Reland "WebRtcVoiceMediaChannel::AddRecvStream: Don't call SetRecPayloadType"

BUG=webrtc:5805

Review-Url: https://codereview.webrtc.org/2774833003
Cr-Commit-Position: refs/heads/master@{#17391}

webrtc/modules/audio_coding/neteq/decoder_database.cc

@@ -123,6 +123,38 @@ void DecoderDatabase::Reset() {
   active_cng_decoder_type_ = -1;
 }
 
+std::vector<int> DecoderDatabase::SetCodecs(
+    const std::map<int, SdpAudioFormat>& codecs) {
+  // First collect all payload types that we'll remove or reassign, then remove
+  // them from the database.
+  std::vector<int> changed_payload_types;
+  for (const std::pair<uint8_t, const DecoderInfo&> kv : decoders_) {
+    auto i = codecs.find(kv.first);
+    if (i == codecs.end() || i->second != kv.second.GetFormat()) {
+      changed_payload_types.push_back(kv.first);
+    }
+  }
+  for (int pl_type : changed_payload_types) {
+    Remove(pl_type);
+  }
+
+  // Enter the new and changed payload type mappings into the database.
+  for (const auto& kv : codecs) {
+    const int& rtp_payload_type = kv.first;
+    const SdpAudioFormat& audio_format = kv.second;
+    RTC_DCHECK_GE(rtp_payload_type, 0);
+    RTC_DCHECK_LE(rtp_payload_type, 0x7f);
+    if (decoders_.count(rtp_payload_type) == 0) {
+      decoders_.insert(std::make_pair(
+          rtp_payload_type, DecoderInfo(audio_format, decoder_factory_.get())));
+    } else {
+      // The mapping for this payload type hasn't changed.
+    }
+  }
+
+  return changed_payload_types;
+}
+
 int DecoderDatabase::RegisterPayload(uint8_t rtp_payload_type,
                                      NetEqDecoder codec_type,
                                      const std::string& name) {

webrtc/modules/audio_coding/neteq/decoder_database.h

@@ -149,6 +149,11 @@ class DecoderDatabase {
   // using InsertExternal().
   virtual void Reset();
 
+  // Replaces the existing set of decoders with the given set. Returns the
+  // payload types that were reassigned or removed while doing so.
+  virtual std::vector<int> SetCodecs(
+      const std::map<int, SdpAudioFormat>& codecs);
+
   // Registers |rtp_payload_type| as a decoder of type |codec_type|. The |name|
   // is only used to populate the name field in the DecoderInfo struct in the
   // database, and can be arbitrary (including empty). Returns kOK on success;

webrtc/modules/audio_coding/neteq/include/neteq.h

@@ -157,6 +157,9 @@ class NetEq {
   // Returns kOK on success, or kFail in case of an error.
   virtual int GetAudio(AudioFrame* audio_frame, bool* muted) = 0;
 
+  // Replaces the current set of decoders with the given one.
+  virtual void SetCodecs(const std::map<int, SdpAudioFormat>& codecs) = 0;
+
   // Associates |rtp_payload_type| with |codec| and |codec_name|, and stores the
   // information in the codec database. Returns 0 on success, -1 on failure.
   // The name is only used to provide information back to the caller about the

webrtc/modules/audio_coding/neteq/neteq_impl.cc

@@ -212,6 +212,15 @@ int NetEqImpl::GetAudio(AudioFrame* audio_frame, bool* muted) {
   return kOK;
 }
 
+void NetEqImpl::SetCodecs(const std::map<int, SdpAudioFormat>& codecs) {
+  rtc::CritScope lock(&crit_sect_);
+  const std::vector<int> changed_payload_types =
+      decoder_database_->SetCodecs(codecs);
+  for (const int pt : changed_payload_types) {
+    packet_buffer_->DiscardPacketsWithPayloadType(pt);
+  }
+}
+
 int NetEqImpl::RegisterPayloadType(NetEqDecoder codec,
                                    const std::string& name,
                                    uint8_t rtp_payload_type) {

webrtc/modules/audio_coding/neteq/neteq_impl.h

@@ -111,6 +111,8 @@ class NetEqImpl : public webrtc::NetEq {
 
   int GetAudio(AudioFrame* audio_frame, bool* muted) override;
 
+  void SetCodecs(const std::map<int, SdpAudioFormat>& codecs) override;
+
   int RegisterPayloadType(NetEqDecoder codec,
                           const std::string& codec_name,
                           uint8_t rtp_payload_type) override;