| /* |
| * Copyright (c) 2012 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_sender_audio.h" |
| |
| #include <string.h> |
| |
| #include <memory> |
| #include <optional> |
| #include <utility> |
| #include <vector> |
| |
| #include "absl/strings/match.h" |
| #include "api/audio_codecs/audio_format.h" |
| #include "api/rtp_headers.h" |
| #include "modules/audio_coding/include/audio_coding_module_typedefs.h" |
| #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h" |
| #include "modules/rtp_rtcp/source/absolute_capture_time_sender.h" |
| #include "modules/rtp_rtcp/source/byte_io.h" |
| #include "modules/rtp_rtcp/source/ntp_time_util.h" |
| #include "modules/rtp_rtcp/source/rtp_header_extensions.h" |
| #include "modules/rtp_rtcp/source/rtp_packet.h" |
| #include "modules/rtp_rtcp/source/rtp_packet_to_send.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/logging.h" |
| #include "rtc_base/numerics/safe_conversions.h" |
| #include "system_wrappers/include/ntp_time.h" |
| |
| namespace webrtc { |
| |
| RTPSenderAudio::RTPSenderAudio(Clock* clock, RTPSender* rtp_sender) |
| : clock_(clock), |
| rtp_sender_(rtp_sender), |
| absolute_capture_time_sender_(clock) { |
| RTC_DCHECK(clock_); |
| } |
| |
| RTPSenderAudio::~RTPSenderAudio() {} |
| |
| int32_t RTPSenderAudio::RegisterAudioPayload(absl::string_view payload_name, |
| const int8_t payload_type, |
| const uint32_t frequency, |
| const size_t /* channels */, |
| const uint32_t /* rate */) { |
| if (absl::EqualsIgnoreCase(payload_name, "cn")) { |
| MutexLock lock(&send_audio_mutex_); |
| // we can have multiple CNG payload types |
| switch (frequency) { |
| case 8000: |
| cngnb_payload_type_ = payload_type; |
| break; |
| case 16000: |
| cngwb_payload_type_ = payload_type; |
| break; |
| case 32000: |
| cngswb_payload_type_ = payload_type; |
| break; |
| case 48000: |
| cngfb_payload_type_ = payload_type; |
| break; |
| default: |
| return -1; |
| } |
| } else if (absl::EqualsIgnoreCase(payload_name, "telephone-event")) { |
| MutexLock lock(&send_audio_mutex_); |
| // Don't add it to the list |
| // we dont want to allow send with a DTMF payloadtype |
| dtmf_payload_type_ = payload_type; |
| dtmf_payload_freq_ = frequency; |
| return 0; |
| } else if (payload_name == "audio") { |
| MutexLock lock(&send_audio_mutex_); |
| encoder_rtp_timestamp_frequency_ = rtc::dchecked_cast<int>(frequency); |
| return 0; |
| } |
| return 0; |
| } |
| |
| bool RTPSenderAudio::MarkerBit(AudioFrameType frame_type, int8_t payload_type) { |
| MutexLock lock(&send_audio_mutex_); |
| // for audio true for first packet in a speech burst |
| bool marker_bit = false; |
| if (last_payload_type_ != payload_type) { |
| if (payload_type != -1 && (cngnb_payload_type_ == payload_type || |
| cngwb_payload_type_ == payload_type || |
| cngswb_payload_type_ == payload_type || |
| cngfb_payload_type_ == payload_type)) { |
| // Only set a marker bit when we change payload type to a non CNG |
| return false; |
| } |
| |
| // payload_type differ |
| if (last_payload_type_ == -1) { |
| if (frame_type != AudioFrameType::kAudioFrameCN) { |
| // first packet and NOT CNG |
| return true; |
| } else { |
| // first packet and CNG |
| inband_vad_active_ = true; |
| return false; |
| } |
| } |
| |
| // not first packet AND |
| // not CNG AND |
| // payload_type changed |
| |
| // set a marker bit when we change payload type |
| marker_bit = true; |
| } |
| |
| // For G.723 G.729, AMR etc we can have inband VAD |
| if (frame_type == AudioFrameType::kAudioFrameCN) { |
| inband_vad_active_ = true; |
| } else if (inband_vad_active_) { |
| inband_vad_active_ = false; |
| marker_bit = true; |
| } |
| return marker_bit; |
| } |
| |
| bool RTPSenderAudio::SendAudio(const RtpAudioFrame& frame) { |
| RTC_DCHECK_GE(frame.payload_id, 0); |
| RTC_DCHECK_LE(frame.payload_id, 127); |
| |
| // From RFC 4733: |
| // A source has wide latitude as to how often it sends event updates. A |
| // natural interval is the spacing between non-event audio packets. [...] |
| // Alternatively, a source MAY decide to use a different spacing for event |
| // updates, with a value of 50 ms RECOMMENDED. |
| constexpr int kDtmfIntervalTimeMs = 50; |
| uint32_t dtmf_payload_freq = 0; |
| std::optional<AbsoluteCaptureTime> absolute_capture_time; |
| { |
| MutexLock lock(&send_audio_mutex_); |
| dtmf_payload_freq = dtmf_payload_freq_; |
| if (frame.capture_time.has_value()) { |
| // Send absolute capture time periodically in order to optimize and save |
| // network traffic. Missing absolute capture times can be interpolated on |
| // the receiving end if sending intervals are small enough. |
| absolute_capture_time = absolute_capture_time_sender_.OnSendPacket( |
| rtp_sender_->SSRC(), frame.rtp_timestamp, |
| // Replace missing value with 0 (invalid frequency), this will trigger |
| // absolute capture time sending. |
| encoder_rtp_timestamp_frequency_.value_or(0), |
| clock_->ConvertTimestampToNtpTime(*frame.capture_time), |
| /*estimated_capture_clock_offset=*/0); |
| } |
| } |
| |
| // Check if we have pending DTMFs to send |
| if (!dtmf_event_is_on_ && dtmf_queue_.PendingDtmf()) { |
| if ((clock_->TimeInMilliseconds() - dtmf_time_last_sent_) > |
| kDtmfIntervalTimeMs) { |
| // New tone to play |
| dtmf_timestamp_ = frame.rtp_timestamp; |
| if (dtmf_queue_.NextDtmf(&dtmf_current_event_)) { |
| dtmf_event_first_packet_sent_ = false; |
| dtmf_length_samples_ = |
| dtmf_current_event_.duration_ms * (dtmf_payload_freq / 1000); |
| dtmf_event_is_on_ = true; |
| } |
| } |
| } |
| |
| // A source MAY send events and coded audio packets for the same time |
| // but we don't support it |
| if (dtmf_event_is_on_) { |
| if (frame.type == AudioFrameType::kEmptyFrame) { |
| // kEmptyFrame is used to drive the DTMF when in CN mode |
| // it can be triggered more frequently than we want to send the |
| // DTMF packets. |
| const unsigned int dtmf_interval_time_rtp = |
| dtmf_payload_freq * kDtmfIntervalTimeMs / 1000; |
| if ((frame.rtp_timestamp - dtmf_timestamp_last_sent_) < |
| dtmf_interval_time_rtp) { |
| // not time to send yet |
| return true; |
| } |
| } |
| dtmf_timestamp_last_sent_ = frame.rtp_timestamp; |
| uint32_t dtmf_duration_samples = frame.rtp_timestamp - dtmf_timestamp_; |
| bool ended = false; |
| bool send = true; |
| |
| if (dtmf_length_samples_ > dtmf_duration_samples) { |
| if (dtmf_duration_samples <= 0) { |
| // Skip send packet at start, since we shouldn't use duration 0 |
| send = false; |
| } |
| } else { |
| ended = true; |
| dtmf_event_is_on_ = false; |
| dtmf_time_last_sent_ = clock_->TimeInMilliseconds(); |
| } |
| if (send) { |
| if (dtmf_duration_samples > 0xffff) { |
| // RFC 4733 2.5.2.3 Long-Duration Events |
| SendTelephoneEventPacket(ended, dtmf_timestamp_, |
| static_cast<uint16_t>(0xffff), false); |
| |
| // set new timestap for this segment |
| dtmf_timestamp_ = frame.rtp_timestamp; |
| dtmf_duration_samples -= 0xffff; |
| dtmf_length_samples_ -= 0xffff; |
| |
| return SendTelephoneEventPacket( |
| ended, dtmf_timestamp_, |
| static_cast<uint16_t>(dtmf_duration_samples), false); |
| } else { |
| if (!SendTelephoneEventPacket(ended, dtmf_timestamp_, |
| dtmf_duration_samples, |
| !dtmf_event_first_packet_sent_)) { |
| return false; |
| } |
| dtmf_event_first_packet_sent_ = true; |
| return true; |
| } |
| } |
| return true; |
| } |
| if (frame.payload.empty()) { |
| if (frame.type == AudioFrameType::kEmptyFrame) { |
| // we don't send empty audio RTP packets |
| // no error since we use it to either drive DTMF when we use VAD, or |
| // enter DTX. |
| return true; |
| } |
| return false; |
| } |
| |
| std::unique_ptr<RtpPacketToSend> packet = |
| rtp_sender_->AllocatePacket(frame.csrcs); |
| packet->SetMarker(MarkerBit(frame.type, frame.payload_id)); |
| packet->SetPayloadType(frame.payload_id); |
| packet->SetTimestamp(frame.rtp_timestamp); |
| packet->set_capture_time(clock_->CurrentTime()); |
| // Set audio level extension, if included. |
| packet->SetExtension<AudioLevelExtension>( |
| AudioLevel(frame.type == AudioFrameType::kAudioFrameSpeech, |
| frame.audio_level_dbov.value_or(127))); |
| |
| if (absolute_capture_time.has_value()) { |
| // It also checks that extension was registered during SDP negotiation. If |
| // not then setter won't do anything. |
| packet->SetExtension<AbsoluteCaptureTimeExtension>(*absolute_capture_time); |
| } |
| |
| uint8_t* payload = packet->AllocatePayload(frame.payload.size()); |
| RTC_CHECK(payload); |
| memcpy(payload, frame.payload.data(), frame.payload.size()); |
| |
| { |
| MutexLock lock(&send_audio_mutex_); |
| last_payload_type_ = frame.payload_id; |
| } |
| packet->set_packet_type(RtpPacketMediaType::kAudio); |
| packet->set_allow_retransmission(true); |
| std::vector<std::unique_ptr<RtpPacketToSend>> packets(1); |
| packets[0] = std::move(packet); |
| rtp_sender_->EnqueuePackets(std::move(packets)); |
| if (first_packet_sent_()) { |
| RTC_LOG(LS_INFO) << "First audio RTP packet sent to pacer"; |
| } |
| return true; |
| } |
| |
| // Send a TelephoneEvent tone using RFC 2833 (4733) |
| int32_t RTPSenderAudio::SendTelephoneEvent(uint8_t key, |
| uint16_t time_ms, |
| uint8_t level) { |
| DtmfQueue::Event event; |
| { |
| MutexLock lock(&send_audio_mutex_); |
| if (dtmf_payload_type_ < 0) { |
| // TelephoneEvent payloadtype not configured |
| return -1; |
| } |
| event.payload_type = dtmf_payload_type_; |
| } |
| event.key = key; |
| event.duration_ms = time_ms; |
| event.level = level; |
| return dtmf_queue_.AddDtmf(event) ? 0 : -1; |
| } |
| |
| bool RTPSenderAudio::SendTelephoneEventPacket(bool ended, |
| uint32_t dtmf_timestamp, |
| uint16_t duration, |
| bool marker_bit) { |
| size_t send_count = ended ? 3 : 1; |
| |
| std::vector<std::unique_ptr<RtpPacketToSend>> packets; |
| packets.reserve(send_count); |
| for (size_t i = 0; i < send_count; ++i) { |
| // Send DTMF data. |
| constexpr RtpPacketToSend::ExtensionManager* kNoExtensions = nullptr; |
| constexpr size_t kDtmfSize = 4; |
| auto packet = std::make_unique<RtpPacketToSend>(kNoExtensions, |
| kRtpHeaderSize + kDtmfSize); |
| packet->SetPayloadType(dtmf_current_event_.payload_type); |
| packet->SetMarker(marker_bit); |
| packet->SetSsrc(rtp_sender_->SSRC()); |
| packet->SetTimestamp(dtmf_timestamp); |
| packet->set_capture_time(clock_->CurrentTime()); |
| |
| // Create DTMF data. |
| uint8_t* dtmfbuffer = packet->AllocatePayload(kDtmfSize); |
| RTC_DCHECK(dtmfbuffer); |
| /* From RFC 2833: |
| 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 |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | event |E|R| volume | duration | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| */ |
| // R bit always cleared |
| uint8_t R = 0x00; |
| uint8_t volume = dtmf_current_event_.level; |
| |
| // First packet un-ended |
| uint8_t E = ended ? 0x80 : 0x00; |
| |
| // First byte is Event number, equals key number |
| dtmfbuffer[0] = dtmf_current_event_.key; |
| dtmfbuffer[1] = E | R | volume; |
| ByteWriter<uint16_t>::WriteBigEndian(dtmfbuffer + 2, duration); |
| |
| packet->set_packet_type(RtpPacketMediaType::kAudio); |
| packet->set_allow_retransmission(true); |
| packets.push_back(std::move(packet)); |
| } |
| rtp_sender_->EnqueuePackets(std::move(packets)); |
| return true; |
| } |
| } // namespace webrtc |
