Convert channel layout for cras_input

media/audio/cras/cras_input.cc

 // 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.
 
 #include "media/audio/cras/cras_input.h"
 
 #include <math.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 84 matching lines @@
 
   // Signal to the manager that we're closed and can be removed.
   // Should be last call in the method as it deletes "this".
   audio_manager_->ReleaseInputStream(this);
 }
 
 void CrasInputStream::Start(AudioInputCallback* callback) {
   DCHECK(client_);
   DCHECK(callback);
 
+  // Channel map to CRAS_CHANNEL, values in the same order of
+  // corresponding source in Chromium defined Channels.
+  static const int kChannelMap[] = {
+    CRAS_CH_FL,
+    CRAS_CH_FR,
+    CRAS_CH_FC,
+    CRAS_CH_LFE,
+    CRAS_CH_RL,
+    CRAS_CH_RR,
+    CRAS_CH_FLC,
+    CRAS_CH_FRC,
+    CRAS_CH_RC,
+    CRAS_CH_SL,
+    CRAS_CH_SR
+  };
+  COMPILE_ASSERT(arraysize(kChannelMap) == CHANNELS_MAX + 1,
+                 channel_map_size_do_not_match);
+
   // If already playing, stop before re-starting.
   if (started_)
     return;
 
   StartAgc();
 
   callback_ = callback;
 
   // Prepare |audio_format| and |stream_params| for the stream we
   // will create.
   cras_audio_format* audio_format = cras_audio_format_create(
       AudioManagerCras::BitsToFormat(params_.bits_per_sample()),
       params_.sample_rate(),
       params_.channels());
   if (!audio_format) {
     DLOG(WARNING) << "Error setting up audio parameters.";
     callback_->OnError(this);
     callback_ = NULL;
     return;
   }
 
+  // Initialize channel layout to all -1 to indicate that none of
+  // the channels is set in the layout.
+  int8 layout[CRAS_CH_MAX];
+  for (size_t i = 0; i < arraysize(layout); ++i)
+    layout[i] = -1;
+
+  // Converts to CRAS defined channels. ChannelOrder will return -1
+  // for channels that are not present in params_.channel_layout().
+  for (size_t i = 0; i < arraysize(kChannelMap); ++i) {
+    layout[kChannelMap[i]] = ChannelOrder(params_.channel_layout(),
+                                          static_cast<Channels>(i));
+  }
+  if (cras_audio_format_set_channel_layout(audio_format, layout) != 0) {
+    DLOG(WARNING) << "Error setting channel layout.";
+    callback->OnError(this);
+    return;
+  }
+
   unsigned int frames_per_packet = params_.frames_per_buffer();
   cras_stream_params* stream_params = cras_client_stream_params_create(
       stream_direction_,
       frames_per_packet,  // Total latency.
       frames_per_packet,  // Call back when this many ready.
       frames_per_packet,  // Minimum Callback level ignored for capture streams.
       CRAS_STREAM_TYPE_DEFAULT,
       0,  // Unused flags.
       this,
       CrasInputStream::SamplesReady,
@@ skipping 131 matching lines @@
 
 double CrasInputStream::GetVolumeRatioFromDecibels(double dB) const {
   return pow(10, dB / 20.0);
 }
 
 double CrasInputStream::GetDecibelsFromVolumeRatio(double volume_ratio) const {
   return 20 * log10(volume_ratio);
 }
 
 }  // namespace media