MPEG2TSExtractor.cpp revision 5d7c3eef1985ff15a56920c548cc4e41d6c9627a 
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#include "include/NuCachedSource2.h"
23
24#include <media/stagefright/foundation/ADebug.h>
25#include <media/stagefright/DataSource.h>
26#include <media/stagefright/MediaDefs.h>
27#include <media/stagefright/MediaErrors.h>
28#include <media/stagefright/MediaSource.h>
29#include <media/stagefright/MetaData.h>
30#include <utils/String8.h>
31
32#include "AnotherPacketSource.h"
33#include "ATSParser.h"
34
35namespace android {
36
37static const size_t kTSPacketSize = 188;
38
39struct MPEG2TSSource : public MediaSource {
40    MPEG2TSSource(
41            const sp<MPEG2TSExtractor> &extractor,
42            const sp<AnotherPacketSource> &impl,
43            bool seekable);
44
45    virtual status_t start(MetaData *params = NULL);
46    virtual status_t stop();
47    virtual sp<MetaData> getFormat();
48
49    virtual status_t read(
50            MediaBuffer **buffer, const ReadOptions *options = NULL);
51
52private:
53    sp<MPEG2TSExtractor> mExtractor;
54    sp<AnotherPacketSource> mImpl;
55
56    // If there are both audio and video streams, only the video stream
57    // will be seekable, otherwise the single stream will be seekable.
58    bool mSeekable;
59
60    DISALLOW_EVIL_CONSTRUCTORS(MPEG2TSSource);
61};
62
63MPEG2TSSource::MPEG2TSSource(
64        const sp<MPEG2TSExtractor> &extractor,
65        const sp<AnotherPacketSource> &impl,
66        bool seekable)
67    : mExtractor(extractor),
68      mImpl(impl),
69      mSeekable(seekable) {
70}
71
72status_t MPEG2TSSource::start(MetaData *params) {
73    return mImpl->start(params);
74}
75
76status_t MPEG2TSSource::stop() {
77    return mImpl->stop();
78}
79
80sp<MetaData> MPEG2TSSource::getFormat() {
81    return mImpl->getFormat();
82}
83
84status_t MPEG2TSSource::read(
85        MediaBuffer **out, const ReadOptions *options) {
86    *out = NULL;
87
88    status_t finalResult;
89    while (!mImpl->hasBufferAvailable(&finalResult)) {
90        if (finalResult != OK) {
91            return ERROR_END_OF_STREAM;
92        }
93
94        status_t err = mExtractor->feedMore();
95        if (err != OK) {
96            mImpl->signalEOS(err);
97        }
98    }
99
100    int64_t seekTimeUs;
101    ReadOptions::SeekMode seekMode;
102    if (mSeekable && options && options->getSeekTo(&seekTimeUs, &seekMode)) {
103        // A seek was requested, but we don't actually support seeking and so can only "seek" to
104        // the current position
105        int64_t nextBufTimeUs;
106        if (mImpl->nextBufferTime(&nextBufTimeUs) != OK || seekTimeUs != nextBufTimeUs) {
107            return ERROR_UNSUPPORTED;
108        }
109    }
110
111    return mImpl->read(out, options);
112}
113
114////////////////////////////////////////////////////////////////////////////////
115
116MPEG2TSExtractor::MPEG2TSExtractor(const sp<DataSource> &source)
117    : mDataSource(source),
118      mParser(new ATSParser),
119      mOffset(0) {
120    init();
121}
122
123size_t MPEG2TSExtractor::countTracks() {
124    return mSourceImpls.size();
125}
126
127sp<MediaSource> MPEG2TSExtractor::getTrack(size_t index) {
128    if (index >= mSourceImpls.size()) {
129        return NULL;
130    }
131
132    bool seekable = true;
133    if (mSourceImpls.size() > 1) {
134        CHECK_EQ(mSourceImpls.size(), 2u);
135
136        sp<MetaData> meta = mSourceImpls.editItemAt(index)->getFormat();
137        const char *mime;
138        CHECK(meta->findCString(kKeyMIMEType, &mime));
139
140        if (!strncasecmp("audio/", mime, 6)) {
141            seekable = false;
142        }
143    }
144
145    return new MPEG2TSSource(this, mSourceImpls.editItemAt(index), seekable);
146}
147
148sp<MetaData> MPEG2TSExtractor::getTrackMetaData(
149        size_t index, uint32_t /* flags */) {
150    return index < mSourceImpls.size()
151        ? mSourceImpls.editItemAt(index)->getFormat() : NULL;
152}
153
154sp<MetaData> MPEG2TSExtractor::getMetaData() {
155    sp<MetaData> meta = new MetaData;
156    meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
157
158    return meta;
159}
160
161void MPEG2TSExtractor::init() {
162    bool haveAudio = false;
163    bool haveVideo = false;
164    int numPacketsParsed = 0;
165
166    while (feedMore() == OK) {
167        if (haveAudio && haveVideo) {
168            break;
169        }
170        if (!haveVideo) {
171            sp<AnotherPacketSource> impl =
172                (AnotherPacketSource *)mParser->getSource(
173                        ATSParser::VIDEO).get();
174
175            if (impl != NULL) {
176                haveVideo = true;
177                mSourceImpls.push(impl);
178            }
179        }
180
181        if (!haveAudio) {
182            sp<AnotherPacketSource> impl =
183                (AnotherPacketSource *)mParser->getSource(
184                        ATSParser::AUDIO).get();
185
186            if (impl != NULL) {
187                haveAudio = true;
188                mSourceImpls.push(impl);
189            }
190        }
191
192        if (++numPacketsParsed > 10000) {
193            break;
194        }
195    }
196
197    ALOGI("haveAudio=%d, haveVideo=%d", haveAudio, haveVideo);
198}
199
200status_t MPEG2TSExtractor::feedMore() {
201    Mutex::Autolock autoLock(mLock);
202
203    uint8_t packet[kTSPacketSize];
204    ssize_t n = mDataSource->readAt(mOffset, packet, kTSPacketSize);
205
206    if (n < (ssize_t)kTSPacketSize) {
207        return (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
208    }
209
210    mOffset += n;
211    return mParser->feedTSPacket(packet, kTSPacketSize);
212}
213
214uint32_t MPEG2TSExtractor::flags() const {
215    return CAN_PAUSE;
216}
217
218////////////////////////////////////////////////////////////////////////////////
219
220bool SniffMPEG2TS(
221        const sp<DataSource> &source, String8 *mimeType, float *confidence,
222        sp<AMessage> *) {
223    for (int i = 0; i < 5; ++i) {
224        char header;
225        if (source->readAt(kTSPacketSize * i, &header, 1) != 1
226                || header != 0x47) {
227            return false;
228        }
229    }
230
231    *confidence = 0.1f;
232    mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
233
234    return true;
235}
236
237}  // namespace android
238