/********** 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 2.1 of the License, or (at your option) any later version. (See .) 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) 1996-2015 Live Networks, Inc. All rights reserved. // A parser for a Matroska file. // Implementation #include "MatroskaFileParser.hh" #include "MatroskaDemuxedTrack.hh" #include #include // for "gettimeofday() MatroskaFileParser::MatroskaFileParser(MatroskaFile& ourFile, FramedSource* inputSource, FramedSource::onCloseFunc* onEndFunc, void* onEndClientData, MatroskaDemux* ourDemux) : StreamParser(inputSource, onEndFunc, onEndClientData, continueParsing, this), fOurFile(ourFile), fInputSource(inputSource), fOnEndFunc(onEndFunc), fOnEndClientData(onEndClientData), fOurDemux(ourDemux), fCurOffsetInFile(0), fSavedCurOffsetInFile(0), fLimitOffsetInFile(0), fNumHeaderBytesToSkip(0), fClusterTimecode(0), fBlockTimecode(0), fFrameSizesWithinBlock(NULL), fPresentationTimeOffset(0.0) { if (ourDemux == NULL) { // Initialization fCurrentParseState = PARSING_START_OF_FILE; continueParsing(); } else { fCurrentParseState = LOOKING_FOR_CLUSTER; // In this case, parsing (of track data) doesn't start until a client starts reading from a track. } } MatroskaFileParser::~MatroskaFileParser() { delete[] fFrameSizesWithinBlock; Medium::close(fInputSource); } void MatroskaFileParser::seekToTime(double& seekNPT) { #ifdef DEBUG fprintf(stderr, "seekToTime(%f)\n", seekNPT); #endif if (seekNPT <= 0.0) { #ifdef DEBUG fprintf(stderr, "\t=> start of file\n"); #endif seekNPT = 0.0; seekToFilePosition(0); } else if (seekNPT >= fOurFile.fileDuration()) { #ifdef DEBUG fprintf(stderr, "\t=> end of file\n"); #endif seekNPT = fOurFile.fileDuration(); seekToEndOfFile(); } else { u_int64_t clusterOffsetInFile; unsigned blockNumWithinCluster; if (!fOurFile.lookupCuePoint(seekNPT, clusterOffsetInFile, blockNumWithinCluster)) { #ifdef DEBUG fprintf(stderr, "\t=> not supported\n"); #endif return; // seeking not supported } #ifdef DEBUG fprintf(stderr, "\t=> seek time %f, file position %llu, block number within cluster %d\n", seekNPT, clusterOffsetInFile, blockNumWithinCluster); #endif seekToFilePosition(clusterOffsetInFile); fCurrentParseState = LOOKING_FOR_BLOCK; // LATER handle "blockNumWithinCluster"; for now, we assume that it's 0 ##### } } void MatroskaFileParser ::continueParsing(void* clientData, unsigned char* /*ptr*/, unsigned /*size*/, struct timeval /*presentationTime*/) { ((MatroskaFileParser*)clientData)->continueParsing(); } void MatroskaFileParser::continueParsing() { if (fInputSource != NULL) { if (fInputSource->isCurrentlyAwaitingData()) return; // Our input source is currently being read. Wait until that read completes if (!parse()) { // We didn't complete the parsing, because we had to read more data from the source, or because we're waiting for // another read from downstream. Once that happens, we'll get called again. return; } } // We successfully parsed the file. Call our 'done' function now: if (fOnEndFunc != NULL) (*fOnEndFunc)(fOnEndClientData); } Boolean MatroskaFileParser::parse() { Boolean areDone = False; try { skipRemainingHeaderBytes(True); // if any do { switch (fCurrentParseState) { case PARSING_START_OF_FILE: { areDone = parseStartOfFile(); break; } case LOOKING_FOR_TRACKS: { lookForNextTrack(); break; } case PARSING_TRACK: { areDone = parseTrack(); if (areDone && fOurFile.fCuesOffset > 0) { // We've finished parsing the 'Track' information. There are also 'Cues' in the file, so parse those before finishing: // Seek to the specified position in the file. We were already told that the 'Cues' begins there: #ifdef DEBUG fprintf(stderr, "Seeking to file position %llu (the previously-reported location of 'Cues')\n", fOurFile.fCuesOffset); #endif seekToFilePosition(fOurFile.fCuesOffset); fCurrentParseState = PARSING_CUES; areDone = False; } break; } case PARSING_CUES: { areDone = parseCues(); break; } case LOOKING_FOR_CLUSTER: { if (fOurFile.fClusterOffset > 0) { // Optimization: Seek to the specified position in the file. We were already told that the 'Cluster' begins there: #ifdef DEBUG fprintf(stderr, "Optimization: Seeking to file position %llu (the previously-reported location of a 'Cluster')\n", fOurFile.fClusterOffset); #endif seekToFilePosition(fOurFile.fClusterOffset); } fCurrentParseState = LOOKING_FOR_BLOCK; break; } case LOOKING_FOR_BLOCK: { lookForNextBlock(); break; } case PARSING_BLOCK: { parseBlock(); break; } case DELIVERING_FRAME_WITHIN_BLOCK: { if (!deliverFrameWithinBlock()) return False; break; } case DELIVERING_FRAME_BYTES: { deliverFrameBytes(); return False; // Halt parsing for now. A new 'read' from downstream will cause parsing to resume. break; } } } while (!areDone); return True; } catch (int /*e*/) { #ifdef DEBUG fprintf(stderr, "MatroskaFileParser::parse() EXCEPTION (This is normal behavior - *not* an error)\n"); #endif return False; // the parsing got interrupted } } Boolean MatroskaFileParser::parseStartOfFile() { #ifdef DEBUG fprintf(stderr, "parsing start of file\n"); #endif EBMLId id; EBMLDataSize size; // The file must begin with the standard EBML header (which we skip): if (!parseEBMLIdAndSize(id, size) || id != MATROSKA_ID_EBML) { fOurFile.envir() << "ERROR: File does not begin with an EBML header\n"; return True; // We're done with the file, because it's not valid } #ifdef DEBUG fprintf(stderr, "MatroskaFileParser::parseStartOfFile(): Parsed id 0x%s (%s), size: %lld\n", id.hexString(), id.stringName(), size.val()); #endif fCurrentParseState = LOOKING_FOR_TRACKS; skipHeader(size); return False; // because we have more parsing to do - inside the 'Track' header } void MatroskaFileParser::lookForNextTrack() { #ifdef DEBUG fprintf(stderr, "looking for Track\n"); #endif EBMLId id; EBMLDataSize size; // Read and skip over (or enter) each Matroska header, until we get to a 'Track'. while (fCurrentParseState == LOOKING_FOR_TRACKS) { while (!parseEBMLIdAndSize(id, size)) {} #ifdef DEBUG fprintf(stderr, "MatroskaFileParser::lookForNextTrack(): Parsed id 0x%s (%s), size: %lld\n", id.hexString(), id.stringName(), size.val()); #endif switch (id.val()) { case MATROSKA_ID_SEGMENT: { // 'Segment' header: enter this // Remember the position, within the file, of the start of Segment data, because Seek Positions are relative to this: fOurFile.fSegmentDataOffset = fCurOffsetInFile; break; } case MATROSKA_ID_SEEK_HEAD: { // 'Seek Head' header: enter this break; } case MATROSKA_ID_SEEK: { // 'Seek' header: enter this break; } case MATROSKA_ID_SEEK_ID: { // 'Seek ID' header: get this value if (parseEBMLNumber(fLastSeekId)) { #ifdef DEBUG fprintf(stderr, "\tSeek ID 0x%s:\t%s\n", fLastSeekId.hexString(), fLastSeekId.stringName()); #endif } break; } case MATROSKA_ID_SEEK_POSITION: { // 'Seek Position' header: get this value u_int64_t seekPosition; if (parseEBMLVal_unsigned64(size, seekPosition)) { u_int64_t offsetInFile = fOurFile.fSegmentDataOffset + seekPosition; #ifdef DEBUG fprintf(stderr, "\tSeek Position %llu (=> offset within the file: %llu (0x%llx))\n", seekPosition, offsetInFile, offsetInFile); #endif // The only 'Seek Position's that we care about are for 'Cluster' and 'Cues': if (fLastSeekId == MATROSKA_ID_CLUSTER) { fOurFile.fClusterOffset = offsetInFile; } else if (fLastSeekId == MATROSKA_ID_CUES) { fOurFile.fCuesOffset = offsetInFile; } } break; } case MATROSKA_ID_INFO: { // 'Segment Info' header: enter this break; } case MATROSKA_ID_TIMECODE_SCALE: { // 'Timecode Scale' header: get this value unsigned timecodeScale; if (parseEBMLVal_unsigned(size, timecodeScale) && timecodeScale > 0) { fOurFile.fTimecodeScale = timecodeScale; #ifdef DEBUG fprintf(stderr, "\tTimecode Scale %u ns (=> Segment Duration == %f seconds)\n", fOurFile.timecodeScale(), fOurFile.segmentDuration()*(fOurFile.fTimecodeScale/1000000000.0f)); #endif } break; } case MATROSKA_ID_DURATION: { // 'Segment Duration' header: get this value if (parseEBMLVal_float(size, fOurFile.fSegmentDuration)) { #ifdef DEBUG fprintf(stderr, "\tSegment Duration %f (== %f seconds)\n", fOurFile.segmentDuration(), fOurFile.segmentDuration()*(fOurFile.fTimecodeScale/1000000000.0f)); #endif } break; } #ifdef DEBUG case MATROSKA_ID_TITLE: { // 'Segment Title': display this value char* title; if (parseEBMLVal_string(size, title)) { #ifdef DEBUG fprintf(stderr, "\tTitle: %s\n", title); #endif delete[] title; } break; } #endif case MATROSKA_ID_TRACKS: { // enter this, and move on to parsing 'Tracks' fLimitOffsetInFile = fCurOffsetInFile + size.val(); // Make sure we don't read past the end of this header fCurrentParseState = PARSING_TRACK; break; } default: { // skip over this header skipHeader(size); break; } } setParseState(); } } Boolean MatroskaFileParser::parseTrack() { #ifdef DEBUG fprintf(stderr, "parsing Track\n"); #endif // Read and process each Matroska header, until we get to the end of the Track: MatroskaTrack* track = NULL; EBMLId id; EBMLDataSize size; while (fCurOffsetInFile < fLimitOffsetInFile) { while (!parseEBMLIdAndSize(id, size)) {} #ifdef DEBUG if (id == MATROSKA_ID_TRACK_ENTRY) fprintf(stderr, "\n"); // makes debugging output easier to read fprintf(stderr, "MatroskaFileParser::parseTrack(): Parsed id 0x%s (%s), size: %lld\n", id.hexString(), id.stringName(), size.val()); #endif switch (id.val()) { case MATROSKA_ID_TRACK_ENTRY: { // 'Track Entry' header: enter this // Create a new "MatroskaTrack" object for this entry: if (track != NULL && track->trackNumber == 0) delete track; // We had a previous "MatroskaTrack" object that was never used track = new MatroskaTrack; break; } case MATROSKA_ID_TRACK_NUMBER: { unsigned trackNumber; if (parseEBMLVal_unsigned(size, trackNumber)) { #ifdef DEBUG fprintf(stderr, "\tTrack Number %d\n", trackNumber); #endif if (track != NULL && trackNumber != 0) { track->trackNumber = trackNumber; fOurFile.addTrack(track, trackNumber); } } break; } case MATROSKA_ID_TRACK_TYPE: { unsigned trackType; if (parseEBMLVal_unsigned(size, trackType) && track != NULL) { // We convert the Matroska 'track type' code into our own code (which we can use as a bitmap): track->trackType = trackType == 1 ? MATROSKA_TRACK_TYPE_VIDEO : trackType == 2 ? MATROSKA_TRACK_TYPE_AUDIO : trackType == 0x11 ? MATROSKA_TRACK_TYPE_SUBTITLE : MATROSKA_TRACK_TYPE_OTHER; #ifdef DEBUG fprintf(stderr, "\tTrack Type 0x%02x (%s)\n", trackType, track->trackType == MATROSKA_TRACK_TYPE_VIDEO ? "video" : track->trackType == MATROSKA_TRACK_TYPE_AUDIO ? "audio" : track->trackType == MATROSKA_TRACK_TYPE_SUBTITLE ? "subtitle" : ""); #endif } break; } case MATROSKA_ID_FLAG_ENABLED: { unsigned flagEnabled; if (parseEBMLVal_unsigned(size, flagEnabled)) { #ifdef DEBUG fprintf(stderr, "\tTrack is Enabled: %d\n", flagEnabled); #endif if (track != NULL) track->isEnabled = flagEnabled != 0; } break; } case MATROSKA_ID_FLAG_DEFAULT: { unsigned flagDefault; if (parseEBMLVal_unsigned(size, flagDefault)) { #ifdef DEBUG fprintf(stderr, "\tTrack is Default: %d\n", flagDefault); #endif if (track != NULL) track->isDefault = flagDefault != 0; } break; } case MATROSKA_ID_FLAG_FORCED: { unsigned flagForced; if (parseEBMLVal_unsigned(size, flagForced)) { #ifdef DEBUG fprintf(stderr, "\tTrack is Forced: %d\n", flagForced); #endif if (track != NULL) track->isForced = flagForced != 0; } break; } case MATROSKA_ID_DEFAULT_DURATION: { unsigned defaultDuration; if (parseEBMLVal_unsigned(size, defaultDuration)) { #ifdef DEBUG fprintf(stderr, "\tDefault duration %f ms\n", defaultDuration/1000000.0); #endif if (track != NULL) track->defaultDuration = defaultDuration; } break; } case MATROSKA_ID_MAX_BLOCK_ADDITION_ID: { unsigned maxBlockAdditionID; if (parseEBMLVal_unsigned(size, maxBlockAdditionID)) { #ifdef DEBUG fprintf(stderr, "\tMax Block Addition ID: %u\n", maxBlockAdditionID); #endif } break; } case MATROSKA_ID_NAME: { char* name; if (parseEBMLVal_string(size, name)) { #ifdef DEBUG fprintf(stderr, "\tName: %s\n", name); #endif if (track != NULL) { delete[] track->name; track->name = name; } else { delete[] name; } } break; } case MATROSKA_ID_LANGUAGE: { char* language; if (parseEBMLVal_string(size, language)) { #ifdef DEBUG fprintf(stderr, "\tLanguage: %s\n", language); #endif if (track != NULL) { delete[] track->language; track->language = language; } else { delete[] language; } } break; } case MATROSKA_ID_CODEC: { char* codecID; if (parseEBMLVal_string(size, codecID)) { #ifdef DEBUG fprintf(stderr, "\tCodec ID: %s\n", codecID); #endif if (track != NULL) { delete[] track->codecID; track->codecID = codecID; // Also set the track's "mimeType" field, if we can deduce it from the "codecID": if (strncmp(codecID, "A_MPEG", 6) == 0) { track->mimeType = "audio/MPEG"; } else if (strncmp(codecID, "A_AAC", 5) == 0) { track->mimeType = "audio/AAC"; } else if (strncmp(codecID, "A_AC3", 5) == 0) { track->mimeType = "audio/AC3"; } else if (strncmp(codecID, "A_VORBIS", 8) == 0) { track->mimeType = "audio/VORBIS"; } else if (strcmp(codecID, "A_OPUS") == 0) { track->mimeType = "audio/OPUS"; track->codecIsOpus = True; } else if (strcmp(codecID, "V_MPEG4/ISO/AVC") == 0) { track->mimeType = "video/H264"; } else if (strcmp(codecID, "V_MPEGH/ISO/HEVC") == 0) { track->mimeType = "video/H265"; } else if (strncmp(codecID, "V_VP8", 5) == 0) { track->mimeType = "video/VP8"; } else if (strncmp(codecID, "V_VP9", 5) == 0) { track->mimeType = "video/VP9"; } else if (strncmp(codecID, "V_THEORA", 8) == 0) { track->mimeType = "video/THEORA"; } else if (strncmp(codecID, "S_TEXT", 6) == 0) { track->mimeType = "text/T140"; } } else { delete[] codecID; } } break; } case MATROSKA_ID_CODEC_PRIVATE: { u_int8_t* codecPrivate; unsigned codecPrivateSize; if (parseEBMLVal_binary(size, codecPrivate)) { codecPrivateSize = (unsigned)size.val(); #ifdef DEBUG fprintf(stderr, "\tCodec Private: "); for (unsigned i = 0; i < codecPrivateSize; ++i) fprintf(stderr, "%02x:", codecPrivate[i]); fprintf(stderr, "\n"); #endif if (track != NULL) { delete[] track->codecPrivate; track->codecPrivate = codecPrivate; track->codecPrivateSize = codecPrivateSize; // Hack for H.264 and H.265: The 'codec private' data contains // the size of NAL unit lengths: if (track->codecID != NULL) { if (strcmp(track->codecID, "V_MPEG4/ISO/AVC") == 0) { // H.264 // Byte 4 of the 'codec private' data contains 'lengthSizeMinusOne': if (codecPrivateSize >= 5) track->subframeSizeSize = (codecPrivate[4]&0x3) + 1; } else if (strcmp(track->codecID, "V_MPEGH/ISO/HEVC") == 0) { // H.265 // H.265 'codec private' data is *supposed* to use the format that's described in // http://lists.matroska.org/pipermail/matroska-devel/2013-September/004567.html // However, some Matroska files use the same format that was used for H.264. // We check for this here, by checking various fields that are supposed to be // 'all-1' in the 'correct' format: if (codecPrivateSize < 23 || (codecPrivate[13]&0xF0) != 0xF0 || (codecPrivate[15]&0xFC) != 0xFC || (codecPrivate[16]&0xFC) != 0xFC || (codecPrivate[17]&0xF8) != 0xF8 || (codecPrivate[18]&0xF8) != 0xF8) { // The 'correct' format isn't being used, so assume the H.264 format instead: track->codecPrivateUsesH264FormatForH265 = True; // Byte 4 of the 'codec private' data contains 'lengthSizeMinusOne': if (codecPrivateSize >= 5) track->subframeSizeSize = (codecPrivate[4]&0x3) + 1; } else { // This looks like the 'correct' format: track->codecPrivateUsesH264FormatForH265 = False; // Byte 21 of the 'codec private' data contains 'lengthSizeMinusOne': track->subframeSizeSize = (codecPrivate[21]&0x3) + 1; } } } } else { delete[] codecPrivate; } } break; } case MATROSKA_ID_VIDEO: { // 'Video settings' header: enter this break; } case MATROSKA_ID_PIXEL_WIDTH: { unsigned pixelWidth; if (parseEBMLVal_unsigned(size, pixelWidth)) { #ifdef DEBUG fprintf(stderr, "\tPixel Width %d\n", pixelWidth); #endif } break; } case MATROSKA_ID_PIXEL_HEIGHT: { unsigned pixelHeight; if (parseEBMLVal_unsigned(size, pixelHeight)) { #ifdef DEBUG fprintf(stderr, "\tPixel Height %d\n", pixelHeight); #endif } break; } case MATROSKA_ID_DISPLAY_WIDTH: { unsigned displayWidth; if (parseEBMLVal_unsigned(size, displayWidth)) { #ifdef DEBUG fprintf(stderr, "\tDisplay Width %d\n", displayWidth); #endif } break; } case MATROSKA_ID_DISPLAY_HEIGHT: { unsigned displayHeight; if (parseEBMLVal_unsigned(size, displayHeight)) { #ifdef DEBUG fprintf(stderr, "\tDisplay Height %d\n", displayHeight); #endif } break; } case MATROSKA_ID_DISPLAY_UNIT: { unsigned displayUnit; if (parseEBMLVal_unsigned(size, displayUnit)) { #ifdef DEBUG fprintf(stderr, "\tDisplay Unit %d\n", displayUnit); #endif } break; } case MATROSKA_ID_AUDIO: { // 'Audio settings' header: enter this break; } case MATROSKA_ID_SAMPLING_FREQUENCY: { float samplingFrequency; if (parseEBMLVal_float(size, samplingFrequency)) { if (track != NULL) { track->samplingFrequency = (unsigned)samplingFrequency; #ifdef DEBUG fprintf(stderr, "\tSampling frequency %f (->%d)\n", samplingFrequency, track->samplingFrequency); #endif } } break; } case MATROSKA_ID_OUTPUT_SAMPLING_FREQUENCY: { float outputSamplingFrequency; if (parseEBMLVal_float(size, outputSamplingFrequency)) { #ifdef DEBUG fprintf(stderr, "\tOutput sampling frequency %f\n", outputSamplingFrequency); #endif } break; } case MATROSKA_ID_CHANNELS: { unsigned numChannels; if (parseEBMLVal_unsigned(size, numChannels)) { #ifdef DEBUG fprintf(stderr, "\tChannels %d\n", numChannels); #endif if (track != NULL) track->numChannels = numChannels; } break; } case MATROSKA_ID_BIT_DEPTH: { unsigned bitDepth; if (parseEBMLVal_unsigned(size, bitDepth)) { #ifdef DEBUG fprintf(stderr, "\tBit Depth %d\n", bitDepth); #endif } break; } case MATROSKA_ID_CONTENT_ENCODINGS: case MATROSKA_ID_CONTENT_ENCODING: { // 'Content Encodings' or 'Content Encoding' header: enter this break; } case MATROSKA_ID_CONTENT_COMPRESSION: { // 'Content Compression' header: enter this // Note: We currently support only 'Header Stripping' compression, not 'zlib' compression (the default algorithm). // Therefore, we disable this track, unless/until we later see that 'Header Stripping' is supported: if (track != NULL) track->isEnabled = False; break; } case MATROSKA_ID_CONTENT_COMP_ALGO: { unsigned contentCompAlgo; if (parseEBMLVal_unsigned(size, contentCompAlgo)) { #ifdef DEBUG fprintf(stderr, "\tContent Compression Algorithm %d (%s)\n", contentCompAlgo, contentCompAlgo == 0 ? "zlib" : contentCompAlgo == 3 ? "Header Stripping" : ""); #endif // The only compression algorithm that we support is #3: Header Stripping; disable the track otherwise if (track != NULL) track->isEnabled = contentCompAlgo == 3; } break; } case MATROSKA_ID_CONTENT_COMP_SETTINGS: { u_int8_t* headerStrippedBytes; unsigned headerStrippedBytesSize; if (parseEBMLVal_binary(size, headerStrippedBytes)) { headerStrippedBytesSize = (unsigned)size.val(); #ifdef DEBUG fprintf(stderr, "\tHeader Stripped Bytes: "); for (unsigned i = 0; i < headerStrippedBytesSize; ++i) fprintf(stderr, "%02x:", headerStrippedBytes[i]); fprintf(stderr, "\n"); #endif if (track != NULL) { delete[] track->headerStrippedBytes; track->headerStrippedBytes = headerStrippedBytes; track->headerStrippedBytesSize = headerStrippedBytesSize; } else { delete[] headerStrippedBytes; } } break; } case MATROSKA_ID_CONTENT_ENCRYPTION: { // 'Content Encrpytion' header: skip this // Note: We don't currently support encryption at all. Therefore, we disable this track: if (track != NULL) track->isEnabled = False; // Fall through to... } default: { // We don't process this header, so just skip over it: skipHeader(size); break; } } setParseState(); } fLimitOffsetInFile = 0; // reset if (track != NULL && track->trackNumber == 0) delete track; // We had a previous "MatroskaTrack" object that was never used return True; // we're done parsing track entries } void MatroskaFileParser::lookForNextBlock() { #ifdef DEBUG fprintf(stderr, "looking for Block\n"); #endif // Read and skip over each Matroska header, until we get to a 'Cluster': EBMLId id; EBMLDataSize size; while (fCurrentParseState == LOOKING_FOR_BLOCK) { while (!parseEBMLIdAndSize(id, size)) {} #ifdef DEBUG fprintf(stderr, "MatroskaFileParser::lookForNextBlock(): Parsed id 0x%s (%s), size: %lld\n", id.hexString(), id.stringName(), size.val()); #endif switch (id.val()) { case MATROSKA_ID_SEGMENT: { // 'Segment' header: enter this break; } case MATROSKA_ID_CLUSTER: { // 'Cluster' header: enter this break; } case MATROSKA_ID_TIMECODE: { // 'Timecode' header: get this value unsigned timecode; if (parseEBMLVal_unsigned(size, timecode)) { fClusterTimecode = timecode; #ifdef DEBUG fprintf(stderr, "\tCluster timecode: %d (== %f seconds)\n", fClusterTimecode, fClusterTimecode*(fOurFile.fTimecodeScale/1000000000.0)); #endif } break; } case MATROSKA_ID_BLOCK_GROUP: { // 'Block Group' header: enter this break; } case MATROSKA_ID_SIMPLEBLOCK: case MATROSKA_ID_BLOCK: { // 'SimpleBlock' or 'Block' header: enter this (and we're done) fBlockSize = (unsigned)size.val(); fCurrentParseState = PARSING_BLOCK; break; } case MATROSKA_ID_BLOCK_DURATION: { // 'Block Duration' header: get this value (but we currently don't do anything with it) unsigned blockDuration; if (parseEBMLVal_unsigned(size, blockDuration)) { #ifdef DEBUG fprintf(stderr, "\tblock duration: %d (== %f ms)\n", blockDuration, (float)(blockDuration*fOurFile.fTimecodeScale/1000000.0)); #endif } break; } // Attachments are parsed only if we're in DEBUG mode (otherwise we just skip over them): #ifdef DEBUG case MATROSKA_ID_ATTACHMENTS: { // 'Attachments': enter this break; } case MATROSKA_ID_ATTACHED_FILE: { // 'Attached File': enter this break; } case MATROSKA_ID_FILE_DESCRIPTION: { // 'File Description': get this value char* fileDescription; if (parseEBMLVal_string(size, fileDescription)) { #ifdef DEBUG fprintf(stderr, "\tFile Description: %s\n", fileDescription); #endif delete[] fileDescription; } break; } case MATROSKA_ID_FILE_NAME: { // 'File Name': get this value char* fileName; if (parseEBMLVal_string(size, fileName)) { #ifdef DEBUG fprintf(stderr, "\tFile Name: %s\n", fileName); #endif delete[] fileName; } break; } case MATROSKA_ID_FILE_MIME_TYPE: { // 'File MIME Type': get this value char* fileMIMEType; if (parseEBMLVal_string(size, fileMIMEType)) { #ifdef DEBUG fprintf(stderr, "\tFile MIME Type: %s\n", fileMIMEType); #endif delete[] fileMIMEType; } break; } case MATROSKA_ID_FILE_UID: { // 'File UID': get this value unsigned fileUID; if (parseEBMLVal_unsigned(size, fileUID)) { #ifdef DEBUG fprintf(stderr, "\tFile UID: 0x%x\n", fileUID); #endif } break; } #endif default: { // skip over this header skipHeader(size); break; } } setParseState(); } } Boolean MatroskaFileParser::parseCues() { #if defined(DEBUG) || defined(DEBUG_CUES) fprintf(stderr, "parsing Cues\n"); #endif EBMLId id; EBMLDataSize size; // Read the next header, which should be MATROSKA_ID_CUES: if (!parseEBMLIdAndSize(id, size) || id != MATROSKA_ID_CUES) return True; // The header wasn't what we expected, so we're done fLimitOffsetInFile = fCurOffsetInFile + size.val(); // Make sure we don't read past the end of this header double currentCueTime = 0.0; u_int64_t currentClusterOffsetInFile = 0; while (fCurOffsetInFile < fLimitOffsetInFile) { while (!parseEBMLIdAndSize(id, size)) {} #ifdef DEBUG_CUES if (id == MATROSKA_ID_CUE_POINT) fprintf(stderr, "\n"); // makes debugging output easier to read fprintf(stderr, "MatroskaFileParser::parseCues(): Parsed id 0x%s (%s), size: %lld\n", id.hexString(), id.stringName(), size.val()); #endif switch (id.val()) { case MATROSKA_ID_CUE_POINT: { // 'Cue Point' header: enter this break; } case MATROSKA_ID_CUE_TIME: { // 'Cue Time' header: get this value unsigned cueTime; if (parseEBMLVal_unsigned(size, cueTime)) { currentCueTime = cueTime*(fOurFile.fTimecodeScale/1000000000.0); #ifdef DEBUG_CUES fprintf(stderr, "\tCue Time %d (== %f seconds)\n", cueTime, currentCueTime); #endif } break; } case MATROSKA_ID_CUE_TRACK_POSITIONS: { // 'Cue Track Positions' header: enter this break; } case MATROSKA_ID_CUE_TRACK: { // 'Cue Track' header: get this value (but only for debugging; we don't do anything with it) unsigned cueTrack; if (parseEBMLVal_unsigned(size, cueTrack)) { #ifdef DEBUG_CUES fprintf(stderr, "\tCue Track %d\n", cueTrack); #endif } break; } case MATROSKA_ID_CUE_CLUSTER_POSITION: { // 'Cue Cluster Position' header: get this value u_int64_t cueClusterPosition; if (parseEBMLVal_unsigned64(size, cueClusterPosition)) { currentClusterOffsetInFile = fOurFile.fSegmentDataOffset + cueClusterPosition; #ifdef DEBUG_CUES fprintf(stderr, "\tCue Cluster Position %llu (=> offset within the file: %llu (0x%llx))\n", cueClusterPosition, currentClusterOffsetInFile, currentClusterOffsetInFile); #endif // Record this cue point: fOurFile.addCuePoint(currentCueTime, currentClusterOffsetInFile, 1/*default block number within cluster*/); } break; } case MATROSKA_ID_CUE_BLOCK_NUMBER: { // 'Cue Block Number' header: get this value unsigned cueBlockNumber; if (parseEBMLVal_unsigned(size, cueBlockNumber) && cueBlockNumber != 0) { #ifdef DEBUG_CUES fprintf(stderr, "\tCue Block Number %d\n", cueBlockNumber); #endif // Record this cue point (overwriting any existing entry for this cue time): fOurFile.addCuePoint(currentCueTime, currentClusterOffsetInFile, cueBlockNumber); } break; } default: { // We don't process this header, so just skip over it: skipHeader(size); break; } } setParseState(); } fLimitOffsetInFile = 0; // reset #if defined(DEBUG) || defined(DEBUG_CUES) fprintf(stderr, "done parsing Cues\n"); #endif #ifdef DEBUG_CUES fprintf(stderr, "Cue Point tree: "); fOurFile.printCuePoints(stderr); fprintf(stderr, "\n"); #endif return True; // we're done parsing Cues } typedef enum { NoLacing, XiphLacing, FixedSizeLacing, EBMLLacing } MatroskaLacingType; void MatroskaFileParser::parseBlock() { #ifdef DEBUG fprintf(stderr, "parsing SimpleBlock or Block\n"); #endif do { unsigned blockStartPos = curOffset(); // The block begins with the track number: EBMLNumber trackNumber; if (!parseEBMLNumber(trackNumber)) break; fBlockTrackNumber = (unsigned)trackNumber.val(); // If this track is not being read, then skip the rest of this block, and look for another one: if (fOurDemux->lookupDemuxedTrack(fBlockTrackNumber) == NULL) { unsigned headerBytesSeen = curOffset() - blockStartPos; if (headerBytesSeen < fBlockSize) { skipBytes(fBlockSize - headerBytesSeen); } #ifdef DEBUG fprintf(stderr, "\tSkipped block for unused track number %d\n", fBlockTrackNumber); #endif fCurrentParseState = LOOKING_FOR_BLOCK; setParseState(); return; } MatroskaTrack* track = fOurFile.lookup(fBlockTrackNumber); if (track == NULL) break; // shouldn't happen // The next two bytes are the block's timecode (relative to the cluster timecode) fBlockTimecode = (get1Byte()<<8)|get1Byte(); // The next byte indicates the type of 'lacing' used: u_int8_t c = get1Byte(); c &= 0x6; // we're interested in bits 5-6 only MatroskaLacingType lacingType = (c==0x0)?NoLacing : (c==0x02)?XiphLacing : (c==0x04)?FixedSizeLacing : EBMLLacing; #ifdef DEBUG fprintf(stderr, "\ttrack number %d, timecode %d (=> %f seconds), %s lacing\n", fBlockTrackNumber, fBlockTimecode, (fClusterTimecode+fBlockTimecode)*(fOurFile.fTimecodeScale/1000000000.0), (lacingType==NoLacing)?"no" : (lacingType==XiphLacing)?"Xiph" : (lacingType==FixedSizeLacing)?"fixed-size" : "EBML"); #endif if (lacingType == NoLacing) { fNumFramesInBlock = 1; } else { // The next byte tells us how many frames are present in this block fNumFramesInBlock = get1Byte() + 1; } delete[] fFrameSizesWithinBlock; fFrameSizesWithinBlock = new unsigned[fNumFramesInBlock]; if (fFrameSizesWithinBlock == NULL) break; if (lacingType == NoLacing) { unsigned headerBytesSeen = curOffset() - blockStartPos; if (headerBytesSeen > fBlockSize) break; fFrameSizesWithinBlock[0] = fBlockSize - headerBytesSeen; } else if (lacingType == FixedSizeLacing) { unsigned headerBytesSeen = curOffset() - blockStartPos; if (headerBytesSeen > fBlockSize) break; unsigned frameBytesAvailable = fBlockSize - headerBytesSeen; unsigned constantFrameSize = frameBytesAvailable/fNumFramesInBlock; for (unsigned i = 0; i < fNumFramesInBlock; ++i) { fFrameSizesWithinBlock[i] = constantFrameSize; } // If there are any bytes left over, assign them to the last frame: fFrameSizesWithinBlock[fNumFramesInBlock-1] += frameBytesAvailable%fNumFramesInBlock; } else { // EBML or Xiph lacing unsigned curFrameSize = 0; unsigned frameSizesTotal = 0; unsigned i; for (i = 0; i < fNumFramesInBlock-1; ++i) { if (lacingType == EBMLLacing) { EBMLNumber frameSize; if (!parseEBMLNumber(frameSize)) break; unsigned fsv = (unsigned)frameSize.val(); if (i == 0) { curFrameSize = fsv; } else { // The value we read is a signed value, that's added to the previous frame size, to get the current frame size: unsigned toSubtract = (fsv>0xFFFFFF)?0x07FFFFFF : (fsv>0xFFFF)?0x0FFFFF : (fsv>0xFF)?0x1FFF : 0x3F; int fsv_signed = fsv - toSubtract; curFrameSize += fsv_signed; if ((int)curFrameSize < 0) break; } } else { // Xiph lacing curFrameSize = 0; u_int8_t c; do { c = get1Byte(); curFrameSize += c; } while (c == 0xFF); } fFrameSizesWithinBlock[i] = curFrameSize; frameSizesTotal += curFrameSize; } if (i != fNumFramesInBlock-1) break; // an error occurred within the "for" loop // Compute the size of the final frame within the block (from the block's size, and the frame sizes already computed):) unsigned headerBytesSeen = curOffset() - blockStartPos; if (headerBytesSeen + frameSizesTotal > fBlockSize) break; fFrameSizesWithinBlock[i] = fBlockSize - (headerBytesSeen + frameSizesTotal); } // We're done parsing headers within the block, and (as a result) we now know the sizes of all frames within the block. // If we have 'stripped bytes' that are common to (the front of) all frames, then count them now: if (track->headerStrippedBytesSize != 0) { for (unsigned i = 0; i < fNumFramesInBlock; ++i) fFrameSizesWithinBlock[i] += track->headerStrippedBytesSize; } #ifdef DEBUG fprintf(stderr, "\tThis block contains %d frame(s); size(s):", fNumFramesInBlock); unsigned frameSizesTotal = 0; for (unsigned i = 0; i < fNumFramesInBlock; ++i) { fprintf(stderr, " %d", fFrameSizesWithinBlock[i]); frameSizesTotal += fFrameSizesWithinBlock[i]; } if (fNumFramesInBlock > 1) fprintf(stderr, " (total: %u)", frameSizesTotal); fprintf(stderr, " bytes\n"); #endif // Next, start delivering these frames: fCurrentParseState = DELIVERING_FRAME_WITHIN_BLOCK; fCurOffsetWithinFrame = fNextFrameNumberToDeliver = 0; setParseState(); return; } while (0); // An error occurred. Try to recover: #ifdef DEBUG fprintf(stderr, "parseBlock(): Error parsing data; trying to recover...\n"); #endif fCurrentParseState = LOOKING_FOR_BLOCK; } Boolean MatroskaFileParser::deliverFrameWithinBlock() { #ifdef DEBUG fprintf(stderr, "delivering frame within SimpleBlock or Block\n"); #endif do { MatroskaTrack* track = fOurFile.lookup(fBlockTrackNumber); if (track == NULL) break; // shouldn't happen MatroskaDemuxedTrack* demuxedTrack = fOurDemux->lookupDemuxedTrack(fBlockTrackNumber); if (demuxedTrack == NULL) break; // shouldn't happen if (!demuxedTrack->isCurrentlyAwaitingData()) { // Someone has been reading this stream, but isn't right now. // We can't deliver this frame until he asks for it, so punt for now. // The next time he asks for a frame, he'll get it. #ifdef DEBUG fprintf(stderr, "\tdeferring delivery of frame #%d (%d bytes)", fNextFrameNumberToDeliver, fFrameSizesWithinBlock[fNextFrameNumberToDeliver]); if (track->haveSubframes()) fprintf(stderr, "[offset %d]", fCurOffsetWithinFrame); fprintf(stderr, "\n"); #endif restoreSavedParserState(); // so we read from the beginning next time return False; } unsigned frameSize; u_int8_t const* specialFrameSource = NULL; u_int8_t const opusCommentHeader[16] = {'O','p','u','s','T','a','g','s', 0, 0, 0, 0, 0, 0, 0, 0}; if (track->codecIsOpus && demuxedTrack->fOpusTrackNumber < 2) { // Special case for Opus audio. The first frame (the 'configuration' header) comes from // the 'private data'. The second frame (the 'comment' header) comes is synthesized by // us here: if (demuxedTrack->fOpusTrackNumber == 0) { specialFrameSource = track->codecPrivate; frameSize = track->codecPrivateSize; } else { // demuxedTrack->fOpusTrackNumber == 1 specialFrameSource = opusCommentHeader; frameSize = sizeof opusCommentHeader; } ++demuxedTrack->fOpusTrackNumber; } else { frameSize = fFrameSizesWithinBlock[fNextFrameNumberToDeliver]; if (track->haveSubframes()) { // The next "track->subframeSizeSize" bytes contain the length of a 'subframe': if (fCurOffsetWithinFrame + track->subframeSizeSize > frameSize) break; // sanity check unsigned subframeSize = 0; for (unsigned i = 0; i < track->subframeSizeSize; ++i) { u_int8_t c; getCommonFrameBytes(track, &c, 1, 0); if (fCurFrameNumBytesToGet > 0) { // it'll be 1 c = get1Byte(); ++fCurOffsetWithinFrame; } subframeSize = subframeSize*256 + c; } if (subframeSize == 0 || fCurOffsetWithinFrame + subframeSize > frameSize) break; // sanity check frameSize = subframeSize; } } // Compute the presentation time of this frame (from the cluster timecode, the block timecode, and the default duration): double pt = (fClusterTimecode+fBlockTimecode)*(fOurFile.fTimecodeScale/1000000000.0) + fNextFrameNumberToDeliver*(track->defaultDuration/1000000000.0); if (fPresentationTimeOffset == 0.0) { // This is the first time we've computed a presentation time. Compute an offset to make the presentation times aligned // with 'wall clock' time: struct timeval timeNow; gettimeofday(&timeNow, NULL); double ptNow = timeNow.tv_sec + timeNow.tv_usec/1000000.0; fPresentationTimeOffset = ptNow - pt; } pt += fPresentationTimeOffset; struct timeval presentationTime; presentationTime.tv_sec = (unsigned)pt; presentationTime.tv_usec = (unsigned)((pt - presentationTime.tv_sec)*1000000); unsigned durationInMicroseconds; if (specialFrameSource != NULL) { durationInMicroseconds = 0; } else { // normal case durationInMicroseconds = track->defaultDuration/1000; if (track->haveSubframes()) { // If this is a 'subframe', use a duration of 0 instead (unless it's the last 'subframe'): if (fCurOffsetWithinFrame + frameSize + track->subframeSizeSize < fFrameSizesWithinBlock[fNextFrameNumberToDeliver]) { // There's room for at least one more subframe after this, so give this subframe a duration of 0 durationInMicroseconds = 0; } } } if (track->defaultDuration == 0) { // Adjust the frame duration to keep the sum of frame durations aligned with presentation times. if (demuxedTrack->prevPresentationTime().tv_sec != 0) { // not the first time for this track demuxedTrack->durationImbalance() += (presentationTime.tv_sec - demuxedTrack->prevPresentationTime().tv_sec)*1000000 + (presentationTime.tv_usec - demuxedTrack->prevPresentationTime().tv_usec); } int adjustment = 0; if (demuxedTrack->durationImbalance() > 0) { // The duration needs to be increased. int const adjustmentThreshold = 100000; // don't increase the duration by more than this amount (in case there's a mistake) adjustment = demuxedTrack->durationImbalance() > adjustmentThreshold ? adjustmentThreshold : demuxedTrack->durationImbalance(); } else if (demuxedTrack->durationImbalance() < 0) { // The duration needs to be decreased. adjustment = (unsigned)(-demuxedTrack->durationImbalance()) < durationInMicroseconds ? demuxedTrack->durationImbalance() : -(int)durationInMicroseconds; } durationInMicroseconds += adjustment; demuxedTrack->durationImbalance() -= durationInMicroseconds; // for next time demuxedTrack->prevPresentationTime() = presentationTime; // for next time } demuxedTrack->presentationTime() = presentationTime; demuxedTrack->durationInMicroseconds() = durationInMicroseconds; // Deliver the next block now: if (frameSize > demuxedTrack->maxSize()) { demuxedTrack->numTruncatedBytes() = frameSize - demuxedTrack->maxSize(); demuxedTrack->frameSize() = demuxedTrack->maxSize(); } else { // normal case demuxedTrack->numTruncatedBytes() = 0; demuxedTrack->frameSize() = frameSize; } getCommonFrameBytes(track, demuxedTrack->to(), demuxedTrack->frameSize(), demuxedTrack->numTruncatedBytes()); // Next, deliver (and/or skip) bytes from the input file: if (specialFrameSource != NULL) { memmove(demuxedTrack->to(), specialFrameSource, demuxedTrack->frameSize()); #ifdef DEBUG fprintf(stderr, "\tdelivered special frame: %d bytes", demuxedTrack->frameSize()); if (demuxedTrack->numTruncatedBytes() > 0) fprintf(stderr, " (%d bytes truncated)", demuxedTrack->numTruncatedBytes()); fprintf(stderr, " @%u.%06u (%.06f from start); duration %u us\n", demuxedTrack->presentationTime().tv_sec, demuxedTrack->presentationTime().tv_usec, demuxedTrack->presentationTime().tv_sec+demuxedTrack->presentationTime().tv_usec/1000000.0-fPresentationTimeOffset, demuxedTrack->durationInMicroseconds()); #endif setParseState(); FramedSource::afterGetting(demuxedTrack); // completes delivery } else { // normal case fCurrentParseState = DELIVERING_FRAME_BYTES; setParseState(); } return True; } while (0); // An error occurred. Try to recover: #ifdef DEBUG fprintf(stderr, "deliverFrameWithinBlock(): Error parsing data; trying to recover...\n"); #endif fCurrentParseState = LOOKING_FOR_BLOCK; return True; } void MatroskaFileParser::deliverFrameBytes() { do { MatroskaTrack* track = fOurFile.lookup(fBlockTrackNumber); if (track == NULL) break; // shouldn't happen MatroskaDemuxedTrack* demuxedTrack = fOurDemux->lookupDemuxedTrack(fBlockTrackNumber); if (demuxedTrack == NULL) break; // shouldn't happen unsigned const BANK_SIZE = bankSize(); while (fCurFrameNumBytesToGet > 0) { // Hack: We can get no more than BANK_SIZE bytes at a time: unsigned numBytesToGet = fCurFrameNumBytesToGet > BANK_SIZE ? BANK_SIZE : fCurFrameNumBytesToGet; getBytes(fCurFrameTo, numBytesToGet); fCurFrameTo += numBytesToGet; fCurFrameNumBytesToGet -= numBytesToGet; fCurOffsetWithinFrame += numBytesToGet; setParseState(); } while (fCurFrameNumBytesToSkip > 0) { // Hack: We can skip no more than BANK_SIZE bytes at a time: unsigned numBytesToSkip = fCurFrameNumBytesToSkip > BANK_SIZE ? BANK_SIZE : fCurFrameNumBytesToSkip; skipBytes(numBytesToSkip); fCurFrameNumBytesToSkip -= numBytesToSkip; fCurOffsetWithinFrame += numBytesToSkip; setParseState(); } #ifdef DEBUG fprintf(stderr, "\tdelivered frame #%d: %d bytes", fNextFrameNumberToDeliver, demuxedTrack->frameSize()); if (track->haveSubframes()) fprintf(stderr, "[offset %d]", fCurOffsetWithinFrame - track->subframeSizeSize - demuxedTrack->frameSize() - demuxedTrack->numTruncatedBytes()); if (demuxedTrack->numTruncatedBytes() > 0) fprintf(stderr, " (%d bytes truncated)", demuxedTrack->numTruncatedBytes()); fprintf(stderr, " @%u.%06u (%.06f from start); duration %u us\n", demuxedTrack->presentationTime().tv_sec, demuxedTrack->presentationTime().tv_usec, demuxedTrack->presentationTime().tv_sec+demuxedTrack->presentationTime().tv_usec/1000000.0-fPresentationTimeOffset, demuxedTrack->durationInMicroseconds()); #endif if (!track->haveSubframes() || fCurOffsetWithinFrame + track->subframeSizeSize >= fFrameSizesWithinBlock[fNextFrameNumberToDeliver]) { // Either we don't have subframes, or there's no more room for another subframe => We're completely done with this frame now: ++fNextFrameNumberToDeliver; fCurOffsetWithinFrame = 0; } if (fNextFrameNumberToDeliver == fNumFramesInBlock) { // We've delivered all of the frames from this block. Look for another block next: fCurrentParseState = LOOKING_FOR_BLOCK; } else { fCurrentParseState = DELIVERING_FRAME_WITHIN_BLOCK; } setParseState(); FramedSource::afterGetting(demuxedTrack); // completes delivery return; } while (0); // An error occurred. Try to recover: #ifdef DEBUG fprintf(stderr, "deliverFrameBytes(): Error parsing data; trying to recover...\n"); #endif fCurrentParseState = LOOKING_FOR_BLOCK; } void MatroskaFileParser ::getCommonFrameBytes(MatroskaTrack* track, u_int8_t* to, unsigned numBytesToGet, unsigned numBytesToSkip) { if (track->headerStrippedBytesSize > fCurOffsetWithinFrame) { // We have some common 'header stripped' bytes that remain to be prepended to the frame. Use these first: unsigned numRemainingHeaderStrippedBytes = track->headerStrippedBytesSize - fCurOffsetWithinFrame; unsigned numHeaderStrippedBytesToGet; if (numBytesToGet <= numRemainingHeaderStrippedBytes) { numHeaderStrippedBytesToGet = numBytesToGet; numBytesToGet = 0; if (numBytesToGet + numBytesToSkip <= numRemainingHeaderStrippedBytes) { numBytesToSkip = 0; } else { numBytesToSkip = numBytesToGet + numBytesToSkip - numRemainingHeaderStrippedBytes; } } else { numHeaderStrippedBytesToGet = numRemainingHeaderStrippedBytes; numBytesToGet = numBytesToGet - numRemainingHeaderStrippedBytes; } if (numHeaderStrippedBytesToGet > 0) { memmove(to, &track->headerStrippedBytes[fCurOffsetWithinFrame], numHeaderStrippedBytesToGet); to += numHeaderStrippedBytesToGet; fCurOffsetWithinFrame += numHeaderStrippedBytesToGet; } } fCurFrameTo = to; fCurFrameNumBytesToGet = numBytesToGet; fCurFrameNumBytesToSkip = numBytesToSkip; } Boolean MatroskaFileParser::parseEBMLNumber(EBMLNumber& num) { unsigned i; u_int8_t bitmask = 0x80; for (i = 0; i < EBML_NUMBER_MAX_LEN; ++i) { while (1) { if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) return False; // We've hit our pre-set limit num.data[i] = get1Byte(); ++fCurOffsetInFile; // If we're looking for an id, skip any leading bytes that don't contain a '1' in the first 4 bits: if (i == 0/*we're a leading byte*/ && !num.stripLeading1/*we're looking for an id*/ && (num.data[i]&0xF0) == 0) { setParseState(); // ensures that we make forward progress if the parsing gets interrupted continue; } break; } if ((num.data[0]&bitmask) != 0) { // num[i] is the last byte of the id if (num.stripLeading1) num.data[0] &=~ bitmask; break; } bitmask >>= 1; } if (i == EBML_NUMBER_MAX_LEN) return False; num.len = i+1; return True; } Boolean MatroskaFileParser::parseEBMLIdAndSize(EBMLId& id, EBMLDataSize& size) { return parseEBMLNumber(id) && parseEBMLNumber(size); } Boolean MatroskaFileParser::parseEBMLVal_unsigned64(EBMLDataSize& size, u_int64_t& result) { u_int64_t sv = size.val(); if (sv > 8) return False; // size too large result = 0; // initially for (unsigned i = (unsigned)sv; i > 0; --i) { if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) return False; // We've hit our pre-set limit u_int8_t c = get1Byte(); ++fCurOffsetInFile; result = result*256 + c; } return True; } Boolean MatroskaFileParser::parseEBMLVal_unsigned(EBMLDataSize& size, unsigned& result) { if (size.val() > 4) return False; // size too large u_int64_t result64; if (!parseEBMLVal_unsigned64(size, result64)) return False; result = (unsigned)result64; return True; } Boolean MatroskaFileParser::parseEBMLVal_float(EBMLDataSize& size, float& result) { if (size.val() == 4) { // Normal case. Read the value as if it were a 4-byte integer, then copy it to the 'float' result: unsigned resultAsUnsigned; if (!parseEBMLVal_unsigned(size, resultAsUnsigned)) return False; if (sizeof result != sizeof resultAsUnsigned) return False; memcpy(&result, &resultAsUnsigned, sizeof result); return True; } else if (size.val() == 8) { // Read the value as if it were an 8-byte integer, then copy it to a 'double', the convert that to the 'float' result: u_int64_t resultAsUnsigned64; if (!parseEBMLVal_unsigned64(size, resultAsUnsigned64)) return False; double resultDouble; if (sizeof resultDouble != sizeof resultAsUnsigned64) return False; memcpy(&resultDouble, &resultAsUnsigned64, sizeof resultDouble); result = (float)resultDouble; return True; } else { // Unworkable size return False; } } Boolean MatroskaFileParser::parseEBMLVal_string(EBMLDataSize& size, char*& result) { unsigned resultLength = (unsigned)size.val(); result = new char[resultLength + 1]; // allow for the trailing '\0' if (result == NULL) return False; char* p = result; unsigned i; for (i = 0; i < resultLength; ++i) { if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) break; // We've hit our pre-set limit u_int8_t c = get1Byte(); ++fCurOffsetInFile; *p++ = c; } if (i < resultLength) { // an error occurred delete[] result; result = NULL; return False; } *p = '\0'; return True; } Boolean MatroskaFileParser::parseEBMLVal_binary(EBMLDataSize& size, u_int8_t*& result) { unsigned resultLength = (unsigned)size.val(); result = new u_int8_t[resultLength]; if (result == NULL) return False; u_int8_t* p = result; unsigned i; for (i = 0; i < resultLength; ++i) { if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) break; // We've hit our pre-set limit u_int8_t c = get1Byte(); ++fCurOffsetInFile; *p++ = c; } if (i < resultLength) { // an error occurred delete[] result; result = NULL; return False; } return True; } void MatroskaFileParser::skipHeader(EBMLDataSize const& size) { u_int64_t sv = (unsigned)size.val(); #ifdef DEBUG fprintf(stderr, "\tskipping %llu bytes\n", sv); #endif fNumHeaderBytesToSkip = sv; skipRemainingHeaderBytes(False); } void MatroskaFileParser::skipRemainingHeaderBytes(Boolean isContinuation) { if (fNumHeaderBytesToSkip == 0) return; // common case // Hack: To avoid tripping into a parser 'internal error' if we try to skip an excessively large // distance, break up the skipping into manageable chunks, to ensure forward progress: unsigned const maxBytesToSkip = bankSize(); while (fNumHeaderBytesToSkip > 0) { unsigned numBytesToSkipNow = fNumHeaderBytesToSkip < maxBytesToSkip ? (unsigned)fNumHeaderBytesToSkip : maxBytesToSkip; setParseState(); skipBytes(numBytesToSkipNow); #ifdef DEBUG if (isContinuation || numBytesToSkipNow < fNumHeaderBytesToSkip) { fprintf(stderr, "\t\t(skipped %u bytes; %llu bytes remaining)\n", numBytesToSkipNow, fNumHeaderBytesToSkip - numBytesToSkipNow); } #endif fCurOffsetInFile += numBytesToSkipNow; fNumHeaderBytesToSkip -= numBytesToSkipNow; } } void MatroskaFileParser::setParseState() { fSavedCurOffsetInFile = fCurOffsetInFile; fSavedCurOffsetWithinFrame = fCurOffsetWithinFrame; saveParserState(); } void MatroskaFileParser::restoreSavedParserState() { StreamParser::restoreSavedParserState(); fCurOffsetInFile = fSavedCurOffsetInFile; fCurOffsetWithinFrame = fSavedCurOffsetWithinFrame; } void MatroskaFileParser::seekToFilePosition(u_int64_t offsetInFile) { ByteStreamFileSource* fileSource = (ByteStreamFileSource*)fInputSource; // we know it's a "ByteStreamFileSource" if (fileSource != NULL) { fileSource->seekToByteAbsolute(offsetInFile); resetStateAfterSeeking(); } } void MatroskaFileParser::seekToEndOfFile() { ByteStreamFileSource* fileSource = (ByteStreamFileSource*)fInputSource; // we know it's a "ByteStreamFileSource" if (fileSource != NULL) { fileSource->seekToEnd(); resetStateAfterSeeking(); } } void MatroskaFileParser::resetStateAfterSeeking() { // Because we're resuming parsing after seeking to a new position in the file, reset the parser state: fCurOffsetInFile = fSavedCurOffsetInFile = 0; fCurOffsetWithinFrame = fSavedCurOffsetWithinFrame = 0; flushInput(); }