--- /dev/null
+/*
+ * extract_a52.c
+ * Copyright (C) 2000-2002 Michel Lespinasse <walken@zoy.org>
+ * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *
+ * This file is part of a52dec, a free ATSC A-52 stream decoder.
+ * See http://liba52.sourceforge.net/ for updates.
+ *
+ * a52dec is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * a52dec is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <getopt.h>
+#include <inttypes.h>
+
+#define BUFFER_SIZE 4096
+static uint8_t buffer[BUFFER_SIZE];
+static FILE * in_file;
+static int demux_track = 0x80;
+static int demux_pid = 0;
+
+static void print_usage (char ** argv)
+{
+ fprintf (stderr, "usage: %s [-s <track>] [-t <pid>] <file>\n"
+ "\t-s\tset track number (0-7 or 0x80-0x87)\n"
+ "\t-t\tuse transport stream demultiplexer, pid 0x10-0x1ffe\n",
+ argv[0]);
+
+ exit (1);
+}
+
+static void handle_args (int argc, char ** argv)
+{
+ int c;
+ char * s;
+
+ while ((c = getopt (argc, argv, "s:t:")) != -1)
+ switch (c) {
+ case 's':
+ demux_track = strtol (optarg, &s, 16);
+ if (demux_track < 0x80)
+ demux_track += 0x80;
+ if ((demux_track < 0x80) || (demux_track > 0x87) || (*s)) {
+ fprintf (stderr, "Invalid track number: %s\n", optarg);
+ print_usage (argv);
+ }
+ break;
+
+ case 't':
+ demux_pid = strtol (optarg, &s, 16);
+ if ((demux_pid < 0x10) || (demux_pid > 0x1ffe) || (*s)) {
+ fprintf (stderr, "Invalid pid: %s\n", optarg);
+ print_usage (argv);
+ }
+ break;
+
+ default:
+ print_usage (argv);
+ }
+
+ if (optind < argc) {
+ in_file = fopen (argv[optind], "rb");
+ if (!in_file) {
+ fprintf (stderr, "%s - couldnt open file %s\n", strerror (errno),
+ argv[optind]);
+ exit (1);
+ }
+ } else
+ in_file = stdin;
+}
+
+#define DEMUX_PAYLOAD_START 1
+static int demux (uint8_t * buf, uint8_t * end, int flags)
+{
+ static int mpeg1_skip_table[16] = {
+ 0, 0, 4, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+ };
+
+ /*
+ * the demuxer keeps some state between calls:
+ * if "state" = DEMUX_HEADER, then "head_buf" contains the first
+ * "bytes" bytes from some header.
+ * if "state" == DEMUX_DATA, then we need to copy "bytes" bytes
+ * of ES data before the next header.
+ * if "state" == DEMUX_SKIP, then we need to skip "bytes" bytes
+ * of data before the next header.
+ *
+ * NEEDBYTES makes sure we have the requested number of bytes for a
+ * header. If we dont, it copies what we have into head_buf and returns,
+ * so that when we come back with more data we finish decoding this header.
+ *
+ * DONEBYTES updates "buf" to point after the header we just parsed.
+ */
+
+#define DEMUX_HEADER 0
+#define DEMUX_DATA 1
+#define DEMUX_SKIP 2
+ static int state = DEMUX_SKIP;
+ static int state_bytes = 0;
+ static uint8_t head_buf[268];
+
+ uint8_t * header;
+ int bytes;
+ int len;
+
+#define NEEDBYTES(x) \
+ do { \
+ int missing; \
+ \
+ missing = (x) - bytes; \
+ if (missing > 0) { \
+ if (header == head_buf) { \
+ if (missing <= end - buf) { \
+ memcpy (header + bytes, buf, missing); \
+ buf += missing; \
+ bytes = (x); \
+ } else { \
+ memcpy (header + bytes, buf, end - buf); \
+ state_bytes = bytes + end - buf; \
+ return 0; \
+ } \
+ } else { \
+ memcpy (head_buf, header, bytes); \
+ state = DEMUX_HEADER; \
+ state_bytes = bytes; \
+ return 0; \
+ } \
+ } \
+ } while (0)
+
+#define DONEBYTES(x) \
+ do { \
+ if (header != head_buf) \
+ buf = header + (x); \
+ } while (0)
+
+ if (flags & DEMUX_PAYLOAD_START)
+ goto payload_start;
+ switch (state) {
+ case DEMUX_HEADER:
+ if (state_bytes > 0) {
+ header = head_buf;
+ bytes = state_bytes;
+ goto continue_header;
+ }
+ break;
+ case DEMUX_DATA:
+ if (demux_pid || (state_bytes > end - buf)) {
+ fwrite (buf, end - buf, 1, stdout);
+ state_bytes -= end - buf;
+ return 0;
+ }
+ fwrite (buf, state_bytes, 1, stdout);
+ buf += state_bytes;
+ break;
+ case DEMUX_SKIP:
+ if (demux_pid || (state_bytes > end - buf)) {
+ state_bytes -= end - buf;
+ return 0;
+ }
+ buf += state_bytes;
+ break;
+ }
+
+ while (1) {
+ if (demux_pid) {
+ state = DEMUX_SKIP;
+ return 0;
+ }
+ payload_start:
+ header = buf;
+ bytes = end - buf;
+ continue_header:
+ NEEDBYTES (4);
+ if (header[0] || header[1] || (header[2] != 1)) {
+ if (demux_pid) {
+ state = DEMUX_SKIP;
+ return 0;
+ } else if (header != head_buf) {
+ buf++;
+ goto payload_start;
+ } else {
+ header[0] = header[1];
+ header[1] = header[2];
+ header[2] = header[3];
+ bytes = 3;
+ goto continue_header;
+ }
+ }
+ if (demux_pid && (header[3] != 0xbd)) {
+ fprintf (stderr, "bad stream id %x\n", header[3]);
+ exit (1);
+ }
+ switch (header[3]) {
+ case 0xb9: /* program end code */
+ /* DONEBYTES (4); */
+ /* break; */
+ return 1;
+ case 0xba: /* pack header */
+ NEEDBYTES (12);
+ if ((header[4] & 0xc0) == 0x40) { /* mpeg2 */
+ NEEDBYTES (14);
+ len = 14 + (header[13] & 7);
+ NEEDBYTES (len);
+ DONEBYTES (len);
+ /* header points to the mpeg2 pack header */
+ } else if ((header[4] & 0xf0) == 0x20) { /* mpeg1 */
+ DONEBYTES (12);
+ /* header points to the mpeg1 pack header */
+ } else {
+ fprintf (stderr, "weird pack header\n");
+ exit (1);
+ }
+ break;
+ case 0xbd: /* private stream 1 */
+ NEEDBYTES (7);
+ if ((header[6] & 0xc0) == 0x80) { /* mpeg2 */
+ NEEDBYTES (9);
+ len = 10 + header[8];
+ NEEDBYTES (len);
+ /* header points to the mpeg2 pes header */
+ } else { /* mpeg1 */
+ len = 7;
+ while ((header-1)[len] == 0xff) {
+ len++;
+ NEEDBYTES (len);
+ if (len == 23) {
+ fprintf (stderr, "too much stuffing\n");
+ break;
+ }
+ }
+ if (((header-1)[len] & 0xc0) == 0x40) {
+ len += 2;
+ NEEDBYTES (len);
+ }
+ len += mpeg1_skip_table[(header - 1)[len] >> 4] + 1;
+ NEEDBYTES (len);
+ /* header points to the mpeg1 pes header */
+ }
+ if ((!demux_pid) && ((header-1)[len] != demux_track)) {
+ DONEBYTES (len);
+ bytes = 6 + (header[4] << 8) + header[5] - len;
+ if (bytes <= 0)
+ continue;
+ goto skip;
+ }
+ len += 3;
+ NEEDBYTES (len);
+ DONEBYTES (len);
+ bytes = 6 + (header[4] << 8) + header[5] - len;
+ if (demux_pid || (bytes > end - buf)) {
+ fwrite (buf, end - buf, 1, stdout);
+ state = DEMUX_DATA;
+ state_bytes = bytes - (end - buf);
+ return 0;
+ } else if (bytes <= 0)
+ continue;
+ fwrite (buf, bytes, 1, stdout);
+ buf += bytes;
+ break;
+ default:
+ if (header[3] < 0xb9) {
+ fprintf (stderr,
+ "looks like a video stream, not system stream\n");
+ exit (1);
+ } else {
+ NEEDBYTES (6);
+ DONEBYTES (6);
+ bytes = (header[4] << 8) + header[5];
+ skip:
+ if (bytes > end - buf) {
+ state = DEMUX_SKIP;
+ state_bytes = bytes - (end - buf);
+ return 0;
+ }
+ buf += bytes;
+ }
+ }
+ }
+}
+
+static void ps_loop (void)
+{
+ uint8_t * end;
+
+ do {
+ end = buffer + fread (buffer, 1, BUFFER_SIZE, in_file);
+ if (demux (buffer, end, 0))
+ break; /* hit program_end_code */
+ } while (end == buffer + BUFFER_SIZE);
+}
+
+static void ts_loop (void)
+{
+#define PACKETS (BUFFER_SIZE / 188)
+ uint8_t * buf;
+ uint8_t * data;
+ uint8_t * end;
+ int packets;
+ int i;
+ int pid;
+
+ do {
+ packets = fread (buffer, 188, PACKETS, in_file);
+ for (i = 0; i < packets; i++) {
+ buf = buffer + i * 188;
+ end = buf + 188;
+ if (buf[0] != 0x47) {
+ fprintf (stderr, "bad sync byte\n");
+ exit (1);
+ }
+ pid = ((buf[1] << 8) + buf[2]) & 0x1fff;
+ if (pid != demux_pid)
+ continue;
+ data = buf + 4;
+ if (buf[3] & 0x20) { /* buf contains an adaptation field */
+ data = buf + 5 + buf[4];
+ if (data > end)
+ continue;
+ }
+ if (buf[3] & 0x10)
+ demux (data, end, (buf[1] & 0x40) ? DEMUX_PAYLOAD_START : 0);
+ }
+ } while (packets == PACKETS);
+}
+
+int main (int argc, char ** argv)
+{
+ handle_args (argc, argv);
+
+ if (demux_pid)
+ ts_loop ();
+ else
+ ps_loop ();
+
+ return 0;
+}
projects / goodguy / history.git / blobdiff