1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 package android.speech.tts; 17 18 import android.media.AudioFormat; 19 import android.util.Log; 20 21 import java.io.File; 22 import java.io.FileOutputStream; 23 import java.io.IOException; 24 import java.io.RandomAccessFile; 25 import java.nio.ByteBuffer; 26 import java.nio.ByteOrder; 27 28 /** 29 * Speech synthesis request that writes the audio to a WAV file. 30 */ 31 class FileSynthesisCallback extends AbstractSynthesisCallback { 32 33 private static final String TAG = "FileSynthesisRequest"; 34 private static final boolean DBG = false; 35 36 private static final int MAX_AUDIO_BUFFER_SIZE = 8192; 37 38 private static final int WAV_HEADER_LENGTH = 44; 39 private static final short WAV_FORMAT_PCM = 0x0001; 40 41 private final Object mStateLock = new Object(); 42 private final File mFileName; 43 private int mSampleRateInHz; 44 private int mAudioFormat; 45 private int mChannelCount; 46 private RandomAccessFile mFile; 47 private boolean mStopped = false; 48 private boolean mDone = false; 49 50 FileSynthesisCallback(File fileName) { 51 mFileName = fileName; 52 } 53 54 @Override 55 void stop() { 56 synchronized (mStateLock) { 57 mStopped = true; 58 cleanUp(); 59 } 60 } 61 62 /** 63 * Must be called while holding the monitor on {@link #mStateLock}. 64 */ 65 private void cleanUp() { 66 closeFile(); 67 if (mFile != null) { 68 mFileName.delete(); 69 } 70 } 71 72 /** 73 * Must be called while holding the monitor on {@link #mStateLock}. 74 */ 75 private void closeFile() { 76 try { 77 if (mFile != null) { 78 mFile.close(); 79 mFile = null; 80 } 81 } catch (IOException ex) { 82 Log.e(TAG, "Failed to close " + mFileName + ": " + ex); 83 } 84 } 85 86 @Override 87 public int getMaxBufferSize() { 88 return MAX_AUDIO_BUFFER_SIZE; 89 } 90 91 @Override 92 boolean isDone() { 93 return mDone; 94 } 95 96 @Override 97 public int start(int sampleRateInHz, int audioFormat, int channelCount) { 98 if (DBG) { 99 Log.d(TAG, "FileSynthesisRequest.start(" + sampleRateInHz + "," + audioFormat 100 + "," + channelCount + ")"); 101 } 102 synchronized (mStateLock) { 103 if (mStopped) { 104 if (DBG) Log.d(TAG, "Request has been aborted."); 105 return TextToSpeech.ERROR; 106 } 107 if (mFile != null) { 108 cleanUp(); 109 throw new IllegalArgumentException("FileSynthesisRequest.start() called twice"); 110 } 111 mSampleRateInHz = sampleRateInHz; 112 mAudioFormat = audioFormat; 113 mChannelCount = channelCount; 114 try { 115 mFile = new RandomAccessFile(mFileName, "rw"); 116 // Reserve space for WAV header 117 mFile.write(new byte[WAV_HEADER_LENGTH]); 118 return TextToSpeech.SUCCESS; 119 } catch (IOException ex) { 120 Log.e(TAG, "Failed to open " + mFileName + ": " + ex); 121 cleanUp(); 122 return TextToSpeech.ERROR; 123 } 124 } 125 } 126 127 @Override 128 public int audioAvailable(byte[] buffer, int offset, int length) { 129 if (DBG) { 130 Log.d(TAG, "FileSynthesisRequest.audioAvailable(" + buffer + "," + offset 131 + "," + length + ")"); 132 } 133 synchronized (mStateLock) { 134 if (mStopped) { 135 if (DBG) Log.d(TAG, "Request has been aborted."); 136 return TextToSpeech.ERROR; 137 } 138 if (mFile == null) { 139 Log.e(TAG, "File not open"); 140 return TextToSpeech.ERROR; 141 } 142 try { 143 mFile.write(buffer, offset, length); 144 return TextToSpeech.SUCCESS; 145 } catch (IOException ex) { 146 Log.e(TAG, "Failed to write to " + mFileName + ": " + ex); 147 cleanUp(); 148 return TextToSpeech.ERROR; 149 } 150 } 151 } 152 153 @Override 154 public int done() { 155 if (DBG) Log.d(TAG, "FileSynthesisRequest.done()"); 156 synchronized (mStateLock) { 157 if (mStopped) { 158 if (DBG) Log.d(TAG, "Request has been aborted."); 159 return TextToSpeech.ERROR; 160 } 161 if (mFile == null) { 162 Log.e(TAG, "File not open"); 163 return TextToSpeech.ERROR; 164 } 165 try { 166 // Write WAV header at start of file 167 mFile.seek(0); 168 int dataLength = (int) (mFile.length() - WAV_HEADER_LENGTH); 169 mFile.write( 170 makeWavHeader(mSampleRateInHz, mAudioFormat, mChannelCount, dataLength)); 171 closeFile(); 172 mDone = true; 173 return TextToSpeech.SUCCESS; 174 } catch (IOException ex) { 175 Log.e(TAG, "Failed to write to " + mFileName + ": " + ex); 176 cleanUp(); 177 return TextToSpeech.ERROR; 178 } 179 } 180 } 181 182 @Override 183 public void error() { 184 if (DBG) Log.d(TAG, "FileSynthesisRequest.error()"); 185 synchronized (mStateLock) { 186 cleanUp(); 187 } 188 } 189 190 private byte[] makeWavHeader(int sampleRateInHz, int audioFormat, int channelCount, 191 int dataLength) { 192 // TODO: is AudioFormat.ENCODING_DEFAULT always the same as ENCODING_PCM_16BIT? 193 int sampleSizeInBytes = (audioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 194 int byteRate = sampleRateInHz * sampleSizeInBytes * channelCount; 195 short blockAlign = (short) (sampleSizeInBytes * channelCount); 196 short bitsPerSample = (short) (sampleSizeInBytes * 8); 197 198 byte[] headerBuf = new byte[WAV_HEADER_LENGTH]; 199 ByteBuffer header = ByteBuffer.wrap(headerBuf); 200 header.order(ByteOrder.LITTLE_ENDIAN); 201 202 header.put(new byte[]{ 'R', 'I', 'F', 'F' }); 203 header.putInt(dataLength + WAV_HEADER_LENGTH - 8); // RIFF chunk size 204 header.put(new byte[]{ 'W', 'A', 'V', 'E' }); 205 header.put(new byte[]{ 'f', 'm', 't', ' ' }); 206 header.putInt(16); // size of fmt chunk 207 header.putShort(WAV_FORMAT_PCM); 208 header.putShort((short) channelCount); 209 header.putInt(sampleRateInHz); 210 header.putInt(byteRate); 211 header.putShort(blockAlign); 212 header.putShort(bitsPerSample); 213 header.put(new byte[]{ 'd', 'a', 't', 'a' }); 214 header.putInt(dataLength); 215 216 return headerBuf; 217 } 218 219 } 220
