Use ffmpeg for opus decoding, no need to maintain our decoder.

media/ffmpeg/ffmpeg_common_unittest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <cstring>
 
 #include "base/bind.h"
@@ skipping 104 matching lines @@
     } else {
       // Only process audio/video.
       continue;
     }
   }
 
   ASSERT_TRUE(found_audio);
   ASSERT_TRUE(found_video);
 }
 
-TEST_F(FFmpegCommonTest, OpusAudioDecoderConfig) {
-  AVCodecContext context = {0};
-  context.codec_type = AVMEDIA_TYPE_AUDIO;
-  context.codec_id = AV_CODEC_ID_OPUS;
-  context.channel_layout = CHANNEL_LAYOUT_STEREO;
-  context.channels = 2;
-  context.sample_fmt = AV_SAMPLE_FMT_FLT;
-
-  // During conversion this sample rate should be changed to 48kHz.
-  context.sample_rate = 44100;
-
-  AudioDecoderConfig decoder_config;
-  ASSERT_TRUE(AVCodecContextToAudioDecoderConfig(&context, Unencrypted(),
-                                                 &decoder_config));
-  EXPECT_EQ(48000, decoder_config.samples_per_second());
-}
-
 TEST_F(FFmpegCommonTest, TimeBaseConversions) {
   const int64_t test_data[][5] = {
       {1, 2, 1, 500000, 1}, {1, 3, 1, 333333, 1}, {1, 3, 2, 666667, 2},
   };
 
   for (size_t i = 0; i < arraysize(test_data); ++i) {
     SCOPED_TRACE(i);
 
     AVRational time_base;
     time_base.num = static_cast<int>(test_data[i][0]);
@@ skipping 112 matching lines @@
   // values; diff should verify.
 #if 0
   printf("<enum name=\"FFmpegCodecHashes\" type=\"int\">\n");
   for (const auto& kv : sorted_hashes)
     printf("  <int value=\"%d\" label=\"%s\"/>\n", kv.first, kv.second);
   printf("</enum>\n");
 #endif
 }
 
 }  // namespace media