[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"
@@ skipping 141 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;
   }
 
-  unsigned int frames_per_packet = params_.frames_per_buffer();
-  cras_stream_params* stream_params = cras_client_stream_params_create(
+  // For a hotword hardware stream, only wait for a single callback.
+  // Replace the existing callback with the HotwordSampleReady one that should
+  // only run once.
+  if (params_.effects() & AudioParameters::PlatformEffectsMask::HOTWORD) {
+    if (cras_client_add_hotword_callback(client_, audio_format,
+                                         CrasInputStream::HotwordSampleReady)) {
+      DLOG(WARNING) << "Failed to add the hotword callback.";
+      callback_->OnError(this);
+      callback_ = NULL;
+    }
+  }else {
+    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,
       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;
-  }
+    if (!stream_params) {
+      DLOG(WARNING) << "Error setting up stream parameters.";
+      callback_->OnError(this);
+      callback_ = NULL;
+      cras_audio_format_destroy(audio_format);
+      return;
+    }
 
-  // Before starting the stream, save the number of bytes in a frame for use in
-  // the callback.
-  bytes_per_frame_ = cras_client_format_bytes_per_frame(audio_format);
+    // Before starting the stream, save the number of bytes in a frame for use
+    // in the callback.
+    bytes_per_frame_ = cras_client_format_bytes_per_frame(audio_format);
 
-  // Adding the stream will start the audio callbacks.
-  if (cras_client_add_stream(client_, &stream_id_, stream_params)) {
-    DLOG(WARNING) << "Failed to add the stream.";
-    callback_->OnError(this);
-    callback_ = NULL;
+    // Adding the stream will start the audio callbacks.
+    if (cras_client_add_stream(client_, &stream_id_, stream_params)) {
+      DLOG(WARNING) << "Failed to add the stream.";
+      callback_->OnError(this);
+      callback_ = NULL;
+    }
   }
 
   // Done with config params.
   cras_audio_format_destroy(audio_format);
   cras_client_stream_params_destroy(stream_params);

[dgreid, 2014/09/17 22:03:00]

move stream_params_destory into the else as well.

[rpetterson, 2014/09/17 22:10:46]

Done.

 
   started_ = true;
 }
 
 void CrasInputStream::Stop() {
   DCHECK(client_);
 
   if (!callback_ || !started_)
     return;
 
@@ skipping 11 matching lines @@
                                   cras_stream_id_t stream_id,
                                   uint8* samples,
                                   size_t frames,
                                   const timespec* sample_ts,
                                   void* arg) {
   CrasInputStream* me = static_cast<CrasInputStream*>(arg);
   me->ReadAudio(frames, samples, sample_ts);
   return frames;
 }
 
+// Static callback asking for a single sample. Run on high priority thread.
+int CrasInputStream::HotwordSampleReady(cras_client* client,
+                                        cras_audio_format* fmt,
+                                        uint8* hotword_phrase,
+                                        size_t frames,
+                                        const timespec* sample_ts,
+                                        void* arg) {
+  CrasInputStream* me = static_cast<CrasInputStream*>(arg);
+  me->ReadAudio(frames, single_sample, sample_ts);
+  return frames;
+}
+
 // Static callback for stream errors.
 int CrasInputStream::StreamError(cras_client* client,
                                  cras_stream_id_t stream_id,
                                  int err,
                                  void* arg) {
   CrasInputStream* me = static_cast<CrasInputStream*>(arg);
   me->NotifyStreamError(err);
   return 0;
 }
 
@@ skipping 66 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