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      1 /*
      2  * Copyright 2014 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 NUPLAYER_CCDECODER_H_
     18 
     19 #define NUPLAYER_CCDECODER_H_
     20 
     21 #include "NuPlayer.h"
     22 
     23 namespace android {
     24 
     25 struct NuPlayer::CCDecoder : public RefBase {
     26     enum {
     27         kWhatClosedCaptionData,
     28         kWhatTrackAdded,
     29     };
     30 
     31     enum {
     32         kTrackTypeCEA608,
     33         kTrackTypeCEA708,
     34     };
     35 
     36     explicit CCDecoder(const sp<AMessage> &notify);
     37 
     38     size_t getTrackCount() const;
     39     sp<AMessage> getTrackInfo(size_t index) const;
     40     status_t selectTrack(size_t index, bool select);
     41     bool isSelected() const;
     42     void decode(const sp<ABuffer> &accessUnit);
     43     void display(int64_t timeUs);
     44     void flush();
     45 
     46 private:
     47     // CC track identifier.
     48     struct CCTrack {
     49         CCTrack() : mTrackType(0), mTrackChannel(0) { }
     50 
     51         CCTrack(const int32_t trackType, const size_t trackChannel)
     52             : mTrackType(trackType), mTrackChannel(trackChannel) { }
     53 
     54         int32_t mTrackType;
     55         size_t mTrackChannel;
     56 
     57         // The ordering of CCTracks is to build a map of track to index.
     58         // It is necessary to find the index of the matched CCTrack when CC data comes.
     59         int compare(const NuPlayer::CCDecoder::CCTrack& rhs) const;
     60         inline bool operator<(const NuPlayer::CCDecoder::CCTrack& rhs) const;
     61         inline bool operator==(const NuPlayer::CCDecoder::CCTrack& rhs) const;
     62         inline bool operator!=(const NuPlayer::CCDecoder::CCTrack& rhs) const;
     63     };
     64 
     65     sp<AMessage> mNotify;
     66     KeyedVector<int64_t, sp<ABuffer> > mCCMap;
     67     ssize_t mSelectedTrack;
     68     KeyedVector<CCTrack, size_t> mTrackIndices;
     69     Vector<CCTrack> mTracks;
     70 
     71     // CEA-608 closed caption
     72     size_t mLine21Channels[2]; // The current channels of NTSC_CC_FIELD_{1, 2}
     73 
     74     // CEA-708 closed caption
     75     sp<ABuffer> mDTVCCPacket;
     76 
     77     bool isTrackValid(size_t index) const;
     78     size_t getTrackIndex(int32_t trackType, size_t channel, bool *trackAdded);
     79 
     80     // Extract from H.264 SEIs
     81     bool extractFromSEI(const sp<ABuffer> &accessUnit);
     82     bool parseSEINalUnit(int64_t timeUs, const uint8_t *data, size_t size);
     83 
     84     // Extract from MPEG user data
     85     bool extractFromMPEGUserData(const sp<ABuffer> &accessUnit);
     86     bool parseMPEGUserDataUnit(int64_t timeUs, const uint8_t *data, size_t size);
     87 
     88     // Extract CC tracks from MPEG_cc_data
     89     bool parseMPEGCCData(int64_t timeUs, const uint8_t *data, size_t size);
     90     bool parseDTVCCPacket(int64_t timeUs, const uint8_t *data, size_t size);
     91 
     92     DISALLOW_EVIL_CONSTRUCTORS(CCDecoder);
     93 };
     94 
     95 }  // namespace android
     96 
     97 #endif  // NUPLAYER_CCDECODER_H_
     98