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Diffstat (limited to 'media/libstagefright/httplive/PlaylistFetcher.h')
| -rw-r--r-- | media/libstagefright/httplive/PlaylistFetcher.h | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/media/libstagefright/httplive/PlaylistFetcher.h b/media/libstagefright/httplive/PlaylistFetcher.h new file mode 100644 index 0000000..7e21523 --- /dev/null +++ b/media/libstagefright/httplive/PlaylistFetcher.h @@ -0,0 +1,199 @@ +/* + * Copyright (C) 2012 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. + */ + +#ifndef PLAYLIST_FETCHER_H_ + +#define PLAYLIST_FETCHER_H_ + +#include <media/stagefright/foundation/AHandler.h> + +#include "mpeg2ts/ATSParser.h" +#include "LiveSession.h" + +namespace android { + +struct ABuffer; +struct AnotherPacketSource; +struct DataSource; +struct HTTPBase; +struct LiveDataSource; +struct M3UParser; +struct String8; + +struct PlaylistFetcher : public AHandler { + enum { + kWhatStarted, + kWhatPaused, + kWhatStopped, + kWhatError, + kWhatDurationUpdate, + kWhatTemporarilyDoneFetching, + kWhatPrepared, + kWhatPreparationFailed, + kWhatStartedAt, + }; + + PlaylistFetcher( + const sp<AMessage> ¬ify, + const sp<LiveSession> &session, + const char *uri); + + sp<DataSource> getDataSource(); + + void startAsync( + const sp<AnotherPacketSource> &audioSource, + const sp<AnotherPacketSource> &videoSource, + const sp<AnotherPacketSource> &subtitleSource, + int64_t startTimeUs = -1ll, + int64_t minStartTimeUs = 0ll /* start after this timestamp */, + int32_t startSeqNumberHint = -1 /* try starting at this sequence number */); + + void pauseAsync(); + + void stopAsync(bool selfTriggered = false); + + void resumeUntilAsync(const sp<AMessage> ¶ms); + +protected: + virtual ~PlaylistFetcher(); + virtual void onMessageReceived(const sp<AMessage> &msg); + +private: + enum { + kMaxNumRetries = 5, + }; + + enum { + kWhatStart = 'strt', + kWhatPause = 'paus', + kWhatStop = 'stop', + kWhatMonitorQueue = 'moni', + kWhatResumeUntil = 'rsme', + kWhatDownloadNext = 'dlnx', + }; + + static const int64_t kMinBufferedDurationUs; + static const int64_t kMaxMonitorDelayUs; + static const int32_t kDownloadBlockSize; + static const int32_t kNumSkipFrames; + + static bool bufferStartsWithTsSyncByte(const sp<ABuffer>& buffer); + + // notifications to mSession + sp<AMessage> mNotify; + sp<AMessage> mStartTimeUsNotify; + + sp<LiveSession> mSession; + AString mURI; + + uint32_t mStreamTypeMask; + int64_t mStartTimeUs; + int64_t mMinStartTimeUs; // start fetching no earlier than this value + sp<AMessage> mStopParams; // message containing the latest timestamps we should fetch. + + KeyedVector<LiveSession::StreamType, sp<AnotherPacketSource> > + mPacketSources; + + KeyedVector<AString, sp<ABuffer> > mAESKeyForURI; + + int64_t mLastPlaylistFetchTimeUs; + sp<M3UParser> mPlaylist; + int32_t mSeqNumber; + int32_t mNumRetries; + bool mStartup; + bool mPrepared; + int64_t mNextPTSTimeUs; + + int32_t mMonitorQueueGeneration; + + enum RefreshState { + INITIAL_MINIMUM_RELOAD_DELAY, + FIRST_UNCHANGED_RELOAD_ATTEMPT, + SECOND_UNCHANGED_RELOAD_ATTEMPT, + THIRD_UNCHANGED_RELOAD_ATTEMPT + }; + RefreshState mRefreshState; + + uint8_t mPlaylistHash[16]; + + sp<ATSParser> mTSParser; + + bool mFirstPTSValid; + uint64_t mFirstPTS; + int64_t mAbsoluteTimeAnchorUs; + + // Stores the initialization vector to decrypt the next block of cipher text, which can + // either be derived from the sequence number, read from the manifest, or copied from + // the last block of cipher text (cipher-block chaining). + unsigned char mAESInitVec[16]; + + // Set first to true if decrypting the first segment of a playlist segment. When + // first is true, reset the initialization vector based on the available + // information in the manifest; otherwise, use the initialization vector as + // updated by the last call to AES_cbc_encrypt. + // + // For the input to decrypt correctly, decryptBuffer must be called on + // consecutive byte ranges on block boundaries, e.g. 0..15, 16..47, 48..63, + // and so on. + status_t decryptBuffer( + size_t playlistIndex, const sp<ABuffer> &buffer, + bool first = true); + status_t checkDecryptPadding(const sp<ABuffer> &buffer); + + void postMonitorQueue(int64_t delayUs = 0, int64_t minDelayUs = 0); + void cancelMonitorQueue(); + + int64_t delayUsToRefreshPlaylist() const; + status_t refreshPlaylist(); + + // Returns the media time in us of the segment specified by seqNumber. + // This is computed by summing the durations of all segments before it. + int64_t getSegmentStartTimeUs(int32_t seqNumber) const; + + status_t onStart(const sp<AMessage> &msg); + void onPause(); + void onStop(const sp<AMessage> &msg); + void onMonitorQueue(); + void onDownloadNext(); + + // Resume a fetcher to continue until the stopping point stored in msg. + status_t onResumeUntil(const sp<AMessage> &msg); + + status_t extractAndQueueAccessUnitsFromTs(const sp<ABuffer> &buffer); + + status_t extractAndQueueAccessUnits( + const sp<ABuffer> &buffer, const sp<AMessage> &itemMeta); + + void notifyError(status_t err); + + void queueDiscontinuity( + ATSParser::DiscontinuityType type, const sp<AMessage> &extra); + + int32_t getSeqNumberForTime(int64_t timeUs) const; + + void updateDuration(); + + // Before resuming a fetcher in onResume, check the remaining duration is longer than that + // returned by resumeThreshold. + int64_t resumeThreshold(const sp<AMessage> &msg); + + DISALLOW_EVIL_CONSTRUCTORS(PlaylistFetcher); +}; + +} // namespace android + +#endif // PLAYLIST_FETCHER_H_ + |