/* SSDV - Slow Scan Digital Video */
/*=======================================================================*/
/* Copyright 2011 Philip Heron . */
#include
#include
#include
#include
#include "ssdv.h"
#include "rs8.h"
/* Recognised JPEG markers */
enum {
J_TEM = 0xFF01,
J_SOF0 = 0xFFC0, J_SOF1, J_SOF2, J_SOF3, J_DHT, J_SOF5, J_SOF6, J_SOF7,
J_JPG, J_SOF9, J_SOF10, J_SOF11, J_DAC, J_SOF13, J_SOF14, J_SOF15,
J_RST0, J_RST1, J_RST2, J_RST3, J_RST4, J_RST5, J_RST6, J_RST7,
J_SOI, J_EOI, J_SOS, J_DQT, J_DNL, J_DRI, J_DHP, J_EXP,
J_APP0, J_APP1, J_APP2, J_APP3, J_APP4, J_APP5, J_APP6, J_APP7,
J_APP8, J_APP9, J_APP10, J_APP11, J_APP12, J_APP13, J_APP14, J_APP15,
J_JPG0, J_JPG1, J_JPG2, J_JPG3, J_JPG4, J_JPG5, J_JPG6, J_SOF48,
J_LSE, J_JPG9, J_JPG10, J_JPG11, J_JPG12, J_JPG13, J_COM,
} jpeg_marker_t;
/* APP0 header data */
static uint8_t app0[14] = {
0x4A,0x46,0x49,0x46,0x00,0x01,0x01,0x01,0x00,0x48,0x00,0x48,0x00,0x00,
};
/* SOS header data */
static uint8_t sos[10] = {
0x03,0x01,0x00,0x02,0x11,0x03,0x11,0x00,0x3F,0x00,
};
/* Quantisation tables */
static uint8_t std_dqt0[65] = {
0x00,0x10,0x0C,0x0C,0x0E,0x0C,0x0A,0x10,0x0E,0x0E,0x0E,0x12,0x12,0x10,0x14,0x18,
0x28,0x1A,0x18,0x16,0x16,0x18,0x32,0x24,0x26,0x1E,0x28,0x3A,0x34,0x3E,0x3C,0x3A,
0x34,0x38,0x38,0x40,0x48,0x5C,0x4E,0x40,0x44,0x58,0x46,0x38,0x38,0x50,0x6E,0x52,
0x58,0x60,0x62,0x68,0x68,0x68,0x3E,0x4E,0x72,0x7A,0x70,0x64,0x78,0x5C,0x66,0x68,
0x64,
};
static uint8_t std_dqt1[65] = {
0x01,0x12,0x12,0x12,0x16,0x16,0x16,0x30,0x1A,0x1A,0x30,0x64,0x42,0x38,0x42,0x64,
0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,
0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,
0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,
0x64,
};
/* Decoding DQT -- for input file */
static uint8_t *sdqt[3] = { std_dqt0, std_dqt1, std_dqt1 };
/* Encoding DQT -- for output */
static uint8_t *dqt[3] = { std_dqt0, std_dqt1, std_dqt1 };
/* Standard Huffman tables */
static uint8_t std_dht00[29] = {
0x00,0x00,0x01,0x05,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,
};
static uint8_t std_dht01[29] = {
0x01,0x00,0x03,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,0x00,
0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,
};
static uint8_t std_dht10[179] = {
0x10,0x00,0x02,0x01,0x03,0x03,0x02,0x04,0x03,0x05,0x05,0x04,0x04,0x00,0x00,0x01,
0x7D,0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,
0x07,0x22,0x71,0x14,0x32,0x81,0x91,0xA1,0x08,0x23,0x42,0xB1,0xC1,0x15,0x52,0xD1,
0xF0,0x24,0x33,0x62,0x72,0x82,0x09,0x0A,0x16,0x17,0x18,0x19,0x1A,0x25,0x26,0x27,
0x28,0x29,0x2A,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,
0x49,0x4A,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68,
0x69,0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x83,0x84,0x85,0x86,0x87,0x88,
0x89,0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,0xA6,
0xA7,0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,0xC3,0xC4,
0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xE1,
0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,
0xF8,0xF9,0xFA,
};
static uint8_t std_dht11[179] = {
0x11,0x00,0x02,0x01,0x02,0x04,0x04,0x03,0x04,0x07,0x05,0x04,0x04,0x00,0x01,0x02,
0x77,0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,0x31,0x06,0x12,0x41,0x51,0x07,0x61,
0x71,0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,0xA1,0xB1,0xC1,0x09,0x23,0x33,0x52,
0xF0,0x15,0x62,0x72,0xD1,0x0A,0x16,0x24,0x34,0xE1,0x25,0xF1,0x17,0x18,0x19,0x1A,
0x26,0x27,0x28,0x29,0x2A,0x35,0x36,0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,
0x48,0x49,0x4A,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,
0x68,0x69,0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x82,0x83,0x84,0x85,0x86,
0x87,0x88,0x89,0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,
0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,
0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,
0xDA,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,
0xF8,0xF9,0xFA,
};
/* Decoding DHT -- for input file */
static uint8_t *sdht_dc[3] = { std_dht00, std_dht01, std_dht01 };
static uint8_t *sdht_ac[3] = { std_dht10, std_dht11, std_dht11 };
/* Encoding DHT -- for output */
static uint8_t *dht_dc[3] = { std_dht00, std_dht01, std_dht01 };
static uint8_t *dht_ac[3] = { std_dht10, std_dht11, std_dht11 };
/* Helpers for looking up the current DQT values */
#define SDQT (sdqt[s->component][1 + s->acpart])
#define DDQT (dqt[s->component][1 + s->acpart])
/* Helpers for converting between DQT tables */
#define AADJ(i) (SDQT == DDQT ? (i) : (i / DDQT))
#define UADJ(i) (SDQT == DDQT ? (i) : (i * SDQT))
#define BADJ(i) (SDQT == DDQT ? (i) : (i * SDQT / DDQT))
/*
static char *strbits(uint32_t value, uint8_t bits)
{
static char s[33];
char *ss = s;
while(bits--) *(ss++) = value & 1 << bits ? '1' : '0';
*ss = '\0';
return(s);
}
*/
#ifndef crc_xmodem_update
uint16_t crc_xmodem_update(uint16_t crc, uint8_t data)
{
int i;
crc = crc ^ ((uint16_t) data << 8);
for(i = 0; i < 8; i++)
{
if(crc & 0x8000) crc = (crc << 1) ^ 0x1021;
else crc <<= 1;
}
return(crc);
}
#endif
static inline char jpeg_dht_lookup(ssdv_t *s, uint8_t *symbol, uint8_t *width)
{
uint16_t code = 0;
uint8_t cw, n;
uint8_t *dht, *ss;
/* Select the appropriate huffman table */
if(s->acpart == 0) dht = sdht_dc[s->component];
else dht = sdht_ac[s->component];
ss = &dht[17];
for(cw = 1; cw <= 16; cw++)
{
/* Got enough bits? */
if(cw > s->worklen) return(SSDV_FEED_ME);
/* Compare against each code 'cw' bits wide */
for(n = dht[cw]; n > 0; n--)
{
if(s->workbits >> (s->worklen - cw) == code)
{
/* Found a match */
*symbol = *ss;
*width = cw;
return(SSDV_OK);
}
ss++; code++;
}
code <<= 1;
}
/* No match found - error */
return(SSDV_ERROR);
}
static inline char jpeg_dht_lookup_symbol(uint8_t *dht, uint8_t symbol, uint16_t *bits, uint8_t *width)
{
uint16_t code = 0;
uint8_t cw, n, *ss = &dht[17];
for(cw = 1; cw <= 16; cw++)
{
for(n = dht[cw]; n > 0; n--)
{
if(*ss == symbol)
{
/* Found a match */
*bits = code;
*width = cw;
return(SSDV_OK);
}
ss++; code++;
}
code <<= 1;
}
/* No match found - error */
return(SSDV_ERROR);
}
static inline int jpeg_int(int bits, int width)
{
int b = (1 << width) - 1;
if(bits <= b >> 1) bits = -(bits ^ b);
return(bits);
}
static inline void jpeg_encode_int(int value, int *bits, uint8_t *width)
{
*bits = value;
/* Calculate the number of bits */
if(value < 0) value = -value;
for(*width = 0; value; value >>= 1) (*width)++;
/* Fix negative values */
if(*bits < 0) *bits = -*bits ^ ((1 << *width) - 1);
}
/*****************************************************************************/
static char ssdv_outbits(ssdv_t *s, uint16_t bits, uint8_t length)
{
uint8_t b;
if(length)
{
s->outbits <<= length;
s->outbits |= bits & ((1 << length) - 1);
s->outlen += length;
}
while(s->outlen >= 8 && s->out_len > 0)
{
b = s->outbits >> (s->outlen - 8);
/* Put the byte into the output buffer */
*(s->outp++) = b;
s->outlen -= 8;
s->out_len--;
/* Insert stuffing byte if needed */
if(s->out_stuff && b == 0xFF)
{
s->outbits &= (1 << s->outlen) - 1;
s->outlen += 8;
}
}
return(s->out_len ? SSDV_OK : SSDV_BUFFER_FULL);
}
static char ssdv_outbits_sync(ssdv_t *s)
{
uint8_t b = s->outlen % 8;
if(b) return(ssdv_outbits(s, 0xFF, 8 - b));
return(SSDV_OK);
}
static char ssdv_out_jpeg_int(ssdv_t *s, uint8_t rle, int value)
{
uint16_t huffbits = 0;
int intbits;
uint8_t hufflen = 0, intlen;
uint8_t *dht;
int r;
/* Select the appropriate huffman table */
if(s->acpart == 0) dht = dht_dc[s->component];
else dht = dht_ac[s->component];
jpeg_encode_int(value, &intbits, &intlen);
r = jpeg_dht_lookup_symbol(dht, (rle << 4) | (intlen & 0x0F), &huffbits, &hufflen);
if(r != SSDV_OK) fprintf(stderr, "jpeg_dht_lookup_symbol: %i (%i:%i)\n", r, value, rle);
ssdv_outbits(s, huffbits, hufflen);
if(intlen) ssdv_outbits(s, intbits, intlen);
return(SSDV_OK);
}
static char ssdv_process(ssdv_t *s)
{
if(s->state == S_HUFF)
{
uint8_t symbol, width;
int r;
/* Lookup the code, return if error or not enough bits yet */
if((r = jpeg_dht_lookup(s, &symbol, &width)) != SSDV_OK)
return(r);
if(s->acpart == 0) /* DC */
{
if(symbol == 0x00)
{
/* No change in DC from last block */
if(s->mcupart == 0 || s->mcupart == 4 || s->mcupart == 5)
{
if(s->dcmode == 0) ssdv_out_jpeg_int(s, 0, AADJ(s->dc[s->component]));
else
{
ssdv_out_jpeg_int(s, 0, 0 - s->dc[s->component]);
s->dc[s->component] = 0;
}
}
else ssdv_out_jpeg_int(s, 0, 0);
/* skip to the next AC part immediately */
s->acpart++;
}
else
{
/* DC value follows, 'symbol' bits wide */
s->state = S_INT;
s->needbits = symbol;
}
}
else /* AC */
{
s->acrle = 0;
if(symbol == 0x00)
{
/* EOB -- all remaining AC parts are zero */
ssdv_out_jpeg_int(s, 0, 0);
s->acpart = 64;
}
else if(symbol == 0xF0)
{
/* The next 16 AC parts are zero */
ssdv_out_jpeg_int(s, 15, 0);
s->acpart += 16;
}
else
{
/* Next bits are an integer value */
s->state = S_INT;
s->acrle = symbol >> 4;
s->acpart += s->acrle;
s->needbits = symbol & 0x0F;
}
}
/* Clear processed bits */
s->worklen -= width;
s->workbits &= (1 << s->worklen) - 1;
}
else if(s->state == S_INT)
{
int i;
/* Not enough bits yet? */
if(s->worklen < s->needbits) return(SSDV_FEED_ME);
/* Decode the integer */
i = jpeg_int(s->workbits >> (s->worklen - s->needbits), s->needbits);
if(s->acpart == 0) /* DC */
{
if(s->mcupart == 0 || s->mcupart == 4 || s->mcupart == 5)
{
if(s->dcmode == 0)
{
/* Output absolute DC value */
s->dc[s->component] += UADJ(i);
ssdv_out_jpeg_int(s, 0, AADJ(s->dc[s->component]));
}
else
{
/* Output relative DC value */
ssdv_out_jpeg_int(s, 0, i - s->dc[s->component]);
s->dc[s->component] = i;
}
}
else
{
/* Output relative DC value */
s->dc[s->component] += UADJ(i);
ssdv_out_jpeg_int(s, 0, BADJ(i));
}
}
else /* AC */
{
if((i = BADJ(i)))
{
s->accrle += s->acrle;
while(s->accrle >= 16)
{
ssdv_out_jpeg_int(s, 15, 0);
s->accrle -= 16;
}
ssdv_out_jpeg_int(s, s->accrle, i);
s->accrle = 0;
}
else
{
/* AC value got reduced to 0 in the DQT conversion */
if(s->acpart >= 63)
{
ssdv_out_jpeg_int(s, 0, 0);
s->accrle = 0;
}
else s->accrle += s->acrle + 1;
}
}
/* Next AC part to expect */
s->acpart++;
/* Next bits are a huffman code */
s->state = S_HUFF;
/* Clear processed bits */
s->worklen -= s->needbits;
s->workbits &= (1 << s->worklen) - 1;
}
if(s->acpart >= 64)
{
/* Reached the end of this MCU part */
if(++s->mcupart == 6)
{
s->mcupart = 0;
s->mcu_id++;
/* Test for the end of image */
if(s->mcu_id >= s->mcu_count)
{
/* Flush any remaining bits */
ssdv_outbits_sync(s);
return(SSDV_EOI);
}
/* Set the packet MCU marker - encoder only */
if(s->packet_mcu_id == 0xFFFF)
{
s->packet_mcu_id = s->mcu_id;
s->packet_mcu_offset =
(SSDV_PKT_SIZE_PAYLOAD - s->out_len) * 8 + s->outlen;
}
}
if(s->mcupart < 4) s->component = 0;
else s->component = s->mcupart - 3;
s->acpart = 0;
s->accrle = 0;
}
if(s->out_len == 0) return(SSDV_BUFFER_FULL);
return(SSDV_OK);
}
/*****************************************************************************/
static void ssdv_memset_prng(uint8_t *s, size_t n)
{
/* A very simple PRNG for noise whitening */
uint8_t l = 0x00;
for(; n > 0; n--) *(s++) = (l = l * 245 + 45);
}
static char ssdv_have_marker(ssdv_t *s)
{
switch(s->marker)
{
case J_SOF0:
case J_SOS:
/* Copy the data before processing */
if(s->marker_len > HBUFF_LEN)
{
/* Not enough memory ... shouldn't happen! */
return(SSDV_ERROR);
}
s->marker_data = s->hbuff;
s->marker_data_len = 0;
s->state = S_MARKER_DATA;
break;
case J_DHT:
case J_DQT:
/* Copy the tables into memory */
s->marker_data = malloc(s->marker_len);
s->marker_data_len = 0;
s->state = S_MARKER_DATA;
break;
case J_EOI:
s->state = S_EOI;
break;
default:
/* Ignore other marks, skipping any associated data */
s->in_skip = s->marker_len;
s->state = S_MARKER;
break;
}
return(SSDV_OK);
}
static char ssdv_have_marker_data(ssdv_t *s)
{
uint8_t *d = s->marker_data;
size_t l = s->marker_len;
int i;
switch(s->marker)
{
case J_SOF0:
s->width = (d[3] << 8) | d[4];
s->height = (d[1] << 8) | d[2];
/* Calculate number of MCU blocks in this image -- assumes 16x16 blocks */
s->mcu_count = (s->width >> 4) * (s->height >> 4);
/* Display information about the image... */
fprintf(stderr, "Precision: %i\n", d[0]);
fprintf(stderr, "Resolution: %ix%i\n", s->width, s->height);
fprintf(stderr, "Components: %i\n", d[5]);
fprintf(stderr, "MCU blocks: %i\n", s->mcu_count);
/* The image must have a precision of 8 */
if(d[0] != 8)
{
fprintf(stderr, "Error: The image must have a precision of 8\n");
return(SSDV_ERROR);
}
/* The image must have 3 components (Y'Cb'Cr) */
if(d[5] != 3)
{
fprintf(stderr, "Error: The image must have 3 components\n");
return(SSDV_ERROR);
}
/* The image dimensions must be a multiple of 16 */
if((s->width & 0x0F) || (s->height & 0x0F))
{
fprintf(stderr, "Error: The image dimensions must be a multiple of 16\n");
return(SSDV_ERROR);
}
/* TODO: Read in the quantisation table ID for each component */
// 01 22 00 02 11 01 03 11 01
for(i = 0; i < 3; i++)
{
uint8_t *dq = &d[i * 3 + 6];
if(dq[0] != i + 1)
{
fprintf(stderr, "Error: Components are not in order in the SOF0 header\n");
return(SSDV_ERROR);
}
fprintf(stderr, "DQT table for component %i: %02X, Sampling factor: %ix%i\n", dq[0], dq[2], dq[1] & 0x0F, dq[1] >> 4);
/* The first component must have a factor of 2x2 and the rest 1x1 */
if(dq[0] == 1 && dq[1] != 0x22)
{
fprintf(stderr, "Error: Component 1 sampling factor must be 2x2\n");
return(SSDV_ERROR);
}
else if(dq[0] != 1 && dq[1] != 0x11)
{
fprintf(stderr, "Error: Component %i sampling factor must be 1x1\n", dq[0]);
return(SSDV_ERROR);
}
}
break;
case J_SOS:
fprintf(stderr, "Components: %i\n", d[0]);
/* The image must have 3 components (Y'Cb'Cr) */
if(d[0] != 3)
{
fprintf(stderr, "Error: The image must have 3 components\n");
return(SSDV_ERROR);
}
for(i = 0; i < 3; i++)
{
uint8_t *dh = &d[i * 2 + 1];
if(dh[0] != i + 1)
{
fprintf(stderr, "Error: Components are not in order in the SOF0 header\n");
return(SSDV_ERROR);
}
fprintf(stderr, "Component %i DHT: %02X\n", dh[0], dh[1]);
}
/* Do I need to look at the last three bytes of the SOS data? */
/* 00 3F 00 */
/* The SOS data is followed by the image data */
s->state = S_HUFF;
return(SSDV_OK);
case J_DHT:
while(l > 0)
{
int i, s;
switch(d[0])
{
case 0x00: sdht_dc[0] = d; break;
case 0x01: sdht_dc[1] = sdht_dc[2] = d; break;
case 0x10: sdht_ac[0] = d; break;
case 0x11: sdht_ac[1] = sdht_ac[2] = d; break;
}
/* Skip to the next DHT table */
for(s = 17, i = 1; i <= 16; i++)
s += d[i];
l -= s;
d += s;
}
break;
case J_DQT:
while(l > 0)
{
switch(d[0])
{
case 0x00: sdqt[0] = d; break;
case 0x01: sdqt[1] = sdqt[2] = d; break;
}
/* Skip to the next one, if present */
l -= 65;
d += 65;
}
break;
}
s->state = S_MARKER;
return(SSDV_OK);
}
char ssdv_enc_init(ssdv_t *s, uint8_t image_id)
{
memset(s, 0, sizeof(ssdv_t));
s->image_id = image_id;
return(SSDV_OK);
}
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;
/* Zero the payload memory */
memset(s->out, 0, SSDV_PKT_SIZE);
/* Flush the output bits */
ssdv_outbits(s, 0, 0);
return(SSDV_OK);
}
char ssdv_enc_get_packet(ssdv_t *s)
{
int r;
uint8_t b;
/* Have we reached the end of the image? */
if(s->state == S_EOI) return(SSDV_EOI);
/* If the output buffer is empty, re-initialise */
if(s->out_len == 0) ssdv_enc_set_buffer(s, s->out);
while(s->in_len)
{
b = *(s->inp++);
s->in_len--;
/* Skip bytes if necessary */
if(s->in_skip) { s->in_skip--; continue; }
switch(s->state)
{
case S_MARKER:
s->marker = (s->marker << 8) | b;
if(s->marker == J_TEM ||
(s->marker >= J_RST0 && s->marker <= J_EOI))
{
/* Marker without data */
s->marker_len = 0;
r = ssdv_have_marker(s);
if(r != SSDV_OK) return(r);
}
else if(s->marker >= J_SOF0 && s->marker <= J_COM)
{
/* All other markers are followed by data */
s->marker_len = 0;
s->state = S_MARKER_LEN;
s->needbits = 16;
}
break;
case S_MARKER_LEN:
s->marker_len = (s->marker_len << 8) | b;
if((s->needbits -= 8) == 0)
{
s->marker_len -= 2;
r = ssdv_have_marker(s);
if(r != SSDV_OK) return(r);
}
break;
case S_MARKER_DATA:
s->marker_data[s->marker_data_len++] = b;
if(s->marker_data_len == s->marker_len)
{
r = ssdv_have_marker_data(s);
if(r != SSDV_OK) return(r);
}
break;
case S_HUFF:
case S_INT:
/* Is the next byte a stuffing byte? Skip it */
/* TODO: Test the next byte is actually 0x00 */
if(b == 0xFF) s->in_skip++;
/* Add the new byte to the work area */
s->workbits = (s->workbits << 8) | b;
s->worklen += 8;
/* Process the new data until more needed, or an error occurs */
while((r = ssdv_process(s)) == SSDV_OK);
if(r == SSDV_BUFFER_FULL || r == SSDV_EOI)
{
uint16_t mcu_id = s->packet_mcu_id;
uint16_t mcu_offset = s->packet_mcu_offset;
uint16_t i, x;
if(mcu_offset != 0xFFFF && mcu_offset >= SSDV_PKT_SIZE_PAYLOAD * 8)
{
/* The first MCU begins in the next packet, not this one */
mcu_id = mcu_offset = 0xFFFF;
s->packet_mcu_offset -= SSDV_PKT_SIZE_PAYLOAD * 8;
}
else
{
/* Clear the MCU data for the next packet */
s->packet_mcu_id = s->packet_mcu_offset = 0xFFFF;
}
/* A packet is ready, create the headers */
s->out[0] = 0x55; /* Sync */
s->out[1] = 0x66; /* Type */
s->out[2] = s->image_id; /* Image ID */
s->out[3] = s->packet_id >> 8; /* Packet ID MSB */
s->out[4] = s->packet_id & 0xFF; /* Packet ID LSB */
s->out[5] = s->width >> 4; /* Width / 16 */
s->out[6] = s->height >> 4; /* Height / 16 */
s->out[7] = mcu_offset >> 8; /* Next MCU offset MSB */
s->out[8] = mcu_offset & 0xFF; /* Next MCU offset LSB */
s->out[9] = mcu_id >> 8; /* MCU ID MSB */
s->out[10] = 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);
/* Calculate the CRC codes */
for(i = 1, x = 0xFFFF; i < SSDV_PKT_SIZE - SSDV_PKT_SIZE_RSCODES - SSDV_PKT_SIZE_CRC; i++)
x = crc_xmodem_update(x, s->out[i]);
s->out[i++] = x >> 8;
s->out[i++] = x & 0xFF;
/* Generate the RS codes */
encode_rs_8(&s->out[1], &s->out[i], 0);
s->packet_id++;
/* Have we reached the end of the image data? */
if(r == SSDV_EOI) s->state = S_EOI;
return(SSDV_OK);
}
else if(r != SSDV_FEED_ME)
{
/* An error occured */
fprintf(stderr, "ssdv_process() failed: %i\n", r);
return(SSDV_ERROR);
}
break;
case S_EOI:
/* Shouldn't reach this point */
break;
}
}
/* Need more data */
return(SSDV_FEED_ME);
}
char ssdv_enc_feed(ssdv_t *s, uint8_t *buffer, size_t length)
{
s->inp = buffer;
s->in_len = length;
return(SSDV_OK);
}
/*****************************************************************************/
static void ssdv_write_marker(ssdv_t *s, uint16_t id, uint16_t length, uint8_t *data)
{
ssdv_outbits(s, id, 16);
if(length > 0)
{
ssdv_outbits(s, length + 2, 16);
while(length--) ssdv_outbits(s, *(data++), 8);
}
}
static void ssdv_out_headers(ssdv_t *s)
{
uint8_t *b = s->hbuff;
ssdv_write_marker(s, J_SOI, 0, 0);
ssdv_write_marker(s, J_APP0, 14, app0);
ssdv_write_marker(s, J_DQT, 65, std_dqt0); /* DQT Luminance */
ssdv_write_marker(s, J_DQT, 65, std_dqt1); /* DQT Chrominance */
/* Build SOF0 header */
b[0] = 8; /* Precision */
b[1] = s->height >> 8;
b[2] = s->height & 0xFF;
b[3] = s->width >> 8;
b[4] = s->width & 0xFF;
b[5] = 3; /* Components (Y'Cb'Cr) */
b[6] = 1; /* Y */
b[7] = 0x22;
b[8] = 0x00;
b[9] = 2; /* Cb */
b[10] = 0x11;
b[11] = 0x01;
b[12] = 3; /* Cr */
b[13] = 0x11;
b[14] = 0x01;
ssdv_write_marker(s, J_SOF0, 15, b); /* SOF0 (Baseline DCT) */
ssdv_write_marker(s, J_DHT, 29, std_dht00); /* DHT (DC Luminance) */
ssdv_write_marker(s, J_DHT, 179, std_dht10); /* DHT (AC Luminance) */
ssdv_write_marker(s, J_DHT, 29, std_dht01); /* DHT (DC Chrominance */
ssdv_write_marker(s, J_DHT, 179, std_dht11); /* DHT (AC Chrominance */
ssdv_write_marker(s, J_SOS, 10, sos);
}
static void ssdv_fill_gap(ssdv_t *s, uint16_t next_mcu)
{
if(s->mcupart > 0 || s->acpart > 0)
{
/* Cleanly end the current MCU part */
if(s->acpart > 0)
{
ssdv_out_jpeg_int(s, 0, 0);
s->mcupart++;
}
/* End the current MCU block */
for(; s->mcupart < 6; s->mcupart++)
{
if(s->mcupart < 4) s->component = 0;
else s->component = s->mcupart - 3;
s->acpart = 0; ssdv_out_jpeg_int(s, 0, 0); /* DC */
s->acpart = 1; ssdv_out_jpeg_int(s, 0, 0); /* AC */
}
s->mcu_id++;
}
/* Pad out missing MCUs */
for(; s->mcu_id < next_mcu; s->mcu_id++)
{
/* End the current MCU block */
for(s->mcupart = 0; s->mcupart < 6; s->mcupart++)
{
if(s->mcupart < 4) s->component = 0;
else s->component = s->mcupart - 3;
s->acpart = 0; ssdv_out_jpeg_int(s, 0, 0); /* DC */
s->acpart = 1; ssdv_out_jpeg_int(s, 0, 0); /* AC */
}
}
}
char ssdv_dec_init(ssdv_t *s)
{
memset(s, 0, sizeof(ssdv_t));
/* The packet data should contain only scan data, no headers */
s->state = S_HUFF;
/* Converting absolute values to relative */
s->dcmode = 1;
return(SSDV_OK);
}
char ssdv_dec_set_buffer(ssdv_t *s, uint8_t *buffer, size_t length)
{
size_t c = s->outp - s->out;
s->outp = buffer + c;
s->out = buffer;
s->out_len = length - c;
/* Flush the output bits */
ssdv_outbits(s, 0, 0);
return(SSDV_OK);
}
char ssdv_dec_feed(ssdv_t *s, uint8_t *packet)
{
int i = 0, r;
uint8_t b;
uint16_t packet_id;
/* Read the packet header */
packet_id = (packet[3] << 8) | packet[4];
s->packet_mcu_offset = (packet[7] << 8) | packet[8];
s->packet_mcu_id = (packet[9] << 8) | packet[10];
/* If this is the first packet, write the JPEG headers */
if(s->packet_id == 0)
{
/* Read the fixed headers from the packet */
s->image_id = packet[2];
s->width = packet[5] << 4;
s->height = packet[6] << 4;
s->mcu_count = packet[5] * packet[6];
/* Output JPEG headers and enable byte stuffing */
ssdv_out_headers(s);
s->out_stuff = 1;
}
/* Is this not the packet we expected? */
if(packet_id != s->packet_id)
{
/* One or more packets have been lost! */
fprintf(stderr, "Gap detected between packets %i and %i\n", s->packet_id - 1, packet_id);
/* If this packet has no new MCU, ignore */
if(s->packet_mcu_offset == 0xFFFF) return(SSDV_FEED_ME);
/* Fill the gap left by the missing packet */
ssdv_fill_gap(s, s->packet_mcu_id);
/* Clear the workbits */
s->workbits = s->worklen = 0;
/* Skip the bytes of the lost MCU */
i = s->packet_mcu_offset >> 3;
/* Skip any remaining bits too */
if((r = s->packet_mcu_offset & 7))
{
/* Add the first bits of the new MCU */
r = 8 - r;
b = packet[SSDV_PKT_SIZE_HEADER + i++];
b &= ((1 << r) - 1);
s->workbits = b;
s->worklen += r;
}
/* Reset the JPEG decoder state */
s->state = S_HUFF;
s->component = 0;
s->mcupart = 0;
s->acpart = 0;
s->accrle = 0;
s->packet_id = packet_id;
}
/* Feed the JPEG data into the processor */
for(; i < SSDV_PKT_SIZE_PAYLOAD; i++)
{
b = packet[SSDV_PKT_SIZE_HEADER + i];
/* Add the new byte to the work area */
s->workbits = (s->workbits << 8) | b;
s->worklen += 8;
/* Process the new data until more needed, or an error occurs */
while((r = ssdv_process(s)) == SSDV_OK);
if(r == SSDV_BUFFER_FULL)
{
/* Realloc memory */
}
else if(r == SSDV_EOI)
{
/* All done! */
return(SSDV_OK);
}
else if(r != SSDV_FEED_ME)
{
/* An error occured */
fprintf(stderr, "ssdv_process() failed: %i\n", r);
return(SSDV_ERROR);
}
}
/* The next packet to expect... */
s->packet_id++;
return(SSDV_FEED_ME);
}
char ssdv_dec_get_jpeg(ssdv_t *s, uint8_t **jpeg, size_t *length)
{
/* Is the image complete? */
if(s->mcu_id < s->mcu_count) ssdv_fill_gap(s, s->mcu_count);
/* Sync, and final EOI header and return */
ssdv_outbits_sync(s);
s->out_stuff = 0;
ssdv_write_marker(s, J_EOI, 0, 0);
*jpeg = s->out;
*length = (size_t) (s->outp - s->out);
return(SSDV_OK);
}
char ssdv_dec_is_packet(uint8_t *packet, int *errors)
{
uint8_t pkt[SSDV_PKT_SIZE];
ssdv_packet_info_t p;
uint16_t x;
int i;
/* Testing is destructive, work on a copy */
memcpy(pkt, packet, SSDV_PKT_SIZE);
pkt[0] = 0x55;
pkt[1] = 0x66;
/* 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;
/* Sanity checks */
if(pkt[1] != 0x66) 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 * 8) return(-1);
}
/* Test the checksum */
for(i = 1, x = 0xFFFF; i < SSDV_PKT_SIZE - SSDV_PKT_SIZE_RSCODES - SSDV_PKT_SIZE_CRC; i++)
x = crc_xmodem_update(x, pkt[i]);
if(pkt[i++] != (x >> 8)) return(-1);
if(pkt[i++] != (x & 0xFF)) return(-1);
/* Appears to be a valid packet! Copy it back */
memcpy(packet, pkt, SSDV_PKT_SIZE);
return(0);
}
void ssdv_dec_header(ssdv_packet_info_t *info, uint8_t *packet)
{
info->image_id = packet[2];
info->packet_id = (packet[3] << 8) | packet[4];
info->width = packet[5] << 4;
info->height = packet[6] << 4;
info->mcu_offset = (packet[7] << 8) | packet[8];
info->mcu_id = (packet[9] << 8) | packet[10];
info->mcu_count = packet[5] * packet[6];
}
/*****************************************************************************/