scan.c

dvb在linux下搜索电台的源代码

		t->param.u.qam.modulation = qam_tab[buf[8] & 0x0f];
	t->param.inversion = caps_inversion;

	if (verbosity >= 5) {
		debug("0x%#04x/0x%#04x ", t->network_id, t->transport_stream_id);
		dump_dvb_parameters (stderr, t);
		if (t->scan_done)
			dprintf(5, " (done)");
		if (t->last_tuning_failed)
			dprintf(5, " (no signal)");
		dprintf(5, "\n");
	}
}


static void parse_terrestrial_delivery_system_descriptor (const unsigned char *buf,
						   struct transponder *t)
{
	static const fe_modulation_t m_tab [] = { QPSK, QAM_16, QAM_64, QAM_AUTO };
	static const fe_code_rate_t ofec_tab [8] = { FEC_1_2, FEC_2_3, FEC_3_4,
					       FEC_5_6, FEC_7_8 };
	struct dvb_ofdm_parameters *o;

	if (!t) {
		warning("terrestrial_delivery_system_descriptor outside transport stream definition (ignored)\n");
		return;
	}
	o = &t->param.u.ofdm;
	t->type = FE_OFDM;

	t->param.frequency = (buf[2] << 24) | (buf[3] << 16);
	t->param.frequency |= (buf[4] << 8) | buf[5];
	t->param.frequency *= 10;
	t->param.inversion = caps_inversion;

	o->bandwidth = BANDWIDTH_8_MHZ + ((buf[6] >> 5) & 0x3);
	o->constellation = m_tab[(buf[7] >> 6) & 0x3];
	o->hierarchy_information = HIERARCHY_NONE + ((buf[7] >> 3) & 0x3);

	if ((buf[7] & 0x7) > 4)
		o->code_rate_HP = FEC_AUTO;
	else
		o->code_rate_HP = ofec_tab [buf[7] & 0x7];

	if (((buf[8] >> 5) & 0x7) > 4)
		o->code_rate_LP = FEC_AUTO;
	else
		o->code_rate_LP = ofec_tab [(buf[8] >> 5) & 0x7];

	o->guard_interval = GUARD_INTERVAL_1_32 + ((buf[8] >> 3) & 0x3);

	o->transmission_mode = (buf[8] & 0x2) ?
			       TRANSMISSION_MODE_8K :
			       TRANSMISSION_MODE_2K;

	t->other_frequency_flag = (buf[8] & 0x01);

	if (verbosity >= 5) {
		debug("0x%#04x/0x%#04x ", t->network_id, t->transport_stream_id);
		dump_dvb_parameters (stderr, t);
		if (t->scan_done)
			dprintf(5, " (done)");
		if (t->last_tuning_failed)
			dprintf(5, " (no signal)");
		dprintf(5, "\n");
	}
}

static void parse_frequency_list_descriptor (const unsigned char *buf,
				      struct transponder *t)
{
	int n, i;
	typeof(*t->other_f) f;

	if (!t) {
		warning("frequency_list_descriptor outside transport stream definition (ignored)\n");
		return;
	}
	if (t->other_f)
		return;

	n = (buf[1] - 1) / 4;
	if (n < 1 || (buf[2] & 0x03) != 3)
		return;

	t->other_f = calloc(n, sizeof(*t->other_f));
	t->n_other_f = n;
	buf += 3;
	for (i = 0; i < n; i++) {
		f = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
		t->other_f[i] = f * 10;
		buf += 4;
	}
}

static void parse_service_descriptor (const unsigned char *buf, struct service *s)
{
	unsigned char len;
	unsigned char *src, *dest;

	s->type = buf[2];

	buf += 3;
	len = *buf;
	buf++;

	if (s->provider_name)
		free (s->provider_name);

	s->provider_name = malloc (len + 1);
	memcpy (s->provider_name, buf, len);
	s->provider_name[len] = '\0';

	/* remove control characters (FIXME: handle short/long name) */
	/* FIXME: handle character set correctly (e.g. via iconv)
	 * c.f. EN 300 468 annex A */
	for (src = dest = s->provider_name; *src; src++)
		if (*src >= 0x20 && (*src < 0x80 || *src > 0x9f))
			*dest++ = *src;
	*dest = '\0';
	if (!s->provider_name[0]) {
		/* zap zero length names */
		free (s->provider_name);
		s->provider_name = 0;
	}

	if (s->service_name)
		free (s->service_name);

	buf += len;
	len = *buf;
	buf++;

	s->service_name = malloc (len + 1);
	memcpy (s->service_name, buf, len);
	s->service_name[len] = '\0';

	/* remove control characters (FIXME: handle short/long name) */
	/* FIXME: handle character set correctly (e.g. via iconv)
	 * c.f. EN 300 468 annex A */
	for (src = dest = s->service_name; *src; src++)
		if (*src >= 0x20 && (*src < 0x80 || *src > 0x9f))
			*dest++ = *src;
	*dest = '\0';
	if (!s->service_name[0]) {
		/* zap zero length names */
		free (s->service_name);
		s->service_name = 0;
	}

	info("     %s(%s)\n",
	    s->service_name, s->provider_name);
}

static int find_descriptor(uint8_t tag, const unsigned char *buf,
		int descriptors_loop_len,
		const unsigned char **desc, int *desc_len)
{
	while (descriptors_loop_len > 0) {
		unsigned char descriptor_tag = buf[0];
		unsigned char descriptor_len = buf[1] + 2;

		if (!descriptor_len) {
			warning("descriptor_tag == 0x%02x, len is 0\n", descriptor_tag);
			break;
		}

		if (tag == descriptor_tag) {
			if (desc)
				*desc = buf;
			if (desc_len)
				*desc_len = descriptor_len;
			return 1;
		}

		buf += descriptor_len;
		descriptors_loop_len -= descriptor_len;
	}
	return 0;
}

static void parse_descriptors(enum table_type t, const unsigned char *buf,
			      int descriptors_loop_len, void *data)
{
	while (descriptors_loop_len > 0) {
		unsigned char descriptor_tag = buf[0];
		unsigned char descriptor_len = buf[1] + 2;

		if (!descriptor_len) {
			warning("descriptor_tag == 0x%02x, len is 0\n", descriptor_tag);
			break;
		}

		switch (descriptor_tag) {
		case 0x00:	break;		/* 0x00 MHP application_descriptor */
		case 0x01:	break;		/* 0x01 MHP application_name_desriptor */
		case 0x02:	break;		/* 0x02 MHP transport_protocol_descriptor */
		case 0x03:	break;		/* 0x03 dvb_j_application_descriptor() */
		case 0x04:	break;		/* 0x04 dvb_j_application_location_descriptor */
		case 0x09:			/* 0x09 ca_descriptor, 20080106 */
			if (t == PMT)
				parse_ca_descriptor (buf, data);	
			break;	
		case 0x0A:			/* 0x0A iso_639_language_descriptor */
			if (t == PMT)
				parse_iso639_language_descriptor (buf, data);
			break;
		case 0x0B:	break;		/* 0x0B application_icons_descriptor */
		case 0x13:	break;		/* 0x13 carousel_identifier_descriptor, to do */
		case 0x40:			/* 0x40 network_name_descriptor */
			if (t == NIT)
				parse_network_name_descriptor (buf, data);
			break;
		case 0x41:	break;		/* 0x41 service_list_descriptor */
		case 0x42:	break;		/* 0x42 stuffing_descriptor */
		case 0x43:	break;		/* 0x43 satellite_delivery_system_descriptor */
		case 0x44:			/* 0x44 cable_delivery_system_descriptor */
			if (t == NIT)
				parse_cable_delivery_system_descriptor (buf, data);
			break;
		case 0x45:			/* 0x45 vbi_data_descriptor */
		case 0x46:			/* 0x46 vbi_teletext_descriptor */
		case 0x47:			/* 0x47 bouquet_name_descriptor */
		case 0x48:			/* 0x48 service_descriptor */
			if (t == SDT)
				parse_service_descriptor (buf, data);
			break;
		case 0x49:	break;		/* 0x49 country_availability_descriptor */
		case 0x4A:	break;		/* 0x4A linkage_descriptor */
		case 0x4B:	break;		/* 0x4B nvod_reference_descriptor */
		case 0x4C:	break;		/* 0x4C time_shifted_service_descriptor */
		case 0x4D:	break;		/* 0x4D short_event_descriptor */
		case 0x4E:	break;		/* 0x4E extended_event_descriptor */
		case 0x4F:	break;		/* 0x4F time_shifted_event_descriptor */
		case 0x50:	break;		/* 0x50 component_descriptor */
		case 0x51:	break;		/* 0x51 mosaic_descriptor */
		case 0x52:	break;		/* 0x52 stream_identifier_descriptor */
		case 0x53:			/* 0x53 ca_identifier_descriptor */
			if (t == SDT)
				parse_ca_identifier_descriptor (buf, data);
			break;
		case 0x54:	break;		/* 0x54 content_descriptor */
		case 0x55:	break;		/* 0x55 parental_rating_descriptor */
		case 0x56:	break;		/* 0x56 teletext_descriptor */
		case 0x57:	break;		/* 0x57 telephone_descriptor */
		case 0x58:	break;		/* 0x58 local_time_offset_descriptor */
		case 0x59:	break;		/* 0x59 subtitling_descriptor */
		case 0x5A:			/* 0x5A terrestrial_delivery_system_descriptor */
			if (t == NIT)
				parse_terrestrial_delivery_system_descriptor (buf, data);
			break;
		case 0x5B:	break;		/* 0x5B multilingual_network_name_descriptor */
		case 0x5C:	break;		/* 0x5C multilingual_bouquet_name_descriptor */
		case 0x5D:	break;		/* 0x5D multilingual_service_name_descriptor */
		case 0x5E:	break;		/* 0x5E multilingual_component_descriptor */
		case 0x5F:	break;		/* 0x5F private_data_specifier_descriptor */
		case 0x60:	break;		/* 0x60 service_move_descriptor */
		case 0x61:	break;		/* 0x61 short_smoothing_buffer_descriptor */
		case 0x62:			/* 0x62 frequency_list_descriptor */
			if (t == NIT)
				parse_frequency_list_descriptor (buf, data);
			break;
		case 0x63:	break;		/* 0x63 partial_transport_stream_descriptor */
		case 0x64:	break;		/* 0x64 data_broadcast_descriptor */
		case 0x65:	break;		/* 0x65 scrambling_descriptor */
		case 0x66:	break;		/* 0x66 data_broadcast_id_descriptor */
		case 0x67:	break;		/* 0x67 transport_stream_descriptor */
		case 0x68:	break;		/* 0x68 dsng_descriptor */
		case 0x69:	break;		/* 0x69 pdc_descriptor */
		case 0x6A:	break;		/* 0x6A ac3_descriptor */
		case 0x6B:	break;		/* 0x6B ancillary_data_descriptor */
		case 0x6C:	break;		/* 0x6C cell_list_descriptor */
		case 0x6D:	break;		/* 0x6D cell_frequency_link_descriptor */
		case 0x6E:	break;		/* 0x6E announcement_support_descriptor */
		case 0x6F:	break;		/* 0x6F application_signalling_descriptor */
		case 0x71:	break;		/* 0x71 service_identifier_descriptor (ETSI TS 102 812, MHP) */
		case 0x72:	break;		/* 0x72 service_availbility_descriptor */
		case 0x73:	break;		/* 0x73 default_authority_descriptor (ETSI TS 102 323) */
		case 0x74:	break;		/* 0x74 related_content_descriptor (ETSI TS 102 323) */
		case 0x75:	break;		/* 0x75 tva_id_descriptor (ETSI TS 102 323) */
		case 0x76:	break;		/* 0x76 content_identifier_descriptor (ETSI TS 102 323) */
		case 0x77:	break;		/* 0x77 time_slice_fec_identifier_descriptor (ETSI EN 301 192) */
		case 0x78:	break;		/* 0x78 ecm_repetition_rate_descriptor (ETSI EN 301 192) */
		case 0x79:	break;		/* 0x79 s2_satellite_delivery_system_descriptor */
		case 0x7A:	break;		/* 0x7A enhanced_ac3_descriptor */
		case 0x7B:	break;		/* 0x7B dts_descriptor */
		case 0x7C:	break;		/* 0x7C aac_descriptor */
		case 0x7F:	break;		/* 0x7F extension_descriptor */		
		case 0x83:
			/* 0x83 is in the privately defined range of descriptor tags,
			 * so we parse this only if the user says so to avoid
			 * problems when 0x83 is something entirely different... */
			if (t == NIT && vdr_dump_channum)
				parse_terrestrial_uk_channel_number (buf, data);
			break;
		case 0xF2:	break;		// 0xF2 Private DVB Descriptor  Premiere.de, Content Transmission Descriptor

		default:
			verbosedebug("skip descriptor 0x%02x\n", descriptor_tag);
		};

		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) {
			verbosedebug ("skipping %02x %02x %02x %02x (service_id == 0)\n", buf[0],buf[1],buf[2],buf[3]);
			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 service_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];

	// 20080106, search PMT program info for CA Ids
	buf +=4;
	section_length -= 4;

	while (program_info_len > 0) {
		int descriptor_length = ((int)buf[1]) + 2;
		parse_descriptors(PMT, buf, section_length, s);
		buf += descriptor_length;
		section_length   -= descriptor_length;
		program_info_len -= descriptor_length;
		}

	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]) { // das ist stream type
		case 0x01:// STREAMTYPE ISO/IEC 11172 Video
		case 0x02:// STREAMTYPE ITU-T Rec. H.262 | ISO/IEC 13818-2 Video | ISO/IEC 11172-2 constr. parameter video stream
			moreverbose("  VIDEO     : PID 0x%04x\n", elementary_pid);
			if (s->video_pid == 0)
				s->video_pid = elementary_pid;
			break;
		case 0x03:// STREAMTYPE_11172_AUDIO
		case 0x04:// STREAMTYPE_13818-3_AUDIO
			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 0x05:// STREAMTYPE_13818_PRIVATE (ITU-T Rec. H.222.0 | ISO/IEC 13818-1 private sections)
		case 0x06:// STREAMTYPE_13818_PES_PRIVATE (ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data)
                   /* ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data*/

			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;
			}
                        /* we shouldn't reach this one, usually it should be Teletext, Subtitling or AC3 .. */
                        moreverbose("  unknown private data: PID 0x%04x\n", elementary_pid);
                        break;
 		case 0x07://ISO/IEC 13512 MHEG
			/*
			MHEG-5, or ISO/IEC 13522-5, is part of a set of international standards relating to the
			presentation of multimedia information, standardized by the Multimedia and Hypermedia Experts Group (MHEG).
			It is most commonly used as a language to describe interactive television services. */
 			moreverbose("  MHEG      : PID 0x%04x\n", elementary_pid);
 			break;
		case 0x08://ITU-T Rec. H.222.0 | ISO/IEC 13818-1 Annex A  DSM CC
 			moreverbose("  DSM CC    : PID 0x%04x\n", elementary_pid);