Implement some WiFi Display elementary stream descriptors.

extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.cc

Index: extensions/renderer/api/display_source/wifi_display/wifi_display_elementary_stream_descriptor.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 0000000000000000000000000000000000000000..7f59ce68f4683da75020e8b7e96a4a594be04ec2
--- /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