| /* |
| * Copyright (c) 2016 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_header_extensions.h" |
| |
| #include "modules/rtp_rtcp/include/rtp_cvo.h" |
| #include "modules/rtp_rtcp/source/byte_io.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/logging.h" |
| |
| namespace webrtc { |
| // Absolute send time in RTP streams. |
| // |
| // The absolute send time is signaled to the receiver in-band using the |
| // general mechanism for RTP header extensions [RFC8285]. The payload |
| // of this extension (the transmitted value) is a 24-bit unsigned integer |
| // containing the sender's current time in seconds as a fixed point number |
| // with 18 bits fractional part. |
| // |
| // The form of the absolute send time extension block: |
| // |
| // 0 1 2 3 |
| // 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 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=2 | absolute send time | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr RTPExtensionType AbsoluteSendTime::kId; |
| constexpr uint8_t AbsoluteSendTime::kValueSizeBytes; |
| constexpr const char AbsoluteSendTime::kUri[]; |
| |
| bool AbsoluteSendTime::Parse(rtc::ArrayView<const uint8_t> data, |
| uint32_t* time_24bits) { |
| if (data.size() != 3) |
| return false; |
| *time_24bits = ByteReader<uint32_t, 3>::ReadBigEndian(data.data()); |
| return true; |
| } |
| |
| bool AbsoluteSendTime::Write(rtc::ArrayView<uint8_t> data, |
| uint32_t time_24bits) { |
| RTC_DCHECK_EQ(data.size(), 3); |
| RTC_DCHECK_LE(time_24bits, 0x00FFFFFF); |
| ByteWriter<uint32_t, 3>::WriteBigEndian(data.data(), time_24bits); |
| return true; |
| } |
| |
| // An RTP Header Extension for Client-to-Mixer Audio Level Indication |
| // |
| // https://datatracker.ietf.org/doc/draft-lennox-avt-rtp-audio-level-exthdr/ |
| // |
| // The form of the audio level extension block: |
| // |
| // 0 1 |
| // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=0 |V| level | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // |
| constexpr RTPExtensionType AudioLevel::kId; |
| constexpr uint8_t AudioLevel::kValueSizeBytes; |
| constexpr const char AudioLevel::kUri[]; |
| |
| bool AudioLevel::Parse(rtc::ArrayView<const uint8_t> data, |
| bool* voice_activity, |
| uint8_t* audio_level) { |
| if (data.size() != 1) |
| return false; |
| *voice_activity = (data[0] & 0x80) != 0; |
| *audio_level = data[0] & 0x7F; |
| return true; |
| } |
| |
| bool AudioLevel::Write(rtc::ArrayView<uint8_t> data, |
| bool voice_activity, |
| uint8_t audio_level) { |
| RTC_DCHECK_EQ(data.size(), 1); |
| RTC_CHECK_LE(audio_level, 0x7f); |
| data[0] = (voice_activity ? 0x80 : 0x00) | audio_level; |
| return true; |
| } |
| |
| // From RFC 5450: Transmission Time Offsets in RTP Streams. |
| // |
| // The transmission time is signaled to the receiver in-band using the |
| // general mechanism for RTP header extensions [RFC8285]. The payload |
| // of this extension (the transmitted value) is a 24-bit signed integer. |
| // When added to the RTP timestamp of the packet, it represents the |
| // "effective" RTP transmission time of the packet, on the RTP |
| // timescale. |
| // |
| // The form of the transmission offset extension block: |
| // |
| // 0 1 2 3 |
| // 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 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=2 | transmission offset | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr RTPExtensionType TransmissionOffset::kId; |
| constexpr uint8_t TransmissionOffset::kValueSizeBytes; |
| constexpr const char TransmissionOffset::kUri[]; |
| |
| bool TransmissionOffset::Parse(rtc::ArrayView<const uint8_t> data, |
| int32_t* rtp_time) { |
| if (data.size() != 3) |
| return false; |
| *rtp_time = ByteReader<int32_t, 3>::ReadBigEndian(data.data()); |
| return true; |
| } |
| |
| bool TransmissionOffset::Write(rtc::ArrayView<uint8_t> data, int32_t rtp_time) { |
| RTC_DCHECK_EQ(data.size(), 3); |
| RTC_DCHECK_LE(rtp_time, 0x00ffffff); |
| ByteWriter<int32_t, 3>::WriteBigEndian(data.data(), rtp_time); |
| return true; |
| } |
| |
| // 0 1 2 |
| // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | L=1 |transport wide sequence number | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr RTPExtensionType TransportSequenceNumber::kId; |
| constexpr uint8_t TransportSequenceNumber::kValueSizeBytes; |
| constexpr const char TransportSequenceNumber::kUri[]; |
| |
| bool TransportSequenceNumber::Parse(rtc::ArrayView<const uint8_t> data, |
| uint16_t* value) { |
| if (data.size() != 2) |
| return false; |
| *value = ByteReader<uint16_t>::ReadBigEndian(data.data()); |
| return true; |
| } |
| |
| bool TransportSequenceNumber::Write(rtc::ArrayView<uint8_t> data, |
| uint16_t value) { |
| RTC_DCHECK_EQ(data.size(), 2); |
| ByteWriter<uint16_t>::WriteBigEndian(data.data(), value); |
| return true; |
| } |
| |
| // Coordination of Video Orientation in RTP streams. |
| // |
| // Coordination of Video Orientation consists in signaling of the current |
| // orientation of the image captured on the sender side to the receiver for |
| // appropriate rendering and displaying. |
| // |
| // 0 1 |
| // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=0 |0 0 0 0 C F R R| |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr RTPExtensionType VideoOrientation::kId; |
| constexpr uint8_t VideoOrientation::kValueSizeBytes; |
| constexpr const char VideoOrientation::kUri[]; |
| |
| bool VideoOrientation::Parse(rtc::ArrayView<const uint8_t> data, |
| VideoRotation* rotation) { |
| if (data.size() != 1) |
| return false; |
| *rotation = ConvertCVOByteToVideoRotation(data[0]); |
| return true; |
| } |
| |
| bool VideoOrientation::Write(rtc::ArrayView<uint8_t> data, |
| VideoRotation rotation) { |
| RTC_DCHECK_EQ(data.size(), 1); |
| data[0] = ConvertVideoRotationToCVOByte(rotation); |
| return true; |
| } |
| |
| bool VideoOrientation::Parse(rtc::ArrayView<const uint8_t> data, |
| uint8_t* value) { |
| if (data.size() != 1) |
| return false; |
| *value = data[0]; |
| return true; |
| } |
| |
| bool VideoOrientation::Write(rtc::ArrayView<uint8_t> data, uint8_t value) { |
| RTC_DCHECK_EQ(data.size(), 1); |
| data[0] = value; |
| return true; |
| } |
| |
| // 0 1 2 3 |
| // 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 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=2 | MIN delay | MAX delay | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr RTPExtensionType PlayoutDelayLimits::kId; |
| constexpr uint8_t PlayoutDelayLimits::kValueSizeBytes; |
| constexpr const char PlayoutDelayLimits::kUri[]; |
| |
| bool PlayoutDelayLimits::Parse(rtc::ArrayView<const uint8_t> data, |
| PlayoutDelay* playout_delay) { |
| RTC_DCHECK(playout_delay); |
| if (data.size() != 3) |
| return false; |
| uint32_t raw = ByteReader<uint32_t, 3>::ReadBigEndian(data.data()); |
| uint16_t min_raw = (raw >> 12); |
| uint16_t max_raw = (raw & 0xfff); |
| if (min_raw > max_raw) |
| return false; |
| playout_delay->min_ms = min_raw * kGranularityMs; |
| playout_delay->max_ms = max_raw * kGranularityMs; |
| return true; |
| } |
| |
| bool PlayoutDelayLimits::Write(rtc::ArrayView<uint8_t> data, |
| const PlayoutDelay& playout_delay) { |
| RTC_DCHECK_EQ(data.size(), 3); |
| RTC_DCHECK_LE(0, playout_delay.min_ms); |
| RTC_DCHECK_LE(playout_delay.min_ms, playout_delay.max_ms); |
| RTC_DCHECK_LE(playout_delay.max_ms, kMaxMs); |
| // Convert MS to value to be sent on extension header. |
| uint32_t min_delay = playout_delay.min_ms / kGranularityMs; |
| uint32_t max_delay = playout_delay.max_ms / kGranularityMs; |
| ByteWriter<uint32_t, 3>::WriteBigEndian(data.data(), |
| (min_delay << 12) | max_delay); |
| return true; |
| } |
| |
| // Video Content Type. |
| // |
| // E.g. default video or screenshare. |
| // |
| // 0 1 |
| // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=0 | Content type | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| constexpr RTPExtensionType VideoContentTypeExtension::kId; |
| constexpr uint8_t VideoContentTypeExtension::kValueSizeBytes; |
| constexpr const char VideoContentTypeExtension::kUri[]; |
| |
| bool VideoContentTypeExtension::Parse(rtc::ArrayView<const uint8_t> data, |
| VideoContentType* content_type) { |
| if (data.size() == 1 && |
| videocontenttypehelpers::IsValidContentType(data[0])) { |
| *content_type = static_cast<VideoContentType>(data[0]); |
| return true; |
| } |
| return false; |
| } |
| |
| bool VideoContentTypeExtension::Write(rtc::ArrayView<uint8_t> data, |
| VideoContentType content_type) { |
| RTC_DCHECK_EQ(data.size(), 1); |
| data[0] = static_cast<uint8_t>(content_type); |
| return true; |
| } |
| |
| // Video Timing. |
| // 6 timestamps in milliseconds counted from capture time stored in rtp header: |
| // encode start/finish, packetization complete, pacer exit and reserved for |
| // modification by the network modification. |flags| is a bitmask and has the |
| // following allowed values: |
| // 0 = Valid data, but no flags available (backwards compatibility) |
| // 1 = Frame marked as timing frame due to cyclic timer. |
| // 2 = Frame marked as timing frame due to size being outside limit. |
| // 255 = Invalid. The whole timing frame extension should be ignored. |
| // |
| // 0 1 2 3 |
| // 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 2 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | len=12| flags | encode start ms delta | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | encode finish ms delta | packetizer finish ms delta | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | pacer exit ms delta | network timestamp ms delta | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | network2 timestamp ms delta | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| constexpr RTPExtensionType VideoTimingExtension::kId; |
| constexpr uint8_t VideoTimingExtension::kValueSizeBytes; |
| constexpr const char VideoTimingExtension::kUri[]; |
| |
| bool VideoTimingExtension::Parse(rtc::ArrayView<const uint8_t> data, |
| VideoSendTiming* timing) { |
| RTC_DCHECK(timing); |
| // TODO(sprang): Deprecate support for old wire format. |
| ptrdiff_t off = 0; |
| switch (data.size()) { |
| case kValueSizeBytes - 1: |
| timing->flags = 0; |
| off = 1; // Old wire format without the flags field. |
| break; |
| case kValueSizeBytes: |
| timing->flags = ByteReader<uint8_t>::ReadBigEndian(data.data()); |
| break; |
| default: |
| return false; |
| } |
| |
| timing->encode_start_delta_ms = ByteReader<uint16_t>::ReadBigEndian( |
| data.data() + VideoSendTiming::kEncodeStartDeltaOffset - off); |
| timing->encode_finish_delta_ms = ByteReader<uint16_t>::ReadBigEndian( |
| data.data() + VideoSendTiming::kEncodeFinishDeltaOffset - off); |
| timing->packetization_finish_delta_ms = ByteReader<uint16_t>::ReadBigEndian( |
| data.data() + VideoSendTiming::kPacketizationFinishDeltaOffset - off); |
| timing->pacer_exit_delta_ms = ByteReader<uint16_t>::ReadBigEndian( |
| data.data() + VideoSendTiming::kPacerExitDeltaOffset - off); |
| timing->network_timestamp_delta_ms = ByteReader<uint16_t>::ReadBigEndian( |
| data.data() + VideoSendTiming::kNetworkTimestampDeltaOffset - off); |
| timing->network2_timestamp_delta_ms = ByteReader<uint16_t>::ReadBigEndian( |
| data.data() + VideoSendTiming::kNetwork2TimestampDeltaOffset - off); |
| return true; |
| } |
| |
| bool VideoTimingExtension::Write(rtc::ArrayView<uint8_t> data, |
| const VideoSendTiming& timing) { |
| RTC_DCHECK_EQ(data.size(), 1 + 2 * 6); |
| ByteWriter<uint8_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kFlagsOffset, timing.flags); |
| ByteWriter<uint16_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kEncodeStartDeltaOffset, |
| timing.encode_start_delta_ms); |
| ByteWriter<uint16_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kEncodeFinishDeltaOffset, |
| timing.encode_finish_delta_ms); |
| ByteWriter<uint16_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kPacketizationFinishDeltaOffset, |
| timing.packetization_finish_delta_ms); |
| ByteWriter<uint16_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kPacerExitDeltaOffset, |
| timing.pacer_exit_delta_ms); |
| ByteWriter<uint16_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kNetworkTimestampDeltaOffset, |
| timing.network_timestamp_delta_ms); |
| ByteWriter<uint16_t>::WriteBigEndian( |
| data.data() + VideoSendTiming::kNetwork2TimestampDeltaOffset, |
| timing.network2_timestamp_delta_ms); |
| return true; |
| } |
| |
| bool VideoTimingExtension::Write(rtc::ArrayView<uint8_t> data, |
| uint16_t time_delta_ms, |
| uint8_t offset) { |
| RTC_DCHECK_GE(data.size(), offset + 2); |
| RTC_DCHECK_LE(offset, kValueSizeBytes - sizeof(uint16_t)); |
| ByteWriter<uint16_t>::WriteBigEndian(data.data() + offset, time_delta_ms); |
| return true; |
| } |
| |
| // Frame Marking. |
| // |
| // Meta-information about an RTP stream outside the encrypted media payload, |
| // useful for an RTP switch to do codec-agnostic selective forwarding |
| // without decrypting the payload. |
| // |
| // For non-scalable streams: |
| // 0 1 |
| // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | L = 0 |S|E|I|D|0 0 0 0| |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // |
| // For scalable streams: |
| // 0 1 2 3 |
| // 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 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | ID | L = 2 |S|E|I|D|B| TID | LID | TL0PICIDX | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| constexpr RTPExtensionType FrameMarkingExtension::kId; |
| constexpr const char FrameMarkingExtension::kUri[]; |
| |
| bool FrameMarkingExtension::IsScalable(uint8_t temporal_id, uint8_t layer_id) { |
| return temporal_id != kNoTemporalIdx || layer_id != kNoSpatialIdx; |
| } |
| |
| bool FrameMarkingExtension::Parse(rtc::ArrayView<const uint8_t> data, |
| FrameMarking* frame_marking) { |
| RTC_DCHECK(frame_marking); |
| |
| if (data.size() != 1 && data.size() != 3) |
| return false; |
| |
| frame_marking->start_of_frame = (data[0] & 0x80) != 0; |
| frame_marking->end_of_frame = (data[0] & 0x40) != 0; |
| frame_marking->independent_frame = (data[0] & 0x20) != 0; |
| frame_marking->discardable_frame = (data[0] & 0x10) != 0; |
| |
| if (data.size() == 3) { |
| frame_marking->base_layer_sync = (data[0] & 0x08) != 0; |
| frame_marking->temporal_id = data[0] & 0x7; |
| frame_marking->layer_id = data[1]; |
| frame_marking->tl0_pic_idx = data[2]; |
| } else { |
| // non-scalable |
| frame_marking->base_layer_sync = false; |
| frame_marking->temporal_id = kNoTemporalIdx; |
| frame_marking->layer_id = kNoSpatialIdx; |
| frame_marking->tl0_pic_idx = 0; |
| } |
| return true; |
| } |
| |
| size_t FrameMarkingExtension::ValueSize(const FrameMarking& frame_marking) { |
| if (IsScalable(frame_marking.temporal_id, frame_marking.layer_id)) |
| return 3; |
| else |
| return 1; |
| } |
| |
| bool FrameMarkingExtension::Write(rtc::ArrayView<uint8_t> data, |
| const FrameMarking& frame_marking) { |
| RTC_DCHECK_GE(data.size(), 1); |
| RTC_CHECK_LE(frame_marking.temporal_id, 0x07); |
| data[0] = frame_marking.start_of_frame ? 0x80 : 0x00; |
| data[0] |= frame_marking.end_of_frame ? 0x40 : 0x00; |
| data[0] |= frame_marking.independent_frame ? 0x20 : 0x00; |
| data[0] |= frame_marking.discardable_frame ? 0x10 : 0x00; |
| |
| if (IsScalable(frame_marking.temporal_id, frame_marking.layer_id)) { |
| RTC_DCHECK_EQ(data.size(), 3); |
| data[0] |= frame_marking.base_layer_sync ? 0x08 : 0x00; |
| data[0] |= frame_marking.temporal_id & 0x07; |
| data[1] = frame_marking.layer_id; |
| data[2] = frame_marking.tl0_pic_idx; |
| } |
| return true; |
| } |
| |
| bool BaseRtpStringExtension::Parse(rtc::ArrayView<const uint8_t> data, |
| StringRtpHeaderExtension* str) { |
| if (data.empty() || data[0] == 0) // Valid string extension can't be empty. |
| return false; |
| str->Set(data); |
| RTC_DCHECK(!str->empty()); |
| return true; |
| } |
| |
| bool BaseRtpStringExtension::Write(rtc::ArrayView<uint8_t> data, |
| const StringRtpHeaderExtension& str) { |
| RTC_DCHECK_EQ(data.size(), str.size()); |
| RTC_DCHECK_GE(str.size(), 1); |
| RTC_DCHECK_LE(str.size(), StringRtpHeaderExtension::kMaxSize); |
| memcpy(data.data(), str.data(), str.size()); |
| return true; |
| } |
| |
| bool BaseRtpStringExtension::Parse(rtc::ArrayView<const uint8_t> data, |
| std::string* str) { |
| if (data.empty() || data[0] == 0) // Valid string extension can't be empty. |
| return false; |
| const char* cstr = reinterpret_cast<const char*>(data.data()); |
| // If there is a \0 character in the middle of the |data|, treat it as end |
| // of the string. Well-formed string extensions shouldn't contain it. |
| str->assign(cstr, strnlen(cstr, data.size())); |
| RTC_DCHECK(!str->empty()); |
| return true; |
| } |
| |
| bool BaseRtpStringExtension::Write(rtc::ArrayView<uint8_t> data, |
| const std::string& str) { |
| RTC_DCHECK_EQ(data.size(), str.size()); |
| RTC_DCHECK_GE(str.size(), 1); |
| RTC_DCHECK_LE(str.size(), StringRtpHeaderExtension::kMaxSize); |
| memcpy(data.data(), str.data(), str.size()); |
| return true; |
| } |
| |
| // Constant declarations for string RTP header extension types. |
| |
| constexpr RTPExtensionType RtpStreamId::kId; |
| constexpr const char RtpStreamId::kUri[]; |
| |
| constexpr RTPExtensionType RepairedRtpStreamId::kId; |
| constexpr const char RepairedRtpStreamId::kUri[]; |
| |
| constexpr RTPExtensionType RtpMid::kId; |
| constexpr const char RtpMid::kUri[]; |
| |
| } // namespace webrtc |
