TSPacketizer.h revision 90a92053219ae50ddf4bb54e3d54db2d309e2b8d 
1/*
2 * Copyright 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 TS_PACKETIZER_H_
18
19#define TS_PACKETIZER_H_
20
21#include <media/stagefright/foundation/ABase.h>
22#include <utils/Errors.h>
23#include <utils/RefBase.h>
24#include <utils/Vector.h>
25
26namespace android {
27
28struct ABuffer;
29struct AMessage;
30
31// Forms the packets of a transport stream given access units.
32// Emits metadata tables (PAT and PMT) and timestamp stream (PCR) based
33// on flags.
34struct TSPacketizer : public RefBase {
35    TSPacketizer();
36
37    // Returns trackIndex or error.
38    ssize_t addTrack(const sp<AMessage> &format);
39
40    enum {
41        EMIT_PAT_AND_PMT                = 1,
42        EMIT_PCR                        = 2,
43        IS_ENCRYPTED                    = 4,
44        PREPEND_SPS_PPS_TO_IDR_FRAMES   = 8,
45    };
46    status_t packetize(
47            size_t trackIndex, const sp<ABuffer> &accessUnit,
48            sp<ABuffer> *packets,
49            uint32_t flags,
50            const uint8_t *PES_private_data, size_t PES_private_data_len,
51            size_t numStuffingBytes = 0);
52
53    // XXX to be removed once encoder config option takes care of this for
54    // encrypted mode.
55    sp<ABuffer> prependCSD(
56            size_t trackIndex, const sp<ABuffer> &accessUnit) const;
57
58protected:
59    virtual ~TSPacketizer();
60
61private:
62    enum {
63        kPID_PMT = 0x100,
64        kPID_PCR = 0x1000,
65    };
66
67    struct Track;
68
69    Vector<sp<Track> > mTracks;
70
71    unsigned mPATContinuityCounter;
72    unsigned mPMTContinuityCounter;
73
74    uint32_t mCrcTable[256];
75
76    void initCrcTable();
77    uint32_t crc32(const uint8_t *start, size_t size) const;
78
79    DISALLOW_EVIL_CONSTRUCTORS(TSPacketizer);
80};
81
82}  // namespace android
83
84#endif  // TS_PACKETIZER_H_
85
86