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);
161 ret += parsed; len -= parsed;
162 if (full) // We have to exit early.
163 break; // out of while loop
165 // Log::getInstance()->log("Demuxer", Log::DEBUG, "Put %d; took %d", ret + len, ret);
169 int Demuxer::parse_find_frame(int len)
171 int ret = 0; // return number of bytes parsed
174 // In this function, state_framepos represents
175 // the number of fixed header bytes found so far.
176 if (state_framepos > 3 || state_framepos < 0)
186 switch (state_framepos)
202 state_framepos = 0; // Set initial state for the new frame
206 state_framepos = 1; // Count this as a first header byte!
208 case FRAMETYPE_VID0 ... FRAMETYPE_VIDMAX:
209 case FRAMETYPE_AUD0 ... FRAMETYPE_AUDMAX:
210 state_frametype = byte;
213 // Not a recognised frame type. Go back to Old Kent Road.
220 int Demuxer::parse_video_frame(int len, int* full)
222 int ret = 0; // return number of bytes consumed
223 int stream_sent, bytes_remaining;
225 switch(state_framepos)
227 case 0: // Brand new video frame. Set initial states.
228 state_stream_fill = 0; state_vid_parsed = 0;
229 // Create a local copy of the frame header
230 local_frame[0] = local_frame[1] = 0; local_frame[2] = 1;
231 local_frame[3] = state_frametype;
232 // If no video stream has been set, use this one.
233 if (video_current == -1) video_current = state_frametype;
234 // Get MSB of frame length and copy to local frame.
235 frame_length = *inbuf << 8;
236 local_frame[4] = *inbuf;
237 ++inbuf; ++state_framepos; ++ret; --len;
238 if (len == 0) return ret;
239 // FALL THROUGH TO NEXT BYTE IN STREAM
240 case 1: // Get LSB of frame length and copy to local frame.
241 frame_length += *inbuf;
242 local_frame[5] = *inbuf;
243 ++inbuf; ++state_framepos; ++ret; --len;
244 if (len == 0) return ret;
245 // FALL THROUGH TO NEXT BYTE IN STREAM
246 case 2: // First data byte
247 if (len >= frame_length // If we have the entire frame
248 && !state_vid_parsed) // and haven't parsed it yet
250 if (video_current == state_frametype) // and we're interested
251 parse_video_details(inbuf, frame_length); // then parse it
252 state_vid_parsed = 1;
255 // We are in the frame data
256 bytes_remaining = 2 + frame_length - state_framepos;
257 if (video_current != state_frametype)
259 // We don't want this frame. Throw it away.
260 if (len >= bytes_remaining)
262 inbuf += bytes_remaining;
263 ret += bytes_remaining;
264 state_frametype = state_framepos = 0;
269 inbuf += len; ret += len;
270 state_framepos += len;
273 } // No fall through here
275 if (state_vid_parsed)
277 // We have already parsed the whole frame
278 if (seeking) // Still not found a sync point. Throw this frame away.
280 if (len >= bytes_remaining)
282 inbuf += bytes_remaining;
283 ret += bytes_remaining;
284 state_frametype = state_framepos = 0;
289 inbuf += len; ret += len; return ret;
291 } // No fall through is allowed here
292 // Send frame header to stream
293 if (state_stream_fill < 6)
295 state_stream_fill += videostream.put(local_frame,
296 6 - state_stream_fill);
297 if (state_stream_fill < 6) // stream is full!
299 *full = 1; return ret;
302 // Send all frame data we have to stream
303 if (len >= bytes_remaining) len = bytes_remaining;
304 stream_sent = videostream.put(inbuf, len);
305 inbuf += stream_sent; ret += stream_sent;
306 state_framepos += stream_sent;
307 state_stream_fill += stream_sent;
308 if (stream_sent != len) // stream is full!
310 *full = 1; return ret;
312 if (state_framepos == frame_length + 2) // frame done
314 state_frametype = state_framepos = 0;
317 } // No fall through is allowed here
319 // We haven't parsed the frame yet. It's arriving in pieces.
320 if (bytes_remaining) // There is data yet to copy to local_frame
322 if (len >= bytes_remaining) len = bytes_remaining;
323 memcpy(local_frame + state_framepos + 4, inbuf, len);
324 inbuf += len; ret += len; state_framepos += len;
325 if (len < bytes_remaining) // Not all arrived yet
327 parse_video_details(local_frame+6, frame_length);
328 if (seeking) // Still not found a sync point. Ignore this frame.
331 // We have the whole frame in local_frame. Send it to the stream.
332 state_stream_fill += videostream.put(local_frame,
333 6 + frame_length - state_stream_fill);
334 if (state_stream_fill < frame_length + 6) // stream is full!
336 *full = 1; return ret;
338 state_frametype = state_framepos = 0;
342 int Demuxer::parse_audio_frame(int len, int* full)
344 int ret = 0; // return number of bytes consumed
345 int stream_sent, bytes_remaining;
347 switch(state_framepos)
349 case 0: // Brand new audio frame. Set initial states.
350 state_stream_fill = 0;
351 // Create a local copy of the frame header
352 local_frame[0] = local_frame[1] = 0; local_frame[2] = 1;
353 local_frame[3] = state_frametype;
354 // If no audio stream has been set, use this one.
355 if (audio_current == -1) audio_current = state_frametype;
356 // Get MSB of frame length and copy to local frame.
357 frame_length = *inbuf << 8;
358 local_frame[4] = *inbuf;
359 ++inbuf; ++state_framepos; ++ret; --len;
360 if (len == 0) return ret;
361 // FALL THROUGH TO NEXT BYTE IN STREAM
362 case 1: // Get LSB of frame length and copy to local frame.
363 frame_length += *inbuf;
364 local_frame[5] = *inbuf;
365 ++inbuf; ++state_framepos; ++ret; --len;
366 if (len == 0) return ret;
368 // We are in the frame data
369 bytes_remaining = 2 + frame_length - state_framepos;
370 if (audio_current != state_frametype)
372 // We don't want this frame. Throw it away.
373 if (len >= bytes_remaining)
375 inbuf += bytes_remaining;
376 ret += bytes_remaining;
377 state_frametype = state_framepos = 0;
382 inbuf += len; ret += len;
383 state_framepos += len;
386 } // No fall through is allowed here
388 // Send frame header to stream
389 if (state_stream_fill < 6)
391 state_stream_fill += audiostream.put(local_frame,
392 6 - state_stream_fill);
393 if (state_stream_fill < 6) // stream is full!
395 *full = 1; return ret;
398 // Send all frame data we have to stream
399 if (len >= bytes_remaining) len = bytes_remaining;
400 stream_sent = audiostream.put(inbuf, len);
401 inbuf += stream_sent; ret += stream_sent;
402 state_framepos += stream_sent;
403 state_stream_fill += stream_sent;
404 if (stream_sent != len) // stream is full!
406 *full = 1; return ret;
408 if (state_framepos == frame_length + 2) // frame done
410 state_frametype = state_framepos = 0;
415 void Demuxer::parse_video_details(UCHAR* buf, int len)
419 while (len >= 8) // 8 is length of a GOP header
421 // We are searching for a string of bytes (0,0,1).
422 byte = *(buf++); --len;
428 if (zeros < 2 || byte != 1)
433 // We have found the pattern (0,0,1).
434 // Check the next byte for the sub-frame type.
435 byte = *(buf++); --len;
438 case 0x00: // Picture header
439 // 10 bits: temporal reference
440 // 3 bits: coding type (I/P/B)
443 if ( (buf[1] & 0x38) == 0x08 ) // I-frame
445 buf += 4; // Minimum length of picture header
448 case 0xb3: // Sequence header
449 // 12 bits: Horizontal size
450 // 12 bits: Vertical size
451 // 4 bits: Aspect ratio
452 // 4 bits: Frame rate code
453 // 18 bits: Bit rate value
456 horizontal_size = ((int)buf[0] << 4) | ((int)buf[1] >> 4);
457 vertical_size = (((int)buf[1] & 0xf) << 8) | (int)buf[2];
458 aspect_ratio = (enum AspectRatio)(buf[3] >> 4);
459 frame_rate = buf[3] & 0x0f;
460 if (frame_rate >= 1 && frame_rate <= 8)
461 frame_rate = FrameRates[frame_rate];
464 bit_rate = ((int)buf[4] << 10) |
468 buf += 8; // Minimum length of sequence header
471 case 0xb8: // Group header
472 // We're not going to bother parsing anything.
474 buf += 4; // Minimum length of group header