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
|
/*
* Copyright (C) 2017 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 org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts;
import static org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.FLAG_DATA_ALIGNMENT_INDICATOR;
import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
import org.mozilla.thirdparty.com.google.android.exoplayer2.Format;
import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorOutput;
import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.TrackOutput;
import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.DvbSubtitleInfo;
import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
import org.mozilla.thirdparty.com.google.android.exoplayer2.util.MimeTypes;
import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray;
import java.util.Collections;
import java.util.List;
/**
* Parses DVB subtitle data and extracts individual frames.
*/
public final class DvbSubtitleReader implements ElementaryStreamReader {
private final List<DvbSubtitleInfo> subtitleInfos;
private final TrackOutput[] outputs;
private boolean writingSample;
private int bytesToCheck;
private int sampleBytesWritten;
private long sampleTimeUs;
/**
* @param subtitleInfos Information about the DVB subtitles associated to the stream.
*/
public DvbSubtitleReader(List<DvbSubtitleInfo> subtitleInfos) {
this.subtitleInfos = subtitleInfos;
outputs = new TrackOutput[subtitleInfos.size()];
}
@Override
public void seek() {
writingSample = false;
}
@Override
public void createTracks(ExtractorOutput extractorOutput, TrackIdGenerator idGenerator) {
for (int i = 0; i < outputs.length; i++) {
DvbSubtitleInfo subtitleInfo = subtitleInfos.get(i);
idGenerator.generateNewId();
TrackOutput output = extractorOutput.track(idGenerator.getTrackId(), C.TRACK_TYPE_TEXT);
output.format(
Format.createImageSampleFormat(
idGenerator.getFormatId(),
MimeTypes.APPLICATION_DVBSUBS,
null,
Format.NO_VALUE,
0,
Collections.singletonList(subtitleInfo.initializationData),
subtitleInfo.language,
null));
outputs[i] = output;
}
}
@Override
public void packetStarted(long pesTimeUs, @TsPayloadReader.Flags int flags) {
if ((flags & FLAG_DATA_ALIGNMENT_INDICATOR) == 0) {
return;
}
writingSample = true;
sampleTimeUs = pesTimeUs;
sampleBytesWritten = 0;
bytesToCheck = 2;
}
@Override
public void packetFinished() {
if (writingSample) {
for (TrackOutput output : outputs) {
output.sampleMetadata(sampleTimeUs, C.BUFFER_FLAG_KEY_FRAME, sampleBytesWritten, 0, null);
}
writingSample = false;
}
}
@Override
public void consume(ParsableByteArray data) {
if (writingSample) {
if (bytesToCheck == 2 && !checkNextByte(data, 0x20)) {
// Failed to check data_identifier
return;
}
if (bytesToCheck == 1 && !checkNextByte(data, 0x00)) {
// Check and discard the subtitle_stream_id
return;
}
int dataPosition = data.getPosition();
int bytesAvailable = data.bytesLeft();
for (TrackOutput output : outputs) {
data.setPosition(dataPosition);
output.sampleData(data, bytesAvailable);
}
sampleBytesWritten += bytesAvailable;
}
}
private boolean checkNextByte(ParsableByteArray data, int expectedValue) {
if (data.bytesLeft() == 0) {
return false;
}
if (data.readUnsignedByte() != expectedValue) {
writingSample = false;
}
bytesToCheck--;
return writingSample;
}
}
|
