[Hotword] Adding audio parameters to handle audio coming from the DSP.

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"
 #include "base/time/time.h"
 #include "media/audio/audio_manager.h"
 #include "media/audio/cras/audio_manager_cras.h"
 
 namespace media {
 
+// Flag to indicate hotword stream.
+static const uint32_t kHotwordParam = 1;

[dgreid, 2014/12/10 00:23:35]

This will be 0x03. or even better HOTWORD_STREAM from cras_types.h once this
lands:
https://chromium-review.googlesource.com/#/c/233104/2/cras/src/common/cras_ty...

[rpetterson, 2014/12/10 00:37:43]

Cool. When do you think that will land?

[dgreid, 2014/12/10 00:54:50]

hopefully soon. I need to get a build without it and dependencies to push to dev
and make sure a crash is fixed, then I can land it.

[rpetterson, 2014/12/13 01:04:00]

I've updated the way I think you mean. Let me know if it looks okay.

+
 CrasInputStream::CrasInputStream(const AudioParameters& params,
                                  AudioManagerCras* manager,
                                  const std::string& device_id)
     : audio_manager_(manager),
       bytes_per_frame_(0),
       callback_(NULL),
       client_(NULL),
       params_(params),
       started_(false),
       stream_id_(0),
@@ skipping 125 matching lines @@
   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;
   }
 
+  uint32_t flags = 0;
+  if (params_.effects() & AudioParameters::PlatformEffectsMask::HOTWORD)
+    flags = kHotwordParam;
+
   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.
+      flags,
       this,
       CrasInputStream::SamplesReady,
       CrasInputStream::StreamError,
       audio_format);
   if (!stream_params) {
     DLOG(WARNING) << "Error setting up stream parameters.";
     callback_->OnError(this);
     callback_ = NULL;
     cras_audio_format_destroy(audio_format);
     return;
@@ skipping 123 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