webrtc/modules/rtp_rtcp/source/rtp_dependency_descriptor_writer.h
Danil Chapovalov e3296b6d4c Ignore inactive chains when writing DependencyDescriptor rtp header extension.
To implement rule
"Chains protecting no active decode targets MUST be ignored."
from https://aomediacodec.github.io/av1-rtp-spec/#a44-switching

Bug: webrtc:10342
Change-Id: Ibe5e0b7b6ab8955419d0d9f996c6397f442e1cda
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/177668
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31566}
2020-06-25 14:59:38 +00:00

89 lines
3.1 KiB
C++

/*
* 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_WRITER_H_
#define MODULES_RTP_RTCP_SOURCE_RTP_DEPENDENCY_DESCRIPTOR_WRITER_H_
#include <bitset>
#include <cstddef>
#include <cstdint>
#include <vector>
#include "api/array_view.h"
#include "api/transport/rtp/dependency_descriptor.h"
#include "rtc_base/bit_buffer.h"
namespace webrtc {
class RtpDependencyDescriptorWriter {
public:
// Assumes |structure| and |descriptor| are valid and
// |descriptor| matches the |structure|.
RtpDependencyDescriptorWriter(rtc::ArrayView<uint8_t> data,
const FrameDependencyStructure& structure,
std::bitset<32> active_chains,
const DependencyDescriptor& descriptor);
// Serializes DependencyDescriptor rtp header extension.
// Returns false if |data| is too small to serialize the |descriptor|.
bool Write();
// Returns minimum number of bits needed to serialize descriptor with respect
// to the |structure|. Returns 0 if |descriptor| can't be serialized.
int ValueSizeBits() const;
private:
// Used both as pointer to the template and as index in the templates vector.
using TemplateIterator = std::vector<FrameDependencyTemplate>::const_iterator;
struct TemplateMatch {
TemplateIterator template_position;
bool need_custom_dtis;
bool need_custom_fdiffs;
bool need_custom_chains;
// Size in bits to store frame-specific details, i.e.
// excluding mandatory fields and template dependency structure.
int extra_size_bits;
};
int StructureSizeBits() const;
TemplateMatch CalculateMatch(TemplateIterator frame_template) const;
void FindBestTemplate();
bool ShouldWriteActiveDecodeTargetsBitmask() const;
bool HasExtendedFields() const;
uint64_t TemplateId() const;
void WriteBits(uint64_t val, size_t bit_count);
void WriteNonSymmetric(uint32_t value, uint32_t num_values);
// Functions to read template dependency structure.
void WriteTemplateDependencyStructure();
void WriteTemplateLayers();
void WriteTemplateDtis();
void WriteTemplateFdiffs();
void WriteTemplateChains();
void WriteResolutions();
// Function to read details for the current frame.
void WriteMandatoryFields();
void WriteExtendedFields();
void WriteFrameDependencyDefinition();
void WriteFrameDtis();
void WriteFrameFdiffs();
void WriteFrameChains();
bool build_failed_ = false;
const DependencyDescriptor& descriptor_;
const FrameDependencyStructure& structure_;
std::bitset<32> active_chains_;
rtc::BitBufferWriter bit_writer_;
TemplateMatch best_template_;
};
} // namespace webrtc
#endif // MODULES_RTP_RTCP_SOURCE_RTP_DEPENDENCY_DESCRIPTOR_WRITER_H_