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rfc2435.c
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#include "rfc2435.h"
#include <stdint.h>
#include <string.h>
#define u_char uint8_t
#define u_short uint16_t
/*
* Table K.1 from JPEG spec.
*/
static const int jpeg_luma_quantizer[64] = {
16, 11, 10, 16, 24, 40, 51, 61, 12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56, 14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77, 24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101, 72, 92, 95, 98, 112, 100, 103, 99};
/*
* Table K.2 from JPEG spec.
*/
static const int jpeg_chroma_quantizer[64] = {
17, 18, 24, 47, 99, 99, 99, 99, 18, 21, 26, 66, 99, 99, 99, 99, 24, 26, 56, 99, 99, 99,
99, 99, 47, 66, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99};
/*
* Call MakeTables with the Q factor and two u_char[64] return arrays
*/
static void MakeTables(int q, u_char *lqt, u_char *cqt) {
int i;
int factor = q;
if (q < 1) factor = 1;
if (q > 99) factor = 99;
if (q < 50)
q = 5000 / factor;
else
q = 200 - factor * 2;
for (i = 0; i < 64; i++) {
int lq = (jpeg_luma_quantizer[i] * q + 50) / 100;
int cq = (jpeg_chroma_quantizer[i] * q + 50) / 100;
/* Limit the quantizers to 1 <= q <= 255 */
if (lq < 1)
lq = 1;
else if (lq > 255)
lq = 255;
lqt[i] = lq;
if (cq < 1)
cq = 1;
else if (cq > 255)
cq = 255;
cqt[i] = cq;
}
}
static const u_char lum_dc_codelens[] = {
0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
};
static const u_char lum_dc_symbols[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
};
static const u_char lum_ac_codelens[] = {
0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d,
};
static const u_char lum_ac_symbols[] = {
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 const u_char chm_dc_codelens[] = {
0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
};
static const u_char chm_dc_symbols[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
};
static const u_char chm_ac_codelens[] = {
0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77,
};
static const u_char chm_ac_symbols[] = {
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,
};
static u_char *MakeQuantHeader(u_char *p, const u_char *qt, int tableNo) {
*p++ = 0xff;
*p++ = 0xdb; /* DQT */
*p++ = 0; /* length msb */
*p++ = 67; /* length lsb */
*p++ = tableNo;
memcpy(p, qt, 64);
return (p + 64);
}
static u_char *MakeHuffmanHeader(u_char *p, const u_char *codelens, int ncodes,
const u_char *symbols, int nsymbols, int tableNo, int tableClass) {
*p++ = 0xff;
*p++ = 0xc4; /* DHT */
*p++ = 0; /* length msb */
*p++ = 3 + ncodes + nsymbols; /* length lsb */
*p++ = (tableClass << 4) | tableNo;
memcpy(p, codelens, ncodes);
p += ncodes;
memcpy(p, symbols, nsymbols);
p += nsymbols;
return (p);
}
static u_char *MakeDRIHeader(u_char *p, u_short dri) {
*p++ = 0xff;
*p++ = 0xdd; /* DRI */
*p++ = 0x0; /* length msb */
*p++ = 4; /* length lsb */
*p++ = dri >> 8; /* dri msb */
*p++ = dri & 0xff; /* dri lsb */
return (p);
}
/*
* Arguments:
* type, width, height: as supplied in RTP/JPEG header
* lqt, cqt: quantization tables as either derived from
* the Q field using MakeTables() or as specified
* in section 4.2.
* dri: restart interval in MCUs, or 0 if no restarts.
*
* p: pointer to return area
*
* Return value:
* The length of the generated headers.
*
* Generate a frame and scan headers that can be prepended to the
* RTP/JPEG data payload to produce a JPEG compressed image in
* interchange format (except for possible trailing garbage and
* absence of an EOI marker to terminate the scan).
*/
static int MakeHeaders(u_char *p, int type, int w, int h, const u_char *lqt, const u_char *cqt,
u_short dri) {
u_char *start = p;
/* convert from blocks to pixels */
w <<= 3;
h <<= 3;
*p++ = 0xff;
*p++ = 0xd8; /* SOI */
p = MakeQuantHeader(p, lqt, 0);
p = MakeQuantHeader(p, cqt, 1);
if (dri != 0) p = MakeDRIHeader(p, dri);
*p++ = 0xff;
*p++ = 0xc0; /* SOF */
*p++ = 0; /* length msb */
*p++ = 17; /* length lsb */
*p++ = 8; /* 8-bit precision */
*p++ = h >> 8; /* height msb */
*p++ = h; /* height lsb */
*p++ = w >> 8; /* width msb */
*p++ = w; /* wudth lsb */
*p++ = 3; /* number of components */
*p++ = 0; /* comp 0 */
if (type == 0)
*p++ = 0x21; /* hsamp = 2, vsamp = 1 */
else
*p++ = 0x22; /* hsamp = 2, vsamp = 2 */
*p++ = 0; /* quant table 0 */
*p++ = 1; /* comp 1 */
*p++ = 0x11; /* hsamp = 1, vsamp = 1 */
*p++ = 1; /* quant table 1 */
*p++ = 2; /* comp 2 */
*p++ = 0x11; /* hsamp = 1, vsamp = 1 */
*p++ = 1; /* quant table 1 */
p = MakeHuffmanHeader(p, lum_dc_codelens, sizeof(lum_dc_codelens), lum_dc_symbols,
sizeof(lum_dc_symbols), 0, 0);
p = MakeHuffmanHeader(p, lum_ac_codelens, sizeof(lum_ac_codelens), lum_ac_symbols,
sizeof(lum_ac_symbols), 0, 1);
p = MakeHuffmanHeader(p, chm_dc_codelens, sizeof(chm_dc_codelens), chm_dc_symbols,
sizeof(chm_dc_symbols), 1, 0);
p = MakeHuffmanHeader(p, chm_ac_codelens, sizeof(chm_ac_codelens), chm_ac_symbols,
sizeof(chm_ac_symbols), 1, 1);
*p++ = 0xff;
*p++ = 0xda; /* SOS */
*p++ = 0; /* length msb */
*p++ = 12; /* length lsb */
*p++ = 3; /* 3 components */
*p++ = 0; /* comp 0 */
*p++ = 0; /* huffman table 0 */
*p++ = 1; /* comp 1 */
*p++ = 0x11; /* huffman table 1 */
*p++ = 2; /* comp 2 */
*p++ = 0x11; /* huffman table 1 */
*p++ = 0; /* first DCT coeff */
*p++ = 63; /* last DCT coeff */
*p++ = 0; /* sucessive approx. */
return (p - start);
}
void rfc2435_make_tables(int q, uint8_t *lqt, uint8_t *cqt) { MakeTables(q, lqt, cqt); }
int rfc2435_make_headers(uint8_t *p, int type, int w, int h, const uint8_t *lqt, const uint8_t *cqt,
uint16_t dri) {
return MakeHeaders(p, type, w, h, lqt, cqt, dri);
}