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 BUFFER_SIZE 4096
39 static uint8_t buffer[BUFFER_SIZE];
40 static FILE * in_file;
41 static int demux_track = 0x80;
42 static int demux_pid = 0;
43 static int demux_pes = 0;
44
print_usage(char ** argv)45 static void print_usage (char ** argv)
46 {
47 fprintf (stderr, "usage: %s [-h] [-s <track>] [-t <pid>] <file>\n"
48 "\t-h\tdisplay help\n"
49 "\t-s\tset track number (0-7 or 0x80-0x87)\n"
50 "\t-t\tuse transport stream demultiplexer, pid 0x10-0x1ffe\n"
51 "\t-T\tuse transport stream PES demultiplexer\n",
52 argv[0]);
53
54 exit (1);
55 }
56
handle_args(int argc,char ** argv)57 static void handle_args (int argc, char ** argv)
58 {
59 int c;
60 char * s;
61
62 while ((c = getopt (argc, argv, "hs:t:T")) != -1)
63 switch (c) {
64 case 's':
65 demux_track = strtol (optarg, &s, 0);
66 if (demux_track < 0x80)
67 demux_track += 0x80;
68 if (demux_track < 0x80 || demux_track > 0x87 || *s) {
69 fprintf (stderr, "Invalid track number: %s\n", optarg);
70 print_usage (argv);
71 }
72 break;
73
74 case 't':
75 demux_pid = strtol (optarg, &s, 0);
76 if (demux_pid < 0x10 || demux_pid > 0x1ffe || *s) {
77 fprintf (stderr, "Invalid pid: %s\n", optarg);
78 print_usage (argv);
79 }
80 break;
81
82 case 'T':
83 demux_pes = 1;
84 break;
85
86 default:
87 print_usage (argv);
88 }
89
90 if (optind < argc) {
91 in_file = fopen (argv[optind], "rb");
92 if (!in_file) {
93 fprintf (stderr, "%s - could not open file %s\n", strerror (errno),
94 argv[optind]);
95 exit (1);
96 }
97 } else
98 in_file = stdin;
99 }
100
101 #define DEMUX_PAYLOAD_START 1
demux(uint8_t * buf,uint8_t * end,int flags)102 static int demux (uint8_t * buf, uint8_t * end, int flags)
103 {
104 static int mpeg1_skip_table[16] = {
105 0, 0, 4, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
106 };
107
108 /*
109 * the demuxer keeps some state between calls:
110 * if "state" = DEMUX_HEADER, then "head_buf" contains the first
111 * "bytes" bytes from some header.
112 * if "state" == DEMUX_DATA, then we need to copy "bytes" bytes
113 * of ES data before the next header.
114 * if "state" == DEMUX_SKIP, then we need to skip "bytes" bytes
115 * of data before the next header.
116 *
117 * NEEDBYTES makes sure we have the requested number of bytes for a
118 * header. If we dont, it copies what we have into head_buf and returns,
119 * so that when we come back with more data we finish decoding this header.
120 *
121 * DONEBYTES updates "buf" to point after the header we just parsed.
122 */
123
124 #define DEMUX_HEADER 0
125 #define DEMUX_DATA 1
126 #define DEMUX_SKIP 2
127 static int state = DEMUX_SKIP;
128 static int state_bytes = 0;
129 static uint8_t head_buf[268];
130
131 uint8_t * header;
132 int bytes;
133 int len;
134
135 #define NEEDBYTES(x) \
136 do { \
137 int missing; \
138 \
139 missing = (x) - bytes; \
140 if (missing > 0) { \
141 if (header == head_buf) { \
142 if (missing <= end - buf) { \
143 memcpy (header + bytes, buf, missing); \
144 buf += missing; \
145 bytes = (x); \
146 } else { \
147 memcpy (header + bytes, buf, end - buf); \
148 state_bytes = bytes + end - buf; \
149 return 0; \
150 } \
151 } else { \
152 memcpy (head_buf, header, bytes); \
153 state = DEMUX_HEADER; \
154 state_bytes = bytes; \
155 return 0; \
156 } \
157 } \
158 } while (0)
159
160 #define DONEBYTES(x) \
161 do { \
162 if (header != head_buf) \
163 buf = header + (x); \
164 } while (0)
165
166 if (flags & DEMUX_PAYLOAD_START)
167 goto payload_start;
168 switch (state) {
169 case DEMUX_HEADER:
170 if (state_bytes > 0) {
171 header = head_buf;
172 bytes = state_bytes;
173 goto continue_header;
174 }
175 break;
176 case DEMUX_DATA:
177 if (demux_pid || (state_bytes > end - buf)) {
178 fwrite (buf, end - buf, 1, stdout);
179 state_bytes -= end - buf;
180 return 0;
181 }
182 fwrite (buf, state_bytes, 1, stdout);
183 buf += state_bytes;
184 break;
185 case DEMUX_SKIP:
186 if (demux_pid || (state_bytes > end - buf)) {
187 state_bytes -= end - buf;
188 return 0;
189 }
190 buf += state_bytes;
191 break;
192 }
193
194 while (1) {
195 if (demux_pid) {
196 state = DEMUX_SKIP;
197 return 0;
198 }
199 payload_start:
200 header = buf;
201 bytes = end - buf;
202 continue_header:
203 NEEDBYTES (4);
204 if (header[0] || header[1] || (header[2] != 1)) {
205 if (demux_pid) {
206 state = DEMUX_SKIP;
207 return 0;
208 } else if (header != head_buf) {
209 buf++;
210 goto payload_start;
211 } else {
212 header[0] = header[1];
213 header[1] = header[2];
214 header[2] = header[3];
215 bytes = 3;
216 goto continue_header;
217 }
218 }
219 if (demux_pid || demux_pes) {
220 if (header[3] != 0xbd) {
221 fprintf (stderr, "bad stream id %x\n", header[3]);
222 exit (1);
223 }
224 NEEDBYTES (9);
225 if ((header[6] & 0xc0) != 0x80) { /* not mpeg2 */
226 fprintf (stderr, "bad multiplex - not mpeg2\n");
227 exit (1);
228 }
229 len = 9 + header[8];
230 NEEDBYTES (len);
231 DONEBYTES (len);
232 bytes = 6 + (header[4] << 8) + header[5] - len;
233 if (bytes > end - buf) {
234 fwrite (buf, end - buf, 1, stdout);
235 state = DEMUX_DATA;
236 state_bytes = bytes - (end - buf);
237 return 0;
238 } else if (bytes > 0) {
239 fwrite (buf, bytes, 1, stdout);
240 buf += bytes;
241 }
242 } else switch (header[3]) {
243 case 0xb9: /* program end code */
244 /* DONEBYTES (4); */
245 /* break; */
246 return 1;
247 case 0xba: /* pack header */
248 NEEDBYTES (5);
249 if ((header[4] & 0xc0) == 0x40) { /* mpeg2 */
250 NEEDBYTES (14);
251 len = 14 + (header[13] & 7);
252 NEEDBYTES (len);
253 DONEBYTES (len);
254 /* header points to the mpeg2 pack header */
255 } else if ((header[4] & 0xf0) == 0x20) { /* mpeg1 */
256 NEEDBYTES (12);
257 DONEBYTES (12);
258 /* header points to the mpeg1 pack header */
259 } else {
260 fprintf (stderr, "weird pack header\n");
261 DONEBYTES (5);
262 }
263 break;
264 case 0xbd: /* private stream 1 */
265 NEEDBYTES (7);
266 if ((header[6] & 0xc0) == 0x80) { /* mpeg2 */
267 NEEDBYTES (9);
268 len = 10 + header[8];
269 NEEDBYTES (len);
270 /* header points to the mpeg2 pes header */
271 } else { /* mpeg1 */
272 len = 7;
273 while ((header-1)[len] == 0xff) {
274 len++;
275 NEEDBYTES (len);
276 if (len == 23) {
277 fprintf (stderr, "too much stuffing\n");
278 break;
279 }
280 }
281 if (((header-1)[len] & 0xc0) == 0x40) {
282 len += 2;
283 NEEDBYTES (len);
284 }
285 len += mpeg1_skip_table[(header - 1)[len] >> 4] + 1;
286 NEEDBYTES (len);
287 /* header points to the mpeg1 pes header */
288 }
289 if ((header-1)[len] != demux_track) {
290 DONEBYTES (len);
291 bytes = 6 + (header[4] << 8) + header[5] - len;
292 if (bytes <= 0)
293 continue;
294 goto skip;
295 }
296 len += 3;
297 NEEDBYTES (len);
298 DONEBYTES (len);
299 bytes = 6 + (header[4] << 8) + header[5] - len;
300 if (bytes > end - buf) {
301 fwrite (buf, end - buf, 1, stdout);
302 state = DEMUX_DATA;
303 state_bytes = bytes - (end - buf);
304 return 0;
305 } else if (bytes > 0) {
306 fwrite (buf, bytes, 1, stdout);
307 buf += bytes;
308 }
309 break;
310 default:
311 if (header[3] < 0xb9) {
312 fprintf (stderr,
313 "looks like a video stream, not system stream\n");
314 exit (1);
315 } else {
316 NEEDBYTES (6);
317 DONEBYTES (6);
318 bytes = (header[4] << 8) + header[5];
319 skip:
320 if (bytes > end - buf) {
321 state = DEMUX_SKIP;
322 state_bytes = bytes - (end - buf);
323 return 0;
324 }
325 buf += bytes;
326 }
327 }
328 }
329 }
330
ps_loop(void)331 static void ps_loop (void)
332 {
333 uint8_t * end;
334
335 do {
336 end = buffer + fread (buffer, 1, BUFFER_SIZE, in_file);
337 if (demux (buffer, end, 0))
338 break; /* hit program_end_code */
339 } while (end == buffer + BUFFER_SIZE);
340 }
341
ts_loop(void)342 static void ts_loop (void)
343 {
344 uint8_t * buf;
345 uint8_t * nextbuf;
346 uint8_t * data;
347 uint8_t * end;
348 int pid;
349
350 buf = buffer;
351 while (1) {
352 end = buf + fread (buf, 1, buffer + BUFFER_SIZE - buf, in_file);
353 buf = buffer;
354 for (; (nextbuf = buf + 188) <= end; buf = nextbuf) {
355 if (*buf != 0x47) {
356 fprintf (stderr, "bad sync byte\n");
357 nextbuf = buf + 1;
358 continue;
359 }
360 pid = ((buf[1] << 8) + buf[2]) & 0x1fff;
361 if (pid != demux_pid)
362 continue;
363 data = buf + 4;
364 if (buf[3] & 0x20) { /* buf contains an adaptation field */
365 data = buf + 5 + buf[4];
366 if (data > nextbuf)
367 continue;
368 }
369 if (buf[3] & 0x10)
370 demux (data, nextbuf,
371 (buf[1] & 0x40) ? DEMUX_PAYLOAD_START : 0);
372 }
373 if (end != buffer + BUFFER_SIZE)
374 break;
375 memcpy (buffer, buf, end - buf);
376 buf = buffer + (end - buf);
377 }
378 }
379
main(int argc,char ** argv)380 int main (int argc, char ** argv)
381 {
382 #ifdef HAVE_IO_H
383 setmode (fileno (stdin), O_BINARY);
384 setmode (fileno (stdout), O_BINARY);
385 #endif
386
387 handle_args (argc, argv);
388
389 if (demux_pid)
390 ts_loop ();
391 else
392 ps_loop ();
393
394 return 0;
395 }
396