[chrome.displaySource] Implement some elementary stream descriptors.

WiFi Display elementary stream descriptors are used for passing descriptive
information about elementary streams to a WiFi Display transport stream
packetizer which then packetizes that information so that it can be passed
to a remote sink.

This is part of a WiFi Display packetizer patch series:
 * https://codereview.chromium.org/1796123002/
   WiFi Display elementary stream packetizer
 * https://codereview.chromium.org/1800493003/  <-- this CL
   WiFi Display elementary stream descriptors
 * https://codereview.chromium.org/1797953002/
   WiFi Display transport stream packetizer
 * https://codereview.chromium.org/1796073003/
   WiFi Display media packetizer

BUG=242107

Review URL: https://codereview.chromium.org/1800493003

Cr-Commit-Position: refs/heads/master@{#382245}

5 files changed, 441 insertions, 0 deletions

diff --git a/extensions/extensions.gypi b/extensions/extensions.gypi
index b9c9ec0..99897d6 100644
--- a/extensions/extensions.gypi
+++ b/extensions/extensions.gypi
@@ -1034,6 +1034,8 @@
       'renderer/worker_script_context_set.h',
     ],
     'extensions_renderer_sources_wifi_display': [
+      'renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.cc',
+      'renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.h',
       'renderer/api/display_source/wifi_display/wifi_display_elementary_stream_packetizer.cc',
       'renderer/api/display_source/wifi_display/wifi_display_elementary_stream_packetizer.h',
       'renderer/api/display_source/wifi_display/wifi_display_media_manager.cc',
diff --git a/extensions/extensions_tests.gypi b/extensions/extensions_tests.gypi
index b14063c..5463453 100644
--- a/extensions/extensions_tests.gypi
+++ b/extensions/extensions_tests.gypi
@@ -171,6 +171,7 @@
       'utility/unpacker_unittest.cc',
     ],
     'extensions_unittests_sources_wifi_display': [
+      'renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor_unittest.cc',
       'renderer/api/display_source/wifi_display/wifi_display_media_packetizer_unittest.cc',
     ],
   },
diff --git a/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.cc b/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.cc
new file mode 100644
index 0000000..7f59ce6
--- /dev/null
+++ b/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.cc
@@ -0,0 +1,165 @@
+// 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.
+
+#include "extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.h"
+
+#include <cstring>
+
+namespace extensions {
+
+WiFiDisplayElementaryStreamDescriptor::WiFiDisplayElementaryStreamDescriptor(
+    const WiFiDisplayElementaryStreamDescriptor& other) {
+  if (!other.empty()) {
+    data_.reset(new uint8_t[other.size()]);
+    std::memcpy(data(), other.data(), other.size());
+  }
+}
+
+WiFiDisplayElementaryStreamDescriptor::WiFiDisplayElementaryStreamDescriptor(
+    WiFiDisplayElementaryStreamDescriptor&&) = default;
+
+WiFiDisplayElementaryStreamDescriptor::WiFiDisplayElementaryStreamDescriptor(
+    DescriptorTag tag,
+    uint8_t length)
+    : data_(new uint8_t[kHeaderSize + length]) {
+  uint8_t* p = data();
+  *p++ = tag;
+  *p++ = length;
+  DCHECK_EQ(private_data(), p);
+}
+
+WiFiDisplayElementaryStreamDescriptor::
+    ~WiFiDisplayElementaryStreamDescriptor() {}
+
+WiFiDisplayElementaryStreamDescriptor& WiFiDisplayElementaryStreamDescriptor::
+operator=(WiFiDisplayElementaryStreamDescriptor&&) = default;
+
+const uint8_t* WiFiDisplayElementaryStreamDescriptor::data() const {
+  return data_.get();
+}
+
+uint8_t* WiFiDisplayElementaryStreamDescriptor::data() {
+  return data_.get();
+}
+
+size_t WiFiDisplayElementaryStreamDescriptor::size() const {
+  if (empty())
+    return 0u;
+  return kHeaderSize + length();
+}
+
+WiFiDisplayElementaryStreamDescriptor
+WiFiDisplayElementaryStreamDescriptor::AVCTimingAndHRD::Create() {
+  WiFiDisplayElementaryStreamDescriptor descriptor(
+      DESCRIPTOR_TAG_AVC_TIMING_AND_HRD, 2u);
+  uint8_t* p = descriptor.private_data();
+  *p++ = (false << 7) |  // hrd_management_valid_flag
+         (0x3Fu << 1) |  // reserved (all six bits on)
+         (false << 0);   // picture_and_timing_info_present
+                         // No picture nor timing info bits.
+  *p++ = (false << 7) |  // fixed_frame_rate_flag
+         (false << 6) |  // temporal_poc_flag
+         (false << 5) |  // picture_to_display_conversion_flag
+         (0x1Fu << 0);   // reserved (all five bits on)
+  DCHECK_EQ(descriptor.end(), p);
+  return descriptor;
+}
+
+WiFiDisplayElementaryStreamDescriptor
+WiFiDisplayElementaryStreamDescriptor::AVCVideo::Create(
+    uint8_t profile_idc,
+    bool constraint_set0_flag,
+    bool constraint_set1_flag,
+    bool constraint_set2_flag,
+    uint8_t avc_compatible_flags,
+    uint8_t level_idc,
+    bool avc_still_present) {
+  const bool avc_24_hour_picture_flag = false;
+  WiFiDisplayElementaryStreamDescriptor descriptor(DESCRIPTOR_TAG_AVC_VIDEO,
+                                                   4u);
+  uint8_t* p = descriptor.private_data();
+  *p++ = profile_idc;
+  *p++ = (constraint_set0_flag << 7) | (constraint_set1_flag << 6) |
+         (constraint_set2_flag << 5) | (avc_compatible_flags << 0);
+  *p++ = level_idc;
+  *p++ = (avc_still_present << 7) | (avc_24_hour_picture_flag << 6) |
+         (0x3Fu << 0);  // Reserved (all 6 bits on)
+  DCHECK_EQ(descriptor.end(), p);
+  return descriptor;
+}
+
+namespace {
+struct LPCMAudioStreamByte0 {
+  enum : uint8_t {
+    kBitsPerSampleShift = 3u,
+    kBitsPerSampleMask = ((1u << 2) - 1u) << kBitsPerSampleShift,
+    kEmphasisFlagShift = 0u,
+    kEmphasisFlagMask = 1u << kEmphasisFlagShift,
+    kReservedOnBitsShift = 1u,
+    kReservedOnBitsMask = ((1u << 2) - 1u) << kReservedOnBitsShift,
+    kSamplingFrequencyShift = 5u,
+    kSamplingFrequencyMask = ((1u << 3) - 1u) << kSamplingFrequencyShift,
+  };
+};
+
+struct LPCMAudioStreamByte1 {
+  enum : uint8_t {
+    kNumberOfChannelsShift = 5u,
+    kNumberOfChannelsMask = ((1u << 3) - 1u) << kNumberOfChannelsShift,
+    kReservedOnBitsShift = 0u,
+    kReservedOnBitsMask = ((1u << 4) - 1u) << kReservedOnBitsShift,
+    // The bit not listed above having a shift 4u is a reserved off bit.
+  };
+};
+}  // namespace
+
+WiFiDisplayElementaryStreamDescriptor
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::Create(
+    SamplingFrequency sampling_frequency,
+    BitsPerSample bits_per_sample,
+    bool emphasis_flag,
+    NumberOfChannels number_of_channels) {
+  WiFiDisplayElementaryStreamDescriptor descriptor(
+      DESCRIPTOR_TAG_LPCM_AUDIO_STREAM, 2u);
+  uint8_t* p = descriptor.private_data();
+  *p++ = (sampling_frequency << LPCMAudioStreamByte0::kSamplingFrequencyShift) |
+         (bits_per_sample << LPCMAudioStreamByte0::kBitsPerSampleShift) |
+         LPCMAudioStreamByte0::kReservedOnBitsMask |
+         (emphasis_flag << LPCMAudioStreamByte0::kEmphasisFlagShift);
+  *p++ = (number_of_channels << LPCMAudioStreamByte1::kNumberOfChannelsShift) |
+         LPCMAudioStreamByte1::kReservedOnBitsMask;
+  DCHECK_EQ(descriptor.end(), p);
+  return descriptor;
+}
+
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::BitsPerSample
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::bits_per_sample()
+    const {
+  return static_cast<BitsPerSample>(
+      (private_data()[0] & LPCMAudioStreamByte0::kBitsPerSampleMask) >>
+      LPCMAudioStreamByte0::kBitsPerSampleShift);
+}
+
+bool WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::emphasis_flag()
+    const {
+  return (private_data()[0] & LPCMAudioStreamByte0::kEmphasisFlagMask) != 0u;
+}
+
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::NumberOfChannels
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::number_of_channels()
+    const {
+  return static_cast<NumberOfChannels>(
+      (private_data()[1] & LPCMAudioStreamByte1::kNumberOfChannelsMask) >>
+      LPCMAudioStreamByte1::kNumberOfChannelsShift);
+}
+
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::SamplingFrequency
+WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream::sampling_frequency()
+    const {
+  return static_cast<SamplingFrequency>(
+      (private_data()[0] & LPCMAudioStreamByte0::kSamplingFrequencyMask) >>
+      LPCMAudioStreamByte0::kSamplingFrequencyShift);
+}
+
+}  // namespace extensions
diff --git a/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.h b/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.h
new file mode 100644
index 0000000..c149af8
--- /dev/null
+++ b/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.h
@@ -0,0 +1,122 @@
+// 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 EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_ELEMENTARY_STREAM_DESCRIPTOR_H_
+#define EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_ELEMENTARY_STREAM_DESCRIPTOR_H_
+
+#include <stdint.h>
+#include <type_traits>
+
+#include "base/memory/scoped_ptr.h"
+
+namespace extensions {
+
+// WiFi Display elementary stream descriptors are used for passing descriptive
+// information about elementary streams to WiFiDisplayTransportStreamPacketizer
+// which then packetizes that information so that it can be passed to a remote
+// sink.
+class WiFiDisplayElementaryStreamDescriptor {
+ public:
+  enum { kHeaderSize = 2u };
+
+  enum DescriptorTag : uint8_t {
+    DESCRIPTOR_TAG_AVC_VIDEO = 0x28u,
+    DESCRIPTOR_TAG_AVC_TIMING_AND_HRD = 0x2A,
+    DESCRIPTOR_TAG_LPCM_AUDIO_STREAM = 0x83u,
+  };
+
+  // Make Google Test treat this class as a container.
+  using const_iterator = const uint8_t*;
+  using iterator = const uint8_t*;
+
+  WiFiDisplayElementaryStreamDescriptor(
+      const WiFiDisplayElementaryStreamDescriptor&);
+  WiFiDisplayElementaryStreamDescriptor(
+      WiFiDisplayElementaryStreamDescriptor&&);
+  ~WiFiDisplayElementaryStreamDescriptor();
+
+  WiFiDisplayElementaryStreamDescriptor& operator=(
+      WiFiDisplayElementaryStreamDescriptor&&);
+
+  const uint8_t* begin() const { return data(); }
+  const uint8_t* data() const;
+  bool empty() const { return !data_; }
+  const uint8_t* end() const { return data() + size(); }
+  size_t size() const;
+
+  DescriptorTag tag() const { return static_cast<DescriptorTag>(data()[0]); }
+  uint8_t length() const { return data()[1]; }
+
+  // AVC (Advanced Video Coding) timing and HRD (Hypothetical Reference
+  // Decoder) descriptor provides timing and HRD parameters for a video stream.
+  struct AVCTimingAndHRD {
+    static WiFiDisplayElementaryStreamDescriptor Create();
+  };
+
+  // AVC (Advanced Video Coding) video descriptor provides basic coding
+  // parameters for a video stream.
+  struct AVCVideo {
+    static WiFiDisplayElementaryStreamDescriptor Create(
+        uint8_t profile_idc,
+        bool constraint_set0_flag,
+        bool constraint_set1_flag,
+        bool constraint_set2_flag,
+        uint8_t avc_compatible_flags,
+        uint8_t level_idc,
+        bool avc_still_present);
+  };
+
+  class LPCMAudioStream;
+
+ protected:
+  WiFiDisplayElementaryStreamDescriptor(DescriptorTag tag, uint8_t length);
+
+  uint8_t* data();
+  const uint8_t* private_data() const { return data() + kHeaderSize; }
+  uint8_t* private_data() { return data() + kHeaderSize; }
+
+ private:
+  scoped_ptr<uint8_t[]> data_;
+};
+
+// LPCM (Linear pulse-code modulation) audio stream descriptor provides basic
+// coding parameters for a private WiFi Display LPCM audio stream.
+class WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream
+    : public WiFiDisplayElementaryStreamDescriptor {
+ public:
+  enum { kTag = DESCRIPTOR_TAG_LPCM_AUDIO_STREAM };
+  enum BitsPerSample : uint8_t { BITS_PER_SAMPLE_16 = 0u };
+  enum NumberOfChannels : uint8_t {
+    NUMBER_OF_CHANNELS_DUAL_MONO = 0u,
+    NUMBER_OF_CHANNELS_STEREO = 1u
+  };
+  enum SamplingFrequency : uint8_t {
+    SAMPLING_FREQUENCY_44_1K = 1u,
+    SAMPLING_FREQUENCY_48K = 2u
+  };
+
+  static WiFiDisplayElementaryStreamDescriptor Create(
+      SamplingFrequency sampling_frequency,
+      BitsPerSample bits_per_sample,
+      bool emphasis_flag,
+      NumberOfChannels number_of_channels);
+
+  BitsPerSample bits_per_sample() const;
+  bool emphasis_flag() const;
+  NumberOfChannels number_of_channels() const;
+  SamplingFrequency sampling_frequency() const;
+};
+
+// Subclasses of WiFiDisplayElementaryStreamDescriptor MUST NOT define new
+// member variables but only new non-virtual member functions which parse
+// the inherited data. This allows WiFiDisplayElementaryStreamDescriptor
+// pointers to be cast to subclass pointers.
+static_assert(
+    std::is_standard_layout<
+        WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream>::value,
+    "Forbidden memory layout for an elementary stream descriptor");
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_ELEMENTARY_STREAM_DESCRIPTOR_H_
diff --git a/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor_unittest.cc b/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor_unittest.cc
new file mode 100644
index 0000000..4e049db
--- /dev/null
+++ b/extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor_unittest.cc
@@ -0,0 +1,151 @@
+// 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.
+
+#include "extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+using LPCMAudioStreamDescriptor =
+    extensions::WiFiDisplayElementaryStreamDescriptor::LPCMAudioStream;
+
+namespace extensions {
+
+namespace {
+
+// Copy constructors cannot always be tested by calling them directly as
+// a compiler is allowed to optimize copy constructor calls away in certain
+// cases (that is called return value optimization). Therefore, this helper
+// function is needed to really create a copy of an object.
+template <typename T>
+T Copy(const T& t) {
+  return t;
+}
+
+class Data : public std::vector<uint8_t> {
+ public:
+  template <size_t N>
+  explicit Data(const char (&str)[N]) {
+    EXPECT_EQ('\0', str[N - 1]);
+    insert(end(), str, str + N - 1);
+  }
+
+  bool operator==(const WiFiDisplayElementaryStreamDescriptor& rhs) const {
+    return size() == rhs.size() && std::equal(begin(), end(), rhs.begin());
+  }
+};
+
+TEST(WiFiDisplayElementaryStreamDescriptorTest, AVCTimingAndHRDDescriptor) {
+  using AVCTimingAndHRDDescriptor =
+      WiFiDisplayElementaryStreamDescriptor::AVCTimingAndHRD;
+  EXPECT_EQ(Data("\x2A\x02\x7E\x1F"), AVCTimingAndHRDDescriptor::Create());
+  EXPECT_EQ(Data("\x2A\x02\x7E\x1F"),
+            Copy(AVCTimingAndHRDDescriptor::Create()));
+}
+
+TEST(WiFiDisplayElementaryStreamDescriptorTest, AVCVideoDescriptor) {
+  using AVCVideoDescriptor = WiFiDisplayElementaryStreamDescriptor::AVCVideo;
+  EXPECT_EQ(
+      Data("\x28\x04\x00\x00\x00\x3F"),
+      AVCVideoDescriptor::Create(0x0u, false, false, false, 0x0u, 0x0u, false));
+  EXPECT_EQ(Data("\x28\x04\x00\x00\x00\x3F"),
+            Copy(AVCVideoDescriptor::Create(0x0u, false, false, false, 0x0u,
+                                            0x0u, false)));
+  EXPECT_EQ(Data("\x28\x04\xFF\x00\x00\x3F"),
+            AVCVideoDescriptor::Create(0xFFu, false, false, false, 0x0u, 0x0u,
+                                       false));
+  EXPECT_EQ(
+      Data("\x28\x04\x00\x80\x00\x3F"),
+      AVCVideoDescriptor::Create(0x0u, true, false, false, 0x0u, 0x0u, false));
+  EXPECT_EQ(
+      Data("\x28\x04\x00\x40\x00\x3F"),
+      AVCVideoDescriptor::Create(0x0u, false, true, false, 0x0u, 0x0u, false));
+  EXPECT_EQ(
+      Data("\x28\x04\x00\x20\x00\x3F"),
+      AVCVideoDescriptor::Create(0x0u, false, false, true, 0x0u, 0x0u, false));
+  EXPECT_EQ(Data("\x28\x04\x00\x1F\x00\x3F"),
+            AVCVideoDescriptor::Create(0x0u, false, false, false, 0x1Fu, 0x0u,
+                                       false));
+  EXPECT_EQ(Data("\x28\x04\x00\x00\xFF\x3F"),
+            AVCVideoDescriptor::Create(0x0u, false, false, false, 0x0u, 0xFFu,
+                                       false));
+  EXPECT_EQ(
+      Data("\x28\x04\x00\x00\x00\xBF"),
+      AVCVideoDescriptor::Create(0x0u, false, false, false, 0x0u, 0x0u, true));
+}
+
+class LPCMAudioStreamDescriptorTest
+    : public testing::TestWithParam<
+          testing::tuple<LPCMAudioStreamDescriptor::SamplingFrequency,
+                         LPCMAudioStreamDescriptor::BitsPerSample,
+                         bool,
+                         LPCMAudioStreamDescriptor::NumberOfChannels,
+                         Data>> {
+ protected:
+  LPCMAudioStreamDescriptorTest()
+      : sampling_frequency_(testing::get<0>(GetParam())),
+        bits_per_sample_(testing::get<1>(GetParam())),
+        emphasis_flag_(testing::get<2>(GetParam())),
+        number_of_channels_(testing::get<3>(GetParam())),
+        expected_data_(testing::get<4>(GetParam())),
+        descriptor_(LPCMAudioStreamDescriptor::Create(sampling_frequency_,
+                                                      bits_per_sample_,
+                                                      emphasis_flag_,
+                                                      number_of_channels_)) {}
+
+  const LPCMAudioStreamDescriptor::SamplingFrequency sampling_frequency_;
+  const LPCMAudioStreamDescriptor::BitsPerSample bits_per_sample_;
+  const bool emphasis_flag_;
+  const LPCMAudioStreamDescriptor::NumberOfChannels number_of_channels_;
+  const Data expected_data_;
+  const WiFiDisplayElementaryStreamDescriptor descriptor_;
+};
+
+TEST_P(LPCMAudioStreamDescriptorTest, Create) {
+  EXPECT_EQ(expected_data_, descriptor_);
+  EXPECT_EQ(expected_data_, Copy(descriptor_));
+}
+
+TEST_P(LPCMAudioStreamDescriptorTest, Accessors) {
+  ASSERT_EQ(LPCMAudioStreamDescriptor::kTag, descriptor_.tag());
+  const LPCMAudioStreamDescriptor& descriptor =
+      *static_cast<const LPCMAudioStreamDescriptor*>(&descriptor_);
+  EXPECT_EQ(sampling_frequency_, descriptor.sampling_frequency());
+  EXPECT_EQ(bits_per_sample_, descriptor.bits_per_sample());
+  EXPECT_EQ(emphasis_flag_, descriptor.emphasis_flag());
+  EXPECT_EQ(number_of_channels_, descriptor.number_of_channels());
+}
+
+INSTANTIATE_TEST_CASE_P(
+    WiFiDisplayElementaryStreamDescriptorTests,
+    LPCMAudioStreamDescriptorTest,
+    testing::Values(testing::make_tuple(
+                        LPCMAudioStreamDescriptor::SAMPLING_FREQUENCY_44_1K,
+                        LPCMAudioStreamDescriptor::BITS_PER_SAMPLE_16,
+                        false,
+                        LPCMAudioStreamDescriptor::NUMBER_OF_CHANNELS_DUAL_MONO,
+                        Data("\x83\x02\x26\x0F")),
+                    testing::make_tuple(
+                        LPCMAudioStreamDescriptor::SAMPLING_FREQUENCY_48K,
+                        LPCMAudioStreamDescriptor::BITS_PER_SAMPLE_16,
+                        false,
+                        LPCMAudioStreamDescriptor::NUMBER_OF_CHANNELS_DUAL_MONO,
+                        Data("\x83\x02\x46\x0F")),
+                    testing::make_tuple(
+                        LPCMAudioStreamDescriptor::SAMPLING_FREQUENCY_44_1K,
+                        LPCMAudioStreamDescriptor::BITS_PER_SAMPLE_16,
+                        true,
+                        LPCMAudioStreamDescriptor::NUMBER_OF_CHANNELS_DUAL_MONO,
+                        Data("\x83\x02\x27\x0F")),
+                    testing::make_tuple(
+                        LPCMAudioStreamDescriptor::SAMPLING_FREQUENCY_44_1K,
+                        LPCMAudioStreamDescriptor::BITS_PER_SAMPLE_16,
+                        false,
+                        LPCMAudioStreamDescriptor::NUMBER_OF_CHANNELS_STEREO,
+                        Data("\x83\x02\x26\x2F"))));
+
+}  // namespace
+}  // namespace extensions