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.os.FileUtils; 20 import android.util.Log; 21 22 import java.io.File; 23 import java.io.FileOutputStream; 24 import java.io.IOException; 25 import java.io.RandomAccessFile; 26 import java.nio.ByteBuffer; 27 import java.nio.ByteOrder; 28 import java.nio.channels.FileChannel; 29 30 /** 31 * Speech synthesis request that writes the audio to a WAV file. 32 */ 33 class FileSynthesisCallback extends AbstractSynthesisCallback { 34 35 private static final String TAG = "FileSynthesisRequest"; 36 private static final boolean DBG = false; 37 38 private static final int MAX_AUDIO_BUFFER_SIZE = 8192; 39 40 private static final int WAV_HEADER_LENGTH = 44; 41 private static final short WAV_FORMAT_PCM = 0x0001; 42 43 private final Object mStateLock = new Object(); 44 45 private int mSampleRateInHz; 46 private int mAudioFormat; 47 private int mChannelCount; 48 49 private FileChannel mFileChannel; 50 51 private boolean mStarted = false; 52 private boolean mStopped = false; 53 private boolean mDone = false; 54 55 FileSynthesisCallback(FileChannel fileChannel) { 56 mFileChannel = fileChannel; 57 } 58 59 @Override 60 void stop() { 61 synchronized (mStateLock) { 62 mStopped = true; 63 cleanUp(); 64 } 65 } 66 67 /** 68 * Must be called while holding the monitor on {@link #mStateLock}. 69 */ 70 private void cleanUp() { 71 closeFile(); 72 } 73 74 /** 75 * Must be called while holding the monitor on {@link #mStateLock}. 76 */ 77 private void closeFile() { 78 try { 79 if (mFileChannel != null) { 80 mFileChannel.close(); 81 mFileChannel = null; 82 } 83 } catch (IOException ex) { 84 Log.e(TAG, "Failed to close output file descriptor", ex); 85 } 86 } 87 88 @Override 89 public int getMaxBufferSize() { 90 return MAX_AUDIO_BUFFER_SIZE; 91 } 92 93 @Override 94 boolean isDone() { 95 return mDone; 96 } 97 98 @Override 99 public int start(int sampleRateInHz, int audioFormat, int channelCount) { 100 if (DBG) { 101 Log.d(TAG, "FileSynthesisRequest.start(" + sampleRateInHz + "," + audioFormat 102 + "," + channelCount + ")"); 103 } 104 synchronized (mStateLock) { 105 if (mStopped) { 106 if (DBG) Log.d(TAG, "Request has been aborted."); 107 return TextToSpeech.ERROR; 108 } 109 if (mStarted) { 110 cleanUp(); 111 throw new IllegalArgumentException("FileSynthesisRequest.start() called twice"); 112 } 113 mStarted = true; 114 mSampleRateInHz = sampleRateInHz; 115 mAudioFormat = audioFormat; 116 mChannelCount = channelCount; 117 118 try { 119 mFileChannel.write(ByteBuffer.allocate(WAV_HEADER_LENGTH)); 120 return TextToSpeech.SUCCESS; 121 } catch (IOException ex) { 122 Log.e(TAG, "Failed to write wav header to output file descriptor" + ex); 123 cleanUp(); 124 return TextToSpeech.ERROR; 125 } 126 } 127 } 128 129 @Override 130 public int audioAvailable(byte[] buffer, int offset, int length) { 131 if (DBG) { 132 Log.d(TAG, "FileSynthesisRequest.audioAvailable(" + buffer + "," + offset 133 + "," + length + ")"); 134 } 135 synchronized (mStateLock) { 136 if (mStopped) { 137 if (DBG) Log.d(TAG, "Request has been aborted."); 138 return TextToSpeech.ERROR; 139 } 140 if (mFileChannel == null) { 141 Log.e(TAG, "File not open"); 142 return TextToSpeech.ERROR; 143 } 144 try { 145 mFileChannel.write(ByteBuffer.wrap(buffer, offset, length)); 146 return TextToSpeech.SUCCESS; 147 } catch (IOException ex) { 148 Log.e(TAG, "Failed to write to output file descriptor", ex); 149 cleanUp(); 150 return TextToSpeech.ERROR; 151 } 152 } 153 } 154 155 @Override 156 public int done() { 157 if (DBG) Log.d(TAG, "FileSynthesisRequest.done()"); 158 synchronized (mStateLock) { 159 if (mDone) { 160 if (DBG) Log.d(TAG, "Duplicate call to done()"); 161 // This preserves existing behaviour. Earlier, if done was called twice 162 // we'd return ERROR because mFile == null and we'd add to logspam. 163 return TextToSpeech.ERROR; 164 } 165 if (mStopped) { 166 if (DBG) Log.d(TAG, "Request has been aborted."); 167 return TextToSpeech.ERROR; 168 } 169 if (mFileChannel == null) { 170 Log.e(TAG, "File not open"); 171 return TextToSpeech.ERROR; 172 } 173 try { 174 // Write WAV header at start of file 175 mFileChannel.position(0); 176 int dataLength = (int) (mFileChannel.size() - WAV_HEADER_LENGTH); 177 mFileChannel.write( 178 makeWavHeader(mSampleRateInHz, mAudioFormat, mChannelCount, dataLength)); 179 closeFile(); 180 mDone = true; 181 return TextToSpeech.SUCCESS; 182 } catch (IOException ex) { 183 Log.e(TAG, "Failed to write to output file descriptor", ex); 184 cleanUp(); 185 return TextToSpeech.ERROR; 186 } 187 } 188 } 189 190 @Override 191 public void error() { 192 if (DBG) Log.d(TAG, "FileSynthesisRequest.error()"); 193 synchronized (mStateLock) { 194 cleanUp(); 195 } 196 } 197 198 private ByteBuffer makeWavHeader(int sampleRateInHz, int audioFormat, int channelCount, 199 int dataLength) { 200 // TODO: is AudioFormat.ENCODING_DEFAULT always the same as ENCODING_PCM_16BIT? 201 int sampleSizeInBytes = (audioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 202 int byteRate = sampleRateInHz * sampleSizeInBytes * channelCount; 203 short blockAlign = (short) (sampleSizeInBytes * channelCount); 204 short bitsPerSample = (short) (sampleSizeInBytes * 8); 205 206 byte[] headerBuf = new byte[WAV_HEADER_LENGTH]; 207 ByteBuffer header = ByteBuffer.wrap(headerBuf); 208 header.order(ByteOrder.LITTLE_ENDIAN); 209 210 header.put(new byte[]{ 'R', 'I', 'F', 'F' }); 211 header.putInt(dataLength + WAV_HEADER_LENGTH - 8); // RIFF chunk size 212 header.put(new byte[]{ 'W', 'A', 'V', 'E' }); 213 header.put(new byte[]{ 'f', 'm', 't', ' ' }); 214 header.putInt(16); // size of fmt chunk 215 header.putShort(WAV_FORMAT_PCM); 216 header.putShort((short) channelCount); 217 header.putInt(sampleRateInHz); 218 header.putInt(byteRate); 219 header.putShort(blockAlign); 220 header.putShort(bitsPerSample); 221 header.put(new byte[]{ 'd', 'a', 't', 'a' }); 222 header.putInt(dataLength); 223 header.flip(); 224 225 return header; 226 } 227 228 } 229
