Index: content/renderer/speech_recognition_audio_source_provider.h |
diff --git a/content/renderer/speech_recognition_audio_source_provider.h b/content/renderer/speech_recognition_audio_source_provider.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..6b1fd487c7757f78456b1cc09e2fe0e10dddf365 |
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+++ b/content/renderer/speech_recognition_audio_source_provider.h |
@@ -0,0 +1,125 @@ |
+// Copyright 2014 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 CONTENT_RENDERER_SPEECH_RECOGNITION_AUDIO_SOURCE_PROVIDER_H_ |
+#define CONTENT_RENDERER_SPEECH_RECOGNITION_AUDIO_SOURCE_PROVIDER_H_ |
+ |
+#include "base/callback.h" |
+#include "base/memory/scoped_ptr.h" |
+#include "base/memory/shared_memory.h" |
+#include "base/native_sync_socket.h" |
+#include "base/threading/thread_checker.h" |
+#include "base/threading/thread_restrictions.h" |
+#include "content/common/content_export.h" |
+#include "content/public/renderer/media_stream_audio_sink.h" |
+#include "content/renderer/media/media_stream_audio_source.h" |
+#include "media/audio/audio_device_thread.h" |
+#include "media/base/audio_converter.h" |
+#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h" |
+ |
+namespace media { |
+class AudioBus; |
+class AudioConverter; |
+class AudioFifo; |
+class AudioParameters; |
+} |
+ |
+namespace content { |
+ |
+// SpeechRecognitionAudioSourceProvider works as a sink to the |
+// WebRtcLocalAudioTrack and stores the capture data to a FIFO. |
+// When the FIFO has enough buffer, it passes the buffer to |
+// the speech recognizer. |
+// |
+class CONTENT_EXPORT SpeechRecognitionAudioSourceProvider |
+ : NON_EXPORTED_BASE(public media::AudioConverter::InputCallback), |
+ NON_EXPORTED_BASE(public MediaStreamAudioSink) { |
+ public: |
+ SpeechRecognitionAudioSourceProvider( |
+ const blink::WebMediaStreamTrack& track, |
+ const media::AudioParameters& params, |
+ base::SharedMemoryHandle memory, |
+ base::NativeSyncSocket::Descriptor socket, |
+ int memory_length); |
+ virtual ~SpeechRecognitionAudioSourceProvider(); |
+ // determines the policy on what types of tracks are allowed |
tommi (sloooow) - chröme
2014/08/29 11:25:31
nit: empty line above this comment for readability
burnik
2014/08/29 13:26:17
Done.
|
+ static bool IsAllowedAudioTrack(const blink::WebMediaStreamTrack& track); |
+ |
+ private: |
+ // MediaStreamAudioSink implementation. |
+ virtual void OnData(const int16* audio_data, |
+ int sample_rate, |
+ int number_of_channels, |
+ int number_of_frames) OVERRIDE; |
+ virtual void OnSetFormat(const media::AudioParameters& params) OVERRIDE; |
+ virtual void OnReadyStateChanged( |
+ blink::WebMediaStreamSource::ReadyState state) OVERRIDE; |
+ |
+ // media::AudioConverter::Inputcallback implementation. |
+ // This function is triggered by provideInput() on the WebAudio audio thread, |
+ // so it has been under the protection of |lock_|. |
+ virtual double ProvideInput(media::AudioBus* audio_bus, |
+ base::TimeDelta buffer_delay) OVERRIDE; |
+ |
+ private: |
+ // Allows for some delays on the client |
+ static const int kNumberOfBuffersInFifo = 2; |
no longer working on chromium
2014/08/29 12:23:07
move it to the implementation.
burnik
2014/08/29 13:26:17
Done.
|
+ |
+ // Number of frames per buffer in FIFO. When the buffer is full we convert and |
+ // consume it on the |output_bus_|. Size of the buffer is depends on the |
+ // resampler. Example: for 44.1 to 16.0 conversion, it should be 4100 frames. |
+ int fifo_buffer_size_; |
+ |
+ // Since |Receive| on |socket_| is blocking, we don't want to miss out on |
+ // frames delivered to |OnData|. so we use |ReceiveWithTimeout|. |
+ base::TimeDelta max_sync_delay_time_delta_; |
+ |
+ // Used to DCHECK that some methods are called on the main render thread. |
+ base::ThreadChecker main_render_thread_checker_; |
+ |
+ // Used to DCHECK that some methods are called on the capture audio thread. |
+ base::ThreadChecker capture_thread_checker_; |
+ |
+ // The audio track that this source provider is connected to. |
+ blink::WebMediaStreamTrack track_; |
+ |
+ // Shared memory used by audio buses on both browser and renderer processes. |
+ base::SharedMemory shared_memory_; |
+ |
+ // Socket for syncronization of audio bus reads/writes. |
+ base::SyncSocket socket_; |
+ |
+ // Used as a resampler to deliver appropriate format to speech recognition. |
+ scoped_ptr<media::AudioConverter> audio_converter_; |
+ |
+ // FIFO is used for queueing audio frames before we resample. |
+ scoped_ptr<media::AudioFifo> fifo_; |
+ |
+ // Audio delivered from source. |
+ scoped_ptr<media::AudioBus> input_bus_; |
+ |
+ // Audio bus shared with the browser process via |shared_memory_|. |
+ scoped_ptr<media::AudioBus> output_bus_; |
+ |
+ // Params of the source audio. |
+ media::AudioParameters input_params_; |
+ |
+ // Params used by speech recognition. |
+ media::AudioParameters output_params_; |
+ |
+ // We attach the resampler once we have enough data in FIFO and not before. |
no longer working on chromium
2014/08/29 12:23:07
confusing comment, can it make it more clear on wh
burnik
2014/08/29 13:26:17
Done.
On 2014/08/29 12:23:07, xians1 wrote:
|
+ bool attached_converter_; |
+ |
+ // Whether the track has been stopped on the input. |
+ bool track_stopped_; |
+ |
+ // Making sure all buffers are consumed by the client in order. |
+ uint32 buffer_index_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(SpeechRecognitionAudioSourceProvider); |
+}; |
+ |
+} // namespace content |
+ |
+#endif // CONTENT_RENDERER_SPEECH_RECOGNITION_AUDIO_SOURCE_PROVIDER_H_ |