SynthesisPlaybackQueueItem.java revision 65c50784564d0bae9276fde5472dd8898a781bcd
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 */ 16package android.speech.tts; 17 18import android.speech.tts.TextToSpeechService.AudioOutputParams; 19import android.speech.tts.TextToSpeechService.UtteranceProgressDispatcher; 20import android.media.AudioTrack; 21import android.util.Log; 22 23import java.util.LinkedList; 24import java.util.concurrent.locks.Condition; 25import java.util.concurrent.locks.Lock; 26import java.util.concurrent.locks.ReentrantLock; 27import java.util.concurrent.ConcurrentLinkedQueue; 28 29/** 30 * Manages the playback of a list of byte arrays representing audio data that are queued by the 31 * engine to an audio track. 32 */ 33final class SynthesisPlaybackQueueItem extends PlaybackQueueItem 34 implements AudioTrack.OnPlaybackPositionUpdateListener { 35 private static final String TAG = "TTS.SynthQueueItem"; 36 private static final boolean DBG = false; 37 38 /** 39 * Maximum length of audio we leave unconsumed by the audio track. 40 * Calls to {@link #put(byte[])} will block until we have less than 41 * this amount of audio left to play back. 42 */ 43 private static final long MAX_UNCONSUMED_AUDIO_MS = 500; 44 45 /** 46 * Guards accesses to mDataBufferList and mUnconsumedBytes. 47 */ 48 private final Lock mListLock = new ReentrantLock(); 49 private final Condition mReadReady = mListLock.newCondition(); 50 private final Condition mNotFull = mListLock.newCondition(); 51 52 // Guarded by mListLock. 53 private final LinkedList<ListEntry> mDataBufferList = new LinkedList<ListEntry>(); 54 // Guarded by mListLock. 55 private int mUnconsumedBytes; 56 57 /* 58 * While mStopped and mIsError can be written from any thread, mDone is written 59 * only from the synthesis thread. All three variables are read from the 60 * audio playback thread. 61 */ 62 private volatile boolean mStopped; 63 private volatile boolean mDone; 64 private volatile int mStatusCode; 65 66 private final BlockingAudioTrack mAudioTrack; 67 private final AbstractEventLogger mLogger; 68 69 // Stores a queue of markers. When the marker in front is reached the client is informed and we 70 // wait for the next one. 71 private ConcurrentLinkedQueue<ProgressMarker> markerList = new ConcurrentLinkedQueue<>(); 72 73 SynthesisPlaybackQueueItem(AudioOutputParams audioParams, int sampleRate, 74 int audioFormat, int channelCount, UtteranceProgressDispatcher dispatcher, 75 Object callerIdentity, AbstractEventLogger logger) { 76 super(dispatcher, callerIdentity); 77 78 mUnconsumedBytes = 0; 79 80 mStopped = false; 81 mDone = false; 82 mStatusCode = TextToSpeech.SUCCESS; 83 84 mAudioTrack = new BlockingAudioTrack(audioParams, sampleRate, audioFormat, channelCount); 85 mLogger = logger; 86 } 87 88 89 @Override 90 public void run() { 91 final UtteranceProgressDispatcher dispatcher = getDispatcher(); 92 dispatcher.dispatchOnStart(); 93 94 if (!mAudioTrack.init()) { 95 dispatcher.dispatchOnError(TextToSpeech.ERROR_OUTPUT); 96 return; 97 } 98 99 mAudioTrack.setPlaybackPositionUpdateListener(this); 100 101 try { 102 byte[] buffer = null; 103 104 // take() will block until: 105 // 106 // (a) there is a buffer available to tread. In which case 107 // a non null value is returned. 108 // OR (b) stop() is called in which case it will return null. 109 // OR (c) done() is called in which case it will return null. 110 while ((buffer = take()) != null) { 111 mAudioTrack.write(buffer); 112 mLogger.onAudioDataWritten(); 113 } 114 115 } catch (InterruptedException ie) { 116 if (DBG) Log.d(TAG, "Interrupted waiting for buffers, cleaning up."); 117 } 118 119 mAudioTrack.waitAndRelease(); 120 121 if (mStatusCode == TextToSpeech.SUCCESS) { 122 dispatcher.dispatchOnSuccess(); 123 } else if(mStatusCode == TextToSpeech.STOPPED) { 124 dispatcher.dispatchOnStop(); 125 } else { 126 dispatcher.dispatchOnError(mStatusCode); 127 } 128 129 mLogger.onCompleted(mStatusCode); 130 } 131 132 @Override 133 void stop(int statusCode) { 134 try { 135 mListLock.lock(); 136 137 // Update our internal state. 138 mStopped = true; 139 mStatusCode = statusCode; 140 141 // Wake up the audio playback thread if it was waiting on take(). 142 // take() will return null since mStopped was true, and will then 143 // break out of the data write loop. 144 mReadReady.signal(); 145 146 // Wake up the synthesis thread if it was waiting on put(). Its 147 // buffers will no longer be copied since mStopped is true. The 148 // PlaybackSynthesisCallback that this synthesis corresponds to 149 // would also have been stopped, and so all calls to 150 // Callback.onDataAvailable( ) will return errors too. 151 mNotFull.signal(); 152 } finally { 153 mListLock.unlock(); 154 } 155 156 // Stop the underlying audio track. This will stop sending 157 // data to the mixer and discard any pending buffers that the 158 // track holds. 159 mAudioTrack.stop(); 160 } 161 162 void done() { 163 try { 164 mListLock.lock(); 165 166 // Update state. 167 mDone = true; 168 169 // Unblocks the audio playback thread if it was waiting on take() 170 // after having consumed all available buffers. It will then return 171 // null and leave the write loop. 172 mReadReady.signal(); 173 174 // Just so that engines that try to queue buffers after 175 // calling done() don't block the synthesis thread forever. Ideally 176 // this should be called from the same thread as put() is, and hence 177 // this call should be pointless. 178 mNotFull.signal(); 179 } finally { 180 mListLock.unlock(); 181 } 182 } 183 184 /** Convenience class for passing around TTS markers. */ 185 private class ProgressMarker { 186 // The index in frames of this marker. 187 public final int frames; 188 // The start index in the text of the utterance. 189 public final int start; 190 // The end index (exclusive) in the text of the utterance. 191 public final int end; 192 193 public ProgressMarker(int frames, int start, int end) { 194 this.frames = frames; 195 this.start = start; 196 this.end = end; 197 } 198 } 199 200 /** Set a callback for the first marker in the queue. */ 201 void updateMarker() { 202 ProgressMarker marker = markerList.peek(); 203 if (marker != null) { 204 // Zero is used to disable the marker. The documentation recommends to use a non-zero 205 // position near zero such as 1. 206 int markerInFrames = marker.frames == 0 ? 1 : marker.frames; 207 mAudioTrack.setNotificationMarkerPosition(markerInFrames); 208 } 209 } 210 211 /** Informs us that at markerInFrames, the range between start and end is about to be spoken. */ 212 void rangeStart(int markerInFrames, int start, int end) { 213 markerList.add(new ProgressMarker(markerInFrames, start, end)); 214 updateMarker(); 215 } 216 217 @Override 218 public void onMarkerReached(AudioTrack track) { 219 ProgressMarker marker = markerList.poll(); 220 if (marker == null) { 221 Log.e(TAG, "onMarkerReached reached called but no marker in queue"); 222 return; 223 } 224 // Inform the client. 225 getDispatcher().dispatchOnUtteranceRangeStart(marker.start, marker.end); 226 // Listen for the next marker. 227 // It's ok if this marker is in the past, in that case onMarkerReached will be called again. 228 updateMarker(); 229 } 230 231 @Override 232 public void onPeriodicNotification(AudioTrack track) {} 233 234 void put(byte[] buffer) throws InterruptedException { 235 try { 236 mListLock.lock(); 237 long unconsumedAudioMs = 0; 238 239 while ((unconsumedAudioMs = mAudioTrack.getAudioLengthMs(mUnconsumedBytes)) > 240 MAX_UNCONSUMED_AUDIO_MS && !mStopped) { 241 mNotFull.await(); 242 } 243 244 // Don't bother queueing the buffer if we've stopped. The playback thread 245 // would have woken up when stop() is called (if it was blocked) and will 246 // proceed to leave the write loop since take() will return null when 247 // stopped. 248 if (mStopped) { 249 return; 250 } 251 252 mDataBufferList.add(new ListEntry(buffer)); 253 mUnconsumedBytes += buffer.length; 254 mReadReady.signal(); 255 } finally { 256 mListLock.unlock(); 257 } 258 } 259 260 private byte[] take() throws InterruptedException { 261 try { 262 mListLock.lock(); 263 264 // Block if there are no available buffers, and stop() has not 265 // been called and done() has not been called. 266 while (mDataBufferList.size() == 0 && !mStopped && !mDone) { 267 mReadReady.await(); 268 } 269 270 // If stopped, return null so that we can exit the playback loop 271 // as soon as possible. 272 if (mStopped) { 273 return null; 274 } 275 276 // Remove the first entry from the queue. 277 ListEntry entry = mDataBufferList.poll(); 278 279 // This is the normal playback loop exit case, when done() was 280 // called. (mDone will be true at this point). 281 if (entry == null) { 282 return null; 283 } 284 285 mUnconsumedBytes -= entry.mBytes.length; 286 // Unblock the waiting writer. We use signal() and not signalAll() 287 // because there will only be one thread waiting on this (the 288 // Synthesis thread). 289 mNotFull.signal(); 290 291 return entry.mBytes; 292 } finally { 293 mListLock.unlock(); 294 } 295 } 296 297 static final class ListEntry { 298 final byte[] mBytes; 299 300 ListEntry(byte[] bytes) { 301 mBytes = bytes; 302 } 303 } 304} 305