Add color metadata info to VideoDecoderConfig.

media/base/hdr_metadata.h

+// Copyright 2016 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.
+
+#ifndef MEDIA_BASE_HDR_METADATA_H_
+#define MEDIA_BASE_HDR_METADATA_H_
+
+#include <cstdint>
+#include "media/base/media_export.h"
+
+namespace media {
+
+// The definitions below are copied from the current libwebm top-of-tree.
+// Chromium's third_party/libwebm doesn't have these yet. We can probably just
+// include libwebm header directly in the future.
+// ---- Begin copy/paste from libwebm/webm_parser/include/webm/dom_types.h ----
+
+/**
+ A parsed \WebMID{MatrixCoefficients} element.
+
+ Matroska/WebM adopted these values from Table 4 of ISO/IEC 23001-8:2013/DCOR1.
+ See that document for further details.
+ */
+enum class MatrixCoefficients : std::uint64_t {

[hubbe, 2016/09/14 17:34:16]

Plase use gfx::ColorSpace

[servolk, 2016/09/14 22:34:35]

Ah, ok, thank for the pointer I didn't know about gfx::ColorSpace enums. I'll
switch to using gfx::ColorSpace.
Btw, I have noticed that while most of the values can be mapped directly, there
are some missing values. E.g. I don't see any gfx::ColorSpace::TransferID value
corresponding to ARIB STD B67 transfer function (aka hybrid-log gamma, HLG) we
should probably add a new value for this.
Also atm there are only two possible values for gfx::ColorSpace::Range enum,
while there are 4 values in the WebM definitions. This one is less clear to me -
should we also add the UNDEFINED and DERIVED values to gfx::ColorSpace::Range,
or remap somehow?

[hubbe, 2016/09/14 22:41:25]

We made the range an enum specifically so that we can add new values, so please
go ahead and add new values as needed. :)
Just make sure you update gfx::ColorTransform as well.

At some point we'll need to make gfx::ColorTransform aware of HDR mapping as
well, which means that some of the other parameters below will need to be moved
over to gfx:: as well, but one step at a time is fine by me... :)

+  /**
+   The identity matrix.
+
+   Typically used for GBR (often referred to as RGB); however, may also be used
+   for YZX (often referred to as XYZ).
+   */
+  kRgb = 0,
+
+  /**
+   Rec. ITU-R BT.709-5.
+   */
+  kBt709 = 1,
+
+  /**
+   Image characteristics are unknown or are determined by the application.
+   */
+  kUnspecified = 2,
+
+  /**
+   United States Federal Communications Commission Title 47 Code of Federal
+   Regulations (2003) 73.682 (a) (20).
+   */
+  kFcc = 4,
+
+  /**
+   Rec. ITU-R BT.470‑6 System B, G (historical).
+   */
+  kBt470Bg = 5,
+
+  /**
+   Society of Motion Picture and Television Engineers 170M (2004).
+   */
+  kSmpte170M = 6,
+
+  /**
+   Society of Motion Picture and Television Engineers 240M (1999).
+   */
+  kSmpte240M = 7,
+
+  /**
+   YCgCo.
+   */
+  kYCgCo = 8,
+
+  /**
+   Rec. ITU-R BT.2020 (non-constant luminance).
+   */
+  kBt2020NonconstantLuminance = 9,
+
+  /**
+   Rec. ITU-R BT.2020 (constant luminance).
+   */
+  kBt2020ConstantLuminance = 10,
+};
+
+/**
+ A parsed \WebMID{Range} element.
+ */
+enum class Range : std::uint64_t {
+  /**
+   Unspecified.
+   */
+  kUnspecified = 0,
+
+  /**
+   Broadcast range.
+   */
+  kBroadcast = 1,
+
+  /**
+   Full range (no clipping).
+   */
+  kFull = 2,
+
+  /**
+   Defined by MatrixCoefficients/TransferCharacteristics.
+   */
+  kDerived = 3,
+};
+
+/**
+ A parsed \WebMID{TransferCharacteristics} element.
+
+ Matroska/WebM adopted these values from Table 3 of ISO/IEC 23001-8:2013/DCOR1.
+ See that document for further details.
+ */
+enum class TransferCharacteristics : std::uint64_t {
+  /**
+   Rec. ITU-R BT.709-6.
+   */
+  kBt709 = 1,
+
+  /**
+   Image characteristics are unknown or are determined by the application.
+   */
+  kUnspecified = 2,
+
+  /**
+   Rec. ITU‑R BT.470‑6 System M (historical) with assumed display gamma 2.2.
+   */
+  kGamma22curve = 4,
+
+  /**
+   Rec. ITU‑R BT.470-6 System B, G (historical) with assumed display gamma 2.8.
+   */
+  kGamma28curve = 5,
+
+  /**
+   Society of Motion Picture and Television Engineers 170M (2004).
+   */
+  kSmpte170M = 6,
+
+  /**
+   Society of Motion Picture and Television Engineers 240M (1999).
+   */
+  kSmpte240M = 7,
+
+  /**
+   Linear transfer characteristics.
+   */
+  kLinear = 8,
+
+  /**
+   Logarithmic transfer characteristic (100:1 range).
+   */
+  kLog = 9,
+
+  /**
+   Logarithmic transfer characteristic (100 * Sqrt(10) : 1 range).
+   */
+  kLogSqrt = 10,
+
+  /**
+   IEC 61966-2-4.
+   */
+  kIec6196624 = 11,
+
+  /**
+   Rec. ITU‑R BT.1361-0 extended colour gamut system (historical).
+   */
+  kBt1361ExtendedColourGamut = 12,
+
+  /**
+   IEC 61966-2-1 sRGB or sYCC.
+   */
+  kIec6196621 = 13,
+
+  /**
+   Rec. ITU-R BT.2020-2 (10-bit system).
+   */
+  k10BitBt2020 = 14,
+
+  /**
+   Rec. ITU-R BT.2020-2 (12-bit system).
+   */
+  k12BitBt2020 = 15,
+
+  /**
+   Society of Motion Picture and Television Engineers ST 2084.
+   */
+  kSmpteSt2084 = 16,
+
+  /**
+   Society of Motion Picture and Television Engineers ST 428-1.
+   */
+  kSmpteSt4281 = 17,
+
+  /**
+   Association of Radio Industries and Businesses (ARIB) STD-B67.
+   */
+  kAribStdB67Hlg = 18,
+};
+
+/**
+ A parsed \WebMID{Primaries} element.
+
+ Matroska/WebM adopted these values from Table 2 of ISO/IEC 23001-8:2013/DCOR1.
+ See that document for further details.
+ */
+enum class Primaries : std::uint64_t {
+  /**
+   Rec. ITU‑R BT.709-6.
+   */
+  kBt709 = 1,
+
+  /**
+   Image characteristics are unknown or are determined by the application.
+   */
+  kUnspecified = 2,
+
+  /**
+   Rec. ITU‑R BT.470‑6 System M (historical).
+   */
+  kBt470M = 4,
+
+  /**
+   Rec. ITU‑R BT.470‑6 System B, G (historical).
+   */
+  kBt470Bg = 5,
+
+  /**
+   Society of Motion Picture and Television Engineers 170M (2004).
+   */
+  kSmpte170M = 6,
+
+  /**
+   Society of Motion Picture and Television Engineers 240M (1999).
+   */
+  kSmpte240M = 7,
+
+  /**
+   Generic film.
+   */
+  kFilm = 8,
+
+  /**
+   Rec. ITU-R BT.2020-2.
+   */
+  kBt2020 = 9,
+
+  /**
+   Society of Motion Picture and Television Engineers ST 428-1.
+   */
+  kSmpteSt4281 = 10,
+
+  /**
+   JEDEC P22 phosphors/EBU Tech. 3213-E (1975).
+   */
+  kJedecP22Phosphors = 22,
+};
+
+// ---- End copy/paste from libwebm/webm_parser/include/webm/dom_types.h ----
+
+// SMPTE ST 2086 mastering metadata.
+struct MEDIA_EXPORT MasteringMetadata {
+  float PrimaryRChromaticityX = 0;

[halliwell, 2016/09/14 18:58:40]

nit: here and below, not following standard for member naming.

[servolk, 2016/09/15 01:50:03]

Done.

+  float PrimaryRChromaticityY = 0;
+  float PrimaryGChromaticityX = 0;
+  float PrimaryGChromaticityY = 0;
+  float PrimaryBChromaticityX = 0;
+  float PrimaryBChromaticityY = 0;
+  float WhitePointChromaticityX = 0;
+  float WhitePointChromaticityY = 0;
+  float LuminanceMax = 0;
+  float LuminanceMin = 0;
+
+  MasteringMetadata();
+  MasteringMetadata(const MasteringMetadata& rhs);
+};
+
+// HDR metadata common for HDR10 and WebM/VP9-based HDR formats.
+struct MEDIA_EXPORT HDRMetadata {
+  MasteringMetadata mastering_metadata;
+  unsigned MaxCLL = 0;
+  unsigned MaxFALL = 0;
+
+  HDRMetadata();
+  HDRMetadata(const HDRMetadata& rhs);
+};
+
+// WebM color information, containing HDR metadata:
+// http://www.webmproject.org/docs/container/#Colour
+struct MEDIA_EXPORT ColorMetadata {

[halliwell, 2016/09/14 18:58:40]

nit, shouldn't the file be called color_metadata?  as this seems like the
top-level struct here.

[servolk, 2016/09/14 22:34:35]

I'm actually not sure about it yes, since this ColorMetadata in WebM specific
and probably doesn't belong here. Now that hubbe@ pointed out that we already
have similar enums defined in gfx::ColorSpace I'm planning to move this
definition back to WebM parser, which is probably a better place for it.
HDRMetadata (i.e. SMPTE 2086 MasteringMetadata + MaxCLL + MaxFALL) seems to be
generic enough to stay here, since it can be shared between WebM HDR and HDR10.

+  MatrixCoefficients matrix_coefficients = MatrixCoefficients::kUnspecified;
+  unsigned BitsPerChannel = 0;
+  unsigned ChromaSubsamplingHorz = 0;
+  unsigned ChromaSubsamplingVert = 0;
+  unsigned CbSubsamplingHorz = 0;
+  unsigned CbSubsamplingVert = 0;
+  unsigned ChromaSitingHorz = 0;
+  unsigned ChromaSitingVert = 0;
+  Range range = Range::kUnspecified;
+  TransferCharacteristics transfer_characteristics =
+      TransferCharacteristics::kUnspecified;
+  Primaries primaries = Primaries::kUnspecified;
+
+  HDRMetadata hdr_metadata;
+
+  ColorMetadata();
+  ColorMetadata(const ColorMetadata& rhs);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_HDR_METADATA_H_