Make an enum class out of NetEqDecoder, and hide the neteq_decoders_ table

webrtc/modules/audio_coding/main/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 79 matching lines @@
 #ifndef WEBRTC_CODEC_RED
     kRED = -1,
 #endif
 #ifndef ENABLE_48000_HZ
     kCNFB = -1,
 #endif
 
     kNone = -1
   };
 
+  enum class NetEqDecoder {
+    kDecoderPCMu,
+    kDecoderPCMa,
+    kDecoderPCMu_2ch,
+    kDecoderPCMa_2ch,
+    kDecoderILBC,
+    kDecoderISAC,
+    kDecoderISACswb,
+    kDecoderPCM16B,
+    kDecoderPCM16Bwb,
+    kDecoderPCM16Bswb32kHz,
+    kDecoderPCM16Bswb48kHz,
+    kDecoderPCM16B_2ch,
+    kDecoderPCM16Bwb_2ch,
+    kDecoderPCM16Bswb32kHz_2ch,
+    kDecoderPCM16Bswb48kHz_2ch,
+    kDecoderPCM16B_5ch,
+    kDecoderG722,
+    kDecoderG722_2ch,
+    kDecoderRED,
+    kDecoderAVT,
+    kDecoderCNGnb,
+    kDecoderCNGwb,
+    kDecoderCNGswb32kHz,
+    kDecoderCNGswb48kHz,
+    kDecoderArbitrary,
+    kDecoderOpus,
+    kDecoderOpus_2ch,
+  };
+
   static inline size_t NumberOfCodecs() {
     return static_cast<size_t>(CodecId::kNumCodecs);
   }
 
   static inline rtc::Maybe<int> CodecIndexFromId(CodecId codec_id) {
     const int i = static_cast<int>(codec_id);
     return i < static_cast<int>(NumberOfCodecs()) ? i : rtc::Maybe<int>();
   }
 
   static inline rtc::Maybe<CodecId> CodecIdFromIndex(int codec_index) {
     return static_cast<size_t>(codec_index) < NumberOfCodecs()
                ? static_cast<RentACodec::CodecId>(codec_index)
                : rtc::Maybe<RentACodec::CodecId>();
   }
 
   static rtc::Maybe<CodecId> CodecIdByParams(const char* payload_name,
                                              int sampling_freq_hz,
                                              int channels);
   static rtc::Maybe<CodecInst> CodecInstById(CodecId codec_id);
   static rtc::Maybe<CodecInst> CodecInstByParams(const char* payload_name,
                                                  int sampling_freq_hz,
                                                  int channels);
   static bool IsCodecValid(const CodecInst& codec_inst);
   static rtc::ArrayView<const CodecInst> Database();
+
+  static rtc::Maybe<NetEqDecoder> NetEqDecoderFromCodecId(CodecId codec_id,
+                                                          int num_channels);
 };
 
 }  // namespace acm2
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_MAIN_ACM2_RENT_A_CODEC_H_