Pass ownership of external encoders to the ACM

webrtc/modules/audio_coding/acm2/rent_a_codec.cc

 /*
  *  Copyright (c) 2015 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 161 matching lines @@
     return std::unique_ptr<AudioEncoder>(new AudioEncoderIlbc(speech_inst));
 #endif
 #ifdef WEBRTC_CODEC_G722
   if (STR_CASE_CMP(speech_inst.plname, "g722") == 0)
     return std::unique_ptr<AudioEncoder>(new AudioEncoderG722(speech_inst));
 #endif
   LOG_F(LS_ERROR) << "Could not create encoder of type " << speech_inst.plname;
   return std::unique_ptr<AudioEncoder>();
 }
 
-std::unique_ptr<AudioEncoder> CreateRedEncoder(AudioEncoder* encoder,
-                                               int red_payload_type) {
+std::unique_ptr<AudioEncoder> CreateRedEncoder(
+    std::unique_ptr<AudioEncoder> encoder,
+    int red_payload_type) {
 #ifdef WEBRTC_CODEC_RED
   AudioEncoderCopyRed::Config config;
   config.payload_type = red_payload_type;
-  config.speech_encoder = encoder;
-  return std::unique_ptr<AudioEncoder>(new AudioEncoderCopyRed(config));
+  config.speech_encoder = std::move(encoder);
+  return std::unique_ptr<AudioEncoder>(
+      new AudioEncoderCopyRed(std::move(config)));
 #else
   return std::unique_ptr<AudioEncoder>();
 #endif
 }
 
-std::unique_ptr<AudioEncoder> CreateCngEncoder(AudioEncoder* encoder,
-                                               int payload_type,
-                                               ACMVADMode vad_mode) {
+std::unique_ptr<AudioEncoder> CreateCngEncoder(
+    std::unique_ptr<AudioEncoder> encoder,
+    int payload_type,
+    ACMVADMode vad_mode) {
   AudioEncoderCng::Config config;
   config.num_channels = encoder->NumChannels();
   config.payload_type = payload_type;
-  config.speech_encoder = encoder;
+  config.speech_encoder = std::move(encoder);
   switch (vad_mode) {
     case VADNormal:
       config.vad_mode = Vad::kVadNormal;
       break;
     case VADLowBitrate:
       config.vad_mode = Vad::kVadLowBitrate;
       break;
     case VADAggr:
       config.vad_mode = Vad::kVadAggressive;
       break;
     case VADVeryAggr:
       config.vad_mode = Vad::kVadVeryAggressive;
       break;
     default:
       FATAL();
   }
-  return std::unique_ptr<AudioEncoder>(new AudioEncoderCng(config));
+  return std::unique_ptr<AudioEncoder>(new AudioEncoderCng(std::move(config)));
 }
 
 std::unique_ptr<AudioDecoder> CreateIsacDecoder(
     LockedIsacBandwidthInfo* bwinfo) {
 #if defined(WEBRTC_CODEC_ISACFX)
   return std::unique_ptr<AudioDecoder>(new AudioDecoderIsacFix(bwinfo));
 #elif defined(WEBRTC_CODEC_ISAC)
   return std::unique_ptr<AudioDecoder>(new AudioDecoderIsac(bwinfo));
 #else
   FATAL() << "iSAC is not supported.";
   return std::unique_ptr<AudioDecoder>();
 #endif
 }
 
 }  // namespace
 
 RentACodec::RentACodec() = default;
 RentACodec::~RentACodec() = default;
 
-AudioEncoder* RentACodec::RentEncoder(const CodecInst& codec_inst) {
-  std::unique_ptr<AudioEncoder> enc =
-      CreateEncoder(codec_inst, &isac_bandwidth_info_);
-  if (!enc)
-    return nullptr;
-  speech_encoder_ = std::move(enc);
-  return speech_encoder_.get();
+std::unique_ptr<AudioEncoder> RentACodec::RentEncoder(
+    const CodecInst& codec_inst) {
+  return CreateEncoder(codec_inst, &isac_bandwidth_info_);
 }
 
 RentACodec::StackParameters::StackParameters() {
   // Register the default payload types for RED and CNG.
   for (const CodecInst& ci : RentACodec::Database()) {
     RentACodec::RegisterCngPayloadType(&cng_payload_types, ci);
     RentACodec::RegisterRedPayloadType(&red_payload_types, ci);
   }
 }
 
 RentACodec::StackParameters::~StackParameters() = default;
 
-AudioEncoder* RentACodec::RentEncoderStack(StackParameters* param) {
+std::unique_ptr<AudioEncoder> RentACodec::RentEncoderStack(
+    StackParameters* param) {
   RTC_DCHECK(param->speech_encoder);
 
   if (param->use_codec_fec) {
     // Switch FEC on. On failure, remember that FEC is off.
     if (!param->speech_encoder->SetFec(true))
       param->use_codec_fec = false;
   } else {
     // Switch FEC off. This shouldn't fail.
     const bool success = param->speech_encoder->SetFec(false);
     RTC_DCHECK(success);
   }
 
   auto pt = [&param](const std::map<int, int>& m) {
     auto it = m.find(param->speech_encoder->SampleRateHz());
     return it == m.end() ? rtc::Optional<int>()
                          : rtc::Optional<int>(it->second);
   };
   auto cng_pt = pt(param->cng_payload_types);
   param->use_cng =
       param->use_cng && cng_pt && param->speech_encoder->NumChannels() == 1;
   auto red_pt = pt(param->red_payload_types);
   param->use_red = param->use_red && red_pt;
 
   if (param->use_cng || param->use_red) {
     // The RED and CNG encoders need to be in sync with the speech encoder, so
     // reset the latter to ensure its buffer is empty.
     param->speech_encoder->Reset();
   }
-  AudioEncoder* encoder_stack = param->speech_encoder;
+  std::unique_ptr<AudioEncoder> encoder_stack =
+      std::move(param->speech_encoder);
   if (param->use_red) {
-    red_encoder_ = CreateRedEncoder(encoder_stack, *red_pt);
-    if (red_encoder_)
-      encoder_stack = red_encoder_.get();
-  } else {
-    red_encoder_.reset();
+    encoder_stack = CreateRedEncoder(std::move(encoder_stack), *red_pt);
   }
   if (param->use_cng) {
-    cng_encoder_ = CreateCngEncoder(encoder_stack, *cng_pt, param->vad_mode);
-    encoder_stack = cng_encoder_.get();
-  } else {
-    cng_encoder_.reset();
+    encoder_stack =
+        CreateCngEncoder(std::move(encoder_stack), *cng_pt, param->vad_mode);
   }
   return encoder_stack;
 }
 
 AudioDecoder* RentACodec::RentIsacDecoder() {
   if (!isac_decoder_)
     isac_decoder_ = CreateIsacDecoder(&isac_bandwidth_info_);
   return isac_decoder_.get();
 }
 
 }  // namespace acm2
 }  // namespace webrtc