| /* |
| * Copyright 2016 Google Inc. All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef COBALT_SPEECH_SPEECH_RECOGNIZER_H_ |
| #define COBALT_SPEECH_SPEECH_RECOGNIZER_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/threading/thread.h" |
| #include "cobalt/network/network_module.h" |
| #include "cobalt/speech/audio_encoder_flac.h" |
| #include "cobalt/speech/speech_recognition_config.h" |
| #include "cobalt/speech/speech_recognition_event.h" |
| #include "content/browser/speech/chunked_byte_buffer.h" |
| #include "media/base/audio_bus.h" |
| #include "net/url_request/url_fetcher.h" |
| #include "net/url_request/url_fetcher_delegate.h" |
| |
| namespace cobalt { |
| namespace speech { |
| |
| // Interacts with Google speech recognition service, and then parses recognition |
| // results and forms speech recognition event. |
| // It creates an upstream fetcher to upload the encoded audio and a downstream |
| // fetcher to fetch the speech recognition result. The fetched speech |
| // recognition result is parsed by JSON parser and a SpeechRecognitionEvent, |
| // is formed based on the parsed result, would be sent to speech recognition |
| // manager. |
| class SpeechRecognizer : public net::URLFetcherDelegate { |
| public: |
| typedef ::media::ShellAudioBus ShellAudioBus; |
| typedef base::Callback<void(const scoped_refptr<dom::Event>&)> EventCallback; |
| typedef SpeechRecognitionResultList::SpeechRecognitionResults |
| SpeechRecognitionResults; |
| typedef base::Callback<scoped_ptr<net::URLFetcher>( |
| const GURL&, net::URLFetcher::RequestType, net::URLFetcherDelegate*)> |
| URLFetcherCreator; |
| |
| SpeechRecognizer(network::NetworkModule* network_module, |
| const EventCallback& event_callback, |
| const URLFetcherCreator& fetcher_creator); |
| ~SpeechRecognizer() OVERRIDE; |
| |
| // Multiple calls to Start/Stop are allowed, the implementation should take |
| // care of multiple calls. |
| // Start speech recognizer. |
| void Start(const SpeechRecognitionConfig& config, int sample_rate); |
| // Stop speech recognizer. |
| void Stop(); |
| // An encoded audio data is available and ready to be recognized. |
| void RecognizeAudio(scoped_ptr<ShellAudioBus> audio_bus, bool is_last_chunk); |
| |
| // net::URLFetcherDelegate interface |
| void OnURLFetchDownloadData(const net::URLFetcher* source, |
| scoped_ptr<std::string> download_data) OVERRIDE; |
| void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE; |
| bool ShouldSendDownloadData() OVERRIDE { return true; } |
| void OnURLFetchUploadProgress(const net::URLFetcher* /*source*/, |
| int64 /*current*/, int64 /*total*/) OVERRIDE {} |
| |
| private: |
| void StartInternal(const SpeechRecognitionConfig& config, int sample_rate); |
| void StopInternal(); |
| void UploadAudioDataInternal(scoped_ptr<ShellAudioBus> audio_bus, |
| bool is_last_chunk); |
| void ProcessAndFireSuccessEvent(const SpeechRecognitionResults& new_results); |
| |
| // This is used for creating fetchers. |
| network::NetworkModule* network_module_; |
| // Track the start/stop state of speech recognizer. |
| bool started_; |
| |
| // Encoder for encoding raw audio data to flac codec. |
| scoped_ptr<AudioEncoderFlac> encoder_; |
| // Fetcher for posting the audio data. |
| scoped_ptr<net::URLFetcher> upstream_fetcher_; |
| // Fetcher for receiving the streaming results. |
| scoped_ptr<net::URLFetcher> downstream_fetcher_; |
| // Used to send speech recognition event. |
| const EventCallback event_callback_; |
| // Used to create url fetcher. |
| const URLFetcherCreator fetcher_creator_; |
| // Used for processing proto buffer data. |
| content::ChunkedByteBuffer chunked_byte_buffer_; |
| // Used for accumulating final results. |
| SpeechRecognitionResults final_results_; |
| // Speech recognizer is operating in its own thread. |
| base::Thread thread_; |
| }; |
| |
| } // namespace speech |
| } // namespace cobalt |
| |
| #endif // COBALT_SPEECH_SPEECH_RECOGNIZER_H_ |