/
TextTrackRenderer.java
308 lines (268 loc) · 9.38 KB
/
TextTrackRenderer.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.android.exoplayer.text;
import com.google.android.exoplayer.ExoPlaybackException;
import com.google.android.exoplayer.MediaFormatHolder;
import com.google.android.exoplayer.SampleHolder;
import com.google.android.exoplayer.SampleSource;
import com.google.android.exoplayer.TrackRenderer;
import com.google.android.exoplayer.util.Assertions;
import com.google.android.exoplayer.util.VerboseLogUtil;
import android.annotation.TargetApi;
import android.os.Handler;
import android.os.Handler.Callback;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
import java.io.IOException;
/**
* A {@link TrackRenderer} for textual subtitles. The actual rendering of each line of text to a
* suitable output (e.g. the display) is delegated to a {@link TextRenderer}.
*/
@TargetApi(16)
public class TextTrackRenderer extends TrackRenderer implements Callback {
/**
* An interface for components that render text.
*/
public interface TextRenderer {
/**
* Invoked each time there is a change in the text to be rendered.
*
* @param text The text to render, or null if no text is to be rendered.
*/
void onText(String text);
}
private static final String TAG = "TextTrackRenderer";
private static final int MSG_UPDATE_OVERLAY = 0;
private final Handler textRendererHandler;
private final TextRenderer textRenderer;
private final SampleSource source;
private final MediaFormatHolder formatHolder;
private final SubtitleParser subtitleParser;
private int trackIndex;
private long currentPositionUs;
private boolean inputStreamEnded;
private Subtitle subtitle;
private SubtitleParserHelper parserHelper;
private HandlerThread parserThread;
private int nextSubtitleEventIndex;
private boolean textRendererNeedsUpdate;
/**
* @param source A source from which samples containing subtitle data can be read.
* @param subtitleParser A subtitle parser that will parse Subtitle objects from the source.
* @param textRenderer The text renderer.
* @param textRendererLooper The looper associated with the thread on which textRenderer should be
* invoked. If the renderer makes use of standard Android UI components, then this should
* normally be the looper associated with the applications' main thread, which can be
* obtained using {@link android.app.Activity#getMainLooper()}. Null may be passed if the
* renderer should be invoked directly on the player's internal rendering thread.
*/
public TextTrackRenderer(SampleSource source, SubtitleParser subtitleParser,
TextRenderer textRenderer, Looper textRendererLooper) {
this.source = Assertions.checkNotNull(source);
this.subtitleParser = Assertions.checkNotNull(subtitleParser);
this.textRenderer = Assertions.checkNotNull(textRenderer);
this.textRendererHandler = textRendererLooper == null ? null : new Handler(textRendererLooper,
this);
formatHolder = new MediaFormatHolder();
}
@Override
protected int doPrepare() throws ExoPlaybackException {
try {
boolean sourcePrepared = source.prepare();
if (!sourcePrepared) {
return TrackRenderer.STATE_UNPREPARED;
}
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
for (int i = 0; i < source.getTrackCount(); i++) {
if (subtitleParser.canParse(source.getTrackInfo(i).mimeType)) {
trackIndex = i;
return TrackRenderer.STATE_PREPARED;
}
}
return TrackRenderer.STATE_IGNORE;
}
@Override
protected void onEnabled(long timeUs, boolean joining) {
source.enable(trackIndex, timeUs);
parserThread = new HandlerThread("textParser");
parserThread.start();
parserHelper = new SubtitleParserHelper(parserThread.getLooper(), subtitleParser);
seekToInternal(timeUs);
}
@Override
protected void seekTo(long timeUs) {
source.seekToUs(timeUs);
seekToInternal(timeUs);
}
private void seekToInternal(long timeUs) {
inputStreamEnded = false;
currentPositionUs = timeUs;
source.seekToUs(timeUs);
if (subtitle != null && (timeUs < subtitle.getStartTime()
|| subtitle.getLastEventTime() <= timeUs)) {
subtitle = null;
}
parserHelper.flush();
clearTextRenderer();
syncNextEventIndex(timeUs);
textRendererNeedsUpdate = subtitle != null;
}
@Override
protected void doSomeWork(long timeUs) throws ExoPlaybackException {
try {
source.continueBuffering(timeUs);
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
currentPositionUs = timeUs;
if (parserHelper.isParsing()) {
return;
}
Subtitle dequeuedSubtitle = null;
if (subtitle == null) {
try {
dequeuedSubtitle = parserHelper.getAndClearResult();
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
}
if (subtitle == null && dequeuedSubtitle != null) {
// We've dequeued a new subtitle. Sync the event index and update the subtitle.
subtitle = dequeuedSubtitle;
syncNextEventIndex(timeUs);
textRendererNeedsUpdate = true;
} else if (subtitle != null) {
// We're iterating through the events in a subtitle. Set textRendererNeedsUpdate if we
// advance to the next event.
long nextEventTimeUs = getNextEventTime();
while (nextEventTimeUs <= timeUs) {
nextSubtitleEventIndex++;
nextEventTimeUs = getNextEventTime();
textRendererNeedsUpdate = true;
}
if (nextEventTimeUs == Long.MAX_VALUE) {
// We've finished processing the subtitle.
subtitle = null;
}
}
// We don't have a subtitle. Try and read the next one from the source, and if we succeed then
// sync and set textRendererNeedsUpdate.
if (subtitle == null) {
try {
SampleHolder sampleHolder = parserHelper.getSampleHolder();
int result = source.readData(trackIndex, timeUs, formatHolder, sampleHolder, false);
if (result == SampleSource.SAMPLE_READ) {
parserHelper.startParseOperation();
} else if (result == SampleSource.END_OF_STREAM) {
inputStreamEnded = true;
}
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
}
// Update the text renderer if we're both playing and textRendererNeedsUpdate is set.
if (textRendererNeedsUpdate && getState() == TrackRenderer.STATE_STARTED) {
textRendererNeedsUpdate = false;
if (subtitle == null) {
clearTextRenderer();
} else {
updateTextRenderer(timeUs);
}
}
}
@Override
protected void onDisabled() {
source.disable(trackIndex);
subtitle = null;
parserThread.quit();
parserThread = null;
parserHelper = null;
clearTextRenderer();
}
@Override
protected void onReleased() {
source.release();
}
@Override
protected long getCurrentPositionUs() {
return currentPositionUs;
}
@Override
protected long getDurationUs() {
return source.getTrackInfo(trackIndex).durationUs;
}
@Override
protected long getBufferedPositionUs() {
// Don't block playback whilst subtitles are loading.
return END_OF_TRACK_US;
}
@Override
protected boolean isEnded() {
return inputStreamEnded && subtitle == null;
}
@Override
protected boolean isReady() {
// Don't block playback whilst subtitles are loading.
// Note: To change this behavior, it will be necessary to consider [redacted].
return true;
}
private void syncNextEventIndex(long timeUs) {
nextSubtitleEventIndex = subtitle == null ? -1 : subtitle.getNextEventTimeIndex(timeUs);
}
private long getNextEventTime() {
return ((nextSubtitleEventIndex == -1)
|| (nextSubtitleEventIndex >= subtitle.getEventTimeCount())) ? Long.MAX_VALUE
: (subtitle.getEventTime(nextSubtitleEventIndex));
}
private void updateTextRenderer(long timeUs) {
String text = subtitle.getText(timeUs);
log("updateTextRenderer; text=: " + text);
if (textRendererHandler != null) {
textRendererHandler.obtainMessage(MSG_UPDATE_OVERLAY, text).sendToTarget();
} else {
invokeTextRenderer(text);
}
}
private void clearTextRenderer() {
log("clearTextRenderer");
if (textRendererHandler != null) {
textRendererHandler.obtainMessage(MSG_UPDATE_OVERLAY, null).sendToTarget();
} else {
invokeTextRenderer(null);
}
}
@Override
public boolean handleMessage(Message msg) {
switch (msg.what) {
case MSG_UPDATE_OVERLAY:
invokeTextRenderer((String) msg.obj);
return true;
}
return false;
}
private void invokeTextRenderer(String text) {
textRenderer.onText(text);
}
private void log(String logMessage) {
if (VerboseLogUtil.isTagEnabled(TAG)) {
Log.v(TAG, logMessage);
}
}
}