2014 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/h264_parser.h"
 
 #include <limits>
 #include <memory>
 
 #include "base/logging.h"
@@ skipping 107 matching lines @@
 
   return gfx::Rect(crop_left, crop_top,
                    coded_size->width() - crop_left - crop_right,
                    coded_size->height() - crop_top - crop_bottom);
 }
 
 // Based on T-REC-H.264 E.2.1, "VUI parameters semantics",
 // available from http://www.itu.int/rec/T-REC-H.264.
 gfx::ColorSpace H264SPS::GetColorSpace() const {
   if (colour_description_present_flag) {
-    return gfx::ColorSpace(
+    return gfx::ColorSpace::CreateVideo(
         colour_primaries, transfer_characteristics, matrix_coefficients,
         video_full_range_flag ? gfx::ColorSpace::RangeID::FULL
                               : gfx::ColorSpace::RangeID::LIMITED);
   } else {
-    return gfx::ColorSpace(gfx::ColorSpace::PrimaryID::UNSPECIFIED,
-                           gfx::ColorSpace::TransferID::UNSPECIFIED,
-                           gfx::ColorSpace::MatrixID::UNSPECIFIED,
-                           video_full_range_flag
-                               ? gfx::ColorSpace::RangeID::FULL
-                               : gfx::ColorSpace::RangeID::LIMITED);
+    return gfx::ColorSpace(

[hubbe, 2017/02/16 08:20:50]

I'm not sure I like that we're hardcoding our fallback here, but I don't have a
good suggestions for how to make it better right now either...

[ccameron, 2017/02/16 20:45:27]

I've put a "TODO(ccameron/hubbe): determine how to set default values" here.

Another idea would be to have a gfx::ColorSpace::CreateVideoDefault(bool
full_fange);" and use that. But I'll leave that in the TODO.

+        gfx::ColorSpace::PrimaryID::BT709, gfx::ColorSpace::TransferID::BT709,
+        gfx::ColorSpace::MatrixID::BT709,
+        video_full_range_flag ? gfx::ColorSpace::RangeID::FULL
+                              : gfx::ColorSpace::RangeID::LIMITED);
   }
 }
 
 H264PPS::H264PPS() {
   memset(this, 0, sizeof(*this));
 }
 
 H264SliceHeader::H264SliceHeader() {
   memset(this, 0, sizeof(*this));
 }
@@ skipping 1326 matching lines @@
 
     default:
       DVLOG(4) << "Unsupported SEI message";
       break;
   }
 
   return kOk;
 }
 
 }  // namespace media