LiveSession.h revision a93fd2be99d21629bed504b9b7df035fc2f54562 
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#ifndef LIVE_SESSION_H_
18
19#define LIVE_SESSION_H_
20
21#include <media/stagefright/foundation/AHandler.h>
22#include <media/mediaplayer.h>
23
24#include <utils/String8.h>
25
26namespace android {
27
28struct ABuffer;
29struct AnotherPacketSource;
30struct DataSource;
31struct HTTPBase;
32struct IMediaHTTPService;
33struct LiveDataSource;
34struct M3UParser;
35struct PlaylistFetcher;
36struct Parcel;
37
38struct LiveSession : public AHandler {
39    enum Flags {
40        // Don't log any URLs.
41        kFlagIncognito = 1,
42    };
43    LiveSession(
44            const sp<AMessage> &notify,
45            uint32_t flags,
46            const sp<IMediaHTTPService> &httpService);
47
48    enum StreamIndex {
49        kAudioIndex    = 0,
50        kVideoIndex    = 1,
51        kSubtitleIndex = 2,
52        kMaxStreams    = 3,
53    };
54
55    enum StreamType {
56        STREAMTYPE_AUDIO        = 1 << kAudioIndex,
57        STREAMTYPE_VIDEO        = 1 << kVideoIndex,
58        STREAMTYPE_SUBTITLES    = 1 << kSubtitleIndex,
59    };
60    status_t dequeueAccessUnit(StreamType stream, sp<ABuffer> *accessUnit);
61
62    status_t getStreamFormat(StreamType stream, sp<AMessage> *format);
63
64    void connectAsync(
65            const char *url,
66            const KeyedVector<String8, String8> *headers = NULL);
67
68    status_t disconnect();
69
70    // Blocks until seek is complete.
71    status_t seekTo(int64_t timeUs);
72
73    status_t getDuration(int64_t *durationUs) const;
74    size_t getTrackCount() const;
75    sp<AMessage> getTrackInfo(size_t trackIndex) const;
76    status_t selectTrack(size_t index, bool select);
77    ssize_t getSelectedTrack(media_track_type /* type */) const;
78
79    bool isSeekable() const;
80    bool hasDynamicDuration() const;
81
82    enum {
83        kWhatStreamsChanged,
84        kWhatError,
85        kWhatPrepared,
86        kWhatPreparationFailed,
87    };
88
89    // create a format-change discontinuity
90    //
91    // swap:
92    //   whether is format-change discontinuity should trigger a buffer swap
93    sp<ABuffer> createFormatChangeBuffer(bool swap = true);
94protected:
95    virtual ~LiveSession();
96
97    virtual void onMessageReceived(const sp<AMessage> &msg);
98
99private:
100    friend struct PlaylistFetcher;
101
102    enum {
103        kWhatConnect                    = 'conn',
104        kWhatDisconnect                 = 'disc',
105        kWhatSeek                       = 'seek',
106        kWhatFetcherNotify              = 'notf',
107        kWhatCheckBandwidth             = 'bndw',
108        kWhatChangeConfiguration        = 'chC0',
109        kWhatChangeConfiguration2       = 'chC2',
110        kWhatChangeConfiguration3       = 'chC3',
111        kWhatFinishDisconnect2          = 'fin2',
112        kWhatSwapped                    = 'swap',
113        kWhatCheckSwitchDown            = 'ckSD',
114        kWhatSwitchDown                 = 'sDwn',
115    };
116
117    static const size_t kBandwidthHistoryBytes;
118
119    struct BandwidthItem {
120        size_t mPlaylistIndex;
121        unsigned long mBandwidth;
122    };
123
124    struct FetcherInfo {
125        sp<PlaylistFetcher> mFetcher;
126        int64_t mDurationUs;
127        bool mIsPrepared;
128        bool mToBeRemoved;
129    };
130
131    struct StreamItem {
132        const char *mType;
133        AString mUri, mNewUri;
134        size_t mCurDiscontinuitySeq;
135        int64_t mLastDequeuedTimeUs;
136        int64_t mLastSampleDurationUs;
137        StreamItem()
138            : mType(""),
139              mCurDiscontinuitySeq(0),
140              mLastDequeuedTimeUs(0),
141              mLastSampleDurationUs(0) {}
142        StreamItem(const char *type)
143            : mType(type),
144              mCurDiscontinuitySeq(0),
145              mLastDequeuedTimeUs(0),
146              mLastSampleDurationUs(0) {}
147        AString uriKey() {
148            AString key(mType);
149            key.append("URI");
150            return key;
151        }
152    };
153    StreamItem mStreams[kMaxStreams];
154
155    sp<AMessage> mNotify;
156    uint32_t mFlags;
157    sp<IMediaHTTPService> mHTTPService;
158
159    bool mInPreparationPhase;
160    bool mBuffering[kMaxStreams];
161
162    sp<HTTPBase> mHTTPDataSource;
163    KeyedVector<String8, String8> mExtraHeaders;
164
165    AString mMasterURL;
166
167    Vector<BandwidthItem> mBandwidthItems;
168    ssize_t mCurBandwidthIndex;
169
170    sp<M3UParser> mPlaylist;
171
172    KeyedVector<AString, FetcherInfo> mFetcherInfos;
173    uint32_t mStreamMask;
174
175    // Masks used during reconfiguration:
176    // mNewStreamMask: streams in the variant playlist we're switching to;
177    // we don't want to immediately overwrite the original value.
178    uint32_t mNewStreamMask;
179
180    // mSwapMask: streams that have started to playback content in the new variant playlist;
181    // we use this to track reconfiguration progress.
182    uint32_t mSwapMask;
183
184    KeyedVector<StreamType, sp<AnotherPacketSource> > mDiscontinuities;
185    KeyedVector<StreamType, sp<AnotherPacketSource> > mPacketSources;
186    // A second set of packet sources that buffer content for the variant we're switching to.
187    KeyedVector<StreamType, sp<AnotherPacketSource> > mPacketSources2;
188
189    // A mutex used to serialize two sets of events:
190    // * the swapping of packet sources in dequeueAccessUnit on the player thread, AND
191    // * a forced bandwidth switch termination in cancelSwitch on the live looper.
192    Mutex mSwapMutex;
193
194    int32_t mCheckBandwidthGeneration;
195    int32_t mSwitchGeneration;
196    int32_t mSubtitleGeneration;
197
198    size_t mContinuationCounter;
199    sp<AMessage> mContinuation;
200    sp<AMessage> mSeekReply;
201
202    int64_t mLastDequeuedTimeUs;
203    int64_t mRealTimeBaseUs;
204
205    bool mReconfigurationInProgress;
206    bool mSwitchInProgress;
207    uint32_t mDisconnectReplyID;
208    uint32_t mSeekReplyID;
209
210    bool mFirstTimeUsValid;
211    int64_t mFirstTimeUs;
212    int64_t mLastSeekTimeUs;
213    sp<AMessage> mSwitchDownMonitor;
214    KeyedVector<size_t, int64_t> mDiscontinuityAbsStartTimesUs;
215    KeyedVector<size_t, int64_t> mDiscontinuityOffsetTimesUs;
216
217    sp<PlaylistFetcher> addFetcher(const char *uri);
218
219    void onConnect(const sp<AMessage> &msg);
220    status_t onSeek(const sp<AMessage> &msg);
221    void onFinishDisconnect2();
222
223    // If given a non-zero block_size (default 0), it is used to cap the number of
224    // bytes read in from the DataSource. If given a non-NULL buffer, new content
225    // is read into the end.
226    //
227    // The DataSource we read from is responsible for signaling error or EOF to help us
228    // break out of the read loop. The DataSource can be returned to the caller, so
229    // that the caller can reuse it for subsequent fetches (within the initially
230    // requested range).
231    //
232    // For reused HTTP sources, the caller must download a file sequentially without
233    // any overlaps or gaps to prevent reconnection.
234    ssize_t fetchFile(
235            const char *url, sp<ABuffer> *out,
236            /* request/open a file starting at range_offset for range_length bytes */
237            int64_t range_offset = 0, int64_t range_length = -1,
238            /* download block size */
239            uint32_t block_size = 0,
240            /* reuse DataSource if doing partial fetch */
241            sp<DataSource> *source = NULL,
242            String8 *actualUrl = NULL);
243
244    sp<M3UParser> fetchPlaylist(
245            const char *url, uint8_t *curPlaylistHash, bool *unchanged);
246
247    size_t getBandwidthIndex();
248    int64_t latestMediaSegmentStartTimeUs();
249
250    static int SortByBandwidth(const BandwidthItem *, const BandwidthItem *);
251    static StreamType indexToType(int idx);
252    static ssize_t typeToIndex(int32_t type);
253
254    void changeConfiguration(
255            int64_t timeUs, size_t bandwidthIndex, bool pickTrack = false);
256    void onChangeConfiguration(const sp<AMessage> &msg);
257    void onChangeConfiguration2(const sp<AMessage> &msg);
258    void onChangeConfiguration3(const sp<AMessage> &msg);
259    void onSwapped(const sp<AMessage> &msg);
260    void onCheckSwitchDown();
261    void onSwitchDown();
262    void tryToFinishBandwidthSwitch();
263
264    void scheduleCheckBandwidthEvent();
265    void cancelCheckBandwidthEvent();
266
267    // cancelBandwidthSwitch is atomic wrt swapPacketSource; call it to prevent packet sources
268    // from being swapped out on stale discontinuities while manipulating
269    // mPacketSources/mPacketSources2.
270    void cancelBandwidthSwitch();
271
272    bool canSwitchBandwidthTo(size_t bandwidthIndex);
273    void onCheckBandwidth(const sp<AMessage> &msg);
274
275    void finishDisconnect();
276
277    void postPrepared(status_t err);
278
279    void swapPacketSource(StreamType stream);
280    bool canSwitchUp();
281
282    DISALLOW_EVIL_CONSTRUCTORS(LiveSession);
283};
284
285}  // namespace android
286
287#endif  // LIVE_SESSION_H_
288