Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 1 | // Copyright (c) 2012 The WebM project authors. All Rights Reserved. |
| 2 | // |
| 3 | // Use of this source code is governed by a BSD-style license |
| 4 | // that can be found in the LICENSE file in the root of the source |
| 5 | // tree. An additional intellectual property rights grant can be found |
| 6 | // in the file PATENTS. All contributing project authors may |
| 7 | // be found in the AUTHORS file in the root of the source tree. |
| 8 | |
| 9 | #include <cstdio> |
Tom Finegan | e64bf75 | 2016-03-18 09:32:52 -0700 | [diff] [blame] | 10 | #include <cstdlib> |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 11 | #include <cstring> |
| 12 | #include <map> |
| 13 | #include <memory> |
| 14 | #include <string> |
Tom Finegan | baba8b1 | 2016-03-09 14:12:21 -0800 | [diff] [blame] | 15 | #include <utility> |
| 16 | |
Tom Finegan | 504e0f2 | 2016-03-21 11:20:48 -0700 | [diff] [blame] | 17 | #include "mkvparser/mkvparser.h" |
| 18 | #include "mkvparser/mkvreader.h" |
Tom Finegan | 5f1065e | 2016-03-17 15:09:46 -0700 | [diff] [blame] | 19 | #include "webvtt/webvttparser.h" |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 20 | |
| 21 | using std::string; |
| 22 | |
Tom Finegan | e64bf75 | 2016-03-18 09:32:52 -0700 | [diff] [blame] | 23 | namespace libwebm { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 24 | namespace vttdemux { |
| 25 | |
| 26 | typedef long long mkvtime_t; // NOLINT |
Vignesh Venkatasubramanian | 7b24501 | 2014-04-29 00:35:56 -0700 | [diff] [blame] | 27 | typedef long long mkvpos_t; // NOLINT |
Lisa Velden | d707c67 | 2018-01-22 11:41:20 +0100 | [diff] [blame] | 28 | typedef std::unique_ptr<mkvparser::Segment> segment_ptr_t; |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 29 | |
| 30 | // WebVTT metadata tracks have a type (encoded in the CodecID for the track). |
| 31 | // We use |type| to synthesize a filename for the out-of-band WebVTT |file|. |
| 32 | struct MetadataInfo { |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 33 | enum Type { kSubtitles, kCaptions, kDescriptions, kMetadata, kChapters } type; |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 34 | FILE* file; |
| 35 | }; |
| 36 | |
| 37 | // We use a map, indexed by track number, to collect information about |
| 38 | // each track in the input file. |
| 39 | typedef std::map<long, MetadataInfo> metadata_map_t; // NOLINT |
| 40 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 41 | // The distinguished key value we use to store the chapters |
| 42 | // information in the metadata map. |
| 43 | enum { kChaptersKey = 0 }; |
| 44 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 45 | // The data from the original WebVTT Cue is stored as a WebM block. |
| 46 | // The FrameParser is used to parse the lines of text out from the |
| 47 | // block, in order to reconstruct the original WebVTT Cue. |
| 48 | class FrameParser : public libwebvtt::LineReader { |
| 49 | public: |
| 50 | // Bind the FrameParser instance to a WebM block. |
| 51 | explicit FrameParser(const mkvparser::BlockGroup* block_group); |
| 52 | virtual ~FrameParser(); |
| 53 | |
| 54 | // The Webm block (group) to which this instance is bound. We |
| 55 | // treat the payload of the block as a stream of characters. |
| 56 | const mkvparser::BlockGroup* const block_group_; |
| 57 | |
| 58 | protected: |
| 59 | // Read the next character from the character stream (the payload |
| 60 | // of the WebM block). We increment the stream pointer |pos_| as |
| 61 | // each character from the stream is consumed. |
| 62 | virtual int GetChar(char* c); |
| 63 | |
| 64 | // End-of-line handling requires that we put a character back into |
| 65 | // the stream. Here we need only decrement the stream pointer |pos_| |
| 66 | // to unconsume the character. |
| 67 | virtual void UngetChar(char c); |
| 68 | |
| 69 | // The current position in the character stream (the payload of the block). |
| 70 | mkvpos_t pos_; |
| 71 | |
| 72 | // The position of the end of the character stream. When the current |
| 73 | // position |pos_| equals the end position |pos_end_|, the entire |
| 74 | // stream (block payload) has been consumed and end-of-stream is indicated. |
| 75 | mkvpos_t pos_end_; |
| 76 | |
| 77 | private: |
| 78 | // Disable copy ctor and copy assign |
| 79 | FrameParser(const FrameParser&); |
| 80 | FrameParser& operator=(const FrameParser&); |
| 81 | }; |
| 82 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 83 | // The data from the original WebVTT Cue is stored as an MKV Chapters |
| 84 | // Atom element (the cue payload is stored as a Display sub-element). |
| 85 | // The ChapterAtomParser is used to parse the lines of text out from |
| 86 | // the String sub-element of the Display element (though it would be |
| 87 | // admittedly odd if there were more than one line). |
| 88 | class ChapterAtomParser : public libwebvtt::LineReader { |
| 89 | public: |
| 90 | explicit ChapterAtomParser(const mkvparser::Chapters::Display* display); |
| 91 | virtual ~ChapterAtomParser(); |
| 92 | |
| 93 | const mkvparser::Chapters::Display* const display_; |
| 94 | |
| 95 | protected: |
| 96 | // Read the next character from the character stream (the title |
| 97 | // member of the atom's display). We increment the stream pointer |
| 98 | // |str_| as each character from the stream is consumed. |
| 99 | virtual int GetChar(char* c); |
| 100 | |
| 101 | // End-of-line handling requires that we put a character back into |
| 102 | // the stream. Here we need only decrement the stream pointer |str_| |
| 103 | // to unconsume the character. |
| 104 | virtual void UngetChar(char c); |
| 105 | |
| 106 | // The current position in the character stream (the title of the |
| 107 | // atom's display). |
| 108 | const char* str_; |
| 109 | |
| 110 | // The position of the end of the character stream. When the current |
| 111 | // position |str_| equals the end position |str_end_|, the entire |
| 112 | // stream (title of the display) has been consumed and end-of-stream |
| 113 | // is indicated. |
| 114 | const char* str_end_; |
| 115 | |
| 116 | private: |
| 117 | ChapterAtomParser(const ChapterAtomParser&); |
| 118 | ChapterAtomParser& operator=(const ChapterAtomParser&); |
| 119 | }; |
| 120 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 121 | // Parse the EBML header of the WebM input file, to determine whether we |
| 122 | // actually have a WebM file. Returns false if this is not a WebM file. |
| 123 | bool ParseHeader(mkvparser::IMkvReader* reader, mkvpos_t* pos); |
| 124 | |
| 125 | // Parse the Segment of the input file and load all of its clusters. |
| 126 | // Returns false if there was an error parsing the file. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 127 | bool ParseSegment(mkvparser::IMkvReader* reader, mkvpos_t pos, |
| 128 | segment_ptr_t* segment); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 129 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 130 | // If |segment| has a Chapters element (in which case, there will be a |
| 131 | // corresponding entry in |metadata_map|), convert the MKV chapters to |
| 132 | // WebVTT chapter cues and write them to the output file. Returns |
| 133 | // false on error. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 134 | bool WriteChaptersFile(const metadata_map_t& metadata_map, |
| 135 | const mkvparser::Segment* segment); |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 136 | |
| 137 | // Convert an MKV Chapters Atom to a WebVTT cue and write it to the |
| 138 | // output |file|. Returns false on error. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 139 | bool WriteChaptersCue(FILE* file, const mkvparser::Chapters* chapters, |
| 140 | const mkvparser::Chapters::Atom* atom, |
| 141 | const mkvparser::Chapters::Display* display); |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 142 | |
Matthew Heaney | 28222b4 | 2012-11-13 12:44:06 -0800 | [diff] [blame] | 143 | // Write the Cue Identifier line of the WebVTT cue, if it's present. |
| 144 | // Returns false on error. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 145 | bool WriteChaptersCueIdentifier(FILE* file, |
| 146 | const mkvparser::Chapters::Atom* atom); |
Matthew Heaney | 28222b4 | 2012-11-13 12:44:06 -0800 | [diff] [blame] | 147 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 148 | // Use the timecodes from the chapters |atom| to write just the |
| 149 | // timings line of the WebVTT cue. Returns false on error. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 150 | bool WriteChaptersCueTimings(FILE* file, const mkvparser::Chapters* chapters, |
| 151 | const mkvparser::Chapters::Atom* atom); |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 152 | |
| 153 | // Parse the String sub-element of the |display| and write the payload |
| 154 | // of the WebVTT cue. Returns false on error. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 155 | bool WriteChaptersCuePayload(FILE* file, |
| 156 | const mkvparser::Chapters::Display* display); |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 157 | |
| 158 | // Iterate over the tracks of the input file (and any chapters |
| 159 | // element) and cache information about each metadata track. |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 160 | void BuildMap(const mkvparser::Segment* segment, metadata_map_t* metadata_map); |
| 161 | |
| 162 | // For each track listed in the cache, synthesize its output filename |
| 163 | // and open a file handle that designates the out-of-band file. |
| 164 | // Returns false if we were unable to open an output file for a track. |
| 165 | bool OpenFiles(metadata_map_t* metadata_map, const char* filename); |
| 166 | |
| 167 | // Close the file handle for each track in the cache. |
| 168 | void CloseFiles(metadata_map_t* metadata_map); |
| 169 | |
| 170 | // Iterate over the clusters of the input file, and write a WebVTT cue |
| 171 | // for each metadata block. Returns false if processing of a cluster |
| 172 | // failed. |
| 173 | bool WriteFiles(const metadata_map_t& m, mkvparser::Segment* s); |
| 174 | |
| 175 | // Write the WebVTT header for each track in the cache. We do this |
| 176 | // immediately before writing the actual WebVTT cues. Returns false |
| 177 | // if the write failed. |
| 178 | bool InitializeFiles(const metadata_map_t& metadata_map); |
| 179 | |
| 180 | // Iterate over the blocks of the |cluster|, writing a WebVTT cue to |
| 181 | // its associated output file for each block of metadata. Returns |
| 182 | // false if processing a block failed, or there was a parse error. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 183 | bool ProcessCluster(const metadata_map_t& metadata_map, |
| 184 | const mkvparser::Cluster* cluster); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 185 | |
| 186 | // Look up this track number in the cache, and if found (meaning this |
| 187 | // is a metadata track), write a WebVTT cue to the associated output |
| 188 | // file. Returns false if writing the WebVTT cue failed. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 189 | bool ProcessBlockEntry(const metadata_map_t& metadata_map, |
| 190 | const mkvparser::BlockEntry* block_entry); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 191 | |
| 192 | // Parse the lines of text from the |block_group| to reconstruct the |
| 193 | // original WebVTT cue, and write it to the associated output |file|. |
| 194 | // Returns false if there was an error writing to the output file. |
| 195 | bool WriteCue(FILE* file, const mkvparser::BlockGroup* block_group); |
| 196 | |
| 197 | // Consume a line of text from the character stream, and if the line |
| 198 | // is not empty write the cue identifier to the associated output |
| 199 | // file. Returns false if there was an error writing to the file. |
| 200 | bool WriteCueIdentifier(FILE* f, FrameParser* parser); |
| 201 | |
| 202 | // Consume a line of text from the character stream (which holds any |
| 203 | // cue settings) and write the cue timings line for this cue to the |
| 204 | // associated output file. Returns false if there was an error |
| 205 | // writing to the file. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 206 | bool WriteCueTimings(FILE* f, FrameParser* parser); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 207 | |
| 208 | // Write the timestamp (representating either the start time or stop |
| 209 | // time of the cue) to the output file. Returns false if there was an |
| 210 | // error writing to the file. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 211 | bool WriteCueTime(FILE* f, mkvtime_t time_ns); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 212 | |
| 213 | // Consume the remaining lines of text from the character stream |
| 214 | // (these lines are the actual payload of the WebVTT cue), and write |
| 215 | // them to the associated output file. Returns false if there was an |
| 216 | // error writing to the file. |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 217 | bool WriteCuePayload(FILE* f, FrameParser* parser); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 218 | } // namespace vttdemux |
| 219 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 220 | namespace vttdemux { |
| 221 | |
| 222 | FrameParser::FrameParser(const mkvparser::BlockGroup* block_group) |
| 223 | : block_group_(block_group) { |
| 224 | const mkvparser::Block* const block = block_group->GetBlock(); |
| 225 | const mkvparser::Block::Frame& f = block->GetFrame(0); |
| 226 | |
| 227 | // The beginning and end of the character stream corresponds to the |
| 228 | // position of this block's frame within the WebM input file. |
| 229 | |
| 230 | pos_ = f.pos; |
| 231 | pos_end_ = f.pos + f.len; |
| 232 | } |
| 233 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 234 | FrameParser::~FrameParser() {} |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 235 | |
| 236 | int FrameParser::GetChar(char* c) { |
| 237 | if (pos_ >= pos_end_) // end-of-stream |
Vignesh Venkatasubramanian | 7b24501 | 2014-04-29 00:35:56 -0700 | [diff] [blame] | 238 | return 1; // per the semantics of libwebvtt::Reader::GetChar |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 239 | |
| 240 | const mkvparser::Cluster* const cluster = block_group_->GetCluster(); |
| 241 | const mkvparser::Segment* const segment = cluster->m_pSegment; |
| 242 | mkvparser::IMkvReader* const reader = segment->m_pReader; |
| 243 | |
| 244 | unsigned char* const buf = reinterpret_cast<unsigned char*>(c); |
| 245 | const int result = reader->Read(pos_, 1, buf); |
| 246 | |
| 247 | if (result < 0) // error |
| 248 | return -1; |
| 249 | |
| 250 | ++pos_; // consume this character in the stream |
| 251 | return 0; |
| 252 | } |
| 253 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 254 | void FrameParser::UngetChar(char /* c */) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 255 | // All we need to do here is decrement the position in the stream. |
| 256 | // The next time GetChar is called the same character will be |
| 257 | // re-read from the input file. |
| 258 | --pos_; |
| 259 | } |
| 260 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 261 | ChapterAtomParser::ChapterAtomParser( |
| 262 | const mkvparser::Chapters::Display* display) |
| 263 | : display_(display) { |
| 264 | str_ = display->GetString(); |
James Zern | 87bcddf | 2017-03-09 12:41:29 -0800 | [diff] [blame] | 265 | if (str_ == NULL) |
| 266 | return; |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 267 | const size_t len = strlen(str_); |
| 268 | str_end_ = str_ + len; |
| 269 | } |
| 270 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 271 | ChapterAtomParser::~ChapterAtomParser() {} |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 272 | |
| 273 | int ChapterAtomParser::GetChar(char* c) { |
James Zern | 87bcddf | 2017-03-09 12:41:29 -0800 | [diff] [blame] | 274 | if (str_ == NULL || str_ >= str_end_) // end-of-stream |
Vignesh Venkatasubramanian | 7b24501 | 2014-04-29 00:35:56 -0700 | [diff] [blame] | 275 | return 1; // per the semantics of libwebvtt::Reader::GetChar |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 276 | |
| 277 | *c = *str_++; // consume this character in the stream |
| 278 | return 0; |
| 279 | } |
| 280 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 281 | void ChapterAtomParser::UngetChar(char /* c */) { |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 282 | // All we need to do here is decrement the position in the stream. |
| 283 | // The next time GetChar is called the same character will be |
| 284 | // re-read from the input file. |
| 285 | --str_; |
| 286 | } |
| 287 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 288 | } // namespace vttdemux |
| 289 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 290 | bool vttdemux::ParseHeader(mkvparser::IMkvReader* reader, mkvpos_t* pos) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 291 | mkvparser::EBMLHeader h; |
| 292 | const mkvpos_t status = h.Parse(reader, *pos); |
| 293 | |
| 294 | if (status) { |
| 295 | printf("error parsing EBML header\n"); |
| 296 | return false; |
| 297 | } |
| 298 | |
Tom Finegan | 714f3c4 | 2015-09-04 10:18:20 -0700 | [diff] [blame] | 299 | if (h.m_docType == NULL || strcmp(h.m_docType, "webm") != 0) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 300 | printf("bad doctype\n"); |
| 301 | return false; |
| 302 | } |
| 303 | |
| 304 | return true; // success |
| 305 | } |
| 306 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 307 | bool vttdemux::ParseSegment(mkvparser::IMkvReader* reader, mkvpos_t pos, |
| 308 | segment_ptr_t* segment_ptr) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 309 | // We first create the segment object. |
| 310 | |
| 311 | mkvparser::Segment* p; |
| 312 | const mkvpos_t create = mkvparser::Segment::CreateInstance(reader, pos, p); |
| 313 | |
| 314 | if (create) { |
| 315 | printf("error parsing segment element\n"); |
| 316 | return false; |
| 317 | } |
| 318 | |
| 319 | segment_ptr->reset(p); |
| 320 | |
| 321 | // Now parse all of the segment's sub-elements, in toto. |
| 322 | |
| 323 | const long status = p->Load(); // NOLINT |
| 324 | |
| 325 | if (status < 0) { |
| 326 | printf("error loading segment\n"); |
| 327 | return false; |
| 328 | } |
| 329 | |
| 330 | return true; |
| 331 | } |
| 332 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 333 | void vttdemux::BuildMap(const mkvparser::Segment* segment, |
| 334 | metadata_map_t* map_ptr) { |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 335 | metadata_map_t& m = *map_ptr; |
| 336 | m.clear(); |
| 337 | |
| 338 | if (segment->GetChapters()) { |
| 339 | MetadataInfo info; |
| 340 | info.file = NULL; |
| 341 | info.type = MetadataInfo::kChapters; |
| 342 | |
| 343 | m[kChaptersKey] = info; |
| 344 | } |
| 345 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 346 | const mkvparser::Tracks* const tt = segment->GetTracks(); |
| 347 | if (tt == NULL) |
| 348 | return; |
| 349 | |
| 350 | const long tc = tt->GetTracksCount(); // NOLINT |
| 351 | if (tc <= 0) |
| 352 | return; |
| 353 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 354 | // Iterate over the tracks in the intput file. We determine whether |
| 355 | // a track holds metadata by inspecting its CodecID. |
| 356 | |
| 357 | for (long idx = 0; idx < tc; ++idx) { // NOLINT |
| 358 | const mkvparser::Track* const t = tt->GetTrackByIndex(idx); |
| 359 | |
| 360 | if (t == NULL) // weird |
| 361 | continue; |
| 362 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 363 | const long tn = t->GetNumber(); // NOLINT |
| 364 | |
| 365 | if (tn <= 0) // weird |
| 366 | continue; |
| 367 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 368 | const char* const codec_id = t->GetCodecId(); |
| 369 | |
| 370 | if (codec_id == NULL) // weird |
| 371 | continue; |
| 372 | |
| 373 | MetadataInfo info; |
| 374 | info.file = NULL; |
| 375 | |
| 376 | if (strcmp(codec_id, "D_WEBVTT/SUBTITLES") == 0) { |
| 377 | info.type = MetadataInfo::kSubtitles; |
| 378 | } else if (strcmp(codec_id, "D_WEBVTT/CAPTIONS") == 0) { |
| 379 | info.type = MetadataInfo::kCaptions; |
| 380 | } else if (strcmp(codec_id, "D_WEBVTT/DESCRIPTIONS") == 0) { |
| 381 | info.type = MetadataInfo::kDescriptions; |
| 382 | } else if (strcmp(codec_id, "D_WEBVTT/METADATA") == 0) { |
| 383 | info.type = MetadataInfo::kMetadata; |
| 384 | } else { |
| 385 | continue; |
| 386 | } |
| 387 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 388 | m[tn] = info; // create an entry in the cache for this track |
| 389 | } |
| 390 | } |
| 391 | |
| 392 | bool vttdemux::OpenFiles(metadata_map_t* metadata_map, const char* filename) { |
| 393 | if (metadata_map == NULL || metadata_map->empty()) |
| 394 | return false; |
| 395 | |
| 396 | if (filename == NULL) |
| 397 | return false; |
| 398 | |
| 399 | // Find the position of the filename extension. We synthesize the |
| 400 | // output filename from the directory path and basename of the input |
| 401 | // filename. |
| 402 | |
| 403 | const char* const ext = strrchr(filename, '.'); |
| 404 | |
| 405 | if (ext == NULL) // TODO(matthewjheaney): liberalize? |
| 406 | return false; |
| 407 | |
| 408 | // Remember whether a track of this type has already been seen (the |
| 409 | // map key) by keeping a count (the map item). We quality the |
| 410 | // output filename with the track number if there is more than one |
| 411 | // track having a given type. |
| 412 | |
| 413 | std::map<MetadataInfo::Type, int> exists; |
| 414 | |
| 415 | typedef metadata_map_t::iterator iter_t; |
| 416 | |
| 417 | metadata_map_t& m = *metadata_map; |
| 418 | const iter_t ii = m.begin(); |
| 419 | const iter_t j = m.end(); |
| 420 | |
| 421 | // Make a first pass over the cache to determine whether there is |
| 422 | // more than one track corresponding to a given metadata type. |
| 423 | |
| 424 | iter_t i = ii; |
| 425 | while (i != j) { |
| 426 | const metadata_map_t::value_type& v = *i++; |
| 427 | const MetadataInfo& info = v.second; |
| 428 | const MetadataInfo::Type type = info.type; |
| 429 | ++exists[type]; |
| 430 | } |
| 431 | |
| 432 | // Make a second pass over the cache, synthesizing the filename of |
| 433 | // each output file (from the input file basename, the input track |
| 434 | // metadata type, and its track number if necessary), and then |
| 435 | // opening a WebVTT output file having that filename. |
| 436 | |
| 437 | i = ii; |
| 438 | while (i != j) { |
| 439 | metadata_map_t::value_type& v = *i++; |
| 440 | MetadataInfo& info = v.second; |
| 441 | const MetadataInfo::Type type = info.type; |
| 442 | |
| 443 | // Start with the basename of the input file. |
| 444 | |
| 445 | string name(filename, ext); |
| 446 | |
| 447 | // Next append the metadata kind. |
| 448 | |
| 449 | switch (type) { |
| 450 | case MetadataInfo::kSubtitles: |
| 451 | name += "_SUBTITLES"; |
| 452 | break; |
| 453 | |
| 454 | case MetadataInfo::kCaptions: |
| 455 | name += "_CAPTIONS"; |
| 456 | break; |
| 457 | |
| 458 | case MetadataInfo::kDescriptions: |
| 459 | name += "_DESCRIPTIONS"; |
| 460 | break; |
| 461 | |
| 462 | case MetadataInfo::kMetadata: |
| 463 | name += "_METADATA"; |
| 464 | break; |
| 465 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 466 | case MetadataInfo::kChapters: |
| 467 | name += "_CHAPTERS"; |
| 468 | break; |
| 469 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 470 | default: |
| 471 | return false; |
| 472 | } |
| 473 | |
| 474 | // If there is more than one metadata track having a given type |
| 475 | // (the WebVTT-in-WebM spec doesn't preclude this), then qualify |
| 476 | // the output filename with the input track number. |
| 477 | |
| 478 | if (exists[type] > 1) { |
| 479 | enum { kLen = 33 }; |
| 480 | char str[kLen]; // max 126 tracks, so only 4 chars really needed |
Matthew Heaney | 17cf7cc | 2014-02-28 12:33:58 -0800 | [diff] [blame] | 481 | #ifndef _MSC_VER |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 482 | snprintf(str, kLen, "%ld", v.first); // track number |
Matthew Heaney | 17cf7cc | 2014-02-28 12:33:58 -0800 | [diff] [blame] | 483 | #else |
| 484 | _snprintf_s(str, sizeof(str), kLen, "%ld", v.first); // track number |
| 485 | #endif |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 486 | name += str; |
| 487 | } |
| 488 | |
| 489 | // Finally append the output filename extension. |
| 490 | |
| 491 | name += ".vtt"; |
| 492 | |
| 493 | // We have synthesized the full output filename, so attempt to |
| 494 | // open the WebVTT output file. |
| 495 | |
| 496 | info.file = fopen(name.c_str(), "wb"); |
Matthew Heaney | 17cf7cc | 2014-02-28 12:33:58 -0800 | [diff] [blame] | 497 | const bool success = (info.file != NULL); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 498 | |
Matthew Heaney | 17cf7cc | 2014-02-28 12:33:58 -0800 | [diff] [blame] | 499 | if (!success) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 500 | printf("unable to open output file %s\n", name.c_str()); |
| 501 | return false; |
| 502 | } |
| 503 | } |
| 504 | |
| 505 | return true; |
| 506 | } |
| 507 | |
| 508 | void vttdemux::CloseFiles(metadata_map_t* metadata_map) { |
| 509 | if (metadata_map == NULL) |
| 510 | return; |
| 511 | |
| 512 | metadata_map_t& m = *metadata_map; |
| 513 | |
| 514 | typedef metadata_map_t::iterator iter_t; |
| 515 | |
| 516 | iter_t i = m.begin(); |
| 517 | const iter_t j = m.end(); |
| 518 | |
| 519 | // Gracefully close each output file, to ensure all output gets |
| 520 | // propertly flushed. |
| 521 | |
| 522 | while (i != j) { |
| 523 | metadata_map_t::value_type& v = *i++; |
| 524 | MetadataInfo& info = v.second; |
| 525 | |
James Zern | 784fc1b | 2017-04-17 15:55:17 -0700 | [diff] [blame] | 526 | if (info.file != NULL) { |
| 527 | fclose(info.file); |
| 528 | info.file = NULL; |
| 529 | } |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 530 | } |
| 531 | } |
| 532 | |
| 533 | bool vttdemux::WriteFiles(const metadata_map_t& m, mkvparser::Segment* s) { |
| 534 | // First write the WebVTT header. |
| 535 | |
| 536 | InitializeFiles(m); |
| 537 | |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 538 | if (!WriteChaptersFile(m, s)) |
| 539 | return false; |
| 540 | |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 541 | // Now iterate over the clusters, writing the WebVTT cue as we parse |
| 542 | // each metadata block. |
| 543 | |
| 544 | const mkvparser::Cluster* cluster = s->GetFirst(); |
| 545 | |
| 546 | while (cluster != NULL && !cluster->EOS()) { |
| 547 | if (!ProcessCluster(m, cluster)) |
| 548 | return false; |
| 549 | |
| 550 | cluster = s->GetNext(cluster); |
| 551 | } |
| 552 | |
| 553 | return true; |
| 554 | } |
| 555 | |
| 556 | bool vttdemux::InitializeFiles(const metadata_map_t& m) { |
| 557 | // Write the WebVTT header for each output file in the cache. |
| 558 | |
| 559 | typedef metadata_map_t::const_iterator iter_t; |
| 560 | iter_t i = m.begin(); |
| 561 | const iter_t j = m.end(); |
| 562 | |
| 563 | while (i != j) { |
| 564 | const metadata_map_t::value_type& v = *i++; |
| 565 | const MetadataInfo& info = v.second; |
| 566 | FILE* const f = info.file; |
| 567 | |
| 568 | if (fputs("WEBVTT\n", f) < 0) { |
| 569 | printf("unable to initialize output file\n"); |
| 570 | return false; |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | return true; |
| 575 | } |
| 576 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 577 | bool vttdemux::WriteChaptersFile(const metadata_map_t& m, |
| 578 | const mkvparser::Segment* s) { |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 579 | const metadata_map_t::const_iterator info_iter = m.find(kChaptersKey); |
| 580 | if (info_iter == m.end()) // no chapters, so nothing to do |
| 581 | return true; |
| 582 | |
| 583 | const mkvparser::Chapters* const chapters = s->GetChapters(); |
| 584 | if (chapters == NULL) // weird |
| 585 | return true; |
| 586 | |
| 587 | const MetadataInfo& info = info_iter->second; |
| 588 | FILE* const file = info.file; |
| 589 | |
| 590 | const int edition_count = chapters->GetEditionCount(); |
| 591 | |
| 592 | if (edition_count <= 0) // weird |
Vignesh Venkatasubramanian | 7b24501 | 2014-04-29 00:35:56 -0700 | [diff] [blame] | 593 | return true; // nothing to do |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 594 | |
| 595 | if (edition_count > 1) { |
| 596 | // TODO(matthewjheaney): figure what to do here |
| 597 | printf("more than one chapter edition detected\n"); |
| 598 | return false; |
| 599 | } |
| 600 | |
| 601 | const mkvparser::Chapters::Edition* const edition = chapters->GetEdition(0); |
| 602 | |
| 603 | const int atom_count = edition->GetAtomCount(); |
| 604 | |
| 605 | for (int idx = 0; idx < atom_count; ++idx) { |
| 606 | const mkvparser::Chapters::Atom* const atom = edition->GetAtom(idx); |
| 607 | const int display_count = atom->GetDisplayCount(); |
| 608 | |
| 609 | if (display_count <= 0) |
| 610 | continue; |
| 611 | |
| 612 | if (display_count > 1) { |
| 613 | // TODO(matthewjheaney): handle case of multiple languages |
| 614 | printf("more than 1 display in atom detected\n"); |
| 615 | return false; |
| 616 | } |
| 617 | |
| 618 | const mkvparser::Chapters::Display* const display = atom->GetDisplay(0); |
| 619 | |
| 620 | if (const char* language = display->GetLanguage()) { |
| 621 | if (strcmp(language, "eng") != 0) { |
| 622 | // TODO(matthewjheaney): handle case of multiple languages. |
| 623 | |
| 624 | // We must create a separate webvtt file for each language. |
| 625 | // This isn't a simple problem (which is why we defer it for |
| 626 | // now), because there's nothing in the header that tells us |
| 627 | // what languages we have as cues. We must parse the displays |
| 628 | // of each atom to determine that. |
| 629 | |
| 630 | // One solution is to make two passes over the input data. |
| 631 | // First parse the displays, creating an in-memory cache of |
| 632 | // all the chapter cues, sorted according to their language. |
| 633 | // After we have read all of the chapter atoms from the input |
| 634 | // file, we can then write separate output files for each |
| 635 | // language. |
| 636 | |
| 637 | printf("only English-language chapter cues are supported\n"); |
| 638 | return false; |
| 639 | } |
| 640 | } |
| 641 | |
| 642 | if (!WriteChaptersCue(file, chapters, atom, display)) |
| 643 | return false; |
| 644 | } |
| 645 | |
| 646 | return true; |
| 647 | } |
| 648 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 649 | bool vttdemux::WriteChaptersCue(FILE* f, const mkvparser::Chapters* chapters, |
| 650 | const mkvparser::Chapters::Atom* atom, |
| 651 | const mkvparser::Chapters::Display* display) { |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 652 | // We start a new cue by writing a cue separator (an empty line) |
| 653 | // into the stream. |
| 654 | |
| 655 | if (fputc('\n', f) < 0) |
| 656 | return false; |
| 657 | |
| 658 | // A WebVTT Cue comprises 3 things: a cue identifier, followed by |
| 659 | // the cue timings, followed by the payload of the cue. We write |
| 660 | // each part of the cue in sequence. |
| 661 | |
Matthew Heaney | 28222b4 | 2012-11-13 12:44:06 -0800 | [diff] [blame] | 662 | if (!WriteChaptersCueIdentifier(f, atom)) |
| 663 | return false; |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 664 | |
| 665 | if (!WriteChaptersCueTimings(f, chapters, atom)) |
| 666 | return false; |
| 667 | |
| 668 | if (!WriteChaptersCuePayload(f, display)) |
| 669 | return false; |
| 670 | |
| 671 | return true; |
| 672 | } |
| 673 | |
Matthew Heaney | 28222b4 | 2012-11-13 12:44:06 -0800 | [diff] [blame] | 674 | bool vttdemux::WriteChaptersCueIdentifier( |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 675 | FILE* f, const mkvparser::Chapters::Atom* atom) { |
Matthew Heaney | 28222b4 | 2012-11-13 12:44:06 -0800 | [diff] [blame] | 676 | const char* const identifier = atom->GetStringUID(); |
| 677 | |
| 678 | if (identifier == NULL) |
| 679 | return true; // nothing else to do |
| 680 | |
| 681 | if (fprintf(f, "%s\n", identifier) < 0) |
| 682 | return false; |
| 683 | |
| 684 | return true; |
| 685 | } |
| 686 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 687 | bool vttdemux::WriteChaptersCueTimings(FILE* f, |
| 688 | const mkvparser::Chapters* chapters, |
| 689 | const mkvparser::Chapters::Atom* atom) { |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 690 | const mkvtime_t start_ns = atom->GetStartTime(chapters); |
| 691 | |
| 692 | if (start_ns < 0) |
| 693 | return false; |
| 694 | |
| 695 | const mkvtime_t stop_ns = atom->GetStopTime(chapters); |
| 696 | |
| 697 | if (stop_ns < 0) |
| 698 | return false; |
| 699 | |
| 700 | if (!WriteCueTime(f, start_ns)) |
| 701 | return false; |
| 702 | |
| 703 | if (fputs(" --> ", f) < 0) |
| 704 | return false; |
| 705 | |
| 706 | if (!WriteCueTime(f, stop_ns)) |
| 707 | return false; |
| 708 | |
| 709 | if (fputc('\n', f) < 0) |
| 710 | return false; |
| 711 | |
| 712 | return true; |
| 713 | } |
| 714 | |
| 715 | bool vttdemux::WriteChaptersCuePayload( |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 716 | FILE* f, const mkvparser::Chapters::Display* display) { |
Matthew Heaney | c26db03 | 2012-10-26 15:06:28 -0700 | [diff] [blame] | 717 | // Bind a Chapter parser object to the display, which allows us to |
| 718 | // extract each line of text from the title-part of the display. |
| 719 | ChapterAtomParser parser(display); |
| 720 | |
| 721 | int count = 0; // count of lines of payload text written to output file |
| 722 | for (string line;;) { |
| 723 | const int e = parser.GetLine(&line); |
| 724 | |
| 725 | if (e < 0) // error (only -- we allow EOS here) |
| 726 | return false; |
| 727 | |
| 728 | if (line.empty()) // TODO(matthewjheaney): retain this check? |
| 729 | break; |
| 730 | |
| 731 | if (fprintf(f, "%s\n", line.c_str()) < 0) |
| 732 | return false; |
| 733 | |
| 734 | ++count; |
| 735 | } |
| 736 | |
| 737 | if (count <= 0) // WebVTT cue requires non-empty payload |
| 738 | return false; |
| 739 | |
| 740 | return true; |
| 741 | } |
| 742 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 743 | bool vttdemux::ProcessCluster(const metadata_map_t& m, |
| 744 | const mkvparser::Cluster* c) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 745 | // Visit the blocks in this cluster, writing a WebVTT cue for each |
| 746 | // metadata block. |
| 747 | |
| 748 | const mkvparser::BlockEntry* block_entry; |
| 749 | |
| 750 | long result = c->GetFirst(block_entry); // NOLINT |
Vignesh Venkatasubramanian | 7b24501 | 2014-04-29 00:35:56 -0700 | [diff] [blame] | 751 | if (result < 0) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 752 | printf("bad cluster (unable to get first block)\n"); |
| 753 | return false; |
| 754 | } |
| 755 | |
| 756 | while (block_entry != NULL && !block_entry->EOS()) { |
| 757 | if (!ProcessBlockEntry(m, block_entry)) |
| 758 | return false; |
| 759 | |
| 760 | result = c->GetNext(block_entry, block_entry); |
| 761 | if (result < 0) { // error |
| 762 | printf("bad cluster (unable to get next block)\n"); |
| 763 | return false; |
| 764 | } |
| 765 | } |
| 766 | |
| 767 | return true; |
| 768 | } |
| 769 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 770 | bool vttdemux::ProcessBlockEntry(const metadata_map_t& m, |
| 771 | const mkvparser::BlockEntry* block_entry) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 772 | // If the track number for this block is in the cache, then we have |
| 773 | // a metadata block, so write the WebVTT cue to the output file. |
| 774 | |
| 775 | const mkvparser::Block* const block = block_entry->GetBlock(); |
| 776 | const long long tn = block->GetTrackNumber(); // NOLINT |
| 777 | |
| 778 | typedef metadata_map_t::const_iterator iter_t; |
Matthew Heaney | 17cf7cc | 2014-02-28 12:33:58 -0800 | [diff] [blame] | 779 | const iter_t i = m.find(static_cast<metadata_map_t::key_type>(tn)); |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 780 | |
| 781 | if (i == m.end()) // not a metadata track |
Vignesh Venkatasubramanian | 7b24501 | 2014-04-29 00:35:56 -0700 | [diff] [blame] | 782 | return true; // nothing else to do |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 783 | |
| 784 | if (block_entry->GetKind() != mkvparser::BlockEntry::kBlockGroup) |
| 785 | return false; // weird |
| 786 | |
| 787 | typedef mkvparser::BlockGroup BG; |
| 788 | const BG* const block_group = static_cast<const BG*>(block_entry); |
| 789 | |
| 790 | const MetadataInfo& info = i->second; |
| 791 | FILE* const f = info.file; |
| 792 | |
| 793 | return WriteCue(f, block_group); |
| 794 | } |
| 795 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 796 | bool vttdemux::WriteCue(FILE* f, const mkvparser::BlockGroup* block_group) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 797 | // Bind a FrameParser object to the block, which allows us to |
| 798 | // extract each line of text from the payload of the block. |
| 799 | FrameParser parser(block_group); |
| 800 | |
| 801 | // We start a new cue by writing a cue separator (an empty line) |
| 802 | // into the stream. |
| 803 | |
| 804 | if (fputc('\n', f) < 0) |
| 805 | return false; |
| 806 | |
| 807 | // A WebVTT Cue comprises 3 things: a cue identifier, followed by |
| 808 | // the cue timings, followed by the payload of the cue. We write |
| 809 | // each part of the cue in sequence. |
| 810 | |
| 811 | if (!WriteCueIdentifier(f, &parser)) |
| 812 | return false; |
| 813 | |
| 814 | if (!WriteCueTimings(f, &parser)) |
| 815 | return false; |
| 816 | |
| 817 | if (!WriteCuePayload(f, &parser)) |
| 818 | return false; |
| 819 | |
| 820 | return true; |
| 821 | } |
| 822 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 823 | bool vttdemux::WriteCueIdentifier(FILE* f, FrameParser* parser) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 824 | string line; |
| 825 | int e = parser->GetLine(&line); |
| 826 | |
| 827 | if (e) // error or EOS |
| 828 | return false; |
| 829 | |
| 830 | // If the cue identifier line is empty, this means that the original |
| 831 | // WebVTT cue did not have a cue identifier, so we don't bother |
| 832 | // writing an extra line terminator to the output file (though doing |
| 833 | // so would be harmless). |
| 834 | |
| 835 | if (!line.empty()) { |
| 836 | if (fputs(line.c_str(), f) < 0) |
| 837 | return false; |
| 838 | |
| 839 | if (fputc('\n', f) < 0) |
| 840 | return false; |
| 841 | } |
| 842 | |
| 843 | return true; |
| 844 | } |
| 845 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 846 | bool vttdemux::WriteCueTimings(FILE* f, FrameParser* parser) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 847 | const mkvparser::BlockGroup* const block_group = parser->block_group_; |
| 848 | const mkvparser::Cluster* const cluster = block_group->GetCluster(); |
| 849 | const mkvparser::Block* const block = block_group->GetBlock(); |
| 850 | |
| 851 | // A WebVTT Cue "timings" line comprises two parts: the start and |
| 852 | // stop time for this cue, followed by the (optional) cue settings, |
| 853 | // such as orientation of the rendered text or its size. Only the |
| 854 | // settings part of the cue timings line is stored in the WebM |
| 855 | // block. We reconstruct the start and stop times of the WebVTT cue |
| 856 | // from the timestamp and duration of the WebM block. |
| 857 | |
| 858 | const mkvtime_t start_ns = block->GetTime(cluster); |
| 859 | |
| 860 | if (!WriteCueTime(f, start_ns)) |
| 861 | return false; |
| 862 | |
| 863 | if (fputs(" --> ", f) < 0) |
| 864 | return false; |
| 865 | |
| 866 | const mkvtime_t duration_timecode = block_group->GetDurationTimeCode(); |
| 867 | |
| 868 | if (duration_timecode < 0) |
| 869 | return false; |
| 870 | |
| 871 | const mkvparser::Segment* const segment = cluster->m_pSegment; |
| 872 | const mkvparser::SegmentInfo* const info = segment->GetInfo(); |
| 873 | |
| 874 | if (info == NULL) |
| 875 | return false; |
| 876 | |
| 877 | const mkvtime_t timecode_scale = info->GetTimeCodeScale(); |
| 878 | |
| 879 | if (timecode_scale <= 0) |
| 880 | return false; |
| 881 | |
| 882 | const mkvtime_t duration_ns = duration_timecode * timecode_scale; |
| 883 | const mkvtime_t stop_ns = start_ns + duration_ns; |
| 884 | |
| 885 | if (!WriteCueTime(f, stop_ns)) |
| 886 | return false; |
| 887 | |
| 888 | string line; |
| 889 | int e = parser->GetLine(&line); |
| 890 | |
| 891 | if (e) // error or EOS |
| 892 | return false; |
| 893 | |
| 894 | if (!line.empty()) { |
| 895 | if (fputc(' ', f) < 0) |
| 896 | return false; |
| 897 | |
| 898 | if (fputs(line.c_str(), f) < 0) |
| 899 | return false; |
| 900 | } |
| 901 | |
| 902 | if (fputc('\n', f) < 0) |
| 903 | return false; |
| 904 | |
| 905 | return true; |
| 906 | } |
| 907 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 908 | bool vttdemux::WriteCueTime(FILE* f, mkvtime_t time_ns) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 909 | mkvtime_t ms = time_ns / 1000000; // WebVTT time has millisecond resolution |
| 910 | |
| 911 | mkvtime_t sec = ms / 1000; |
| 912 | ms -= sec * 1000; |
| 913 | |
| 914 | mkvtime_t min = sec / 60; |
| 915 | sec -= 60 * min; |
| 916 | |
| 917 | mkvtime_t hr = min / 60; |
| 918 | min -= 60 * hr; |
| 919 | |
| 920 | if (hr > 0) { |
| 921 | if (fprintf(f, "%02lld:", hr) < 0) |
| 922 | return false; |
| 923 | } |
| 924 | |
| 925 | if (fprintf(f, "%02lld:%02lld.%03lld", min, sec, ms) < 0) |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 926 | return false; |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 927 | |
| 928 | return true; |
| 929 | } |
| 930 | |
Vignesh Venkatasubramanian | e3485c9 | 2014-04-14 12:14:06 -0700 | [diff] [blame] | 931 | bool vttdemux::WriteCuePayload(FILE* f, FrameParser* parser) { |
Matthew Heaney | 4a51413 | 2012-08-30 15:16:06 -0700 | [diff] [blame] | 932 | int count = 0; // count of lines of payload text written to output file |
| 933 | for (string line;;) { |
| 934 | const int e = parser->GetLine(&line); |
| 935 | |
| 936 | if (e < 0) // error (only -- we allow EOS here) |
| 937 | return false; |
| 938 | |
| 939 | if (line.empty()) // TODO(matthewjheaney): retain this check? |
| 940 | break; |
| 941 | |
| 942 | if (fprintf(f, "%s\n", line.c_str()) < 0) |
| 943 | return false; |
| 944 | |
| 945 | ++count; |
| 946 | } |
| 947 | |
| 948 | if (count <= 0) // WebVTT cue requires non-empty payload |
| 949 | return false; |
| 950 | |
| 951 | return true; |
| 952 | } |
Tom Finegan | e64bf75 | 2016-03-18 09:32:52 -0700 | [diff] [blame] | 953 | |
| 954 | } // namespace libwebm |
| 955 | |
| 956 | int main(int argc, const char* argv[]) { |
| 957 | if (argc != 2) { |
| 958 | printf("usage: vttdemux <webmfile>\n"); |
| 959 | return EXIT_SUCCESS; |
| 960 | } |
| 961 | |
| 962 | const char* const filename = argv[1]; |
Tom Finegan | cbe5c40 | 2016-03-21 12:16:30 -0700 | [diff] [blame] | 963 | mkvparser::MkvReader reader; |
Tom Finegan | e64bf75 | 2016-03-18 09:32:52 -0700 | [diff] [blame] | 964 | |
| 965 | int e = reader.Open(filename); |
| 966 | |
| 967 | if (e) { // error |
| 968 | printf("unable to open file\n"); |
| 969 | return EXIT_FAILURE; |
| 970 | } |
| 971 | |
| 972 | libwebm::vttdemux::mkvpos_t pos; |
| 973 | |
| 974 | if (!libwebm::vttdemux::ParseHeader(&reader, &pos)) |
| 975 | return EXIT_FAILURE; |
| 976 | |
| 977 | libwebm::vttdemux::segment_ptr_t segment_ptr; |
| 978 | |
| 979 | if (!libwebm::vttdemux::ParseSegment(&reader, pos, &segment_ptr)) |
| 980 | return EXIT_FAILURE; |
| 981 | |
| 982 | libwebm::vttdemux::metadata_map_t metadata_map; |
| 983 | |
| 984 | BuildMap(segment_ptr.get(), &metadata_map); |
| 985 | |
| 986 | if (metadata_map.empty()) { |
| 987 | printf("no WebVTT metadata found\n"); |
| 988 | return EXIT_FAILURE; |
| 989 | } |
| 990 | |
| 991 | if (!OpenFiles(&metadata_map, filename)) { |
| 992 | CloseFiles(&metadata_map); // nothing to flush, so not strictly necessary |
| 993 | return EXIT_FAILURE; |
| 994 | } |
| 995 | |
| 996 | if (!WriteFiles(metadata_map, segment_ptr.get())) { |
| 997 | CloseFiles(&metadata_map); // might as well flush what we do have |
| 998 | return EXIT_FAILURE; |
| 999 | } |
| 1000 | |
| 1001 | CloseFiles(&metadata_map); |
| 1002 | |
| 1003 | return EXIT_SUCCESS; |
Tom Finegan | 5f1065e | 2016-03-17 15:09:46 -0700 | [diff] [blame] | 1004 | } |