Narayan Kamath | 67ae6bc | 2011-11-30 14:51:00 +0000 | [diff] [blame] | 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.speech.tts.TextToSpeechService.UtteranceProgressDispatcher; |
| 19 | import android.util.Log; |
| 20 | |
| 21 | import java.util.LinkedList; |
| 22 | import java.util.concurrent.locks.Condition; |
| 23 | import java.util.concurrent.locks.Lock; |
| 24 | import java.util.concurrent.locks.ReentrantLock; |
| 25 | |
| 26 | /** |
| 27 | * Manages the playback of a list of byte arrays representing audio data |
| 28 | * that are queued by the engine to an audio track. |
| 29 | */ |
| 30 | final class SynthesisPlaybackQueueItem extends PlaybackQueueItem { |
| 31 | private static final String TAG = "TTS.SynthQueueItem"; |
| 32 | private static final boolean DBG = false; |
| 33 | |
| 34 | /** |
| 35 | * Maximum length of audio we leave unconsumed by the audio track. |
| 36 | * Calls to {@link #put(byte[])} will block until we have less than |
| 37 | * this amount of audio left to play back. |
| 38 | */ |
| 39 | private static final long MAX_UNCONSUMED_AUDIO_MS = 500; |
| 40 | |
| 41 | /** |
| 42 | * Guards accesses to mDataBufferList and mUnconsumedBytes. |
| 43 | */ |
| 44 | private final Lock mListLock = new ReentrantLock(); |
| 45 | private final Condition mReadReady = mListLock.newCondition(); |
| 46 | private final Condition mNotFull = mListLock.newCondition(); |
| 47 | |
| 48 | // Guarded by mListLock. |
| 49 | private final LinkedList<ListEntry> mDataBufferList = new LinkedList<ListEntry>(); |
| 50 | // Guarded by mListLock. |
| 51 | private int mUnconsumedBytes; |
| 52 | |
| 53 | /* |
| 54 | * While mStopped and mIsError can be written from any thread, mDone is written |
| 55 | * only from the synthesis thread. All three variables are read from the |
| 56 | * audio playback thread. |
| 57 | */ |
| 58 | private volatile boolean mStopped; |
| 59 | private volatile boolean mDone; |
| 60 | private volatile boolean mIsError; |
| 61 | |
| 62 | private final BlockingAudioTrack mAudioTrack; |
| 63 | private final EventLogger mLogger; |
| 64 | |
| 65 | |
| 66 | SynthesisPlaybackQueueItem(int streamType, int sampleRate, |
| 67 | int audioFormat, int channelCount, |
| 68 | float volume, float pan, UtteranceProgressDispatcher dispatcher, |
| 69 | Object callerIdentity, EventLogger logger) { |
| 70 | super(dispatcher, callerIdentity); |
| 71 | |
| 72 | mUnconsumedBytes = 0; |
| 73 | |
| 74 | mStopped = false; |
| 75 | mDone = false; |
| 76 | mIsError = false; |
| 77 | |
| 78 | mAudioTrack = new BlockingAudioTrack(streamType, sampleRate, audioFormat, |
| 79 | channelCount, volume, pan); |
| 80 | mLogger = logger; |
| 81 | } |
| 82 | |
| 83 | |
| 84 | @Override |
| 85 | public void run() { |
| 86 | final UtteranceProgressDispatcher dispatcher = getDispatcher(); |
| 87 | dispatcher.dispatchOnStart(); |
| 88 | |
| 89 | |
Narayan Kamath | ed4e541 | 2012-06-09 17:31:39 +0100 | [diff] [blame] | 90 | if (!mAudioTrack.init()) { |
| 91 | dispatcher.dispatchOnError(); |
| 92 | return; |
| 93 | } |
Narayan Kamath | 67ae6bc | 2011-11-30 14:51:00 +0000 | [diff] [blame] | 94 | |
| 95 | try { |
| 96 | byte[] buffer = null; |
| 97 | |
| 98 | // take() will block until: |
| 99 | // |
| 100 | // (a) there is a buffer available to tread. In which case |
| 101 | // a non null value is returned. |
| 102 | // OR (b) stop() is called in which case it will return null. |
| 103 | // OR (c) done() is called in which case it will return null. |
| 104 | while ((buffer = take()) != null) { |
| 105 | mAudioTrack.write(buffer); |
| 106 | mLogger.onAudioDataWritten(); |
| 107 | } |
| 108 | |
| 109 | } catch (InterruptedException ie) { |
| 110 | if (DBG) Log.d(TAG, "Interrupted waiting for buffers, cleaning up."); |
| 111 | } |
| 112 | |
| 113 | mAudioTrack.waitAndRelease(); |
| 114 | |
| 115 | if (mIsError) { |
| 116 | dispatcher.dispatchOnError(); |
| 117 | } else { |
| 118 | dispatcher.dispatchOnDone(); |
| 119 | } |
| 120 | |
| 121 | mLogger.onWriteData(); |
| 122 | } |
| 123 | |
| 124 | @Override |
| 125 | void stop(boolean isError) { |
| 126 | try { |
| 127 | mListLock.lock(); |
| 128 | |
| 129 | // Update our internal state. |
| 130 | mStopped = true; |
| 131 | mIsError = isError; |
| 132 | |
| 133 | // Wake up the audio playback thread if it was waiting on take(). |
| 134 | // take() will return null since mStopped was true, and will then |
| 135 | // break out of the data write loop. |
| 136 | mReadReady.signal(); |
| 137 | |
| 138 | // Wake up the synthesis thread if it was waiting on put(). Its |
| 139 | // buffers will no longer be copied since mStopped is true. The |
| 140 | // PlaybackSynthesisCallback that this synthesis corresponds to |
| 141 | // would also have been stopped, and so all calls to |
| 142 | // Callback.onDataAvailable( ) will return errors too. |
| 143 | mNotFull.signal(); |
| 144 | } finally { |
| 145 | mListLock.unlock(); |
| 146 | } |
| 147 | |
| 148 | // Stop the underlying audio track. This will stop sending |
| 149 | // data to the mixer and discard any pending buffers that the |
| 150 | // track holds. |
| 151 | mAudioTrack.stop(); |
| 152 | } |
| 153 | |
| 154 | void done() { |
| 155 | try { |
| 156 | mListLock.lock(); |
| 157 | |
| 158 | // Update state. |
| 159 | mDone = true; |
| 160 | |
| 161 | // Unblocks the audio playback thread if it was waiting on take() |
| 162 | // after having consumed all available buffers. It will then return |
| 163 | // null and leave the write loop. |
| 164 | mReadReady.signal(); |
| 165 | |
| 166 | // Just so that engines that try to queue buffers after |
| 167 | // calling done() don't block the synthesis thread forever. Ideally |
| 168 | // this should be called from the same thread as put() is, and hence |
| 169 | // this call should be pointless. |
| 170 | mNotFull.signal(); |
| 171 | } finally { |
| 172 | mListLock.unlock(); |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | |
| 177 | void put(byte[] buffer) throws InterruptedException { |
| 178 | try { |
| 179 | mListLock.lock(); |
| 180 | long unconsumedAudioMs = 0; |
| 181 | |
| 182 | while ((unconsumedAudioMs = mAudioTrack.getAudioLengthMs(mUnconsumedBytes)) > |
| 183 | MAX_UNCONSUMED_AUDIO_MS && !mStopped) { |
| 184 | mNotFull.await(); |
| 185 | } |
| 186 | |
| 187 | // Don't bother queueing the buffer if we've stopped. The playback thread |
| 188 | // would have woken up when stop() is called (if it was blocked) and will |
| 189 | // proceed to leave the write loop since take() will return null when |
| 190 | // stopped. |
| 191 | if (mStopped) { |
| 192 | return; |
| 193 | } |
| 194 | |
| 195 | mDataBufferList.add(new ListEntry(buffer)); |
| 196 | mUnconsumedBytes += buffer.length; |
| 197 | mReadReady.signal(); |
| 198 | } finally { |
| 199 | mListLock.unlock(); |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | private byte[] take() throws InterruptedException { |
| 204 | try { |
| 205 | mListLock.lock(); |
| 206 | |
| 207 | // Block if there are no available buffers, and stop() has not |
| 208 | // been called and done() has not been called. |
| 209 | while (mDataBufferList.size() == 0 && !mStopped && !mDone) { |
| 210 | mReadReady.await(); |
| 211 | } |
| 212 | |
| 213 | // If stopped, return null so that we can exit the playback loop |
| 214 | // as soon as possible. |
| 215 | if (mStopped) { |
| 216 | return null; |
| 217 | } |
| 218 | |
| 219 | // Remove the first entry from the queue. |
| 220 | ListEntry entry = mDataBufferList.poll(); |
| 221 | |
| 222 | // This is the normal playback loop exit case, when done() was |
| 223 | // called. (mDone will be true at this point). |
| 224 | if (entry == null) { |
| 225 | return null; |
| 226 | } |
| 227 | |
| 228 | mUnconsumedBytes -= entry.mBytes.length; |
| 229 | // Unblock the waiting writer. We use signal() and not signalAll() |
| 230 | // because there will only be one thread waiting on this (the |
| 231 | // Synthesis thread). |
| 232 | mNotFull.signal(); |
| 233 | |
| 234 | return entry.mBytes; |
| 235 | } finally { |
| 236 | mListLock.unlock(); |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | static final class ListEntry { |
| 241 | final byte[] mBytes; |
| 242 | |
| 243 | ListEntry(byte[] bytes) { |
| 244 | mBytes = bytes; |
| 245 | } |
| 246 | } |
| 247 | } |