Update WebmMuxer for audio component of MediaStream recording.

media/filters/opus_constants.cc

+// Copyright 2015 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 <stdint.h>
+#include "media/filters/opus_constants.h"
+
+namespace media {
+
+const uint8_t kDefaultOpusChannelLayout[OPUS_MAX_CHANNELS_WITH_DEFAULT_LAYOUT] =
+ { 0, 1 };
+
+const uint8_t kFFmpegChannelDecodingLayouts [OPUS_MAX_VORBIS_CHANNELS]
+                                            [OPUS_MAX_VORBIS_CHANNELS] = {
+  {0},
+
+  // Stereo: No reorder.
+  {0, 1},
+
+  // 3 Channels, from Vorbis order to:
+  //  L, R, Center
+  {0, 2, 1},
+
+  // 4 Channels: No reorder.
+  {0, 1, 2, 3},
+
+  // 5 Channels, from Vorbis order to:
+  //  Front L, Front R, Center, Back L, Back R
+  {0, 2, 1, 3, 4},
+
+  // 6 Channels (5.1), from Vorbis order to:
+  //  Front L, Front R, Center, LFE, Back L, Back R
+  {0, 2, 1, 5, 3, 4},
+
+  // 7 Channels (6.1), from Vorbis order to:
+  //  Front L, Front R, Front Center, LFE, Side L, Side R, Back Center
+  {0, 2, 1, 6, 3, 4, 5},
+
+  // 8 Channels (7.1), from Vorbis order to:
+  //  Front L, Front R, Center, LFE, Back L, Back R, Side L, Side R
+  {0, 2, 1, 7, 5, 6, 3, 4},
+};
+
+const uint8_t
+kOpusVorbisChannelMap[OPUS_MAX_VORBIS_CHANNELS][OPUS_MAX_VORBIS_CHANNELS] = {
+  {0},
+  {0, 1},
+  {0, 2, 1},
+  {0, 1, 2, 3},
+  {0, 4, 1, 2, 3},
+  {0, 4, 1, 2, 3, 5},
+  {0, 4, 1, 2, 3, 5, 6},
+  {0, 6, 1, 2, 3, 4, 5, 7},
+};
+
+}  // namespace media