1 /*
2 * extract_dca.c
3 * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
4 * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
5 *
6 * This file is part of libdca, a free DTS Coherent Acoustics stream decoder.
7 * See http://www.videolan.org/developers/libdca.html for updates.
8 *
9 * libdca is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * libdca is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the
21 * Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 */
24
25 #include "config.h"
26
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <errno.h>
31 #include <getopt.h>
32 #ifdef HAVE_IO_H
33 #include <fcntl.h>
34 #include <io.h>
35 #endif
36 #include <inttypes.h>
37
38 //#define trace(...) { fprintf (stderr, __VA_ARGS__); }
39 #define trace(fmt,...)
40
41 #define BUFFER_SIZE 4096
42 static uint8_t buffer[BUFFER_SIZE];
43 static FILE * in_file;
44 static int demux_track = 0x80;
45 static int demux_pid = 0;
46 static int demux_pes = 0;
47
print_usage(char ** argv)48 static void print_usage (char ** argv)
49 {
50 trace ( "usage: %s [-h] [-s <track>] [-t <pid>] <file>\n"
51 "\t-h\tdisplay help\n"
52 "\t-s\tset track number (0-7 or 0x80-0x87)\n"
53 "\t-t\tuse transport stream demultiplexer, pid 0x10-0x1ffe\n"
54 "\t-T\tuse transport stream PES demultiplexer\n",
55 argv[0]);
56
57 exit (1);
58 }
59
handle_args(int argc,char ** argv)60 static void handle_args (int argc, char ** argv)
61 {
62 int c;
63 char * s;
64
65 while ((c = getopt (argc, argv, "hs:t:T")) != -1)
66 switch (c) {
67 case 's':
68 demux_track = strtol (optarg, &s, 0);
69 if (demux_track < 0x80)
70 demux_track += 0x80;
71 if (demux_track < 0x80 || demux_track > 0x87 || *s) {
72 trace ( "Invalid track number: %s\n", optarg);
73 print_usage (argv);
74 }
75 break;
76
77 case 't':
78 demux_pid = strtol (optarg, &s, 0);
79 if (demux_pid < 0x10 || demux_pid > 0x1ffe || *s) {
80 trace ( "Invalid pid: %s\n", optarg);
81 print_usage (argv);
82 }
83 break;
84
85 case 'T':
86 demux_pes = 1;
87 break;
88
89 default:
90 print_usage (argv);
91 }
92
93 if (optind < argc) {
94 in_file = fopen (argv[optind], "rb");
95 if (!in_file) {
96 trace ( "%s - could not open file %s\n", strerror (errno),
97 argv[optind]);
98 exit (1);
99 }
100 } else
101 in_file = stdin;
102 }
103
104 #define DEMUX_PAYLOAD_START 1
demux(uint8_t * buf,uint8_t * end,int flags)105 static int demux (uint8_t * buf, uint8_t * end, int flags)
106 {
107 static int mpeg1_skip_table[16] = {
108 0, 0, 4, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
109 };
110
111 /*
112 * the demuxer keeps some state between calls:
113 * if "state" = DEMUX_HEADER, then "head_buf" contains the first
114 * "bytes" bytes from some header.
115 * if "state" == DEMUX_DATA, then we need to copy "bytes" bytes
116 * of ES data before the next header.
117 * if "state" == DEMUX_SKIP, then we need to skip "bytes" bytes
118 * of data before the next header.
119 *
120 * NEEDBYTES makes sure we have the requested number of bytes for a
121 * header. If we dont, it copies what we have into head_buf and returns,
122 * so that when we come back with more data we finish decoding this header.
123 *
124 * DONEBYTES updates "buf" to point after the header we just parsed.
125 */
126
127 #define DEMUX_HEADER 0
128 #define DEMUX_DATA 1
129 #define DEMUX_SKIP 2
130 static int state = DEMUX_SKIP;
131 static int state_bytes = 0;
132 static uint8_t head_buf[268];
133
134 uint8_t * header;
135 int bytes;
136 int len;
137
138 #define NEEDBYTES(x) \
139 do { \
140 int missing; \
141 \
142 missing = (x) - bytes; \
143 if (missing > 0) { \
144 if (header == head_buf) { \
145 if (missing <= end - buf) { \
146 memcpy (header + bytes, buf, missing); \
147 buf += missing; \
148 bytes = (x); \
149 } else { \
150 memcpy (header + bytes, buf, end - buf); \
151 state_bytes = bytes + end - buf; \
152 return 0; \
153 } \
154 } else { \
155 memcpy (head_buf, header, bytes); \
156 state = DEMUX_HEADER; \
157 state_bytes = bytes; \
158 return 0; \
159 } \
160 } \
161 } while (0)
162
163 #define DONEBYTES(x) \
164 do { \
165 if (header != head_buf) \
166 buf = header + (x); \
167 } while (0)
168
169 if (flags & DEMUX_PAYLOAD_START)
170 goto payload_start;
171 switch (state) {
172 case DEMUX_HEADER:
173 if (state_bytes > 0) {
174 header = head_buf;
175 bytes = state_bytes;
176 goto continue_header;
177 }
178 break;
179 case DEMUX_DATA:
180 if (demux_pid || (state_bytes > end - buf)) {
181 fwrite (buf, end - buf, 1, stdout);
182 state_bytes -= end - buf;
183 return 0;
184 }
185 fwrite (buf, state_bytes, 1, stdout);
186 buf += state_bytes;
187 break;
188 case DEMUX_SKIP:
189 if (demux_pid || (state_bytes > end - buf)) {
190 state_bytes -= end - buf;
191 return 0;
192 }
193 buf += state_bytes;
194 break;
195 }
196
197 while (1) {
198 if (demux_pid) {
199 state = DEMUX_SKIP;
200 return 0;
201 }
202 payload_start:
203 header = buf;
204 bytes = end - buf;
205 continue_header:
206 NEEDBYTES (4);
207 if (header[0] || header[1] || (header[2] != 1)) {
208 if (demux_pid) {
209 state = DEMUX_SKIP;
210 return 0;
211 } else if (header != head_buf) {
212 buf++;
213 goto payload_start;
214 } else {
215 header[0] = header[1];
216 header[1] = header[2];
217 header[2] = header[3];
218 bytes = 3;
219 goto continue_header;
220 }
221 }
222 if (demux_pid || demux_pes) {
223 if (header[3] != 0xbd) {
224 trace ( "bad stream id %x\n", header[3]);
225 exit (1);
226 }
227 NEEDBYTES (9);
228 if ((header[6] & 0xc0) != 0x80) { /* not mpeg2 */
229 trace ( "bad multiplex - not mpeg2\n");
230 exit (1);
231 }
232 len = 9 + header[8];
233 NEEDBYTES (len);
234 DONEBYTES (len);
235 bytes = 6 + (header[4] << 8) + header[5] - len;
236 if (bytes > end - buf) {
237 fwrite (buf, end - buf, 1, stdout);
238 state = DEMUX_DATA;
239 state_bytes = bytes - (end - buf);
240 return 0;
241 } else if (bytes > 0) {
242 fwrite (buf, bytes, 1, stdout);
243 buf += bytes;
244 }
245 } else switch (header[3]) {
246 case 0xb9: /* program end code */
247 /* DONEBYTES (4); */
248 /* break; */
249 return 1;
250 case 0xba: /* pack header */
251 NEEDBYTES (5);
252 if ((header[4] & 0xc0) == 0x40) { /* mpeg2 */
253 NEEDBYTES (14);
254 len = 14 + (header[13] & 7);
255 NEEDBYTES (len);
256 DONEBYTES (len);
257 /* header points to the mpeg2 pack header */
258 } else if ((header[4] & 0xf0) == 0x20) { /* mpeg1 */
259 NEEDBYTES (12);
260 DONEBYTES (12);
261 /* header points to the mpeg1 pack header */
262 } else {
263 trace ( "weird pack header\n");
264 DONEBYTES (5);
265 }
266 break;
267 case 0xbd: /* private stream 1 */
268 NEEDBYTES (7);
269 if ((header[6] & 0xc0) == 0x80) { /* mpeg2 */
270 NEEDBYTES (9);
271 len = 10 + header[8];
272 NEEDBYTES (len);
273 /* header points to the mpeg2 pes header */
274 } else { /* mpeg1 */
275 len = 7;
276 while ((header-1)[len] == 0xff) {
277 len++;
278 NEEDBYTES (len);
279 if (len == 23) {
280 trace ( "too much stuffing\n");
281 break;
282 }
283 }
284 if (((header-1)[len] & 0xc0) == 0x40) {
285 len += 2;
286 NEEDBYTES (len);
287 }
288 len += mpeg1_skip_table[(header - 1)[len] >> 4] + 1;
289 NEEDBYTES (len);
290 /* header points to the mpeg1 pes header */
291 }
292 if ((header-1)[len] != demux_track) {
293 DONEBYTES (len);
294 bytes = 6 + (header[4] << 8) + header[5] - len;
295 if (bytes <= 0)
296 continue;
297 goto skip;
298 }
299 len += 3;
300 NEEDBYTES (len);
301 DONEBYTES (len);
302 bytes = 6 + (header[4] << 8) + header[5] - len;
303 if (bytes > end - buf) {
304 fwrite (buf, end - buf, 1, stdout);
305 state = DEMUX_DATA;
306 state_bytes = bytes - (end - buf);
307 return 0;
308 } else if (bytes > 0) {
309 fwrite (buf, bytes, 1, stdout);
310 buf += bytes;
311 }
312 break;
313 default:
314 if (header[3] < 0xb9) {
315 trace (
316 "looks like a video stream, not system stream\n");
317 exit (1);
318 } else {
319 NEEDBYTES (6);
320 DONEBYTES (6);
321 bytes = (header[4] << 8) + header[5];
322 skip:
323 if (bytes > end - buf) {
324 state = DEMUX_SKIP;
325 state_bytes = bytes - (end - buf);
326 return 0;
327 }
328 buf += bytes;
329 }
330 }
331 }
332 }
333
ps_loop(void)334 static void ps_loop (void)
335 {
336 uint8_t * end;
337
338 do {
339 end = buffer + fread (buffer, 1, BUFFER_SIZE, in_file);
340 if (demux (buffer, end, 0))
341 break; /* hit program_end_code */
342 } while (end == buffer + BUFFER_SIZE);
343 }
344
ts_loop(void)345 static void ts_loop (void)
346 {
347 uint8_t * buf;
348 uint8_t * nextbuf;
349 uint8_t * data;
350 uint8_t * end;
351 int pid;
352
353 buf = buffer;
354 while (1) {
355 end = buf + fread (buf, 1, buffer + BUFFER_SIZE - buf, in_file);
356 buf = buffer;
357 for (; (nextbuf = buf + 188) <= end; buf = nextbuf) {
358 if (*buf != 0x47) {
359 trace ( "bad sync byte\n");
360 nextbuf = buf + 1;
361 continue;
362 }
363 pid = ((buf[1] << 8) + buf[2]) & 0x1fff;
364 if (pid != demux_pid)
365 continue;
366 data = buf + 4;
367 if (buf[3] & 0x20) { /* buf contains an adaptation field */
368 data = buf + 5 + buf[4];
369 if (data > nextbuf)
370 continue;
371 }
372 if (buf[3] & 0x10)
373 demux (data, nextbuf,
374 (buf[1] & 0x40) ? DEMUX_PAYLOAD_START : 0);
375 }
376 if (end != buffer + BUFFER_SIZE)
377 break;
378 memcpy (buffer, buf, end - buf);
379 buf = buffer + (end - buf);
380 }
381 }
382
main(int argc,char ** argv)383 int main (int argc, char ** argv)
384 {
385 #ifdef HAVE_IO_H
386 setmode (fileno (stdin), O_BINARY);
387 setmode (fileno (stdout), O_BINARY);
388 #endif
389
390 handle_args (argc, argv);
391
392 if (demux_pid)
393 ts_loop ();
394 else
395 ps_loop ();
396
397 return 0;
398 }
399