blob: 6472216242976da453c96d813fae48eef5a2616d [file] [log] [blame]
/*
* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef MODULES_RTP_RTCP_SOURCE_RTP_DEPENDENCY_DESCRIPTOR_READER_H_
#define MODULES_RTP_RTCP_SOURCE_RTP_DEPENDENCY_DESCRIPTOR_READER_H_
#include <cstdint>
#include <memory>
#include <vector>
#include "api/array_view.h"
#include "api/transport/rtp/dependency_descriptor.h"
#include "rtc_base/bit_buffer.h"
namespace webrtc {
// Deserializes DependencyDescriptor rtp header extension.
class RtpDependencyDescriptorReader {
public:
// Parses the dependency descriptor.
RtpDependencyDescriptorReader(rtc::ArrayView<const uint8_t> raw_data,
const FrameDependencyStructure* structure,
DependencyDescriptor* descriptor);
RtpDependencyDescriptorReader(const RtpDependencyDescriptorReader&) = delete;
RtpDependencyDescriptorReader& operator=(
const RtpDependencyDescriptorReader&) = delete;
// Returns true if parse was successful.
bool ParseSuccessful() { return !parsing_failed_; }
private:
// Reads bits from `buffer_`. If it fails, returns 0 and marks parsing as
// failed, but doesn't stop the parsing.
uint32_t ReadBits(size_t bit_count);
uint32_t ReadNonSymmetric(size_t num_values);
// Functions to read template dependency structure.
void ReadTemplateDependencyStructure();
void ReadTemplateLayers();
void ReadTemplateDtis();
void ReadTemplateFdiffs();
void ReadTemplateChains();
void ReadResolutions();
// Function to read details for the current frame.
void ReadMandatoryFields();
void ReadExtendedFields();
void ReadFrameDependencyDefinition();
void ReadFrameDtis();
void ReadFrameFdiffs();
void ReadFrameChains();
// Output.
bool parsing_failed_ = false;
DependencyDescriptor* const descriptor_;
// Values that are needed while reading the descriptor, but can be discarded
// when reading is complete.
rtc::BitBuffer buffer_;
int frame_dependency_template_id_ = 0;
bool active_decode_targets_present_flag_ = false;
bool custom_dtis_flag_ = false;
bool custom_fdiffs_flag_ = false;
bool custom_chains_flag_ = false;
const FrameDependencyStructure* structure_ = nullptr;
};
} // namespace webrtc
#endif // MODULES_RTP_RTCP_SOURCE_RTP_DEPENDENCY_DESCRIPTOR_READER_H_