| /********** |
| This library is free software; you can redistribute it and/or modify it under |
| the terms of the GNU Lesser General Public License as published by the |
| Free Software Foundation; either version 3 of the License, or (at your |
| option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.) |
| |
| This library is distributed in the hope that it will be useful, but WITHOUT |
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
| FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for |
| more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this library; if not, write to the Free Software Foundation, Inc., |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| **********/ |
| // "liveMedia" |
| // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved. |
| // A parser for a Matroska file. |
| // C++ header |
| |
| #ifndef _MATROSKA_FILE_PARSER_HH |
| |
| #ifndef _STREAM_PARSER_HH |
| #include "StreamParser.hh" |
| #endif |
| #ifndef _MATROSKA_FILE_HH |
| #include "MatroskaFile.hh" |
| #endif |
| #ifndef _EBML_NUMBER_HH |
| #include "EBMLNumber.hh" |
| #endif |
| |
| // An enum representing the current state of the parser: |
| enum MatroskaParseState { |
| PARSING_START_OF_FILE, |
| LOOKING_FOR_TRACKS, |
| PARSING_TRACK, |
| PARSING_CUES, |
| LOOKING_FOR_CLUSTER, |
| LOOKING_FOR_BLOCK, |
| PARSING_BLOCK, |
| DELIVERING_FRAME_WITHIN_BLOCK, |
| DELIVERING_FRAME_BYTES |
| }; |
| |
| class MatroskaFileParser: public StreamParser { |
| public: |
| MatroskaFileParser(MatroskaFile& ourFile, FramedSource* inputSource, |
| FramedSource::onCloseFunc* onEndFunc, void* onEndClientData, |
| MatroskaDemux* ourDemux = NULL); |
| virtual ~MatroskaFileParser(); |
| |
| void seekToTime(double& seekNPT); |
| |
| // StreamParser 'client continue' function: |
| static void continueParsing(void* clientData, unsigned char* ptr, unsigned size, struct timeval presentationTime); |
| void continueParsing(); |
| |
| private: |
| // Parsing functions: |
| Boolean parse(); |
| // returns True iff we have finished parsing to the end of all 'Track' headers (on initialization) |
| |
| Boolean parseStartOfFile(); |
| void lookForNextTrack(); |
| Boolean parseTrack(); |
| Boolean parseCues(); |
| |
| void lookForNextBlock(); |
| void parseBlock(); |
| Boolean deliverFrameWithinBlock(); |
| void deliverFrameBytes(); |
| |
| void getCommonFrameBytes(MatroskaTrack* track, u_int8_t* to, unsigned numBytesToGet, unsigned numBytesToSkip); |
| |
| Boolean parseEBMLNumber(EBMLNumber& num); |
| Boolean parseEBMLIdAndSize(EBMLId& id, EBMLDataSize& size); |
| Boolean parseEBMLVal_unsigned64(EBMLDataSize& size, u_int64_t& result); |
| Boolean parseEBMLVal_unsigned(EBMLDataSize& size, unsigned& result); |
| Boolean parseEBMLVal_float(EBMLDataSize& size, float& result); |
| Boolean parseEBMLVal_string(EBMLDataSize& size, char*& result); |
| // Note: "result" is dynamically allocated; the caller must delete[] it later |
| Boolean parseEBMLVal_binary(EBMLDataSize& size, u_int8_t*& result); |
| // Note: "result" is dynamically allocated; the caller must delete[] it later |
| void skipHeader(EBMLDataSize const& size); |
| void skipRemainingHeaderBytes(Boolean isContinuation); |
| |
| void setParseState(); |
| |
| void seekToFilePosition(u_int64_t offsetInFile); |
| void seekToEndOfFile(); |
| void resetStateAfterSeeking(); // common code, called by both of the above |
| |
| private: // redefined virtual functions |
| virtual void restoreSavedParserState(); |
| |
| private: |
| // General state for parsing: |
| MatroskaFile& fOurFile; |
| FramedSource* fInputSource; |
| FramedSource::onCloseFunc* fOnEndFunc; |
| void* fOnEndClientData; |
| MatroskaDemux* fOurDemux; |
| MatroskaParseState fCurrentParseState; |
| u_int64_t fCurOffsetInFile, fSavedCurOffsetInFile, fLimitOffsetInFile; |
| |
| // For skipping over (possibly large) headers: |
| u_int64_t fNumHeaderBytesToSkip; |
| |
| // For parsing 'Seek ID's: |
| EBMLId fLastSeekId; |
| |
| // Parameters of the most recently-parsed 'Cluster': |
| unsigned fClusterTimecode; |
| |
| // Parameters of the most recently-parsed 'Block': |
| unsigned fBlockSize; |
| unsigned fBlockTrackNumber; |
| short fBlockTimecode; |
| unsigned fNumFramesInBlock; |
| unsigned* fFrameSizesWithinBlock; |
| |
| // Parameters of the most recently-parsed frame within a 'Block': |
| double fPresentationTimeOffset; |
| unsigned fNextFrameNumberToDeliver; |
| unsigned fCurOffsetWithinFrame, fSavedCurOffsetWithinFrame; // used if track->haveSubframes() |
| |
| // Parameters of the (sub)frame that's currently being delivered: |
| u_int8_t* fCurFrameTo; |
| unsigned fCurFrameNumBytesToGet; |
| unsigned fCurFrameNumBytesToSkip; |
| }; |
| |
| #endif |