From 278004fb0c3c6058cca30c58a3d8ab62fbed4b46 Mon Sep 17 00:00:00 2001 From: Philip Heron Date: Thu, 28 Aug 2014 20:13:46 +0100 Subject: [PATCH] Make the non-FEC packets 256 bytes long, same length as normal packets. Non-FEC packets now have a packet type of 0x67. --- main.c | 17 +++++------ ssdv.c | 92 ++++++++++++++++++++++++++++++++++++++-------------------- ssdv.h | 19 ++++++------ 3 files changed, 78 insertions(+), 50 deletions(-) diff --git a/main.c b/main.c index 4629b44..08bb15e 100644 --- a/main.c +++ b/main.c @@ -35,7 +35,7 @@ int main(int argc, char *argv[]) FILE *fin = stdin; FILE *fout = stdout; char encode = -1; - char fec = -1; + char type = SSDV_TYPE_NORMAL; int droptest = 0; char callsign[7]; uint8_t image_id = 0; @@ -53,7 +53,7 @@ int main(int argc, char *argv[]) { case 'e': encode = 1; break; case 'd': encode = 0; break; - case 'n': fec = 0; break; + case 'n': type = SSDV_TYPE_NOFEC; break; case 'c': if(strlen(optarg) > 6) fprintf(stderr, "Warning: callsign is longer than 6 characters.\n"); @@ -101,22 +101,20 @@ int main(int argc, char *argv[]) case 0: /* Decode */ if(droptest > 0) fprintf(stderr, "*** NOTE: Drop test enabled: %i ***\n", droptest); - ssdv_dec_init(&ssdv); + ssdv_dec_init(&ssdv, type); jpeg_length = 1024 * 1024 * 4; jpeg = malloc(jpeg_length); ssdv_dec_set_buffer(&ssdv, jpeg, jpeg_length); - ssdv_set_fec(&ssdv, (fec ? 1 : 0)); - i = 0; - while(fread(pkt, 1, (fec ? SSDV_PKT_SIZE : SSDV_PKT_SIZE - SSDV_PKT_SIZE_RSCODES), fin) > 0) + while(fread(pkt, 1, SSDV_PKT_SIZE, fin) > 0) { /* Drop % of packets */ if(droptest && (rand() / (RAND_MAX / 100) < droptest)) continue; /* Test the packet is valid */ - if(ssdv_dec_is_packet(pkt, NULL, (fec ? 1 : 0)) != 0) continue; + if(ssdv_dec_is_packet(pkt, NULL, type) != 0) continue; /* Feed it to the decoder */ ssdv_dec_feed(&ssdv, pkt); @@ -132,9 +130,8 @@ int main(int argc, char *argv[]) break; case 1: /* Encode */ - ssdv_enc_init(&ssdv, callsign, image_id); + ssdv_enc_init(&ssdv, type, callsign, image_id); ssdv_enc_set_buffer(&ssdv, pkt); - ssdv_set_fec(&ssdv, (fec ? 1 : 0)); i = 0; @@ -163,7 +160,7 @@ int main(int argc, char *argv[]) return(-1); } - fwrite(pkt, 1, (fec ? SSDV_PKT_SIZE : SSDV_PKT_SIZE - SSDV_PKT_SIZE_RSCODES), fout); + fwrite(pkt, 1, SSDV_PKT_SIZE, fout); i++; } diff --git a/ssdv.c b/ssdv.c index bc7ccef..e93954f 100644 --- a/ssdv.c +++ b/ssdv.c @@ -531,7 +531,7 @@ static char ssdv_process(ssdv_t *s) s->reset_mcu = s->mcu_id; s->packet_mcu_id = s->mcu_id; - s->packet_mcu_offset = SSDV_PKT_SIZE_PAYLOAD - s->out_len; + s->packet_mcu_offset = s->pkt_size_payload - s->out_len; } if(s->mode == S_DECODING && s->mcu_id == s->reset_mcu) @@ -557,6 +557,23 @@ static char ssdv_process(ssdv_t *s) return(SSDV_OK); } +static void ssdv_set_packet_conf(ssdv_t *s) +{ + /* Configure the payload size and CRC position */ + switch(s->type) + { + case SSDV_TYPE_NORMAL: + s->pkt_size_payload = SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC - SSDV_PKT_SIZE_RSCODES; + s->pkt_size_crcdata = SSDV_PKT_SIZE_HEADER + s->pkt_size_payload - 1; + break; + + case SSDV_TYPE_NOFEC: + s->pkt_size_payload = SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC; + s->pkt_size_crcdata = SSDV_PKT_SIZE_HEADER + s->pkt_size_payload - 1; + break; + } +} + /*****************************************************************************/ static void ssdv_memset_prng(uint8_t *s, size_t n) @@ -814,13 +831,14 @@ static char ssdv_have_marker_data(ssdv_t *s) return(SSDV_OK); } -char ssdv_enc_init(ssdv_t *s, char *callsign, uint8_t image_id) +char ssdv_enc_init(ssdv_t *s, uint8_t type, char *callsign, uint8_t image_id) { memset(s, 0, sizeof(ssdv_t)); s->image_id = image_id; s->callsign = encode_callsign(callsign); s->mode = S_ENCODING; - s->fec = 1; + s->type = type; + ssdv_set_packet_conf(s); /* Prepare the output JPEG tables */ s->ddqt[0] = dtblcpy(s, std_dqt0, sizeof(std_dqt0)); @@ -837,7 +855,7 @@ char ssdv_enc_set_buffer(ssdv_t *s, uint8_t *buffer) { s->out = buffer; s->outp = buffer + SSDV_PKT_SIZE_HEADER; - s->out_len = SSDV_PKT_SIZE_PAYLOAD; + s->out_len = s->pkt_size_payload; /* Zero the payload memory */ memset(s->out, 0, SSDV_PKT_SIZE); @@ -927,12 +945,12 @@ char ssdv_enc_get_packet(ssdv_t *s) uint8_t i, mcu_offset = s->packet_mcu_offset; uint32_t x; - if(mcu_offset != 0xFF && mcu_offset >= SSDV_PKT_SIZE_PAYLOAD) + if(mcu_offset != 0xFF && mcu_offset >= s->pkt_size_payload) { /* The first MCU begins in the next packet, not this one */ mcu_id = 0xFFFF; mcu_offset = 0xFF; - s->packet_mcu_offset -= SSDV_PKT_SIZE_PAYLOAD; + s->packet_mcu_offset -= s->pkt_size_payload; } else { @@ -943,7 +961,7 @@ char ssdv_enc_get_packet(ssdv_t *s) /* A packet is ready, create the headers */ s->out[0] = 0x55; /* Sync */ - s->out[1] = 0x66; /* Type */ + s->out[1] = 0x66 + s->type; /* Type */ s->out[2] = s->callsign >> 24; s->out[3] = s->callsign >> 16; s->out[4] = s->callsign >> 8; @@ -962,16 +980,17 @@ char ssdv_enc_get_packet(ssdv_t *s) if(s->out_len > 0) ssdv_memset_prng(s->outp, s->out_len); /* Calculate the CRC codes */ - x = crc32(&s->out[1], SSDV_PKT_SIZE_CRCDATA); + x = crc32(&s->out[1], s->pkt_size_crcdata); - i = 1 + SSDV_PKT_SIZE_CRCDATA; + i = 1 + s->pkt_size_crcdata; s->out[i++] = (x >> 24) & 0xFF; s->out[i++] = (x >> 16) & 0xFF; s->out[i++] = (x >> 8) & 0xFF; s->out[i++] = x & 0xFF; /* Generate the RS codes */ - if(s->fec == 1) encode_rs_8(&s->out[1], &s->out[i], 0); + if(s->type == SSDV_TYPE_NORMAL) + encode_rs_8(&s->out[1], &s->out[i], 0); s->packet_id++; @@ -1094,14 +1113,15 @@ static void ssdv_fill_gap(ssdv_t *s, uint16_t next_mcu) } } -char ssdv_dec_init(ssdv_t *s) +char ssdv_dec_init(ssdv_t *s, uint8_t type) { memset(s, 0, sizeof(ssdv_t)); /* The packet data should contain only scan data, no headers */ s->state = S_HUFF; s->mode = S_DECODING; - s->fec = 1; + s->type = type; + ssdv_set_packet_conf(s); /* Prepare the source JPEG tables */ s->sdqt[0] = stblcpy(s, std_dqt0, sizeof(std_dqt0)); @@ -1212,7 +1232,7 @@ char ssdv_dec_feed(ssdv_t *s, uint8_t *packet) } /* Feed the JPEG data into the processor */ - for(; i < SSDV_PKT_SIZE_PAYLOAD; i++) + for(; i < s->pkt_size_payload; i++) { b = packet[SSDV_PKT_SIZE_HEADER + i]; @@ -1262,9 +1282,11 @@ char ssdv_dec_get_jpeg(ssdv_t *s, uint8_t **jpeg, size_t *length) return(SSDV_OK); } -char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t fec) +char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t type) { uint8_t pkt[SSDV_PKT_SIZE]; + uint16_t pkt_size_payload; + uint16_t pkt_size_crcdata; ssdv_packet_info_t p; uint32_t x; int i; @@ -1272,35 +1294,48 @@ char ssdv_dec_is_packet(uint8_t *packet, int *errors, uint8_t fec) /* Testing is destructive, work on a copy */ memcpy(pkt, packet, SSDV_PKT_SIZE); pkt[0] = 0x55; - pkt[1] = 0x66; + pkt[1] = 0x66 + type; - if(fec == 0) - { - if(errors) *errors = 0; - } - else if(fec == 1) + switch(type) { + case SSDV_TYPE_NORMAL: + 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(i < 0) return(-1); /* Reed-solomon decoder failed */ - if(errors) *errors = i; + 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_crcdata = SSDV_PKT_SIZE_HEADER + pkt_size_payload - 1; + + if(errors) *errors = 0; + + break; + + default: + fprintf(stderr, "Invalid packet type\n"); + return(-1); } /* Sanity checks */ - if(pkt[1] != 0x66) return(-1); + if(pkt[1] != 0x66 + type) return(-1); ssdv_dec_header(&p, pkt); if(p.width == 0 || p.height == 0) return(-1); if(p.mcu_id != 0xFFFF) { if(p.mcu_id >= p.mcu_count) return(-1); - if(p.mcu_offset >= SSDV_PKT_SIZE_PAYLOAD) return(-1); + if(p.mcu_offset >= pkt_size_payload) return(-1); } /* Test the checksum */ - x = crc32(&pkt[1], SSDV_PKT_SIZE_CRCDATA); + x = crc32(&pkt[1], pkt_size_crcdata); - i = 1 + SSDV_PKT_SIZE_CRCDATA; + i = 1 + pkt_size_crcdata; if(pkt[i++] != ((x >> 24) & 0xFF)) return(-1); if(pkt[i++] != ((x >> 16) & 0xFF)) return(-1); if(pkt[i++] != ((x >> 8) & 0xFF)) return(-1); @@ -1329,8 +1364,3 @@ void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet) /*****************************************************************************/ -void ssdv_set_fec(ssdv_t *s, uint8_t fec) -{ - s->fec = fec; -} - diff --git a/ssdv.h b/ssdv.h index e10d5d9..956c113 100644 --- a/ssdv.h +++ b/ssdv.h @@ -36,17 +36,21 @@ extern "C" { #define SSDV_PKT_SIZE_HEADER (0x0F) #define SSDV_PKT_SIZE_CRC (0x04) #define SSDV_PKT_SIZE_RSCODES (0x20) -#define SSDV_PKT_SIZE_PAYLOAD (SSDV_PKT_SIZE - SSDV_PKT_SIZE_HEADER - SSDV_PKT_SIZE_CRC - SSDV_PKT_SIZE_RSCODES) -#define SSDV_PKT_SIZE_CRCDATA (SSDV_PKT_SIZE_HEADER + SSDV_PKT_SIZE_PAYLOAD - 1) #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_TYPE_NORMAL (0) +#define SSDV_TYPE_NOFEC (1) + typedef struct { - /* Flags */ - uint8_t fec; /* 0 == None, 1 = RS8 */ + /* Packet type configuration */ + uint8_t type; /* 0 = Normal mode (224 byte packet + 32 bytes FEC), + 1 = No-FEC mode (256 byte packet) */ + uint16_t pkt_size_payload; + uint16_t pkt_size_crcdata; /* Image information */ uint16_t width; @@ -133,13 +137,13 @@ typedef struct { } ssdv_packet_info_t; /* Encoding */ -extern char ssdv_enc_init(ssdv_t *s, char *callsign, uint8_t image_id); +extern char ssdv_enc_init(ssdv_t *s, uint8_t type, char *callsign, uint8_t image_id); extern char ssdv_enc_set_buffer(ssdv_t *s, uint8_t *buffer); extern char ssdv_enc_get_packet(ssdv_t *s); extern char ssdv_enc_feed(ssdv_t *s, uint8_t *buffer, size_t length); /* Decoding */ -extern char ssdv_dec_init(ssdv_t *s); +extern char ssdv_dec_init(ssdv_t *s, uint8_t type); 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_get_jpeg(ssdv_t *s, uint8_t **jpeg, size_t *length); @@ -147,9 +151,6 @@ 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 void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet); -/* Common */ -extern void ssdv_set_fec(ssdv_t *s, uint8_t fec); - #ifdef __cplusplus } #endif