MPEG2TSExtractor.cpp revision e71d10e7ad55ccbcb0756c007caef1c959090384 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of 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,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17//#define LOG_NDEBUG 0
18#define LOG_TAG "MPEG2TSExtractor"
19#include <utils/Log.h>
20
21#include "include/MPEG2TSExtractor.h"
22
23#include <media/stagefright/DataSource.h>
24#include <media/stagefright/MediaDefs.h>
25#include <media/stagefright/MediaErrors.h>
26#include <media/stagefright/MediaSource.h>
27#include <media/stagefright/MetaData.h>
28#include <utils/String8.h>
29
30#include "AnotherPacketSource.h"
31#include "ATSParser.h"
32
33namespace android {
34
35struct MPEG2TSSource : public MediaSource {
36    MPEG2TSSource(
37            const sp<MPEG2TSExtractor> &extractor,
38            const sp<AnotherPacketSource> &impl);
39
40    virtual status_t start(MetaData *params = NULL);
41    virtual status_t stop();
42    virtual sp<MetaData> getFormat();
43
44    virtual status_t read(
45            MediaBuffer **buffer, const ReadOptions *options = NULL);
46
47private:
48    sp<MPEG2TSExtractor> mExtractor;
49    sp<AnotherPacketSource> mImpl;
50
51    DISALLOW_EVIL_CONSTRUCTORS(MPEG2TSSource);
52};
53
54MPEG2TSSource::MPEG2TSSource(
55        const sp<MPEG2TSExtractor> &extractor,
56        const sp<AnotherPacketSource> &impl)
57    : mExtractor(extractor),
58      mImpl(impl) {
59}
60
61status_t MPEG2TSSource::start(MetaData *params) {
62    return mImpl->start(params);
63}
64
65status_t MPEG2TSSource::stop() {
66    return mImpl->stop();
67}
68
69sp<MetaData> MPEG2TSSource::getFormat() {
70    return mImpl->getFormat();
71}
72
73status_t MPEG2TSSource::read(
74        MediaBuffer **out, const ReadOptions *options) {
75    *out = NULL;
76
77    status_t finalResult;
78    while (!mImpl->hasBufferAvailable(&finalResult)) {
79        if (finalResult != OK) {
80            return ERROR_END_OF_STREAM;
81        }
82
83        status_t err = mExtractor->feedMore();
84        if (err != OK) {
85            mImpl->signalEOS(err);
86        }
87    }
88
89    return mImpl->read(out, options);
90}
91
92////////////////////////////////////////////////////////////////////////////////
93
94MPEG2TSExtractor::MPEG2TSExtractor(const sp<DataSource> &source)
95    : mDataSource(source),
96      mParser(new ATSParser),
97      mOffset(0) {
98    init();
99}
100
101size_t MPEG2TSExtractor::countTracks() {
102    return mSourceImpls.size();
103}
104
105sp<MediaSource> MPEG2TSExtractor::getTrack(size_t index) {
106    if (index >= mSourceImpls.size()) {
107        return NULL;
108    }
109
110    return new MPEG2TSSource(this, mSourceImpls.editItemAt(index));
111}
112
113sp<MetaData> MPEG2TSExtractor::getTrackMetaData(
114        size_t index, uint32_t flags) {
115    return index < mSourceImpls.size()
116        ? mSourceImpls.editItemAt(index)->getFormat() : NULL;
117}
118
119sp<MetaData> MPEG2TSExtractor::getMetaData() {
120    sp<MetaData> meta = new MetaData;
121    meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
122
123    return meta;
124}
125
126void MPEG2TSExtractor::init() {
127    bool haveAudio = false;
128    bool haveVideo = false;
129
130    while (feedMore() == OK) {
131        ATSParser::SourceType type;
132        if (haveAudio && haveVideo) {
133            break;
134        }
135        if (haveVideo) {
136            type = ATSParser::MPEG2ADTS_AUDIO;
137        } else {
138            type = ATSParser::AVC_VIDEO;
139        }
140        sp<AnotherPacketSource> impl =
141            (AnotherPacketSource *)mParser->getSource(type).get();
142
143        if (impl != NULL) {
144            if (type == ATSParser::MPEG2ADTS_AUDIO) {
145                haveAudio = true;
146            } else {
147                haveVideo = true;
148            }
149            mSourceImpls.push(impl);
150        }
151    }
152
153    LOGI("haveAudio=%d, haveVideo=%d", haveAudio, haveVideo);
154}
155
156status_t MPEG2TSExtractor::feedMore() {
157    Mutex::Autolock autoLock(mLock);
158
159    static const size_t kTSPacketSize = 188;
160
161    uint8_t packet[kTSPacketSize];
162    ssize_t n = mDataSource->readAt(mOffset, packet, kTSPacketSize);
163
164    if (n < (ssize_t)kTSPacketSize) {
165        return (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
166    }
167
168    mOffset += kTSPacketSize;
169    mParser->feedTSPacket(packet, kTSPacketSize);
170
171    return OK;
172}
173
174////////////////////////////////////////////////////////////////////////////////
175
176bool SniffMPEG2TS(
177        const sp<DataSource> &source, String8 *mimeType, float *confidence) {
178#if 0
179    char header;
180    if (source->readAt(0, &header, 1) != 1 || header != 0x47) {
181        return false;
182    }
183
184    *confidence = 0.05f;
185    mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
186
187    return true;
188#else
189    // For now we're going to never identify this type of stream, since we'd
190    // just base our decision on a single byte...
191    // Instead you can instantiate an MPEG2TSExtractor by explicitly stating
192    // its proper mime type in the call to MediaExtractor::Create(...).
193    return false;
194#endif
195}
196
197}  // namespace android
198