NetEq: Ask AudioDecoder for sample rate instead of passing it as an argument

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 26 matching lines @@
     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 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_);
+      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;
+                      : external_decoder_ ? external_decoder_->SampleRateHz()
+                                          : cng_decoder_->sample_rate_hz;
     }
 
     const NetEqDecoder codec_type;
     const std::string name;
 
    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;

[hlundin-webrtc, 2016/06/01 13:49:21]

What?! No trailing underscore on the member variable? Who reviewed this?

[kwiberg-webrtc, 2016/06/01 13:55:33]

It appears to have been written and reviewed by two utter nincompoops. Luckily
for them, there's no way to find out who they were after all this time.

https://codereview.webrtc.org/2021063002

+    AudioDecoder* const 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
@@ skipping 22 matching lines @@
   // otherwise an error code.
   virtual int RegisterPayload(uint8_t rtp_payload_type,
                               NetEqDecoder codec_type,
                               const std::string& name);
 
   // Registers an externally created AudioDecoder object, and associates it
   // as a decoder of type |codec_type| with |rtp_payload_type|.
   virtual int InsertExternal(uint8_t rtp_payload_type,
                              NetEqDecoder codec_type,
                              const std::string& codec_name,
-                             int fs_hz,
                              AudioDecoder* decoder);
 
   // Removes the entry for |rtp_payload_type| from the database.
   // Returns kDecoderNotFound or kOK depending on the outcome of the operation.
   virtual int Remove(uint8_t rtp_payload_type);
 
   // Returns a pointer to the DecoderInfo struct for |rtp_payload_type|. If
   // no decoder is registered with that |rtp_payload_type|, NULL is returned.
   virtual const DecoderInfo* GetDecoderInfo(uint8_t rtp_payload_type) const;
 
@@ skipping 49 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_