PlaylistFetcher.h revision dcb89b3b505522efde173c105a851c412f947178 
1/*
2 * Copyright (C) 2012 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#ifndef PLAYLIST_FETCHER_H_
18
19#define PLAYLIST_FETCHER_H_
20
21#include <media/stagefright/foundation/AHandler.h>
22
23#include "mpeg2ts/ATSParser.h"
24#include "LiveSession.h"
25
26namespace android {
27
28struct ABuffer;
29struct AnotherPacketSource;
30struct DataSource;
31struct HTTPBase;
32struct LiveDataSource;
33struct M3UParser;
34struct String8;
35
36struct PlaylistFetcher : public AHandler {
37    enum {
38        kWhatStarted,
39        kWhatPaused,
40        kWhatStopped,
41        kWhatError,
42        kWhatDurationUpdate,
43        kWhatTemporarilyDoneFetching,
44        kWhatPrepared,
45        kWhatPreparationFailed,
46    };
47
48    PlaylistFetcher(
49            const sp<AMessage> &notify,
50            const sp<LiveSession> &session,
51            const char *uri);
52
53    sp<DataSource> getDataSource();
54
55    void startAsync(
56            const sp<AnotherPacketSource> &audioSource,
57            const sp<AnotherPacketSource> &videoSource,
58            const sp<AnotherPacketSource> &subtitleSource,
59            int64_t startTimeUs = -1ll);
60
61    void pauseAsync();
62
63    void stopAsync();
64
65protected:
66    virtual ~PlaylistFetcher();
67    virtual void onMessageReceived(const sp<AMessage> &msg);
68
69private:
70    enum {
71        kMaxNumRetries         = 5,
72    };
73
74    enum {
75        kWhatStart          = 'strt',
76        kWhatPause          = 'paus',
77        kWhatStop           = 'stop',
78        kWhatMonitorQueue   = 'moni',
79    };
80
81    static const int64_t kMinBufferedDurationUs;
82
83    sp<AMessage> mNotify;
84    sp<LiveSession> mSession;
85    AString mURI;
86
87    uint32_t mStreamTypeMask;
88    int64_t mStartTimeUs;
89
90    KeyedVector<LiveSession::StreamType, sp<AnotherPacketSource> >
91        mPacketSources;
92
93    KeyedVector<AString, sp<ABuffer> > mAESKeyForURI;
94
95    int64_t mLastPlaylistFetchTimeUs;
96    sp<M3UParser> mPlaylist;
97    int32_t mSeqNumber;
98    int32_t mNumRetries;
99    bool mStartup;
100    int64_t mNextPTSTimeUs;
101
102    int32_t mMonitorQueueGeneration;
103
104    enum RefreshState {
105        INITIAL_MINIMUM_RELOAD_DELAY,
106        FIRST_UNCHANGED_RELOAD_ATTEMPT,
107        SECOND_UNCHANGED_RELOAD_ATTEMPT,
108        THIRD_UNCHANGED_RELOAD_ATTEMPT
109    };
110    RefreshState mRefreshState;
111
112    uint8_t mPlaylistHash[16];
113
114    sp<ATSParser> mTSParser;
115
116    bool mFirstPTSValid;
117    uint64_t mFirstPTS;
118    int64_t mAbsoluteTimeAnchorUs;
119
120    status_t decryptBuffer(
121            size_t playlistIndex, const sp<ABuffer> &buffer);
122
123    void postMonitorQueue(int64_t delayUs = 0);
124    void cancelMonitorQueue();
125
126    bool timeToRefreshPlaylist(int64_t nowUs) const;
127
128    // Returns the media time in us of the segment specified by seqNumber.
129    // This is computed by summing the durations of all segments before it.
130    int64_t getSegmentStartTimeUs(int32_t seqNumber) const;
131
132    status_t onStart(const sp<AMessage> &msg);
133    void onPause();
134    void onStop();
135    void onMonitorQueue();
136    void onDownloadNext();
137
138    status_t extractAndQueueAccessUnits(
139            const sp<ABuffer> &buffer, const sp<AMessage> &itemMeta);
140
141    void notifyError(status_t err);
142
143    void queueDiscontinuity(
144            ATSParser::DiscontinuityType type, const sp<AMessage> &extra);
145
146    int32_t getSeqNumberForTime(int64_t timeUs) const;
147
148    void updateDuration();
149
150    DISALLOW_EVIL_CONSTRUCTORS(PlaylistFetcher);
151};
152
153}  // namespace android
154
155#endif  // PLAYLIST_FETCHER_H_
156
157