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content / browser / speech / speech_recognition_engine.h [blame]
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_ENGINE_H_
#define CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_ENGINE_H_
#include <vector>
#include "components/speech/audio_buffer.h"
#include "content/common/content_export.h"
#include "media/base/audio_parameters.h"
#include "media/mojo/mojom/speech_recognition_error.mojom.h"
#include "media/mojo/mojom/speech_recognition_result.mojom.h"
namespace blink {
namespace mojom {
class SpeechRecognitionError;
} // namespace mojom
} // namespace blink
namespace content {
// This is the interface for any speech recognition engine, local or network.
//
// The expected call sequence is:
// StartRecognition Mandatory at beginning of SR.
// TakeAudioChunk For every audio chunk pushed.
// AudioChunksEnded Finalize the audio stream (omitted in case of errors).
// EndRecognition Mandatory at end of SR (even on errors).
//
// No delegate callbacks are performed before StartRecognition or after
// EndRecognition. If a recognition was started, the caller can free the
// SpeechRecognitionEngine only after calling EndRecognition.
class CONTENT_EXPORT SpeechRecognitionEngine {
public:
class Delegate {
public:
// Called whenever a result is retrieved.
virtual void OnSpeechRecognitionEngineResults(
const std::vector<media::mojom::WebSpeechRecognitionResultPtr>&
results) = 0;
virtual void OnSpeechRecognitionEngineEndOfUtterance() = 0;
virtual void OnSpeechRecognitionEngineError(
const media::mojom::SpeechRecognitionError& error) = 0;
protected:
virtual ~Delegate() = default;
};
SpeechRecognitionEngine() = default;
virtual ~SpeechRecognitionEngine() = default;
virtual void StartRecognition() = 0;
virtual void EndRecognition() = 0;
virtual void TakeAudioChunk(const AudioChunk& data) = 0;
virtual void AudioChunksEnded() = 0;
virtual int GetDesiredAudioChunkDurationMs() const = 0;
void SetAudioParameters(media::AudioParameters audio_parameters);
// set_delegate detached from constructor for lazy dependency injection.
void set_delegate(Delegate* delegate);
protected:
raw_ptr<Delegate> delegate_ = nullptr;
media::AudioParameters audio_parameters_;
};
} // namespace content
#endif // CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_ENGINE_H_