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/*
* 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);
static bool bufferStartsWithWebVTTMagicSequence(const sp<ABuffer>& buffer);
// notifications to mSession
sp<AMessage> mNotify;
sp<AMessage> mStartTimeUsNotify;
sp<LiveSession> mSession;
AString mURI;
AString mVideoMime;
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;
bool mSkipToFirstIDRAfterConnect;
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_
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