From 17d4586ca3727f38a1742dc9c3dbe99e8e64f1f5 Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab@redhat.com>
Date: Sat, 14 Jan 2012 09:59:06 -0200
Subject: [PATCH] dvb: add proper support for AC-3 audio

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
 utils/dvb/descriptors.c | 27 ++++++++++++++-----
 utils/dvb/descriptors.h |  4 +++
 utils/dvb/libscan.c     | 72 ++++++++++++++++++++++++++++++++-----------------
 3 files changed, 72 insertions(+), 31 deletions(-)

diff --git a/utils/dvb/descriptors.c b/utils/dvb/descriptors.c
index 24f6e8a..7a83c3f 100644
--- a/utils/dvb/descriptors.c
+++ b/utils/dvb/descriptors.c
@@ -621,11 +621,6 @@ void parse_descriptor(enum dvb_tables type,
 	if (len == 0)
 		return;
 
-	/*
-	 * FIXME: syntax need to be changed, to avoid parsing an invalid
-	 * descriptor here (e. g. a descriptor at the wrong table)
-	 */
-
 	if (dvb_desc->verbose)
 		printf("Descriptors table len %d\n", len);
 	do {
@@ -637,8 +632,6 @@ void parse_descriptor(enum dvb_tables type,
 				dlen, len);
 			return;
 		}
-		/* FIXME: Not all descriptors are valid for all tables */
-
 		if (dvb_desc->verbose) {
 			printf("%s (0x%02x), len %d",
 			       descriptors[buf[0]], buf[0], buf[1]);
@@ -783,6 +776,26 @@ void parse_descriptor(enum dvb_tables type,
 	} while (len > 0);
 }
 
+int has_descriptor(struct dvb_descriptors *dvb_desc,
+		    unsigned char needed_descriptor,
+	            const unsigned char *buf, int len)
+{
+	if (len == 0)
+		return 0;
+
+	do {
+		int dlen = buf[1];
+
+		if (buf[0] == needed_descriptor)
+			return 1;
+
+		buf += dlen + 2;
+		len -= dlen + 2;
+	} while (len > 0);
+
+	return 0;
+}
+
 #if 0
 	/* TODO: remove those stuff */
 
diff --git a/utils/dvb/descriptors.h b/utils/dvb/descriptors.h
index f33da35..4d557ff 100644
--- a/utils/dvb/descriptors.h
+++ b/utils/dvb/descriptors.h
@@ -160,3 +160,7 @@ enum extension_descriptors {
 void parse_descriptor(enum dvb_tables type,
 		      struct dvb_descriptors *dvb_desc,
 		      const unsigned char *buf, int len);
+
+int has_descriptor(struct dvb_descriptors *dvb_desc,
+		    unsigned char needed_descriptor,
+	            const unsigned char *buf, int len);
diff --git a/utils/dvb/libscan.c b/utils/dvb/libscan.c
index 21ec99f..cc0d8ca 100644
--- a/utils/dvb/libscan.c
+++ b/utils/dvb/libscan.c
@@ -56,6 +56,31 @@ static void parse_pat(struct dvb_descriptors *dvb_desc,
 	dvb_desc->pat_table.pid_table_len = n;
 }
 
+static void add_vpid(struct pid_table *pid_table, uint16_t pid, int verbose)
+{
+	int i;
+
+	if (verbose)
+		printf("video pid 0x%04x\n", pid);
+	i = pid_table->video_pid_len;
+	pid_table->video_pid = realloc(pid_table->video_pid,
+		sizeof(*pid_table->video_pid) * ++pid_table->video_pid_len);
+	pid_table->video_pid[i] = pid;
+}
+
+static void add_apid(struct pid_table *pid_table, uint16_t pid, int verbose)
+{
+	int i;
+
+	if (verbose)
+		printf("audio pid 0x%04x\n", pid);
+	i = pid_table->audio_pid_len;
+	pid_table->audio_pid = realloc(pid_table->audio_pid,
+		sizeof(*pid_table->audio_pid) * ++pid_table->audio_pid_len);
+	pid_table->audio_pid[i] = pid;
+}
+
+
 static void parse_pmt(struct dvb_descriptors *dvb_desc,
 		      const unsigned char *buf, int *section_length,
 		      int id, int version,
@@ -86,31 +111,30 @@ static void parse_pmt(struct dvb_descriptors *dvb_desc,
 		pid = ((buf[1] & 0x1f) << 8) | buf[2];
 
 		switch (buf[0]) {
-		case 0x01:
-		case 0x02:
-		case 0x10:
-		case 0x1b:
-			if (dvb_desc->verbose)
-				printf("video pid 0x%04x\n", pid);
-			i = pid_table->video_pid_len;
-			pid_table->video_pid = realloc(pid_table->video_pid,
-				sizeof(*pid_table->video_pid) *
-				++pid_table->video_pid_len);
-			pid_table->video_pid[i] = pid;
+		case 0x01: /* ISO/IEC 11172-2 Video */
+		case 0x02: /* H.262, ISO/IEC 13818-2 or ISO/IEC 11172-2 video */
+			add_vpid(pid_table, pid, dvb_desc->verbose);
 			break;
-		case 0x03:
-		case 0x04:
-		case 0x0f:
-		case 0x11:
-		case 0x81:
-			if (dvb_desc->verbose)
-				printf("audio pid 0x%04x\n", pid);
-			i = pid_table->audio_pid_len;
-			pid_table->audio_pid = realloc(pid_table->audio_pid,
-				sizeof(*pid_table->audio_pid) *
-				++pid_table->audio_pid_len);
-			pid_table->audio_pid[i] = pid;
-			/* Discard audio language descriptors */
+		case 0x1b: /* H.264 AVC */
+			add_vpid(pid_table, pid, dvb_desc->verbose);
+			break;
+		case 0x03: /* ISO/IEC 11172-3 Audio */
+		case 0x04: /* ISO/IEC 13818-3 Audio */
+		case 0x0f: /* ISO/IEC 13818-7 Audio with ADTS (AAC) */
+		case 0x11: /* ISO/IEC 14496-3 Audio with the LATM */
+		case 0x81: /* user private - in general ATSC Dolby - AC-3 */
+			add_apid(pid_table, pid, dvb_desc->verbose);
+			break;
+		case 0x05: /* private sections */
+		case 0x06: /* private data */
+			/*
+			 * Those can be used by sub-titling, teletext and/or
+			 * DVB AC-3. So, need to seek for the AC-3 descriptors
+			 */
+			if (has_descriptor(dvb_desc, AC_3_descriptor, &buf[5], len) |
+			    has_descriptor(dvb_desc, enhanced_AC_3_descriptor, &buf[5], len))
+				add_apid(pid_table, pid, dvb_desc->verbose);
+
 			break;
 		default:
 			if (dvb_desc->verbose)
-- 
2.7.4