Delete full-band mode from the iSAC codec

webrtc/modules/audio_coding/codecs/isac/audio_encoder_isac_t_impl.h

 /*
  *  Copyright (c) 2014 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 32 matching lines @@
     return false;
   switch (sample_rate_hz) {
     case 16000:
       if (max_bit_rate > 53400)
         return false;
       if (max_payload_size_bytes > 400)
         return false;
       return (frame_size_ms == 30 || frame_size_ms == 60) &&
              (bit_rate == 0 || (bit_rate >= 10000 && bit_rate <= 32000));
     case 32000:
-    case 48000:
       if (max_bit_rate > 160000)
         return false;
       if (max_payload_size_bytes > 600)
         return false;
       return T::has_swb &&
              (frame_size_ms == 30 &&
               (bit_rate == 0 || (bit_rate >= 10000 && bit_rate <= 56000)));
     default:
       return false;
   }
@@ skipping 106 matching lines @@
                                   config.enforce_frame_size));
   } else {
     RTC_CHECK_EQ(0, T::Control(isac_state_, bit_rate, config.frame_size_ms));
   }
   if (config.max_payload_size_bytes != -1)
     RTC_CHECK_EQ(
         0, T::SetMaxPayloadSize(isac_state_, config.max_payload_size_bytes));
   if (config.max_bit_rate != -1)
     RTC_CHECK_EQ(0, T::SetMaxRate(isac_state_, config.max_bit_rate));
 
-  // When config.sample_rate_hz is set to 48000 Hz (iSAC-fb), the decoder is
-  // still set to 32000 Hz, since there is no full-band mode in the decoder.
-  const int decoder_sample_rate_hz = std::min(config.sample_rate_hz, 32000);
-
   // Set the decoder sample rate even though we just use the encoder. This
   // doesn't appear to be necessary to produce a valid encoding, but without it
   // we get an encoding that isn't bit-for-bit identical with what a combined
   // encoder+decoder object produces.
-  RTC_CHECK_EQ(0, T::SetDecSampRate(isac_state_, decoder_sample_rate_hz));
+  RTC_CHECK_EQ(0, T::SetDecSampRate(isac_state_, config.sample_rate_hz));
 
   config_ = config;
 }
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_AUDIO_ENCODER_ISAC_T_IMPL_H_