scan.c

linux TV 源码

		buf += descriptor_len;
		descriptors_loop_len -= descriptor_len;
	}
}


static void parse_pat(const unsigned char *buf, int section_length,
		      int transport_stream_id)
{
	while (section_length > 0) {
		struct service *s;
		int service_id = (buf[0] << 8) | buf[1];

		if (service_id == 0) {
			buf += 4;		/*  skip nit pid entry... */
			section_length -= 4;
			continue;
		}
		/* SDT might have been parsed first... */
		s = find_service(current_tp, service_id);
		if (!s)
			s = alloc_service(current_tp, service_id);
		s->pmt_pid = ((buf[2] & 0x1f) << 8) | buf[3];
		if (!s->priv && s->pmt_pid) {
			s->priv = malloc(sizeof(struct section_buf));
			setup_filter(s->priv, demux_devname,
				     s->pmt_pid, 0x02, 1, 0, 5);

			add_filter (s->priv);
		}

		buf += 4;
		section_length -= 4;
	};
}


static void parse_pmt (const unsigned char *buf, int section_length, int service_id)
{
	int program_info_len;
	struct service *s;
        char msg_buf[14 * AUDIO_CHAN_MAX + 1];
        char *tmp;
        int i;

	s = find_service (current_tp, service_id);
	if (!s) {
		error("PMT for serivce_id 0x%04x was not in PAT\n", service_id);
		return;
	}

	s->pcr_pid = ((buf[0] & 0x1f) << 8) | buf[1];

	program_info_len = ((buf[2] & 0x0f) << 8) | buf[3];

	buf += program_info_len + 4;
	section_length -= program_info_len + 4;

	while (section_length > 0) {
		int ES_info_len = ((buf[3] & 0x0f) << 8) | buf[4];
		int elementary_pid = ((buf[1] & 0x1f) << 8) | buf[2];

		switch (buf[0]) {
		case 0x01:
		case 0x02:
			moreverbose("  VIDEO     : PID 0x%04x\n", elementary_pid);
			if (s->video_pid == 0)
				s->video_pid = elementary_pid;
			break;
		case 0x03:
		case 0x04:
			moreverbose("  AUDIO     : PID 0x%04x\n", elementary_pid);
			if (s->audio_num < AUDIO_CHAN_MAX) {
				s->audio_pid[s->audio_num] = elementary_pid;
				parse_descriptors (PMT, buf + 5, ES_info_len, s);
				s->audio_num++;
			}
			else
				warning("more than %i audio channels, truncating\n",
				     AUDIO_CHAN_MAX);
			break;
		case 0x06:
			if (find_descriptor(0x56, buf + 5, ES_info_len, NULL, NULL)) {
				moreverbose("  TELETEXT  : PID 0x%04x\n", elementary_pid);
				s->teletext_pid = elementary_pid;
				break;
			}
			else if (find_descriptor(0x59, buf + 5, ES_info_len, NULL, NULL)) {
				/* Note: The subtitling descriptor can also signal
				 * teletext subtitling, but then the teletext descriptor
				 * will also be present; so we can be quite confident
				 * that we catch DVB subtitling streams only here, w/o
				 * parsing the descriptor. */
				moreverbose("  SUBTITLING: PID 0x%04x\n", elementary_pid);
				s->subtitling_pid = elementary_pid;
				break;
			}
			else if (find_descriptor(0x6a, buf + 5, ES_info_len, NULL, NULL)) {
				moreverbose("  AC3       : PID 0x%04x\n", elementary_pid);
				s->ac3_pid = elementary_pid;
				break;
			}
			/* fall through */
		default:
			moreverbose("  OTHER     : PID 0x%04x TYPE 0x%02x\n", elementary_pid, buf[0]);
		};

		buf += ES_info_len + 5;
		section_length -= ES_info_len + 5;
	};


        tmp = msg_buf;
        tmp += sprintf(tmp, "0x%04x (%.4s)", s->audio_pid[0], s->audio_lang[0]);

	if (s->audio_num > AUDIO_CHAN_MAX) {
		warning("more than %i audio channels: %i, truncating to %i\n",
		      AUDIO_CHAN_MAX, s->audio_num, AUDIO_CHAN_MAX);
		s->audio_num = AUDIO_CHAN_MAX;
	}

        for (i=1; i<s->audio_num; i++)
                tmp += sprintf(tmp, ", 0x%04x (%.4s)", s->audio_pid[i], s->audio_lang[i]);

        debug("0x%04x 0x%04x: %s -- %s, pmt_pid 0x%04x, vpid 0x%04x, apid %s\n",
	    s->transport_stream_id,
	    s->service_id,
	    s->provider_name, s->service_name,
	    s->pmt_pid, s->video_pid, msg_buf);
}


static void parse_nit (const unsigned char *buf, int section_length, int network_id)
{
	int descriptors_loop_len = ((buf[0] & 0x0f) << 8) | buf[1];

	if (section_length < descriptors_loop_len + 4)
	{
		warning("section too short: network_id == 0x%04x, section_length == %i, "
		     "descriptors_loop_len == %i\n",
		     network_id, section_length, descriptors_loop_len);
		return;
	}

	parse_descriptors (NIT, buf + 2, descriptors_loop_len, NULL);

	section_length -= descriptors_loop_len + 4;
	buf += descriptors_loop_len + 4;

	while (section_length > 6) {
		int transport_stream_id = (buf[0] << 8) | buf[1];
		struct transponder *t, tn;

		descriptors_loop_len = ((buf[4] & 0x0f) << 8) | buf[5];

		if (section_length < descriptors_loop_len + 4 ||
		    !transport_stream_id)
		{
			warning("section too short: transport_stream_id == 0x%04x, "
			     "section_length == %i, descriptors_loop_len == %i\n",
			     transport_stream_id, section_length,
			     descriptors_loop_len);
			break;
		}

		debug("transport_stream_id 0x%04x\n", transport_stream_id);

		memset(&tn, 0, sizeof(tn));
		tn.type = -1;
		tn.network_id = network_id;
		tn.transport_stream_id = transport_stream_id;

		parse_descriptors (NIT, buf + 6, descriptors_loop_len, &tn);

		if (tn.type == fe_info.type) {
			/* only add if develivery_descriptor matches FE type */
			t = find_transponder(tn.param.frequency);
			if (!t)
				t = alloc_transponder(tn.param.frequency);
			copy_transponder(t, &tn);
		}

		section_length -= descriptors_loop_len + 6;
		buf += descriptors_loop_len + 6;
	};
}


static void parse_sdt (const unsigned char *buf, int section_length,
		int transport_stream_id)
{
	buf += 3;	       /*  skip original network id + reserved field */

	while (section_length > 4) {
		int service_id = (buf[0] << 8) | buf[1];
		int descriptors_loop_len = ((buf[3] & 0x0f) << 8) | buf[4];
		struct service *s;

		if (section_length < descriptors_loop_len ||
		    !transport_stream_id ||
		    !descriptors_loop_len)
		{
			warning("section too short: service_id == 0x%02x, section_length == %i"
			     "descriptors_loop_len == %i\n",
			     service_id, section_length,
			     descriptors_loop_len);
			break;
		}

		s = find_service(current_tp, service_id);
		if (!s)
			/* maybe PAT has not yet been parsed... */
			s = alloc_service(current_tp, service_id);

		s->running = (buf[3] >> 5) & 0x7;
		s->scrambled = (buf[3] >> 4) & 1;

		parse_descriptors (SDT, buf + 5, descriptors_loop_len, s);

		section_length -= descriptors_loop_len + 5;
		buf += descriptors_loop_len + 5;
	};
}


static int get_bit (uint8_t *bitfield, int bit)
{
	return (bitfield[bit/8] >> (bit % 8)) & 1;
}

static void set_bit (uint8_t *bitfield, int bit)
{
	bitfield[bit/8] |= 1 << (bit % 8);
}


/**
 *   returns 0 when more sections are expected
 *	   1 when all sections are read on this pid
 *	   -1 on invalid table id
 */
static int parse_section (struct section_buf *s)
{
	const unsigned char *buf = s->buf;
	int table_id;
	int section_length;
	int table_id_ext;
	int section_version_number;
	int section_number;
	int last_section_number;
	int i;

	table_id = buf[0];

	if (s->table_id != table_id)
		return -1;

	section_length = (((buf[1] & 0x0f) << 8) | buf[2]) - 11;

	table_id_ext = (buf[3] << 8) | buf[4];
	section_version_number = (buf[5] >> 1) & 0x1f;
	section_number = buf[6];
	last_section_number = buf[7];

	if (s->segmented && s->table_id_ext != -1 && s->table_id_ext != table_id_ext) {
		/* find or allocate actual section_buf matching table_id_ext */
		while (s->next_seg) {
			s = s->next_seg;
			if (s->table_id_ext == table_id_ext)
				break;
		}
		if (s->table_id_ext != table_id_ext) {
			assert(s->next_seg == NULL);
			s->next_seg = calloc(1, sizeof(struct section_buf));
			s->next_seg->segmented = s->segmented;
			s->next_seg->run_once = s->run_once;
			s->next_seg->timeout = s->timeout;
			s = s->next_seg;
			s->table_id = table_id;
			s->table_id_ext = table_id_ext;
			s->section_version_number = section_version_number;
		}
	}

	if (s->section_version_number != section_version_number ||
			s->table_id_ext != table_id_ext) {
		struct section_buf *next_seg = s->next_seg;

		if (s->section_version_number != -1 && s->table_id_ext != -1)
			debug("section version_number or table_id_ext changed "
				"%d -> %d / %04x -> %04x\n",
				s->section_version_number, section_version_number,
				s->table_id_ext, table_id_ext);
		s->table_id_ext = table_id_ext;
		s->section_version_number = section_version_number;
		s->sectionfilter_done = 0;
		memset (s->section_done, 0, sizeof(s->section_done));
		s->next_seg = next_seg;
	}

	buf += 8;

	if (!get_bit(s->section_done, section_number)) {
		set_bit (s->section_done, section_number);

		debug("pid 0x%02x tid 0x%02x table_id_ext 0x%04x, "
		    "%i/%i (version %i)\n",
		    s->pid, table_id, table_id_ext, section_number,
		    last_section_number, section_version_number);

		switch (table_id) {
		case 0x00:
			verbose("PAT\n");
			parse_pat (buf, section_length, table_id_ext);
			break;

		case 0x02:
			verbose("PMT 0x%04x for service 0x%04x\n", s->pid, table_id_ext);
			parse_pmt (buf, section_length, table_id_ext);
			break;

		case 0x41:
			verbose("////////////////////////////////////////////// NIT other\n");
		case 0x40:
			verbose("NIT (%s TS)\n", table_id == 0x40 ? "actual":"other");
			parse_nit (buf, section_length, table_id_ext);
			break;

		case 0x42:
		case 0x46:
			verbose("SDT (%s TS)\n", table_id == 0x42 ? "actual":"other");
			parse_sdt (buf, section_length, table_id_ext);
			break;

		default:
			;
		};

		for (i = 0; i <= last_section_number; i++)
			if (get_bit (s->section_done, i) == 0)
				break;

		if (i > last_section_number)
			s->sectionfilter_done = 1;
	}

	if (s->segmented) {
		/* always wait for timeout; this is because we don't now how
		 * many segments there are
		 */
		return 0;
	}
	else if (s->sectionfilter_done)
		return 1;

	return 0;
}


static int read_sections (struct section_buf *s)
{
	int section_length, count;

	if (s->sectionfilter_done && !s->segmented)
		return 1;

	/* the section filter API guarantess that we get one full section
	 * per read(), provided that the buffer is large enough (it is)
	 */
	if (((count = read (s->fd, s->buf, sizeof(s->buf))) < 0) && errno == EOVERFLOW)
		count = read (s->fd, s->buf, sizeof(s->buf));
	if (count < 0) {
		errorn("read_sections: read error");
		return -1;
	}

	if (count < 4)
		return -1;

	section_length = ((s->buf[1] & 0x0f) << 8) | s->buf[2];

	if (count != section_length + 3)
		return -1;

	if (parse_section(s) == 1)
		return 1;

	return 0;
}


static LIST_HEAD(running_filters);
static LIST_HEAD(waiting_filters);
static int n_running;
#define MAX_RUNNING 32
static struct pollfd poll_fds[MAX_RUNNING];
static struct section_buf* poll_section_bufs[MAX_RUNNING];


static void setup_filter (struct section_buf* s, const char *dmx_devname,
			  int pid, int tid, int run_once, int segmented, int timeout)
{
	memset (s, 0, sizeof(struct section_buf));

	s->fd = -1;
	s->dmx_devname = dmx_devname;
	s->pid = pid;
	s->table_id = tid;

	s->run_once = run_once;
	s->segmented = segmented;

	if (long_timeout)
		s->timeout = 5 * timeout;
	else
		s->timeout = timeout;

	s->table_id_ext = -1;
	s->section_version_number = -1;

	INIT_LIST_HEAD (&s->list);
}

static void update_poll_fds(void)
{
	struct list_head *p;
	struct section_buf* s;
	int i;

	memset(poll_section_bufs, 0, sizeof(poll_section_bufs));
	for (i = 0; i < MAX_RUNNING; i++)
		poll_fds[i].fd = -1;
	i = 0;
	list_for_each (p, &running_filters) {
		if (i >= MAX_RUNNING)
			fatal("too many poll_fds\n");
		s = list_entry (p, struct section_buf, list);
		if (s->fd == -1)
			fatal("s->fd == -1 on running_filters\n");
		verbosedebug("poll fd %d\n", s->fd);
		poll_fds[i].fd = s->fd;
		poll_fds[i].events = POLLIN;
		poll_fds[i].revents = 0;
		poll_section_bufs[i] = s;
		i++;
	}
	if (i != n_running)
		fatal("n_running is hosed\n");
}

static int start_filter (struct section_buf* s)
{
	struct dmx_sct_filter_params f;

	if (n_running >= MAX_RUNNING)
		goto err0;
	if ((s->fd = open (s->dmx_devname, O_RDWR | O_NONBLOCK)) < 0)
		goto err0;

	verbosedebug("start filter pid 0x%04x table_id 0x%02x\n", s->pid, s->table_id);

	memset(&f, 0, sizeof(f));

	f.pid = (uint16_t) s->pid;

	if (s->table_id < 0x100 && s->table_id > 0) {
		f.filter.filter[0] = (uint8_t) s->table_id;
		f.filter.mask[0]   = 0xff;
	}

	f.timeout = 0;
	f.flags = DMX_IMMEDIATE_START | DMX_CHECK_CRC;

	if (ioctl(s->fd, DMX_SET_FILTER, &f) == -1) {
		errorn ("ioctl DMX_SET_FILTER failed");
		goto err1;
	}

	s->sectionfilter_done = 0;
	time(&s->start_time);

	list_del_init (&s->list);  /* might be in waiting filter list */
	list_add (&s->list, &running_filters);

	n_running++;
	update_poll_fds();

	return 0;

err1:
	ioctl (s->fd, DMX_STOP);
	close (s->fd);
err0:
	return -1;
}


static void stop_filter (struct section_buf *s)
{
	verbosedebug("stop filter pid 0x%04x\n", s->pid);
	ioctl (s->fd, DMX_STOP);
	close (s->fd);
	s->fd = -1;
	list_del (&s->list);
	s->running_time += time(NULL) - s->start_time;

	n_running--;
	update_poll_fds();
}


static void add_filter (struct section_buf *s)
{
	verbosedebug("add filter pid 0x%04x\n", s->pid);
	if (start_filter (s))
		list_add_tail (&s->list, &waiting_filters);
}


static void remove_filter (struct section_buf *s)
{
	verbosedebug("remove filter pid 0x%04x\n", s->pid);
	stop_filter (s);

	while (!list_empty(&waiting_filters)) {
		struct list_head *next = waiting_filters.next;
		s = list_entry (next, struct section_buf, list);
		if (start_filter (s))
			break;
	};
}


static void read_filters (void)
{
	struct section_buf *s;
	int i, n, done;

	n = poll(poll_fds, n_running, 1000);
	if (n == -1)
		errorn("poll");

	for (i = 0; i < n_running; i++) {
		s = poll_section_bufs[i];
		if (!s)
			fatal("poll_section_bufs[%d] is NULL\n", i);
		if (poll_fds[i].revents)
			done = read_sections (s) == 1;
		else
			done = 0; /* timeout */
		if (done || time(NULL) > s->start_time + s->timeout) {
			if (s->run_once) {
				if (done)
					verbosedebug("filter done pid 0x%04x\n", s->pid);
				else
					warning("filter timeout pid 0x%04x\n", s->pid);
				remove_filter (s);
			}
		}
	}
}


static int mem_is_zero (const void *mem, int size)
{
	const char *p = mem;

	while (size) {
		if (*p != 0x00)
			return 0;
		p++;
	}

	return 1;
}


#define SWITCHFREQ 11700000
#define LOF_HI     10600000
#define LOF_LO      9750000

static int switch_pos = 0;

static int __tune_to_transponder (int frontend_fd, struct transponder *t)
{
	struct dvb_frontend_parameters p;
	fe_status_t s;
	int i;

	current_tp = t;

	if (mem_is_zero (&t->param, sizeof(struct dvb_frontend_parameters)))
		return -1;

	memcpy (&p, &t->param, sizeof(struct dvb_frontend_parameters));

	if (verbosity >= 1) {
		dprintf(1, ">>> tune to: ");
		dump_dvb_parameters (stderr, t);
		if (t->last_tuning_failed)
			dprintf(1, " (tuning failed)");
		dprintf(1, "\n");
	}

	if (t->type == FE_QPSK) {