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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "content/browser/speech/audio_encoder.h" | 5 #include "content/browser/speech/audio_encoder.h" |
6 | 6 |
7 #include "base/basictypes.h" | 7 #include "base/basictypes.h" |
8 #include "base/logging.h" | 8 #include "base/logging.h" |
9 #include "base/memory/scoped_ptr.h" | 9 #include "base/memory/scoped_ptr.h" |
10 #include "base/stl_util.h" | 10 #include "base/stl_util.h" |
11 #include "base/string_number_conversions.h" | 11 #include "base/string_number_conversions.h" |
12 #include "third_party/flac/flac.h" | 12 #include "third_party/flac/flac.h" |
13 #include "third_party/speex/speex.h" | 13 #include "third_party/speex/speex.h" |
14 | 14 |
15 using std::string; | 15 using std::string; |
16 | 16 |
17 namespace { | 17 namespace { |
18 | 18 |
19 //-------------------------------- FLACEncoder --------------------------------- | 19 //-------------------------------- FLACEncoder --------------------------------- |
20 | 20 |
21 const char* const kContentTypeFLAC = "audio/x-flac; rate="; | 21 const char* const kContentTypeFLAC = "audio/x-flac; rate="; |
22 const int kFLACCompressionLevel = 0; // 0 for speed | 22 const int kFLACCompressionLevel = 0; // 0 for speed |
23 | 23 |
24 class FLACEncoder : public speech_input::AudioEncoder { | 24 class FLACEncoder : public speech::AudioEncoder { |
25 public: | 25 public: |
26 FLACEncoder(int sampling_rate, int bits_per_sample); | 26 FLACEncoder(int sampling_rate, int bits_per_sample); |
27 virtual ~FLACEncoder(); | 27 virtual ~FLACEncoder(); |
28 virtual void Encode(const short* samples, int num_samples); | 28 virtual void Encode(const short* samples, int num_samples); |
29 virtual void Flush(); | 29 virtual void Flush(); |
30 | 30 |
31 private: | 31 private: |
32 static FLAC__StreamEncoderWriteStatus WriteCallback( | 32 static FLAC__StreamEncoderWriteStatus WriteCallback( |
33 const FLAC__StreamEncoder* encoder, | 33 const FLAC__StreamEncoder* encoder, |
34 const FLAC__byte buffer[], | 34 const FLAC__byte buffer[], |
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100 //-------------------------------- SpeexEncoder -------------------------------- | 100 //-------------------------------- SpeexEncoder -------------------------------- |
101 | 101 |
102 const char* const kContentTypeSpeex = "audio/x-speex-with-header-byte; rate="; | 102 const char* const kContentTypeSpeex = "audio/x-speex-with-header-byte; rate="; |
103 const int kSpeexEncodingQuality = 8; | 103 const int kSpeexEncodingQuality = 8; |
104 const int kMaxSpeexFrameLength = 110; // (44kbps rate sampled at 32kHz). | 104 const int kMaxSpeexFrameLength = 110; // (44kbps rate sampled at 32kHz). |
105 | 105 |
106 // Since the frame length gets written out as a byte in the encoded packet, | 106 // Since the frame length gets written out as a byte in the encoded packet, |
107 // make sure it is within the byte range. | 107 // make sure it is within the byte range. |
108 COMPILE_ASSERT(kMaxSpeexFrameLength <= 0xFF, invalidLength); | 108 COMPILE_ASSERT(kMaxSpeexFrameLength <= 0xFF, invalidLength); |
109 | 109 |
110 class SpeexEncoder : public speech_input::AudioEncoder { | 110 class SpeexEncoder : public speech::AudioEncoder { |
111 public: | 111 public: |
112 explicit SpeexEncoder(int sampling_rate); | 112 explicit SpeexEncoder(int sampling_rate); |
113 virtual ~SpeexEncoder(); | 113 virtual ~SpeexEncoder(); |
114 virtual void Encode(const short* samples, int num_samples); | 114 virtual void Encode(const short* samples, int num_samples); |
115 virtual void Flush() {} | 115 virtual void Flush() {} |
116 | 116 |
117 private: | 117 private: |
118 void* encoder_state_; | 118 void* encoder_state_; |
119 SpeexBits bits_; | 119 SpeexBits bits_; |
120 int samples_per_frame_; | 120 int samples_per_frame_; |
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156 // is the packet format for MIME type x-speex-with-header-byte. | 156 // is the packet format for MIME type x-speex-with-header-byte. |
157 int frame_length = speex_bits_write(&bits_, encoded_frame_data_ + 1, | 157 int frame_length = speex_bits_write(&bits_, encoded_frame_data_ + 1, |
158 kMaxSpeexFrameLength); | 158 kMaxSpeexFrameLength); |
159 encoded_frame_data_[0] = static_cast<char>(frame_length); | 159 encoded_frame_data_[0] = static_cast<char>(frame_length); |
160 AppendToBuffer(new string(encoded_frame_data_, frame_length + 1)); | 160 AppendToBuffer(new string(encoded_frame_data_, frame_length + 1)); |
161 } | 161 } |
162 } | 162 } |
163 | 163 |
164 } // namespace | 164 } // namespace |
165 | 165 |
166 namespace speech_input { | 166 namespace speech { |
167 | 167 |
168 AudioEncoder* AudioEncoder::Create(Codec codec, | 168 AudioEncoder* AudioEncoder::Create(Codec codec, |
169 int sampling_rate, | 169 int sampling_rate, |
170 int bits_per_sample) { | 170 int bits_per_sample) { |
171 if (codec == CODEC_FLAC) | 171 if (codec == CODEC_FLAC) |
172 return new FLACEncoder(sampling_rate, bits_per_sample); | 172 return new FLACEncoder(sampling_rate, bits_per_sample); |
173 return new SpeexEncoder(sampling_rate); | 173 return new SpeexEncoder(sampling_rate); |
174 } | 174 } |
175 | 175 |
176 AudioEncoder::AudioEncoder(const std::string& mime_type) | 176 AudioEncoder::AudioEncoder(const std::string& mime_type) |
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198 | 198 |
199 STLDeleteElements(&audio_buffers_); | 199 STLDeleteElements(&audio_buffers_); |
200 | 200 |
201 return true; | 201 return true; |
202 } | 202 } |
203 | 203 |
204 void AudioEncoder::AppendToBuffer(std::string* item) { | 204 void AudioEncoder::AppendToBuffer(std::string* item) { |
205 audio_buffers_.push_back(item); | 205 audio_buffers_.push_back(item); |
206 } | 206 } |
207 | 207 |
208 } // namespace speech_input | 208 } // namespace speech |
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