VLC output: fix LCN parsing for DVB-T/T2

Thanks to Andrea Sacchetti Picchio for debugging and fixing the bitwise
operations.

Fixes: #13
Fixes: #47

ChangeLog

@@ -1,7 +1,8 @@
 ChangeLog:
 --------------------
 [1.0.15]
-- VLC output: include virtual channel numbers in titles, when available
+- VLC output: include logical channel numbers (LCN) in titles, when available
+- DVB-T/T2: fix LCN parsing
 - remove unused -G/--output-dvbsrc option
 
 [1.0.14] 2022-02-10

src/descriptors.c

@@ -206,6 +206,7 @@ void parse_service_descriptor(const unsigned char *buf, struct service *s,
 				default:;
 				}
 			}
+			__attribute__ ((fallthrough));
 		default:
 			if (emphasis_on)
 				short_len++;
@@ -250,6 +251,7 @@ void parse_service_descriptor(const unsigned char *buf, struct service *s,
 				default:;
 				}
 			}
+			__attribute__ ((fallthrough));
 		default:
 			if (emphasis_on)
 				provider_short_name[short_len++] = *(buf + i);
@@ -325,6 +327,7 @@ void parse_service_descriptor(const unsigned char *buf, struct service *s,
 				default:;
 				}
 			}
+			__attribute__ ((fallthrough));
 		default:
 			if (emphasis_on)
 				short_len++;
@@ -369,6 +372,7 @@ void parse_service_descriptor(const unsigned char *buf, struct service *s,
 				default:;
 				}
 			}
+			__attribute__ ((fallthrough));
 		default:
 			if (emphasis_on)
 				service_short_name[short_len++] = *(buf + i);
@@ -1428,8 +1432,10 @@ void parse_T2_delivery_system_descriptor(const unsigned char *buf,
 void parse_logical_channel_descriptor(const unsigned char *buf,
 				      struct transponder *t)
 {
-	if (t == NULL)
+	if (t == NULL) {
+		info("%s: transponder == NULL\n", __FUNCTION__);
 		return;
+	}
 	hd(buf);
 
 	uint8_t descriptor_length = buf[1];	// descriptor_length        8 uimsbf
@@ -1443,14 +1449,15 @@ void parse_logical_channel_descriptor(const unsigned char *buf,
 		     __FUNCTION__, __LINE__);
 		return;
 	}
-	while (descriptor_length > 3) {	//
+	while (descriptor_length > 3) {
 		service_id = (buf[p] << 8) | buf[p + 1];	// service_id              16 uimsbf
-		s = find_service(t, service_id);	//
-		if (s == NULL)	//
-			return;	//
-		//
+		s = find_service(t, service_id);
+		if (s == NULL) {
+			s = alloc_service(t, service_id);
+		}
 		s->visible_service = (buf[p + 2] & 0x80) > 0;	// visible_service_flag     1 bslbf, reserved NorDig: 1bslbf: Australia: 5 bslbf
-		s->logical_channel_number = (buf[p + 2] & 0x3F) << 8 | buf[p + 3];	// logical_channel_number   NorDig: 14uimbsf; Australia: 10 uimsbf
+		s->logical_channel_number = (buf[p + 2] & 0x3) << 8 | buf[p + 3];	// logical_channel_number   NorDig: 14uimbsf; Australia: 10 uimsbf
+		/*info("(sid=%d,vis=0x%x,lcn=%d)\n", service_id, s->visible_service, s->logical_channel_number);*/
 		descriptor_length -= 4;
 		p += 4;
 	}

src/dump-vlc-m3u.c

@@ -487,11 +487,20 @@ void vlc_dump_service_parameter_set_as_xspf(FILE * f, struct service *s,
 
 	fprintf_tab2("<track>\n");
 
-	// Limit output of logical channel number to DVB-S/S2
+	idx++;
+
 	if (s->logical_channel_number != 0) {
-		fprintf(f, "%s%s%d:%d %s%s\n", T3, "<title>", (s->logical_channel_number >> 10), (s->logical_channel_number % (2^10)), buf, "</title>");
+		if (flags->scantype == SCAN_TERRCABLE_ATSC) {
+			fprintf(f, "%s%s%.3d:%.3d %s%s\n", T3, "<title>",
+				(s->logical_channel_number >> 10),
+				(s->logical_channel_number % (2 << 10)),
+				buf, "</title>");
+		} else {
+			fprintf(f, "%s%s%.4d %s%s\n", T3, "<title>",
+				s->logical_channel_number, buf, "</title>");
+		}
 	} else {
-		fprintf(f, "%s%s%.4d. %s%s\n", T3, "<title>", idx++, buf, "</title>");
+		fprintf(f, "%s%s%.4d. %s%s\n", T3, "<title>", idx, buf, "</title>");
 	}
 
 	vlc_dump_dvb_parameters_as_xspf(f, t, flags, lnbp);

src/scan.c

@@ -1155,7 +1155,7 @@ static void parse_descriptors(enum table_id t, const unsigned char *buf,
 		case logical_channel_descriptor:
 			if ((t == TABLE_NIT_ACT)
 			    || (t == TABLE_NIT_OTH))
-				parse_logical_channel_descriptor(buf, data);
+				parse_logical_channel_descriptor(buf, current_tp);
 			break;
 		case 0xF2:	// 0xF2 Private DVB Descriptor  Premiere.de, Content Transmission Descriptor
 			break;
@@ -2068,7 +2068,7 @@ static int parse_section(struct section_buf *s)
 
 		switch (table_id) {
 		case TABLE_PAT:
-			//verbose("PAT for transport_stream_id %d (0x%04x)\n", table_id_ext, table_id_ext);
+			verbose("PAT for transport_stream_id %d (0x%04x)\n", table_id_ext, table_id_ext);
 			parse_pat(buf, section_length, table_id_ext, s->flags);
 			break;
 		case TABLE_PMT:
@@ -2079,8 +2079,8 @@ static int parse_section(struct section_buf *s)
 			break;
 		case TABLE_NIT_ACT:
 		case TABLE_NIT_OTH:
-			//verbose("NIT(%s TS, network_id %d (0x%04x) )\n", table_id == 0x40 ? "actual":"other",
-			//       table_id_ext, table_id_ext);
+			verbose("NIT(%s TS, network_id %d (0x%04x) )\n", table_id == 0x40 ? "actual":"other",
+			      table_id_ext, table_id_ext);
 			parse_nit(buf, section_length, table_id,
 				  table_id_ext);
 			break;
@@ -3496,7 +3496,7 @@ static int initial_tune(int frontend_fd, int tuning_data)
 		}
 	}
 	/* we should now have here a list of well known transponders. Iterate a second time
-	 * and scan it's PAT, PMT, SDT for services. In parallel NIT actual and NIT other.
+	 * and scan its PAT, PMT, SDT for services. In parallel NIT actual and NIT other.
 	 */
 	return tune_to_next_transponder(frontend_fd);
 }