2 Copyright 2005 Mark Calderbank
4 This file is part of VOMP.
6 VOMP is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 VOMP is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with VOMP; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 const int Demuxer::FrameRates[9] = { 0, 23, 24, 25, 29, 30, 50, 59, 60 };
25 Demuxer* Demuxer::instance = NULL;
40 Demuxer* Demuxer::getInstance()
49 if ( videostream.init(demuxMemory) ||
50 audiostream.init(demuxMemory) ||
51 !(local_frame = (UCHAR *) malloc(0x10000)))
53 printf("failed to initialize demuxer\n");
67 video_current = audio_current = -1;
68 horizontal_size = vertical_size = 0;
69 aspect_ratio = (enum AspectRatio) 0;
70 frame_rate = bit_rate = 0;
73 int Demuxer::shutdown()
75 videostream.shutdown();
76 audiostream.shutdown();
86 state_frametype = state_framepos = 0;
90 void Demuxer::flushAudio()
100 void Demuxer::setAudioStream(int id)
105 void Demuxer::setVideoStream(int id)
110 int Demuxer::scan(UCHAR *buf, int len)
112 // Temporarily, just look for the lowest audio stream and return it
118 // We are searching for a string of bytes (0,0,1).
119 byte = *(buf++); --len;
125 if (zeros < 2 || byte != 1)
130 // We have found the pattern (0,0,1).
131 // Check the next byte for the sub-frame type.
132 byte = *(buf++); --len;
133 if (byte >= 0xc0 && byte <= 0xdf) // Audio
134 if (ret == 0 || ret > byte) ret = byte;
139 int Demuxer::put(UCHAR* buf, int len)
141 int ret = 0; // return number of bytes consumed
142 int parsed = 0; // number of bytes parsed by sub-function
143 int full; // sub-function sets this to tell us to exit early
144 inbuf = buf; // Initialize buffer pointer
149 switch (state_frametype)
151 case 0: // Search for frame
152 parsed = parse_find_frame(len);
154 case FRAMETYPE_VID0 ... FRAMETYPE_VIDMAX:
155 parsed = parse_video_frame(len, &full);
157 case FRAMETYPE_AUD0 ... FRAMETYPE_AUDMAX:
158 parsed = parse_audio_frame(len, &full);
160 case FRAMETYPE_PRIVATE_1:
161 parsed = parse_private1_frame(len, &full);
164 ret += parsed; len -= parsed;
165 if (full) // We have to exit early.
166 break; // out of while loop
168 //Log::getInstance()->log("Demuxer", Log::DEBUG, "Put %d; took %d", ret + len, ret);
172 int Demuxer::parse_find_frame(int len)
174 int ret = 0; // return number of bytes parsed
177 // In this function, state_framepos represents
178 // the number of fixed header bytes found so far.
179 if (state_framepos > 3 || state_framepos < 0)
189 switch (state_framepos)
205 state_framepos = 0; // Set initial state for the new frame
209 state_framepos = 1; // Count this as a first header byte!
211 case FRAMETYPE_VID0 ... FRAMETYPE_VIDMAX:
212 case FRAMETYPE_AUD0 ... FRAMETYPE_AUDMAX:
213 case FRAMETYPE_PRIVATE_1:
214 state_frametype = byte;
217 // Not a recognised frame type. Go back to Old Kent Road.
224 int Demuxer::parse_video_frame(int len, int* full)
226 int ret = 0; // return number of bytes consumed
227 int stream_sent, bytes_remaining;
229 switch(state_framepos)
231 case 0: // Brand new video frame. Set initial states.
232 state_stream_fill = 0; state_vid_parsed = 0;
233 // Create a local copy of the frame header
234 local_frame[0] = local_frame[1] = 0; local_frame[2] = 1;
235 local_frame[3] = state_frametype;
236 // If no video stream has been set, use this one.
237 if (video_current == -1) video_current = state_frametype;
238 // Get MSB of frame length and copy to local frame.
239 frame_length = *inbuf << 8;
240 local_frame[4] = *inbuf;
241 ++inbuf; ++state_framepos; ++ret; --len;
242 if (len == 0) return ret;
243 // FALL THROUGH TO NEXT BYTE IN STREAM
244 case 1: // Get LSB of frame length and copy to local frame.
245 frame_length += *inbuf;
246 local_frame[5] = *inbuf;
247 ++inbuf; ++state_framepos; ++ret; --len;
248 if (len == 0) return ret;
249 // FALL THROUGH TO NEXT BYTE IN STREAM
250 case 2: // First data byte
251 if (len >= frame_length // If we have the entire frame
252 && !state_vid_parsed) // and haven't parsed it yet
254 if (video_current == state_frametype) // and we're interested
255 parse_video_details(inbuf, frame_length); // then parse it
256 state_vid_parsed = 1;
259 // We are in the frame data
260 bytes_remaining = 2 + frame_length - state_framepos;
261 if (video_current != state_frametype)
263 // We don't want this frame. Throw it away.
264 if (len >= bytes_remaining)
266 inbuf += bytes_remaining;
267 ret += bytes_remaining;
268 state_frametype = state_framepos = 0;
273 inbuf += len; ret += len;
274 state_framepos += len;
277 } // No fall through here
279 if (state_vid_parsed)
281 // We have already parsed the whole frame
282 if (seeking) // Still not found a sync point. Throw this frame away.
284 if (len >= bytes_remaining)
286 inbuf += bytes_remaining;
287 ret += bytes_remaining;
288 state_frametype = state_framepos = 0;
293 inbuf += len; ret += len; return ret;
295 } // No fall through is allowed here
296 // Send frame header to stream
297 if (state_stream_fill < 6)
299 state_stream_fill += videostream.put(local_frame,
300 6 - state_stream_fill);
301 if (state_stream_fill < 6) // stream is full!
303 *full = 1; return ret;
306 // Send all frame data we have to stream
307 if (len >= bytes_remaining) len = bytes_remaining;
308 stream_sent = videostream.put(inbuf, len);
309 inbuf += stream_sent; ret += stream_sent;
310 state_framepos += stream_sent;
311 state_stream_fill += stream_sent;
312 if (stream_sent != len) // stream is full!
314 *full = 1; return ret;
316 if (state_framepos == frame_length + 2) // frame done
318 state_frametype = state_framepos = 0;
321 } // No fall through is allowed here
323 // We haven't parsed the frame yet. It's arriving in pieces.
324 if (bytes_remaining) // There is data yet to copy to local_frame
326 if (len >= bytes_remaining) len = bytes_remaining;
327 memcpy(local_frame + state_framepos + 4, inbuf, len);
328 inbuf += len; ret += len; state_framepos += len;
329 if (len < bytes_remaining) // Not all arrived yet
331 parse_video_details(local_frame+6, frame_length);
332 if (seeking) // Still not found a sync point. Ignore this frame.
335 // We have the whole frame in local_frame. Send it to the stream.
336 state_stream_fill += videostream.put(local_frame,
337 6 + frame_length - state_stream_fill);
338 if (state_stream_fill < frame_length + 6) // stream is full!
340 *full = 1; return ret;
342 state_frametype = state_framepos = 0;
346 int Demuxer::parse_audio_frame(int len, int* full)
348 int ret = 0; // return number of bytes consumed
349 int stream_sent, bytes_remaining;
351 switch(state_framepos)
353 case 0: // Brand new audio frame. Set initial states.
354 state_stream_fill = 0;
355 // Create a local copy of the frame header
356 local_frame[0] = local_frame[1] = 0; local_frame[2] = 1;
357 local_frame[3] = state_frametype;
358 // If no audio stream has been set, use this one.
359 if (audio_current == -1) audio_current = state_frametype;
360 // Get MSB of frame length and copy to local frame.
361 frame_length = *inbuf << 8;
362 local_frame[4] = *inbuf;
363 ++inbuf; ++state_framepos; ++ret; --len;
364 if (len == 0) return ret;
365 // FALL THROUGH TO NEXT BYTE IN STREAM
366 case 1: // Get LSB of frame length and copy to local frame.
367 frame_length += *inbuf;
368 local_frame[5] = *inbuf;
369 ++inbuf; ++state_framepos; ++ret; --len;
370 if (len == 0) return ret;
372 // We are in the frame data
373 bytes_remaining = 2 + frame_length - state_framepos;
374 if (audio_current != state_frametype)
376 // We don't want this frame. Throw it away.
377 if (len >= bytes_remaining)
379 inbuf += bytes_remaining;
380 ret += bytes_remaining;
381 state_frametype = state_framepos = 0;
386 inbuf += len; ret += len;
387 state_framepos += len;
390 } // No fall through is allowed here
392 // Send frame header to stream
393 if (state_stream_fill < 6)
395 state_stream_fill += audiostream.put(local_frame,
396 6 - state_stream_fill);
397 if (state_stream_fill < 6) // stream is full!
399 *full = 1; return ret;
402 // Send all frame data we have to stream
403 if (len >= bytes_remaining) len = bytes_remaining;
404 stream_sent = audiostream.put(inbuf, len);
405 inbuf += stream_sent; ret += stream_sent;
406 state_framepos += stream_sent;
407 state_stream_fill += stream_sent;
408 if (stream_sent != len) // stream is full!
410 *full = 1; return ret;
412 if (state_framepos == frame_length + 2) // frame done
414 state_frametype = state_framepos = 0;
419 int Demuxer::parse_private1_frame(int len, int* full)
421 int ret = 0; // return number of bytes consumed
424 switch(state_framepos)
426 case 0: // Brand new frame. Set initial states.
427 // Get MSB of frame length and copy to local frame.
428 frame_length = *inbuf << 8;
429 ++inbuf; ++state_framepos; ++ret; --len;
430 if (len == 0) return ret;
431 // FALL THROUGH TO NEXT BYTE IN STREAM
432 case 1: // Get LSB of frame length and copy to local frame.
433 frame_length += *inbuf;
434 local_frame[5] = *inbuf;
435 ++inbuf; ++state_framepos; ++ret; --len;
436 if (len == 0) return ret;
438 // We are in the frame data
439 bytes_remaining = 2 + frame_length - state_framepos;
440 // Temporary - just discard the frame.
441 if (len >= bytes_remaining)
443 inbuf += bytes_remaining;
444 ret += bytes_remaining;
445 state_frametype = state_framepos = 0;
450 inbuf += len; ret += len;
451 state_framepos += len;
456 void Demuxer::parse_video_details(UCHAR* buf, int len)
460 while (len >= 8) // 8 is length of a GOP header
462 // We are searching for a string of bytes (0,0,1).
463 byte = *(buf++); --len;
469 if (zeros < 2 || byte != 1)
474 // We have found the pattern (0,0,1).
475 // Check the next byte for the sub-frame type.
476 byte = *(buf++); --len;
479 case 0x00: // Picture header
480 // 10 bits: temporal reference
481 // 3 bits: coding type (I/P/B)
484 if ( (buf[1] & 0x38) == 0x08 ) // I-frame
486 buf += 4; // Minimum length of picture header
489 case 0xb3: // Sequence header
490 // 12 bits: Horizontal size
491 // 12 bits: Vertical size
492 // 4 bits: Aspect ratio
493 // 4 bits: Frame rate code
494 // 18 bits: Bit rate value
497 horizontal_size = ((int)buf[0] << 4) | ((int)buf[1] >> 4);
498 vertical_size = (((int)buf[1] & 0xf) << 8) | (int)buf[2];
499 aspect_ratio = (enum AspectRatio)(buf[3] >> 4);
500 frame_rate = buf[3] & 0x0f;
501 if (frame_rate >= 1 && frame_rate <= 8)
502 frame_rate = FrameRates[frame_rate];
505 bit_rate = ((int)buf[4] << 10) |
509 buf += 8; // Minimum length of sequence header
512 case 0xb8: // Group header
513 // We're not going to bother parsing anything.
515 buf += 4; // Minimum length of group header