AcmReceiver: Look up last decoder in NetEq's table of decoders

webrtc/modules/audio_coding/neteq/neteq_impl.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.
  */
 
@@ skipping 413 matching lines @@
   }
   return rtc::Optional<uint32_t>(
       timestamp_scaler_->ToExternal(playout_timestamp_));
 }
 
 int NetEqImpl::last_output_sample_rate_hz() const {
   rtc::CritScope lock(&crit_sect_);
   return last_output_sample_rate_hz_;
 }
 
+rtc::Optional<CodecInst> NetEqImpl::GetDecoder(int payload_type) const {
+  rtc::CritScope lock(&crit_sect_);
+  const DecoderDatabase::DecoderInfo* di =
+      decoder_database_->GetDecoderInfo(payload_type);
+  if (!di) {
+    return rtc::Optional<CodecInst>();
+  }
+
+  // Create a CodecInst with some fields set. The remaining fields are zeroed,
+  // but we tell MSan to consider them uninitialized.
+  CodecInst ci = {0};
+  rtc::MsanMarkUninitialized(rtc::MakeArrayView(&ci, 1));
+  ci.pltype = payload_type;
+  std::strncpy(ci.plname, di->name.c_str(), sizeof(ci.plname));
+  ci.plname[sizeof(ci.plname) - 1] = '\0';
+  ci.plfreq = di->IsRed() || di->IsDtmf() ? 8000 : di->SampleRateHz();
+  AudioDecoder* const decoder = di->GetDecoder();
+  ci.channels = decoder ? decoder->Channels() : 1;
+  return rtc::Optional<CodecInst>(ci);
+}
+
 int NetEqImpl::SetTargetNumberOfChannels() {
   return kNotImplemented;
 }
 
 int NetEqImpl::SetTargetSampleRate() {
   return kNotImplemented;
 }
 
 int NetEqImpl::LastError() const {
   rtc::CritScope lock(&crit_sect_);
@@ skipping 1631 matching lines @@
   }
 }
 
 void NetEqImpl::CreateDecisionLogic() {
   decision_logic_.reset(DecisionLogic::Create(
       fs_hz_, output_size_samples_, playout_mode_, decoder_database_.get(),
       *packet_buffer_.get(), delay_manager_.get(), buffer_level_filter_.get(),
       tick_timer_.get()));
 }
 }  // namespace webrtc