Pass more detailed audio hardware configuration information to the renderer

media/base/channel_layout.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_CHANNEL_LAYOUT_H_
 #define MEDIA_BASE_CHANNEL_LAYOUT_H_
 
 #include "media/base/media_export.h"
 
 namespace media {
@@ skipping 78 matching lines @@
 
   // Front L, Front R, Front C, Side L, Side R, Front LofC, Front RofC
   CHANNEL_LAYOUT_7_0_FRONT = 26,
 
   // Front L, Front R, Front C, Back L, Back R, LFE, Front LofC, Front RofC
   CHANNEL_LAYOUT_7_1_WIDE_BACK = 27,
 
   // Front L, Front R, Front C, Side L, Side R, Rear C, Back L, Back R.
   CHANNEL_LAYOUT_OCTAGONAL = 28,
 
+  // Channels are not explicitly mapped to speakers.
+  CHANNEL_LAYOUT_DISCRETE = 29,
+
   // Total number of layouts.
   CHANNEL_LAYOUT_MAX  // Must always be last!
 };
 
 enum Channels {
   LEFT = 0,
   RIGHT,
   CENTER,
   LFE,
   BACK_LEFT,
   BACK_RIGHT,
   LEFT_OF_CENTER,
   RIGHT_OF_CENTER,
   BACK_CENTER,
   SIDE_LEFT,
   SIDE_RIGHT,
   CHANNELS_MAX
 };
 
 // Returns the expected channel position in an interleaved stream.  Values of -1
 // mean the channel at that index is not used for that layout.  Values range
 // from 0 to CHANNELS_MAX - 1.
 MEDIA_EXPORT int ChannelOrder(ChannelLayout layout, Channels channel);
 
 // Returns the number of channels in a given ChannelLayout.
 MEDIA_EXPORT int ChannelLayoutToChannelCount(ChannelLayout layout);
 
+// Given the number of channels, return the best layout,
+// or return CHANNEL_LAYOUT_UNSUPPORTED if there is no good match.
+MEDIA_EXPORT ChannelLayout GuessChannelLayout(int channels);
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_CHANNEL_LAYOUT_H_