Multi frequency DTMF support - sender side

webrtc/modules/rtp_rtcp/source/rtp_sender_audio.cc

 /*
  *  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 "webrtc/modules/rtp_rtcp/source/rtp_sender_audio.h"
 
 #include <string.h>
 
 #include <memory>
 #include <utility>
 
 #include "webrtc/base/logging.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/base/trace_event.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/rtp_rtcp/source/byte_io.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_packet_to_send.h"
 
 namespace webrtc {
 
-static const int kDtmfFrequencyHz = 8000;
+static const int kDtmfBaseRateHz = 8000;
 
 RTPSenderAudio::RTPSenderAudio(Clock* clock, RTPSender* rtp_sender)
     : clock_(clock),
-      rtp_sender_(rtp_sender),
-      packet_size_samples_(160),
-      dtmf_event_is_on_(false),
-      dtmf_event_first_packet_sent_(false),
-      dtmf_payload_type_(-1),
-      dtmf_timestamp_(0),
-      dtmf_key_(0),
-      dtmf_length_samples_(0),
-      dtmf_level_(0),
-      dtmf_time_last_sent_(0),
-      dtmf_timestamp_last_sent_(0),
-      inband_vad_active_(false),
-      cngnb_payload_type_(-1),
-      cngwb_payload_type_(-1),
-      cngswb_payload_type_(-1),
-      cngfb_payload_type_(-1),
-      last_payload_type_(-1),
-      audio_level_dbov_(0) {}
+      rtp_sender_(rtp_sender) {}
 
 RTPSenderAudio::~RTPSenderAudio() {}
 
 // set audio packet size, used to determine when it's time to send a DTMF packet
 // in silence (CNG)
 int32_t RTPSenderAudio::SetAudioPacketSize(uint16_t packet_size_samples) {
   rtc::CritScope cs(&send_audio_critsect_);
   packet_size_samples_ = packet_size_samples;
   return 0;
 }
@@ skipping 22 matching lines @@
         cngfb_payload_type_ = payload_type;
         break;
       default:
         return -1;
     }
   } else if (RtpUtility::StringCompare(payloadName, "telephone-event", 15)) {
     rtc::CritScope cs(&send_audio_critsect_);
     // Don't add it to the list
     // we dont want to allow send with a DTMF payloadtype
     dtmf_payload_type_ = payload_type;
+    // Frequency is ignored for DTMF - we're using the same RTP timestamp rate
+    // as the audio codec.
     return 0;
-    // The default timestamp rate is 8000 Hz, but other rates may be defined.
   }
   *payload = new RtpUtility::Payload;
   (*payload)->typeSpecific.Audio.frequency = frequency;
   (*payload)->typeSpecific.Audio.channels = channels;
   (*payload)->typeSpecific.Audio.rate = rate;
   (*payload)->audio = true;
   (*payload)->name[RTP_PAYLOAD_NAME_SIZE - 1] = '\0';
   strncpy((*payload)->name, payloadName, RTP_PAYLOAD_NAME_SIZE - 1);
   return 0;
 }
@@ skipping 41 matching lines @@
   return marker_bit;
 }
 
 bool RTPSenderAudio::SendAudio(FrameType frame_type,
                                int8_t payload_type,
                                uint32_t rtp_timestamp,
                                const uint8_t* payload_data,
                                size_t payload_size,
                                const RTPFragmentationHeader* fragmentation) {
   // TODO(pwestin) Breakup function in smaller functions.
-  uint16_t dtmf_length_ms = 0;
-  uint8_t key = 0;
   uint8_t audio_level_dbov;
-  int8_t dtmf_payload_type;
   uint16_t packet_size_samples;
   {
     rtc::CritScope cs(&send_audio_critsect_);
     audio_level_dbov = audio_level_dbov_;
-    dtmf_payload_type = dtmf_payload_type_;
     packet_size_samples = packet_size_samples_;
   }
 
   // Check if we have pending DTMFs to send
   if (!dtmf_event_is_on_ && dtmf_queue_.PendingDTMF()) {
     int64_t delaySinceLastDTMF =
         clock_->TimeInMilliseconds() - dtmf_time_last_sent_;
 
     if (delaySinceLastDTMF > 100) {
       // New tone to play
       dtmf_timestamp_ = rtp_timestamp;
-      if (dtmf_queue_.NextDTMF(&key, &dtmf_length_ms, &dtmf_level_) >= 0) {
+      if (dtmf_queue_.NextDTMF(&dtmf_current_event_) >= 0) {
         dtmf_event_first_packet_sent_ = false;
-        dtmf_key_ = key;
-        dtmf_length_samples_ = (kDtmfFrequencyHz / 1000) * dtmf_length_ms;
+        dtmf_length_samples_ =
+            (kDtmfBaseRateHz / 1000) * dtmf_current_event_.duration_ms;
         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 == kEmptyFrame) {
       // kEmptyFrame is used to drive the DTMF when in CN mode
@@ skipping 15 matching lines @@
         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_payload_type, dtmf_timestamp_,
+        SendTelephoneEventPacket(ended, dtmf_timestamp_,
                                  static_cast<uint16_t>(0xffff), false);
 
         // set new timestap for this segment
         dtmf_timestamp_ = rtp_timestamp;
         dtmf_duration_samples -= 0xffff;
         dtmf_length_samples_ -= 0xffff;
 
-        return SendTelephoneEventPacket(
-            ended, dtmf_payload_type, dtmf_timestamp_,
+        return SendTelephoneEventPacket(ended, dtmf_timestamp_,
             static_cast<uint16_t>(dtmf_duration_samples), false);
       } else {
-        if (!SendTelephoneEventPacket(ended, dtmf_payload_type, dtmf_timestamp_,
+        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;
   }
@@ skipping 55 matching lines @@
   }
   rtc::CritScope cs(&send_audio_critsect_);
   audio_level_dbov_ = level_dbov;
   return 0;
 }
 
 // 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;
   {
     rtc::CritScope lock(&send_audio_critsect_);
     if (dtmf_payload_type_ < 0) {
       // TelephoneEvent payloadtype not configured
       return -1;
     }
+    event.payload_type = dtmf_payload_type_;
   }
-  return dtmf_queue_.AddDTMF(key, time_ms, level);
+  event.key = key;
+  event.duration_ms = time_ms;
+  event.level = level;
+  return dtmf_queue_.AddDTMF(event);
 }
 
 bool RTPSenderAudio::SendTelephoneEventPacket(bool ended,
-                                              int8_t dtmf_payload_type,
                                               uint32_t dtmf_timestamp,
                                               uint16_t duration,
                                               bool marker_bit) {
   uint8_t send_count = 1;
   bool result = true;
 
   if (ended) {
     // resend last packet in an event 3 times
     send_count = 3;
   }
   do {
     // Send DTMF data.
     constexpr RtpPacketToSend::ExtensionManager* kNoExtensions = nullptr;
     constexpr size_t kDtmfSize = 4;
     std::unique_ptr<RtpPacketToSend> packet(
         new RtpPacketToSend(kNoExtensions, kRtpHeaderSize + kDtmfSize));
-    packet->SetPayloadType(dtmf_payload_type);
+    packet->SetPayloadType(dtmf_current_event_.payload_type);
     packet->SetMarker(marker_bit);
     packet->SetSsrc(rtp_sender_->SSRC());
     packet->SetTimestamp(dtmf_timestamp);
     packet->set_capture_time_ms(clock_->TimeInMilliseconds());
     if (!rtp_sender_->AssignSequenceNumber(packet.get()))
       return false;
 
     // 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_level_;
+    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_key_;
+    dtmfbuffer[0] = dtmf_current_event_.key;
     dtmfbuffer[1] = E | R | volume;
     ByteWriter<uint16_t>::WriteBigEndian(dtmfbuffer + 2, duration);
 
     TRACE_EVENT_INSTANT2(
         TRACE_DISABLED_BY_DEFAULT("webrtc_rtp"), "Audio::SendTelephoneEvent",
         "timestamp", packet->Timestamp(), "seqnum", packet->SequenceNumber());
     result = rtp_sender_->SendToNetwork(std::move(packet), kAllowRetransmission,
                                         RtpPacketSender::kHighPriority);
     send_count--;
   } while (send_count > 0 && result);
 
   return result;
 }
 }  // namespace webrtc