b4015689b8
Create a copy of flexfec_header_reader_writer for changing the implementation according to updated RFC. The fork is needed, since the updated RFC is incompatible with flexfec-03. In the updated RFC, we receive the list and the number of protected ssrcs from the RTP header (from it's CSRCs , and CSRC count fields). This Change is only a copy of the existing files. This will make it easier to understand the changes to the implementation in the next change sets. Bug: webrtc:15002 Change-Id: I31bf5eca0d8f3cb23b4caabb477897eeb0ca6d96 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/303240 Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Commit-Queue: Rasmus Brandt <brandtr@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#40103}
89 lines
3.9 KiB
C++
89 lines
3.9 KiB
C++
/*
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* Copyright (c) 2023 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef MODULES_RTP_RTCP_SOURCE_FLEXFEC_HEADER_READER_WRITER2_H_
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#define MODULES_RTP_RTCP_SOURCE_FLEXFEC_HEADER_READER_WRITER2_H_
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#include <stddef.h>
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#include <stdint.h>
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#include "modules/rtp_rtcp/source/forward_error_correction.h"
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namespace webrtc {
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// FlexFEC header, minimum 20 bytes.
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// 0 1 2 3
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 0 |R|F|P|X| CC |M| PT recovery | length recovery |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 4 | TS recovery |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 8 | SSRCCount | reserved |
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// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
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// 12 | SSRC_i |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 16 | SN base_i |k| Mask [0-14] |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 20 |k| Mask [15-45] (optional) |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 24 |k| |
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// +-+ Mask [46-108] (optional) |
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// 28 | |
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// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
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// : ... next in SSRC_i ... :
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//
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//
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// FlexFEC header in 'inflexible' mode (F = 1), 20 bytes.
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// 0 1 2 3
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 0 |0|1|P|X| CC |M| PT recovery | length recovery |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 4 | TS recovery |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 8 | SSRCCount | reserved |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 12 | SSRC_i |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// 16 | SN base_i | M (columns) | N (rows) |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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class FlexfecHeaderReader2 : public FecHeaderReader {
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public:
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FlexfecHeaderReader2();
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~FlexfecHeaderReader2() override;
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bool ReadFecHeader(
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ForwardErrorCorrection::ReceivedFecPacket* fec_packet) const override;
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};
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class FlexfecHeaderWriter2 : public FecHeaderWriter {
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public:
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FlexfecHeaderWriter2();
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~FlexfecHeaderWriter2() override;
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size_t MinPacketMaskSize(const uint8_t* packet_mask,
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size_t packet_mask_size) const override;
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size_t FecHeaderSize(size_t packet_mask_row_size) const override;
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void FinalizeFecHeader(
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uint32_t media_ssrc,
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uint16_t seq_num_base,
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const uint8_t* packet_mask,
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size_t packet_mask_size,
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ForwardErrorCorrection::Packet* fec_packet) const override;
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};
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} // namespace webrtc
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#endif // MODULES_RTP_RTCP_SOURCE_FLEXFEC_HEADER_READER_WRITER2_H_
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