The decoder now auto detects packets without FEC.

Add a verbose option to print data about each packet.
This commit is contained in:
Philip Heron 2015-10-20 09:59:48 +01:00
parent 062537a7e9
commit 421a9be721
3 changed files with 33 additions and 29 deletions

9
main.c
View File

@ -31,7 +31,7 @@ void exit_usage()
" -e Encode JPEG to SSDV packets.\n" " -e Encode JPEG to SSDV packets.\n"
" -d Decode SSDV packets to JPEG.\n" " -d Decode SSDV packets to JPEG.\n"
"\n" "\n"
" -n Encode or decode packets with no FEC.\n" " -n Encode packets with no FEC.\n"
" -t For testing, drops the specified percentage of packets while decoding.\n" " -t For testing, drops the specified percentage of packets while decoding.\n"
" -c Set the callign. Accepts A-Z 0-9 and space, up to 6 characters.\n" " -c Set the callign. Accepts A-Z 0-9 and space, up to 6 characters.\n"
" -i Set the image ID (0-255).\n" " -i Set the image ID (0-255).\n"
@ -115,7 +115,7 @@ int main(int argc, char *argv[])
case 0: /* Decode */ case 0: /* Decode */
if(droptest > 0) fprintf(stderr, "*** NOTE: Drop test enabled: %i ***\n", droptest); if(droptest > 0) fprintf(stderr, "*** NOTE: Drop test enabled: %i ***\n", droptest);
ssdv_dec_init(&ssdv, type); ssdv_dec_init(&ssdv);
jpeg_length = 1024 * 1024 * 4; jpeg_length = 1024 * 1024 * 4;
jpeg = malloc(jpeg_length); jpeg = malloc(jpeg_length);
@ -128,7 +128,7 @@ int main(int argc, char *argv[])
if(droptest && (rand() / (RAND_MAX / 100) < droptest)) continue; if(droptest && (rand() / (RAND_MAX / 100) < droptest)) continue;
/* Test the packet is valid */ /* Test the packet is valid */
if(ssdv_dec_is_packet(pkt, &errors, type) != 0) continue; if(ssdv_dec_is_packet(pkt, &errors) != 0) continue;
if(verbose) if(verbose)
{ {
@ -136,13 +136,14 @@ int main(int argc, char *argv[])
ssdv_dec_header(&p, pkt); 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" 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", ">> Type: %d, EOI: %d, MCU Mode: %d, MCU Offset: %d, MCU ID: %d/%d\n",
p.callsign_s, p.callsign_s,
p.image_id, p.image_id,
p.width, p.width,
p.height, p.height,
p.packet_id, p.packet_id,
errors, errors,
p.type,
p.eoi, p.eoi,
p.mcu_mode, p.mcu_mode,
p.mcu_offset, p.mcu_offset,

48
ssdv.c
View File

@ -1115,15 +1115,13 @@ static void ssdv_fill_gap(ssdv_t *s, uint16_t next_mcu)
} }
} }
char ssdv_dec_init(ssdv_t *s, uint8_t type) char ssdv_dec_init(ssdv_t *s)
{ {
memset(s, 0, sizeof(ssdv_t)); memset(s, 0, sizeof(ssdv_t));
/* The packet data should contain only scan data, no headers */ /* The packet data should contain only scan data, no headers */
s->state = S_HUFF; s->state = S_HUFF;
s->mode = S_DECODING; s->mode = S_DECODING;
s->type = type;
ssdv_set_packet_conf(s);
/* Prepare the source JPEG tables */ /* Prepare the source JPEG tables */
s->sdqt[0] = stblcpy(s, std_dqt0, sizeof(std_dqt0)); s->sdqt[0] = stblcpy(s, std_dqt0, sizeof(std_dqt0));
@ -1178,6 +1176,7 @@ char ssdv_dec_feed(ssdv_t *s, uint8_t *packet)
char callsign[SSDV_MAX_CALLSIGN + 1]; char callsign[SSDV_MAX_CALLSIGN + 1];
/* Read the fixed headers from the packet */ /* Read the fixed headers from the packet */
s->type = packet[1] - 0x66;
s->callsign = (packet[2] << 24) | (packet[3] << 16) | (packet[4] << 8) | packet[5]; s->callsign = (packet[2] << 24) | (packet[3] << 16) | (packet[4] << 8) | packet[5];
s->image_id = packet[6]; s->image_id = packet[6];
s->width = packet[9] << 4; s->width = packet[9] << 4;
@ -1185,6 +1184,9 @@ char ssdv_dec_feed(ssdv_t *s, uint8_t *packet)
s->mcu_count = packet[9] * packet[10]; s->mcu_count = packet[9] * packet[10];
s->mcu_mode = packet[11] & 0x03; s->mcu_mode = packet[11] & 0x03;
/* Configure the payload size and CRC position */
ssdv_set_packet_conf(s);
switch(s->mcu_mode) switch(s->mcu_mode)
{ {
case 0: factor = "2x2"; s->ycparts = 4; break; case 0: factor = "2x2"; s->ycparts = 4; break;
@ -1284,9 +1286,10 @@ char ssdv_dec_get_jpeg(ssdv_t *s, uint8_t **jpeg, size_t *length)
return(SSDV_OK); return(SSDV_OK);
} }
char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t type) char ssdv_dec_is_packet(uint8_t *packet, int *errors)
{ {
uint8_t pkt[SSDV_PKT_SIZE]; uint8_t pkt[SSDV_PKT_SIZE];
uint8_t type;
uint16_t pkt_size_payload; uint16_t pkt_size_payload;
uint16_t pkt_size_crcdata; uint16_t pkt_size_crcdata;
ssdv_packet_info_t p; ssdv_packet_info_t p;
@ -1296,37 +1299,35 @@ char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t type)
/* Testing is destructive, work on a copy */ /* Testing is destructive, work on a copy */
memcpy(pkt, packet, SSDV_PKT_SIZE); memcpy(pkt, packet, SSDV_PKT_SIZE);
pkt[0] = 0x55; pkt[0] = 0x55;
pkt[1] = 0x66 + type;
switch(type) if(pkt[1] == 0x66 + SSDV_TYPE_NOFEC)
{ {
case SSDV_TYPE_NORMAL: type = SSDV_TYPE_NOFEC;
pkt_size_payload = SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC - SSDV_PKT_SIZE_RSCODES;
pkt_size_crcdata = SSDV_PKT_SIZE_HEADER + pkt_size_payload - 1;
/* Run the reed-solomon decoder */
i = decode_rs_8(&pkt[1], 0, 0, 0);
if(errors) *errors = 0;
break;
case SSDV_TYPE_NOFEC:
pkt_size_payload = SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC; pkt_size_payload = SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC;
pkt_size_crcdata = SSDV_PKT_SIZE_HEADER + pkt_size_payload - 1; pkt_size_crcdata = SSDV_PKT_SIZE_HEADER + pkt_size_payload - 1;
if(errors) *errors = 0; if(errors) *errors = 0;
}
else
{
type = SSDV_TYPE_NORMAL;
break; pkt_size_payload = SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC - SSDV_PKT_SIZE_RSCODES;
pkt_size_crcdata = SSDV_PKT_SIZE_HEADER + pkt_size_payload - 1;
default:
fprintf(stderr, "Invalid packet type\n"); /* Run the reed-solomon decoder */
return(-1); pkt[1] = 0x66 + SSDV_TYPE_NORMAL;
i = decode_rs_8(&pkt[1], 0, 0, 0);
if(i < 0) return(-1); /* Reed-solomon decoder failed */
if(errors) *errors = i;
} }
/* Sanity checks */ /* Sanity checks */
if(pkt[1] != 0x66 + type) return(-1);
ssdv_dec_header(&p, pkt); ssdv_dec_header(&p, pkt);
if(p.type != type) return(-1);
if(p.width == 0 || p.height == 0) return(-1); if(p.width == 0 || p.height == 0) return(-1);
if(p.mcu_id != 0xFFFF) if(p.mcu_id != 0xFFFF)
{ {
@ -1351,6 +1352,7 @@ 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) void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet)
{ {
info->type = packet[1] - 0x66;
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); decode_callsign(info->callsign_s, info->callsign);
info->image_id = packet[6]; info->image_id = packet[6];

5
ssdv.h
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@ -126,6 +126,7 @@ typedef struct
} ssdv_t; } ssdv_t;
typedef struct { typedef struct {
uint8_t type;
uint32_t callsign; uint32_t callsign;
char callsign_s[SSDV_MAX_CALLSIGN + 1]; char callsign_s[SSDV_MAX_CALLSIGN + 1];
uint8_t image_id; uint8_t image_id;
@ -146,12 +147,12 @@ extern char ssdv_enc_get_packet(ssdv_t *s);
extern char ssdv_enc_feed(ssdv_t *s, uint8_t *buffer, size_t length); extern char ssdv_enc_feed(ssdv_t *s, uint8_t *buffer, size_t length);
/* Decoding */ /* Decoding */
extern char ssdv_dec_init(ssdv_t *s, uint8_t type); extern char ssdv_dec_init(ssdv_t *s);
extern char ssdv_dec_set_buffer(ssdv_t *s, uint8_t *buffer, size_t length); extern char ssdv_dec_set_buffer(ssdv_t *s, uint8_t *buffer, size_t length);
extern char ssdv_dec_feed(ssdv_t *s, uint8_t *packet); extern char ssdv_dec_feed(ssdv_t *s, uint8_t *packet);
extern char ssdv_dec_get_jpeg(ssdv_t *s, uint8_t **jpeg, size_t *length); extern char ssdv_dec_get_jpeg(ssdv_t *s, uint8_t **jpeg, size_t *length);
extern char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t fec); extern char ssdv_dec_is_packet(uint8_t *packet, int *errors);
extern void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet); extern void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet);
#ifdef __cplusplus #ifdef __cplusplus