Add an EOI (End of Image / Last Packet) flag to the encoder.

Trim callsign correctly if longer than 6 characters.
Add a verbose mode for the decoder.

main.c

@@ -47,6 +47,8 @@ int main(int argc, char *argv[])
 	char encode = -1;
 	char type = SSDV_TYPE_NORMAL;
 	int droptest = 0;
+	int verbose = 0;
+	int errors;
 	char callsign[7];
 	uint8_t image_id = 0;
 	ssdv_t ssdv;
@@ -57,7 +59,7 @@ int main(int argc, char *argv[])
 	callsign[0] = '\0';
 	
 	opterr = 0;
-	while((c = getopt(argc, argv, "ednc:i:t:")) != -1)
+	while((c = getopt(argc, argv, "ednc:i:t:v")) != -1)
 	{
 		switch(c)
 		{
@@ -71,6 +73,7 @@ int main(int argc, char *argv[])
 			break;
 		case 'i': image_id = atoi(optarg); break;
 		case 't': droptest = atoi(optarg); break;
+		case 'v': verbose = 1; break;
 		case '?': exit_usage();
 		}
 	}
@@ -124,7 +127,28 @@ int main(int argc, char *argv[])
 			if(droptest && (rand() / (RAND_MAX / 100) < droptest)) continue;
 			
 			/* Test the packet is valid */
-			if(ssdv_dec_is_packet(pkt, NULL, type) != 0) continue;
+			if(ssdv_dec_is_packet(pkt, &errors, type) != 0) continue;
+			
+			if(verbose)
+			{
+				ssdv_packet_info_t p;
+				
+				ssdv_dec_header(&p, pkt);
+				fprintf(stderr, "Decoded image packet. Callsign: %s, Image ID: %d, Resolution: %dx%d, Packet ID: %d (%d errors corrected)\n"
+				                ">> EOI: %d, MCU Mode: %d, MCU Offset: %d, MCU ID: %d/%d\n",
+					p.callsign_s,
+					p.image_id,
+					p.width,
+					p.height,
+					p.packet_id,
+					errors,
+					p.eoi,
+					p.mcu_mode,
+					p.mcu_offset,
+					p.mcu_id,
+					p.mcu_count
+				);
+			}
 			
 			/* Feed it to the decoder */
 			ssdv_dec_feed(&ssdv, pkt);

ssdv.c

@@ -177,8 +177,8 @@ static uint32_t encode_callsign(char *callsign)
 	uint32_t x;
 	char *c;
 	
-	/* Point c at the end of the callsign */
+	/* Point c at the end of the callsign, maximum of 6 characters */
-	for(c = callsign; *c; c++);
+	for(x = 0, c = callsign; x < SSDV_MAX_CALLSIGN && *c; x++, c++);
 	
 	/* Encode it backwards */
 	x = 0;
@@ -960,21 +960,23 @@ char ssdv_enc_get_packet(ssdv_t *s)
 				}
 				
 				/* A packet is ready, create the headers */
-				s->out[0]  = 0x55;                /* Sync */
+				s->out[0]   = 0x55;                /* Sync */
-				s->out[1]  = 0x66 + s->type;      /* Type */
+				s->out[1]   = 0x66 + s->type;      /* Type */
-				s->out[2]  = s->callsign >> 24;
+				s->out[2]   = s->callsign >> 24;
-				s->out[3]  = s->callsign >> 16;
+				s->out[3]   = s->callsign >> 16;
-				s->out[4]  = s->callsign >> 8;
+				s->out[4]   = s->callsign >> 8;
-				s->out[5]  = s->callsign;
+				s->out[5]   = s->callsign;
-				s->out[6]  = s->image_id;         /* Image ID */
+				s->out[6]   = s->image_id;         /* Image ID */
-				s->out[7]  = s->packet_id >> 8;   /* Packet ID MSB */
+				s->out[7]   = s->packet_id >> 8;   /* Packet ID MSB */
-				s->out[8]  = s->packet_id & 0xFF; /* Packet ID LSB */
+				s->out[8]   = s->packet_id & 0xFF; /* Packet ID LSB */
-				s->out[9]  = s->width >> 4;       /* Width / 16 */
+				s->out[9]   = s->width >> 4;       /* Width / 16 */
-				s->out[10] = s->height >> 4;      /* Height / 16 */
+				s->out[10]  = s->height >> 4;      /* Height / 16 */
-				s->out[11] = s->mcu_mode & 0x03;  /* MCU mode (2 bits) */
+				s->out[11]  = 0x00;
-				s->out[12] = mcu_offset;          /* Next MCU offset */
+				s->out[11] |= (r == SSDV_EOI ? 1 : 0) << 2; /* EOI flag (1 bit) */
-				s->out[13] = mcu_id >> 8;         /* MCU ID MSB */
+				s->out[11] |= s->mcu_mode & 0x03;  /* MCU mode (2 bits) */
-				s->out[14] = mcu_id & 0xFF;       /* MCU ID LSB */
+				s->out[12]  = mcu_offset;          /* Next MCU offset */
+				s->out[13]  = mcu_id >> 8;         /* MCU ID MSB */
+				s->out[14]  = mcu_id & 0xFF;       /* MCU ID LSB */
 				
 				/* Fill any remaining bytes with noise */
 				if(s->out_len > 0) ssdv_memset_prng(s->outp, s->out_len);
@@ -1173,7 +1175,7 @@ char ssdv_dec_feed(ssdv_t *s, uint8_t *packet)
 	if(s->packet_id == 0)
 	{
 		const char *factor;
-		char callsign[7];
+		char callsign[SSDV_MAX_CALLSIGN + 1];
 		
 		/* Read the fixed headers from the packet */
 		s->callsign  = (packet[2] << 24) | (packet[3] << 16) | (packet[4] << 8) | packet[5];
@@ -1349,11 +1351,13 @@ char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t type)
 
 void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet)
 {
-	info->callsign  = (packet[2] << 24) | (packet[3] << 16) | (packet[4] << 8) | packet[5];
+	info->callsign   = (packet[2] << 24) | (packet[3] << 16) | (packet[4] << 8) | packet[5];
+	decode_callsign(info->callsign_s, info->callsign);
 	info->image_id   = packet[6];
 	info->packet_id  = (packet[7] << 8) | packet[8];
 	info->width      = packet[9] << 4;
 	info->height     = packet[10] << 4;
+	info->eoi        = (packet[11] >> 2) & 1;
 	info->mcu_mode   = packet[11] & 0x03;
 	info->mcu_offset = packet[12];
 	info->mcu_id     = (packet[13] << 8) | packet[14];

ssdv.h

@@ -39,7 +39,8 @@ extern "C" {
 
 #define TBL_LEN (546) /* Maximum size of the DQT and DHT tables */
 #define HBUFF_LEN (16) /* Extra space for reading marker data */
-//#define COMPONENTS (3)
+
+#define SSDV_MAX_CALLSIGN (6) /* Maximum number of characters in a callsign */
 
 #define SSDV_TYPE_NORMAL (0)
 #define SSDV_TYPE_NOFEC  (1)
@@ -126,10 +127,12 @@ typedef struct
 
 typedef struct {
 	uint32_t callsign;
+	char     callsign_s[SSDV_MAX_CALLSIGN + 1];
 	uint8_t  image_id;
 	uint16_t packet_id;
 	uint16_t width;
 	uint16_t height;
+	uint8_t  eoi;
 	uint16_t mcu_mode;
 	uint8_t  mcu_offset;
 	uint16_t mcu_id;