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// Copyright (c) 2010 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_BROWSER_SPEECH_AUDIO_ENCODER_H_
#define CONTENT_BROWSER_SPEECH_AUDIO_ENCODER_H_
#include <list>
#include <string>
#include "base/basictypes.h"
namespace speech_input {
// Provides a simple interface to encode raw audio using the various speech
// codecs.
class AudioEncoder {
public:
enum Codec {
CODEC_FLAC,
CODEC_SPEEX,
};
static AudioEncoder* Create(Codec codec,
int sampling_rate,
int bits_per_sample);
virtual ~AudioEncoder();
// Encodes each frame of raw audio in |samples| to the internal buffer. Use
// |GetEncodedData| to read the result after this call or when recording
// completes.
virtual void Encode(const short* samples, int num_samples) = 0;
// Finish encoding and flush any pending encoded bits out.
virtual void Flush() = 0;
// Copies the encoded audio to the given string. Returns true if the output
// is not empty.
bool GetEncodedData(std::string* encoded_data);
const std::string& mime_type() { return mime_type_; }
protected:
AudioEncoder(const std::string& mime_type);
void AppendToBuffer(std::string* item);
private:
// Buffer holding the recorded audio. Owns the strings inside the list.
typedef std::list<std::string*> AudioBufferQueue;
AudioBufferQueue audio_buffers_;
std::string mime_type_;
DISALLOW_COPY_AND_ASSIGN(AudioEncoder);
};
} // namespace speech_input
#endif // CONTENT_BROWSER_SPEECH_AUDIO_ENCODER_H_
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