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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 A_TS_PARSER_H_
18 
19 #define A_TS_PARSER_H_
20 
21 #include <sys/types.h>
22 
23 #include <media/stagefright/foundation/ABase.h>
24 #include <media/stagefright/foundation/AMessage.h>
25 #include <media/stagefright/MediaSource.h>
26 #include <utils/KeyedVector.h>
27 #include <utils/Vector.h>
28 #include <utils/RefBase.h>
29 #include <vector>
30 
31 namespace android {
32 namespace hardware {
33 namespace cas {
34 namespace V1_0 {
35 struct ICas;
36 }}}
37 using hardware::cas::V1_0::ICas;
38 
39 class ABitReader;
40 struct ABuffer;
41 struct AnotherPacketSource;
42 
43 struct ATSParser : public RefBase {
44     enum DiscontinuityType {
45         DISCONTINUITY_NONE              = 0,
46         DISCONTINUITY_TIME              = 1,
47         DISCONTINUITY_AUDIO_FORMAT      = 2,
48         DISCONTINUITY_VIDEO_FORMAT      = 4,
49         DISCONTINUITY_ABSOLUTE_TIME     = 8,
50         DISCONTINUITY_TIME_OFFSET       = 16,
51 
52         // For legacy reasons this also implies a time discontinuity.
53         DISCONTINUITY_FORMATCHANGE      =
54             DISCONTINUITY_AUDIO_FORMAT
55                 | DISCONTINUITY_VIDEO_FORMAT
56                 | DISCONTINUITY_TIME,
57         DISCONTINUITY_FORMAT_ONLY       =
58             DISCONTINUITY_AUDIO_FORMAT
59                 | DISCONTINUITY_VIDEO_FORMAT,
60     };
61 
62     enum Flags {
63         // The 90kHz clock (PTS/DTS) is absolute, i.e. PTS=0 corresponds to
64         // a media time of 0.
65         // If this flag is _not_ specified, the first PTS encountered in a
66         // program of this stream will be assumed to correspond to media time 0
67         // instead.
68         TS_TIMESTAMPS_ARE_ABSOLUTE = 1,
69         // Video PES packets contain exactly one (aligned) access unit.
70         ALIGNED_VIDEO_DATA         = 2,
71     };
72 
73     enum SourceType {
74         VIDEO = 0,
75         AUDIO = 1,
76         META  = 2,
77         NUM_SOURCE_TYPES = 3
78     };
79 
80     // Event is used to signal sync point event at feedTSPacket().
81     struct SyncEvent {
82         explicit SyncEvent(off64_t offset);
83 
84         void init(off64_t offset, const sp<MediaSource> &source,
85                 int64_t timeUs, SourceType type);
86 
hasReturnedDataATSParser::SyncEvent87         bool hasReturnedData() const { return mHasReturnedData; }
88         void reset();
getOffsetATSParser::SyncEvent89         off64_t getOffset() const { return mOffset; }
getMediaSourceATSParser::SyncEvent90         const sp<MediaSource> &getMediaSource() const { return mMediaSource; }
getTimeUsATSParser::SyncEvent91         int64_t getTimeUs() const { return mTimeUs; }
getTypeATSParser::SyncEvent92         SourceType getType() const { return mType; }
93 
94     private:
95         bool mHasReturnedData;
96         /*
97          * mHasReturnedData == false: the current offset (or undefined if the returned data
98                                       has been invalidated via reset())
99          * mHasReturnedData == true: the start offset of sync payload
100          */
101         off64_t mOffset;
102         /* The media source object for this event. */
103         sp<MediaSource> mMediaSource;
104         /* The timestamp of the sync frame. */
105         int64_t mTimeUs;
106         SourceType mType;
107     };
108 
109     explicit ATSParser(uint32_t flags = 0);
110 
111     status_t setMediaCas(const sp<ICas> &cas);
112 
113     // Feed a TS packet into the parser. uninitialized event with the start
114     // offset of this TS packet goes in, and if the parser detects PES with
115     // a sync frame, the event will be initiailzed with the start offset of the
116     // PES. Note that the offset of the event can be different from what we fed,
117     // as a PES may consist of multiple TS packets.
118     //
119     // Even in the case feedTSPacket() returns non-OK value, event still may be
120     // initialized if the parsing failed after the detection.
121     status_t feedTSPacket(
122             const void *data, size_t size, SyncEvent *event = NULL);
123 
124     void signalDiscontinuity(
125             DiscontinuityType type, const sp<AMessage> &extra);
126 
127     void signalEOS(status_t finalResult);
128 
129     sp<MediaSource> getSource(SourceType type);
130     bool hasSource(SourceType type) const;
131 
132     bool PTSTimeDeltaEstablished();
133 
134     int64_t getFirstPTSTimeUs();
135 
136     void signalNewSampleAesKey(const sp<AMessage> &keyItem);
137 
138     enum {
139         // From ISO/IEC 13818-1: 2000 (E), Table 2-29
140         STREAMTYPE_RESERVED             = 0x00,
141         STREAMTYPE_MPEG1_VIDEO          = 0x01,
142         STREAMTYPE_MPEG2_VIDEO          = 0x02,
143         STREAMTYPE_MPEG1_AUDIO          = 0x03,
144         STREAMTYPE_MPEG2_AUDIO          = 0x04,
145         STREAMTYPE_MPEG2_AUDIO_ADTS     = 0x0f,
146         STREAMTYPE_MPEG4_VIDEO          = 0x10,
147         STREAMTYPE_METADATA             = 0x15,
148         STREAMTYPE_H264                 = 0x1b,
149 
150         // From ATSC A/53 Part 3:2009, 6.7.1
151         STREAMTYPE_AC3                  = 0x81,
152 
153         // Stream type 0x83 is non-standard,
154         // it could be LPCM or TrueHD AC3
155         STREAMTYPE_LPCM_AC3             = 0x83,
156 
157         //Sample Encrypted types
158         STREAMTYPE_H264_ENCRYPTED       = 0xDB,
159         STREAMTYPE_AAC_ENCRYPTED        = 0xCF,
160         STREAMTYPE_AC3_ENCRYPTED        = 0xC1,
161     };
162 
163 protected:
164     virtual ~ATSParser();
165 
166 private:
167     struct Program;
168     struct Stream;
169     struct PSISection;
170     struct CasManager;
171     struct CADescriptor {
172         int32_t mSystemID;
173         unsigned mPID;
174         std::vector<uint8_t> mPrivateData;
175     };
176 
177     sp<CasManager> mCasManager;
178 
179     uint32_t mFlags;
180     Vector<sp<Program> > mPrograms;
181 
182     // Keyed by PID
183     KeyedVector<unsigned, sp<PSISection> > mPSISections;
184 
185     int64_t mAbsoluteTimeAnchorUs;
186 
187     bool mTimeOffsetValid;
188     int64_t mTimeOffsetUs;
189     int64_t mLastRecoveredPTS;
190 
191     size_t mNumTSPacketsParsed;
192 
193     sp<AMessage> mSampleAesKeyItem;
194 
195     void parseProgramAssociationTable(ABitReader *br);
196     void parseProgramMap(ABitReader *br);
197     // Parse PES packet where br is pointing to. If the PES contains a sync
198     // frame, set event with the time and the start offset of this PES.
199     // Note that the method itself does not touch event.
200     void parsePES(ABitReader *br, SyncEvent *event);
201 
202     // Strip remaining packet headers and pass to appropriate program/stream
203     // to parse the payload. If the payload turns out to be PES and contains
204     // a sync frame, event shall be set with the time and start offset of the
205     // PES.
206     // Note that the method itself does not touch event.
207     status_t parsePID(
208         ABitReader *br, unsigned PID,
209         unsigned continuity_counter,
210         unsigned payload_unit_start_indicator,
211         unsigned transport_scrambling_control,
212         unsigned random_access_indicator,
213         SyncEvent *event);
214 
215     status_t parseAdaptationField(
216             ABitReader *br, unsigned PID, unsigned *random_access_indicator);
217 
218     // see feedTSPacket().
219     status_t parseTS(ABitReader *br, SyncEvent *event);
220 
221     void updatePCR(unsigned PID, uint64_t PCR, uint64_t byteOffsetFromStart);
222 
223     uint64_t mPCR[2];
224     uint64_t mPCRBytes[2];
225     int64_t mSystemTimeUs[2];
226     size_t mNumPCRs;
227 
228     DISALLOW_EVIL_CONSTRUCTORS(ATSParser);
229 };
230 
231 }  // namespace android
232 
233 #endif  // A_TS_PARSER_H_
234