Pass ownership of external encoders to the ACM

webrtc/modules/audio_coding/acm2/rent_a_codec.h

 /*
  *  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 179 matching lines @@
   enum class RegistrationResult { kOk, kSkip, kBadFreq };
   static RegistrationResult RegisterCngPayloadType(std::map<int, int>* pt_map,
                                                    const CodecInst& codec_inst);
   static RegistrationResult RegisterRedPayloadType(std::map<int, int>* pt_map,
                                                    const CodecInst& codec_inst);
 
   RentACodec();
   ~RentACodec();
 
   // Creates and returns an audio encoder built to the given specification.
-  // Returns null in case of error. The returned encoder is live until the next
-  // successful call to this function, or until the Rent-A-Codec is destroyed.
-  AudioEncoder* RentEncoder(const CodecInst& codec_inst);
+  // Returns null in case of error.
+  std::unique_ptr<AudioEncoder> RentEncoder(const CodecInst& codec_inst);

[hlundin-webrtc, 2016/03/08 13:29:24]

The name RentEncoder is no longer adequate, but I'll accept it anyway.

[kwiberg-webrtc, 2016/03/08 13:59:12]

Yeah, the class name isn't a good fit anymore either. But all these names are
going away soon-ish.

 
   struct StackParameters {
     StackParameters();
     ~StackParameters();
 
-    AudioEncoder* speech_encoder = nullptr;
+    std::unique_ptr<AudioEncoder> speech_encoder;
+
     bool use_codec_fec = false;
     bool use_red = false;
     bool use_cng = false;
     ACMVADMode vad_mode = VADNormal;
 
     // Maps from RTP timestamp rate (in Hz) to payload type.
     std::map<int, int> cng_payload_types;
     std::map<int, int> red_payload_types;
   };
 
   // Creates and returns an audio encoder stack constructed to the given
   // specification. If the specification isn't compatible with the encoder, it
-  // will be changed to match (things will be switched off). The returned
-  // encoder is live until the next successful call to this function, or until
-  // the Rent-A-Codec is destroyed.
-  AudioEncoder* RentEncoderStack(StackParameters* param);
+  // will be changed to match (things will be switched off). The speech encoder
+  // will be stolen.
+  std::unique_ptr<AudioEncoder> RentEncoderStack(StackParameters* param);
 
   // Creates and returns an iSAC decoder, which will remain live until the
   // Rent-A-Codec is destroyed. Subsequent calls will simply return the same
   // object.
   AudioDecoder* RentIsacDecoder();
 
  private:
   std::unique_ptr<AudioEncoder> speech_encoder_;
   std::unique_ptr<AudioEncoder> cng_encoder_;
   std::unique_ptr<AudioEncoder> red_encoder_;
   std::unique_ptr<AudioDecoder> isac_decoder_;
   LockedIsacBandwidthInfo isac_bandwidth_info_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(RentACodec);
 };
 
 }  // namespace acm2
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_ACM2_RENT_A_CODEC_H_