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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:13:27 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:13:27 +0000 |
commit | 40a355a42d4a9444dc753c04c6608dade2f06a23 (patch) | |
tree | 871fc667d2de662f171103ce5ec067014ef85e61 /third_party/libwebrtc/modules/rtp_rtcp/source/rtp_packetizer_h265.cc | |
parent | Adding upstream version 124.0.1. (diff) | |
download | firefox-40a355a42d4a9444dc753c04c6608dade2f06a23.tar.xz firefox-40a355a42d4a9444dc753c04c6608dade2f06a23.zip |
Adding upstream version 125.0.1.upstream/125.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/modules/rtp_rtcp/source/rtp_packetizer_h265.cc')
-rw-r--r-- | third_party/libwebrtc/modules/rtp_rtcp/source/rtp_packetizer_h265.cc | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/rtp_rtcp/source/rtp_packetizer_h265.cc b/third_party/libwebrtc/modules/rtp_rtcp/source/rtp_packetizer_h265.cc new file mode 100644 index 0000000000..313680cc87 --- /dev/null +++ b/third_party/libwebrtc/modules/rtp_rtcp/source/rtp_packetizer_h265.cc @@ -0,0 +1,350 @@ +/* + * Copyright (c) 2023 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. + */ + +#include "modules/rtp_rtcp/source/rtp_packetizer_h265.h" + +#include <vector> + +#include "absl/types/optional.h" +#include "common_video/h264/h264_common.h" +#include "common_video/h265/h265_common.h" +#include "modules/rtp_rtcp/source/byte_io.h" +#include "rtc_base/logging.h" + +namespace webrtc { +namespace { + +// The payload header consists of the same +// fields (F, Type, LayerId and TID) as the NAL unit header. Refer to +// section 4.2 in RFC 7798. +constexpr size_t kH265PayloadHeaderSize = 2; +// Unlike H.264, H265 NAL header is 2-bytes. +constexpr size_t kH265NalHeaderSize = 2; +// H265's FU is constructed of 2-byte payload header, 1-byte FU header and FU +// payload. +constexpr size_t kH265FuHeaderSize = 1; +// The NALU size for H265 RTP aggregated packet indicates the size of the NAL +// unit is 2-bytes. +constexpr size_t kH265LengthFieldSize = 2; + +enum H265NalHdrMasks { + kH265FBit = 0x80, + kH265TypeMask = 0x7E, + kH265LayerIDHMask = 0x1, + kH265LayerIDLMask = 0xF8, + kH265TIDMask = 0x7, + kH265TypeMaskN = 0x81, + kH265TypeMaskInFuHeader = 0x3F +}; + +// Bit masks for FU headers. +enum H265FuBitmasks { + kH265SBitMask = 0x80, + kH265EBitMask = 0x40, + kH265FuTypeBitMask = 0x3F +}; + +} // namespace + +RtpPacketizerH265::RtpPacketizerH265(rtc::ArrayView<const uint8_t> payload, + PayloadSizeLimits limits) + : limits_(limits), num_packets_left_(0) { + for (const auto& nalu : + H264::FindNaluIndices(payload.data(), payload.size())) { + input_fragments_.push_back( + payload.subview(nalu.payload_start_offset, nalu.payload_size)); + } + + if (!GeneratePackets()) { + // If failed to generate all the packets, discard already generated + // packets in case the caller would ignore return value and still try to + // call NextPacket(). + num_packets_left_ = 0; + while (!packets_.empty()) { + packets_.pop(); + } + } +} + +RtpPacketizerH265::~RtpPacketizerH265() = default; + +size_t RtpPacketizerH265::NumPackets() const { + return num_packets_left_; +} + +bool RtpPacketizerH265::GeneratePackets() { + for (size_t i = 0; i < input_fragments_.size();) { + int fragment_len = input_fragments_[i].size(); + int single_packet_capacity = limits_.max_payload_len; + if (input_fragments_.size() == 1) { + single_packet_capacity -= limits_.single_packet_reduction_len; + } else if (i == 0) { + single_packet_capacity -= limits_.first_packet_reduction_len; + } else if (i + 1 == input_fragments_.size()) { + // Pretend that last fragment is larger instead of making last packet + // smaller. + single_packet_capacity -= limits_.last_packet_reduction_len; + } + if (fragment_len > single_packet_capacity) { + if (!PacketizeFu(i)) { + return false; + } + ++i; + } else { + i = PacketizeAp(i); + } + } + return true; +} + +bool RtpPacketizerH265::PacketizeFu(size_t fragment_index) { + // Fragment payload into packets (FU). + // Strip out the original header and leave room for the FU header. + rtc::ArrayView<const uint8_t> fragment = input_fragments_[fragment_index]; + PayloadSizeLimits limits = limits_; + // Refer to section 4.4.3 in RFC7798, each FU fragment will have a 2-bytes + // payload header and a one-byte FU header. DONL is not supported so ignore + // its size when calculating max_payload_len. + limits.max_payload_len -= kH265FuHeaderSize + kH265PayloadHeaderSize; + + // Update single/first/last packet reductions unless it is single/first/last + // fragment. + if (input_fragments_.size() != 1) { + // if this fragment is put into a single packet, it might still be the + // first or the last packet in the whole sequence of packets. + if (fragment_index == input_fragments_.size() - 1) { + limits.single_packet_reduction_len = limits_.last_packet_reduction_len; + } else if (fragment_index == 0) { + limits.single_packet_reduction_len = limits_.first_packet_reduction_len; + } else { + limits.single_packet_reduction_len = 0; + } + } + if (fragment_index != 0) { + limits.first_packet_reduction_len = 0; + } + if (fragment_index != input_fragments_.size() - 1) { + limits.last_packet_reduction_len = 0; + } + + // Strip out the original header. + size_t payload_left = fragment.size() - kH265NalHeaderSize; + int offset = kH265NalHeaderSize; + + std::vector<int> payload_sizes = SplitAboutEqually(payload_left, limits); + if (payload_sizes.empty()) { + return false; + } + + for (size_t i = 0; i < payload_sizes.size(); ++i) { + int packet_length = payload_sizes[i]; + RTC_CHECK_GT(packet_length, 0); + uint16_t header = (fragment[0] << 8) | fragment[1]; + packets_.push({.source_fragment = fragment.subview(offset, packet_length), + .first_fragment = (i == 0), + .last_fragment = (i == payload_sizes.size() - 1), + .aggregated = false, + .header = header}); + offset += packet_length; + payload_left -= packet_length; + } + num_packets_left_ += payload_sizes.size(); + RTC_CHECK_EQ(payload_left, 0); + return true; +} + +int RtpPacketizerH265::PacketizeAp(size_t fragment_index) { + // Aggregate fragments into one packet. + size_t payload_size_left = limits_.max_payload_len; + if (input_fragments_.size() == 1) { + payload_size_left -= limits_.single_packet_reduction_len; + } else if (fragment_index == 0) { + payload_size_left -= limits_.first_packet_reduction_len; + } + int aggregated_fragments = 0; + size_t fragment_headers_length = 0; + rtc::ArrayView<const uint8_t> fragment = input_fragments_[fragment_index]; + RTC_CHECK_GE(payload_size_left, fragment.size()); + ++num_packets_left_; + + auto payload_size_needed = [&] { + size_t fragment_size = fragment.size() + fragment_headers_length; + if (input_fragments_.size() == 1) { + // Single fragment, single packet, payload_size_left already adjusted + // with limits_.single_packet_reduction_len. + return fragment_size; + } + if (fragment_index == input_fragments_.size() - 1) { + // Last fragment, so this might be the last packet. + return fragment_size + limits_.last_packet_reduction_len; + } + return fragment_size; + }; + + while (payload_size_left >= payload_size_needed()) { + RTC_CHECK_GT(fragment.size(), 0); + packets_.push({.source_fragment = fragment, + .first_fragment = (aggregated_fragments == 0), + .last_fragment = false, + .aggregated = true, + .header = fragment[0]}); + payload_size_left -= fragment.size(); + payload_size_left -= fragment_headers_length; + + fragment_headers_length = kH265LengthFieldSize; + // If we are going to try to aggregate more fragments into this packet + // we need to add the AP NALU header and a length field for the first + // NALU of this packet. + if (aggregated_fragments == 0) { + fragment_headers_length += kH265PayloadHeaderSize + kH265LengthFieldSize; + } + ++aggregated_fragments; + + // Next fragment. + ++fragment_index; + if (fragment_index == input_fragments_.size()) { + break; + } + fragment = input_fragments_[fragment_index]; + } + RTC_CHECK_GT(aggregated_fragments, 0); + packets_.back().last_fragment = true; + return fragment_index; +} + +bool RtpPacketizerH265::NextPacket(RtpPacketToSend* rtp_packet) { + RTC_DCHECK(rtp_packet); + + if (packets_.empty()) { + return false; + } + + PacketUnit packet = packets_.front(); + + if (packet.first_fragment && packet.last_fragment) { + // Single NAL unit packet. Do not support DONL for single NAL unit packets, + // DONL field is not present. + size_t bytes_to_send = packet.source_fragment.size(); + uint8_t* buffer = rtp_packet->AllocatePayload(bytes_to_send); + memcpy(buffer, packet.source_fragment.data(), bytes_to_send); + packets_.pop(); + input_fragments_.pop_front(); + } else if (packet.aggregated) { + NextAggregatePacket(rtp_packet); + } else { + NextFragmentPacket(rtp_packet); + } + rtp_packet->SetMarker(packets_.empty()); + --num_packets_left_; + return true; +} + +void RtpPacketizerH265::NextAggregatePacket(RtpPacketToSend* rtp_packet) { + size_t payload_capacity = rtp_packet->FreeCapacity(); + RTC_CHECK_GE(payload_capacity, kH265PayloadHeaderSize); + uint8_t* buffer = rtp_packet->AllocatePayload(payload_capacity); + RTC_CHECK(buffer); + PacketUnit* packet = &packets_.front(); + RTC_CHECK(packet->first_fragment); + + /* + +---------------+---------------+ + |0|1|2|3|4|5|6|7|0|1|2|3|4|5|6|7| + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |F| Type | LayerId | TID | + +-------------+-----------------+ + */ + // Refer to section section 4.4.2 for aggregation packets and modify type to + // 48 in PayloadHdr for aggregate packet. Do not support DONL for aggregation + // packets, DONL field is not present. + uint8_t payload_hdr_h = packet->header >> 8; + uint8_t payload_hdr_l = packet->header & 0xFF; + uint8_t layer_id_h = payload_hdr_h & kH265LayerIDHMask; + payload_hdr_h = (payload_hdr_h & kH265TypeMaskN) | + (H265::NaluType::kAp << 1) | layer_id_h; + buffer[0] = payload_hdr_h; + buffer[1] = payload_hdr_l; + + int index = kH265PayloadHeaderSize; + bool is_last_fragment = packet->last_fragment; + while (packet->aggregated) { + // Add NAL unit length field. + rtc::ArrayView<const uint8_t> fragment = packet->source_fragment; + ByteWriter<uint16_t>::WriteBigEndian(&buffer[index], fragment.size()); + index += kH265LengthFieldSize; + // Add NAL unit. + memcpy(&buffer[index], fragment.data(), fragment.size()); + index += fragment.size(); + packets_.pop(); + input_fragments_.pop_front(); + if (is_last_fragment) { + break; + } + packet = &packets_.front(); + is_last_fragment = packet->last_fragment; + } + RTC_CHECK(is_last_fragment); + rtp_packet->SetPayloadSize(index); +} + +void RtpPacketizerH265::NextFragmentPacket(RtpPacketToSend* rtp_packet) { + PacketUnit* packet = &packets_.front(); + // NAL unit fragmented over multiple packets (FU). + // We do not send original NALU header, so it will be replaced by the + // PayloadHdr of the first packet. + /* + +---------------+---------------+ + |0|1|2|3|4|5|6|7|0|1|2|3|4|5|6|7| + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |F| Type | LayerId | TID | + +-------------+-----------------+ + */ + // Refer to section section 4.4.3 for aggregation packets and modify type to + // 49 in PayloadHdr for aggregate packet. + uint8_t payload_hdr_h = + packet->header >> 8; // 1-bit F, 6-bit type, 1-bit layerID highest-bit + uint8_t payload_hdr_l = packet->header & 0xFF; + uint8_t layer_id_h = payload_hdr_h & kH265LayerIDHMask; + uint8_t fu_header = 0; + /* + +---------------+ + |0|1|2|3|4|5|6|7| + +-+-+-+-+-+-+-+-+ + |S|E| FuType | + +---------------+ + */ + // S bit indicates the start of a fragmented NAL unit. + // E bit indicates the end of a fragmented NAL unit. + // FuType must be equal to the field type value of the fragmented NAL unit. + fu_header |= (packet->first_fragment ? kH265SBitMask : 0); + fu_header |= (packet->last_fragment ? kH265EBitMask : 0); + uint8_t type = (payload_hdr_h & kH265TypeMask) >> 1; + fu_header |= type; + // Now update payload_hdr_h with FU type. + payload_hdr_h = (payload_hdr_h & kH265TypeMaskN) | + (H265::NaluType::kFu << 1) | layer_id_h; + rtc::ArrayView<const uint8_t> fragment = packet->source_fragment; + uint8_t* buffer = rtp_packet->AllocatePayload( + kH265FuHeaderSize + kH265PayloadHeaderSize + fragment.size()); + RTC_CHECK(buffer); + buffer[0] = payload_hdr_h; + buffer[1] = payload_hdr_l; + buffer[2] = fu_header; + + // Do not support DONL for fragmentation units, DONL field is not present. + memcpy(buffer + kH265FuHeaderSize + kH265PayloadHeaderSize, fragment.data(), + fragment.size()); + if (packet->last_fragment) { + input_fragments_.pop_front(); + } + packets_.pop(); +} + +} // namespace webrtc |