NetEq decoder database: Don't keep track of sample rate for builtin decoders

webrtc/modules/audio_coding/neteq/decoder_database.h

 /*
  *  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 23 matching lines @@
     kCodecNotSupported = -2,
     kInvalidSampleRate = -3,
     kDecoderExists = -4,
     kDecoderNotFound = -5,
     kInvalidPointer = -6
   };
 
   // Class that stores decoder info in the database.
   class DecoderInfo {
    public:
+    DecoderInfo(NetEqDecoder ct, const std::string& nm);
     DecoderInfo(NetEqDecoder ct,
                 const std::string& nm,
-                int fs,
+                int sample_rate_hz,
                 AudioDecoder* ext_dec);
     DecoderInfo(DecoderInfo&&);
     ~DecoderInfo();
 
     // Get the AudioDecoder object, creating it first if necessary.
     AudioDecoder* GetDecoder(AudioDecoderFactory* factory);
 
     // Delete the AudioDecoder object, unless it's external. (This means we can
     // always recreate it later if we need it.)
     void DropDecoder() { decoder_.reset(); }
 
+    int SampleRateHz() const {
+      RTC_DCHECK_EQ(1, !!decoder_ + !!external_decoder + !!cng_decoder_);
+      return decoder_ ? decoder_->SampleRateHz()
+                      : external_decoder ? external_decoder->sample_rate_hz
+                                         : cng_decoder_->sample_rate_hz;
+    }
+
     const NetEqDecoder codec_type;
     const std::string name;
-    const int fs_hz;
-    AudioDecoder* const external_decoder;
 
    private:
     const rtc::Optional<SdpAudioFormat> audio_format_;
     std::unique_ptr<AudioDecoder> decoder_;
+
+    // Set iff this is an external decoder.
+    struct ExternalDecoder {
+      // TODO(kwiberg): Remove sample_rate_hz once we can trust all decoders to
+      // implement SampleRateHz().
+      int sample_rate_hz;
+      AudioDecoder* decoder;
+    };
+    const rtc::Optional<ExternalDecoder> external_decoder;
+
+    // Set iff this is a comfort noise decoder.
+    struct CngDecoder {
+      static rtc::Optional<CngDecoder> Create(NetEqDecoder ct);
+      int sample_rate_hz;
+    };
+    const rtc::Optional<CngDecoder> cng_decoder_;
   };
 
   // Maximum value for 8 bits, and an invalid RTP payload type (since it is
   // only 7 bits).
   static const uint8_t kRtpPayloadTypeError = 0xFF;
 
   DecoderDatabase(
       const rtc::scoped_refptr<AudioDecoderFactory>& decoder_factory);
 
   virtual ~DecoderDatabase();
@@ skipping 85 matching lines @@
   int active_decoder_type_;
   int active_cng_decoder_type_;
   std::unique_ptr<ComfortNoiseDecoder> active_cng_decoder_;
   rtc::scoped_refptr<AudioDecoderFactory> decoder_factory_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DecoderDatabase);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECODER_DATABASE_H_