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jpge.cc
1213 lines (1091 loc) · 39.5 KB
/
jpge.cc
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// jpge.cpp - C++ class for JPEG compression.
// Public domain, Rich Geldreich <richgel99@gmail.com>
// v1.01, Dec. 18, 2010 - Initial release
// v1.02, Apr. 6, 2011 - Removed 2x2 ordered dither in H2V1 chroma subsampling
// method load_block_16_8_8(). (The rounding factor was 2, when it should have
// been 1. Either way, it wasn't helping.)
// v1.03, Apr. 16, 2011 - Added support for optimized Huffman code tables,
// optimized dynamic memory allocation down to only 1 alloc.
// Also from Alex Evans: Added RGBA support, linear
// memory allocator (no longer needed in v1.03).
// v1.04, May. 19, 2012: Forgot to set m_pFile ptr to NULL in
// cfile_stream::close(). Thanks to Owen Kaluza for reporting this bug.
// Code tweaks to fix VS2008 static code analysis warnings
// (all looked harmless).
// Code review revealed method load_block_16_8_8() (used
// for the non-default H2V1 sampling mode to downsample
// chroma) somehow didn't get the rounding factor fix from
// v1.02.
#include "jpge.h"
#include <stdlib.h>
#include <string.h>
#ifdef __APPLE__
#else
#include <malloc.h>
#endif
#define JPGE_MAX(a, b) (((a) > (b)) ? (a) : (b))
#define JPGE_MIN(a, b) (((a) < (b)) ? (a) : (b))
namespace jpge {
static inline void *jpge_malloc(size_t nSize) { return malloc(nSize); }
static inline void jpge_free(void *p) { free(p); }
// Various JPEG enums and tables.
enum {
M_SOF0 = 0xC0,
M_DHT = 0xC4,
M_SOI = 0xD8,
M_EOI = 0xD9,
M_SOS = 0xDA,
M_DQT = 0xDB,
M_APP0 = 0xE0
};
enum {
DC_LUM_CODES = 12,
AC_LUM_CODES = 256,
DC_CHROMA_CODES = 12,
AC_CHROMA_CODES = 256,
MAX_HUFF_SYMBOLS = 257,
MAX_HUFF_CODESIZE = 32
};
static uint8 s_zag[64] = {0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18,
11, 4, 5, 12, 19, 26, 33, 40, 48, 41, 34, 27, 20,
13, 6, 7, 14, 21, 28, 35, 42, 49, 56, 57, 50, 43,
36, 29, 22, 15, 23, 30, 37, 44, 51, 58, 59, 52, 45,
38, 31, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63};
static int16 s_std_lum_quant[64] = {
16, 11, 12, 14, 12, 10, 16, 14, 13, 14, 18, 17, 16, 19, 24, 40,
26, 24, 22, 22, 24, 49, 35, 37, 29, 40, 58, 51, 61, 60, 57, 51,
56, 55, 64, 72, 92, 78, 64, 68, 87, 69, 55, 56, 80, 109, 81, 87,
95, 98, 103, 104, 103, 62, 77, 113, 121, 112, 100, 120, 92, 101, 103, 99};
static int16 s_std_croma_quant[64] = {
17, 18, 18, 24, 21, 24, 47, 26, 26, 47, 99, 66, 56, 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, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99};
static uint8 s_dc_lum_bits[17] = {0, 0, 1, 5, 1, 1, 1, 1, 1,
1, 0, 0, 0, 0, 0, 0, 0};
static uint8 s_dc_lum_val[DC_LUM_CODES] = {0, 1, 2, 3, 4, 5,
6, 7, 8, 9, 10, 11};
static uint8 s_ac_lum_bits[17] = {0, 0, 2, 1, 3, 3, 2, 4, 3,
5, 5, 4, 4, 0, 0, 1, 0x7d};
static uint8 s_ac_lum_val[AC_LUM_CODES] = {
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 s_dc_chroma_bits[17] = {0, 0, 3, 1, 1, 1, 1, 1, 1,
1, 1, 1, 0, 0, 0, 0, 0};
static uint8 s_dc_chroma_val[DC_CHROMA_CODES] = {0, 1, 2, 3, 4, 5,
6, 7, 8, 9, 10, 11};
static uint8 s_ac_chroma_bits[17] = {0, 0, 2, 1, 2, 4, 4, 3, 4,
7, 5, 4, 4, 0, 1, 2, 0x77};
static uint8 s_ac_chroma_val[AC_CHROMA_CODES] = {
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};
// Low-level helper functions.
template <class T> inline void clear_obj(T &obj) {
memset(&obj, 0, sizeof(obj));
}
const int YR = 19595, YG = 38470, YB = 7471, CB_R = -11059, CB_G = -21709,
CB_B = 32768, CR_R = 32768, CR_G = -27439, CR_B = -5329;
static inline uint8 clamp(int i) {
if (static_cast<uint>(i) > 255U) {
if (i < 0)
i = 0;
else if (i > 255)
i = 255;
}
return static_cast<uint8>(i);
}
static void RGB_to_YCC(uint8 *pDst, const uint8 *pSrc, int num_pixels) {
for (; num_pixels; pDst += 3, pSrc += 3, num_pixels--) {
const int r = pSrc[0], g = pSrc[1], b = pSrc[2];
pDst[0] = static_cast<uint8>((r * YR + g * YG + b * YB + 32768) >> 16);
pDst[1] = clamp(128 + ((r * CB_R + g * CB_G + b * CB_B + 32768) >> 16));
pDst[2] = clamp(128 + ((r * CR_R + g * CR_G + b * CR_B + 32768) >> 16));
}
}
static void RGB_to_Y(uint8 *pDst, const uint8 *pSrc, int num_pixels) {
for (; num_pixels; pDst++, pSrc += 3, num_pixels--)
pDst[0] = static_cast<uint8>(
(pSrc[0] * YR + pSrc[1] * YG + pSrc[2] * YB + 32768) >> 16);
}
static void RGBA_to_YCC(uint8 *pDst, const uint8 *pSrc, int num_pixels) {
for (; num_pixels; pDst += 3, pSrc += 4, num_pixels--) {
const int r = pSrc[0], g = pSrc[1], b = pSrc[2];
pDst[0] = static_cast<uint8>((r * YR + g * YG + b * YB + 32768) >> 16);
pDst[1] = clamp(128 + ((r * CB_R + g * CB_G + b * CB_B + 32768) >> 16));
pDst[2] = clamp(128 + ((r * CR_R + g * CR_G + b * CR_B + 32768) >> 16));
}
}
static void RGBA_to_Y(uint8 *pDst, const uint8 *pSrc, int num_pixels) {
for (; num_pixels; pDst++, pSrc += 4, num_pixels--)
pDst[0] = static_cast<uint8>(
(pSrc[0] * YR + pSrc[1] * YG + pSrc[2] * YB + 32768) >> 16);
}
static void Y_to_YCC(uint8 *pDst, const uint8 *pSrc, int num_pixels) {
for (; num_pixels; pDst += 3, pSrc++, num_pixels--) {
pDst[0] = pSrc[0];
pDst[1] = 128;
pDst[2] = 128;
}
}
// Forward DCT - DCT derived from jfdctint.
enum { CONST_BITS = 13, ROW_BITS = 2 };
#define DCT_DESCALE(x, n) (((x) + (((int32)1) << ((n)-1))) >> (n))
#define DCT_MUL(var, c) (static_cast<int16>(var) * static_cast<int32>(c))
#define DCT1D(s0, s1, s2, s3, s4, s5, s6, s7) \
int32 t0 = s0 + s7, t7 = s0 - s7, t1 = s1 + s6, t6 = s1 - s6, t2 = s2 + s5, \
t5 = s2 - s5, t3 = s3 + s4, t4 = s3 - s4; \
int32 t10 = t0 + t3, t13 = t0 - t3, t11 = t1 + t2, t12 = t1 - t2; \
int32 u1 = DCT_MUL(t12 + t13, 4433); \
s2 = u1 + DCT_MUL(t13, 6270); \
s6 = u1 + DCT_MUL(t12, -15137); \
u1 = t4 + t7; \
int32 u2 = t5 + t6, u3 = t4 + t6, u4 = t5 + t7; \
int32 z5 = DCT_MUL(u3 + u4, 9633); \
t4 = DCT_MUL(t4, 2446); \
t5 = DCT_MUL(t5, 16819); \
t6 = DCT_MUL(t6, 25172); \
t7 = DCT_MUL(t7, 12299); \
u1 = DCT_MUL(u1, -7373); \
u2 = DCT_MUL(u2, -20995); \
u3 = DCT_MUL(u3, -16069); \
u4 = DCT_MUL(u4, -3196); \
u3 += z5; \
u4 += z5; \
s0 = t10 + t11; \
s1 = t7 + u1 + u4; \
s3 = t6 + u2 + u3; \
s4 = t10 - t11; \
s5 = t5 + u2 + u4; \
s7 = t4 + u1 + u3;
static void DCT2D(int32 *p) {
int32 c, *q = p;
for (c = 7; c >= 0; c--, q += 8) {
int32 s0 = q[0], s1 = q[1], s2 = q[2], s3 = q[3], s4 = q[4], s5 = q[5],
s6 = q[6], s7 = q[7];
DCT1D(s0, s1, s2, s3, s4, s5, s6, s7);
q[0] = s0 << ROW_BITS;
q[1] = DCT_DESCALE(s1, CONST_BITS - ROW_BITS);
q[2] = DCT_DESCALE(s2, CONST_BITS - ROW_BITS);
q[3] = DCT_DESCALE(s3, CONST_BITS - ROW_BITS);
q[4] = s4 << ROW_BITS;
q[5] = DCT_DESCALE(s5, CONST_BITS - ROW_BITS);
q[6] = DCT_DESCALE(s6, CONST_BITS - ROW_BITS);
q[7] = DCT_DESCALE(s7, CONST_BITS - ROW_BITS);
}
for (q = p, c = 7; c >= 0; c--, q++) {
int32 s0 = q[0 * 8], s1 = q[1 * 8], s2 = q[2 * 8], s3 = q[3 * 8],
s4 = q[4 * 8], s5 = q[5 * 8], s6 = q[6 * 8], s7 = q[7 * 8];
DCT1D(s0, s1, s2, s3, s4, s5, s6, s7);
q[0 * 8] = DCT_DESCALE(s0, ROW_BITS + 3);
q[1 * 8] = DCT_DESCALE(s1, CONST_BITS + ROW_BITS + 3);
q[2 * 8] = DCT_DESCALE(s2, CONST_BITS + ROW_BITS + 3);
q[3 * 8] = DCT_DESCALE(s3, CONST_BITS + ROW_BITS + 3);
q[4 * 8] = DCT_DESCALE(s4, ROW_BITS + 3);
q[5 * 8] = DCT_DESCALE(s5, CONST_BITS + ROW_BITS + 3);
q[6 * 8] = DCT_DESCALE(s6, CONST_BITS + ROW_BITS + 3);
q[7 * 8] = DCT_DESCALE(s7, CONST_BITS + ROW_BITS + 3);
}
}
struct sym_freq {
uint m_key, m_sym_index;
};
// Radix sorts sym_freq[] array by 32-bit key m_key. Returns ptr to sorted
// values.
static inline sym_freq *radix_sort_syms(uint num_syms, sym_freq *pSyms0,
sym_freq *pSyms1) {
const uint cMaxPasses = 4;
uint32 hist[256 * cMaxPasses];
clear_obj(hist);
for (uint i = 0; i < num_syms; i++) {
uint freq = pSyms0[i].m_key;
hist[freq & 0xFF]++;
hist[256 + ((freq >> 8) & 0xFF)]++;
hist[256 * 2 + ((freq >> 16) & 0xFF)]++;
hist[256 * 3 + ((freq >> 24) & 0xFF)]++;
}
sym_freq *pCur_syms = pSyms0, *pNew_syms = pSyms1;
uint total_passes = cMaxPasses;
while ((total_passes > 1) && (num_syms == hist[(total_passes - 1) * 256]))
total_passes--;
for (uint pass_shift = 0, pass = 0; pass < total_passes;
pass++, pass_shift += 8) {
const uint32 *pHist = &hist[pass << 8];
uint offsets[256], cur_ofs = 0;
for (uint i = 0; i < 256; i++) {
offsets[i] = cur_ofs;
cur_ofs += pHist[i];
}
for (uint i = 0; i < num_syms; i++)
pNew_syms[offsets[(pCur_syms[i].m_key >> pass_shift) & 0xFF]++] =
pCur_syms[i];
sym_freq *t = pCur_syms;
pCur_syms = pNew_syms;
pNew_syms = t;
}
return pCur_syms;
}
// calculate_minimum_redundancy() originally written by: Alistair Moffat,
// alistair@cs.mu.oz.au, Jyrki Katajainen, jyrki@diku.dk, November 1996.
static void calculate_minimum_redundancy(sym_freq *A, int n) {
int root, leaf, next, avbl, used, dpth;
if (n == 0)
return;
else if (n == 1) {
A[0].m_key = 1;
return;
}
A[0].m_key += A[1].m_key;
root = 0;
leaf = 2;
for (next = 1; next < n - 1; next++) {
if (leaf >= n || A[root].m_key < A[leaf].m_key) {
A[next].m_key = A[root].m_key;
A[root++].m_key = next;
} else
A[next].m_key = A[leaf++].m_key;
if (leaf >= n || (root < next && A[root].m_key < A[leaf].m_key)) {
A[next].m_key += A[root].m_key;
A[root++].m_key = next;
} else
A[next].m_key += A[leaf++].m_key;
}
A[n - 2].m_key = 0;
for (next = n - 3; next >= 0; next--)
A[next].m_key = A[A[next].m_key].m_key + 1;
avbl = 1;
used = dpth = 0;
root = n - 2;
next = n - 1;
while (avbl > 0) {
while (root >= 0 && (int)A[root].m_key == dpth) {
used++;
root--;
}
while (avbl > used) {
A[next--].m_key = dpth;
avbl--;
}
avbl = 2 * used;
dpth++;
used = 0;
}
}
// Limits canonical Huffman code table's max code size to max_code_size.
static void huffman_enforce_max_code_size(int *pNum_codes, int code_list_len,
int max_code_size) {
if (code_list_len <= 1)
return;
for (int i = max_code_size + 1; i <= MAX_HUFF_CODESIZE; i++)
pNum_codes[max_code_size] += pNum_codes[i];
uint32 total = 0;
for (int i = max_code_size; i > 0; i--)
total += (((uint32)pNum_codes[i]) << (max_code_size - i));
while (total != (1UL << max_code_size)) {
pNum_codes[max_code_size]--;
for (int i = max_code_size - 1; i > 0; i--) {
if (pNum_codes[i]) {
pNum_codes[i]--;
pNum_codes[i + 1] += 2;
break;
}
}
total--;
}
}
// Generates an optimized offman table.
void jpeg_encoder::optimize_huffman_table(int table_num, int table_len) {
sym_freq syms0[MAX_HUFF_SYMBOLS], syms1[MAX_HUFF_SYMBOLS];
syms0[0].m_key = 1;
syms0[0].m_sym_index =
0; // dummy symbol, assures that no valid code contains all 1's
int num_used_syms = 1;
const uint32 *pSym_count = &m_huff_count[table_num][0];
for (int i = 0; i < table_len; i++)
if (pSym_count[i]) {
syms0[num_used_syms].m_key = pSym_count[i];
syms0[num_used_syms++].m_sym_index = i + 1;
}
sym_freq *pSyms = radix_sort_syms(num_used_syms, syms0, syms1);
calculate_minimum_redundancy(pSyms, num_used_syms);
// Count the # of symbols of each code size.
int num_codes[1 + MAX_HUFF_CODESIZE];
clear_obj(num_codes);
for (int i = 0; i < num_used_syms; i++)
num_codes[pSyms[i].m_key]++;
const uint JPGE_CODE_SIZE_LIMIT = 16; // the maximum possible size of a JPEG
// Huffman code (valid range is [9,16] -
// 9 vs. 8 because of the dummy symbol)
huffman_enforce_max_code_size(num_codes, num_used_syms, JPGE_CODE_SIZE_LIMIT);
// Compute m_huff_bits array, which contains the # of symbols per code size.
clear_obj(m_huff_bits[table_num]);
for (int i = 1; i <= (int)JPGE_CODE_SIZE_LIMIT; i++)
m_huff_bits[table_num][i] = static_cast<uint8>(num_codes[i]);
// Remove the dummy symbol added above, which must be in largest bucket.
for (int i = JPGE_CODE_SIZE_LIMIT; i >= 1; i--) {
if (m_huff_bits[table_num][i]) {
m_huff_bits[table_num][i]--;
break;
}
}
// Compute the m_huff_val array, which contains the symbol indices sorted by
// code size (smallest to largest).
for (int i = num_used_syms - 1; i >= 1; i--)
m_huff_val[table_num][num_used_syms - 1 - i] =
static_cast<uint8>(pSyms[i].m_sym_index - 1);
}
// JPEG marker generation.
void jpeg_encoder::emit_byte(uint8 i) {
m_all_stream_writes_succeeded =
m_all_stream_writes_succeeded && m_pStream->put_obj(i);
}
void jpeg_encoder::emit_word(uint i) {
emit_byte(uint8(i >> 8));
emit_byte(uint8(i & 0xFF));
}
void jpeg_encoder::emit_marker(int marker) {
emit_byte(uint8(0xFF));
emit_byte(uint8(marker));
}
// Emit JFIF marker
void jpeg_encoder::emit_jfif_app0() {
emit_marker(M_APP0);
emit_word(2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1);
emit_byte(0x4A);
emit_byte(0x46);
emit_byte(0x49);
emit_byte(0x46); /* Identifier: ASCII "JFIF" */
emit_byte(0);
emit_byte(1); /* Major version */
emit_byte(1); /* Minor version */
emit_byte(0); /* Density unit */
emit_word(1);
emit_word(1);
emit_byte(0); /* No thumbnail image */
emit_byte(0);
}
// Emit quantization tables
void jpeg_encoder::emit_dqt() {
for (int i = 0; i < ((m_num_components == 3) ? 2 : 1); i++) {
emit_marker(M_DQT);
emit_word(64 + 1 + 2);
emit_byte(static_cast<uint8>(i));
for (int j = 0; j < 64; j++)
emit_byte(static_cast<uint8>(m_quantization_tables[i][j]));
}
}
// Emit start of frame marker
void jpeg_encoder::emit_sof() {
emit_marker(M_SOF0); /* baseline */
emit_word(3 * m_num_components + 2 + 5 + 1);
emit_byte(8); /* precision */
emit_word(m_image_y);
emit_word(m_image_x);
emit_byte(m_num_components);
for (int i = 0; i < m_num_components; i++) {
emit_byte(static_cast<uint8>(i + 1)); /* component ID */
emit_byte((m_comp_h_samp[i] << 4) +
m_comp_v_samp[i]); /* h and v sampling */
emit_byte(i > 0); /* quant. table num */
}
}
// Emit Huffman table.
void jpeg_encoder::emit_dht(uint8 *bits, uint8 *val, int index, bool ac_flag) {
emit_marker(M_DHT);
int length = 0;
for (int i = 1; i <= 16; i++)
length += bits[i];
emit_word(length + 2 + 1 + 16);
emit_byte(static_cast<uint8>(index + (ac_flag << 4)));
for (int i = 1; i <= 16; i++)
emit_byte(bits[i]);
for (int i = 0; i < length; i++)
emit_byte(val[i]);
}
// Emit all Huffman tables.
void jpeg_encoder::emit_dhts() {
emit_dht(m_huff_bits[0 + 0], m_huff_val[0 + 0], 0, false);
emit_dht(m_huff_bits[2 + 0], m_huff_val[2 + 0], 0, true);
if (m_num_components == 3) {
emit_dht(m_huff_bits[0 + 1], m_huff_val[0 + 1], 1, false);
emit_dht(m_huff_bits[2 + 1], m_huff_val[2 + 1], 1, true);
}
}
// emit start of scan
void jpeg_encoder::emit_sos() {
emit_marker(M_SOS);
emit_word(2 * m_num_components + 2 + 1 + 3);
emit_byte(m_num_components);
for (int i = 0; i < m_num_components; i++) {
emit_byte(static_cast<uint8>(i + 1));
if (i == 0)
emit_byte((0 << 4) + 0);
else
emit_byte((1 << 4) + 1);
}
emit_byte(0); /* spectral selection */
emit_byte(63);
emit_byte(0);
}
// Emit all markers at beginning of image file.
void jpeg_encoder::emit_markers() {
emit_marker(M_SOI);
emit_jfif_app0();
emit_dqt();
emit_sof();
emit_dhts();
emit_sos();
}
// Compute the actual canonical Huffman codes/code sizes given the JPEG huff
// bits and val arrays.
void jpeg_encoder::compute_huffman_table(uint *codes, uint8 *code_sizes,
uint8 *bits, uint8 *val) {
int i, l, last_p, si;
uint8 huff_size[257];
uint huff_code[257];
uint code;
int p = 0;
for (l = 1; l <= 16; l++)
for (i = 1; i <= bits[l]; i++)
huff_size[p++] = (char)l;
huff_size[p] = 0;
last_p = p; // write sentinel
code = 0;
si = huff_size[0];
p = 0;
while (huff_size[p]) {
while (huff_size[p] == si)
huff_code[p++] = code++;
code <<= 1;
si++;
}
memset(codes, 0, sizeof(codes[0]) * 256);
memset(code_sizes, 0, sizeof(code_sizes[0]) * 256);
for (p = 0; p < last_p; p++) {
codes[val[p]] = huff_code[p];
code_sizes[val[p]] = huff_size[p];
}
}
// Quantization table generation.
void jpeg_encoder::compute_quant_table(int32 *pDst, int16 *pSrc) {
int32 q;
if (m_params.m_quality < 50)
q = 5000 / m_params.m_quality;
else
q = 200 - m_params.m_quality * 2;
for (int i = 0; i < 64; i++) {
int32 j = *pSrc++;
j = (j * q + 50L) / 100L;
*pDst++ = JPGE_MIN(JPGE_MAX(j, 1), 255);
}
}
// Higher-level methods.
void jpeg_encoder::first_pass_init() {
m_bit_buffer = 0;
m_bits_in = 0;
memset(m_last_dc_val, 0, 3 * sizeof(m_last_dc_val[0]));
m_mcu_y_ofs = 0;
m_pass_num = 1;
}
bool jpeg_encoder::second_pass_init() {
compute_huffman_table(&m_huff_codes[0 + 0][0], &m_huff_code_sizes[0 + 0][0],
m_huff_bits[0 + 0], m_huff_val[0 + 0]);
compute_huffman_table(&m_huff_codes[2 + 0][0], &m_huff_code_sizes[2 + 0][0],
m_huff_bits[2 + 0], m_huff_val[2 + 0]);
if (m_num_components > 1) {
compute_huffman_table(&m_huff_codes[0 + 1][0], &m_huff_code_sizes[0 + 1][0],
m_huff_bits[0 + 1], m_huff_val[0 + 1]);
compute_huffman_table(&m_huff_codes[2 + 1][0], &m_huff_code_sizes[2 + 1][0],
m_huff_bits[2 + 1], m_huff_val[2 + 1]);
}
first_pass_init();
emit_markers();
m_pass_num = 2;
return true;
}
bool jpeg_encoder::jpg_open(int p_x_res, int p_y_res, int src_channels) {
m_num_components = 3;
switch (m_params.m_subsampling) {
case Y_ONLY: {
m_num_components = 1;
m_comp_h_samp[0] = 1;
m_comp_v_samp[0] = 1;
m_mcu_x = 8;
m_mcu_y = 8;
break;
}
case H1V1: {
m_comp_h_samp[0] = 1;
m_comp_v_samp[0] = 1;
m_comp_h_samp[1] = 1;
m_comp_v_samp[1] = 1;
m_comp_h_samp[2] = 1;
m_comp_v_samp[2] = 1;
m_mcu_x = 8;
m_mcu_y = 8;
break;
}
case H2V1: {
m_comp_h_samp[0] = 2;
m_comp_v_samp[0] = 1;
m_comp_h_samp[1] = 1;
m_comp_v_samp[1] = 1;
m_comp_h_samp[2] = 1;
m_comp_v_samp[2] = 1;
m_mcu_x = 16;
m_mcu_y = 8;
break;
}
case H2V2: {
m_comp_h_samp[0] = 2;
m_comp_v_samp[0] = 2;
m_comp_h_samp[1] = 1;
m_comp_v_samp[1] = 1;
m_comp_h_samp[2] = 1;
m_comp_v_samp[2] = 1;
m_mcu_x = 16;
m_mcu_y = 16;
}
}
m_image_x = p_x_res;
m_image_y = p_y_res;
m_image_bpp = src_channels;
m_image_bpl = m_image_x * src_channels;
m_image_x_mcu = (m_image_x + m_mcu_x - 1) & (~(m_mcu_x - 1));
m_image_y_mcu = (m_image_y + m_mcu_y - 1) & (~(m_mcu_y - 1));
m_image_bpl_xlt = m_image_x * m_num_components;
m_image_bpl_mcu = m_image_x_mcu * m_num_components;
m_mcus_per_row = m_image_x_mcu / m_mcu_x;
if ((m_mcu_lines[0] = static_cast<uint8 *>(
jpge_malloc(m_image_bpl_mcu * m_mcu_y))) == NULL)
return false;
for (int i = 1; i < m_mcu_y; i++)
m_mcu_lines[i] = m_mcu_lines[i - 1] + m_image_bpl_mcu;
compute_quant_table(m_quantization_tables[0], s_std_lum_quant);
compute_quant_table(m_quantization_tables[1],
m_params.m_no_chroma_discrim_flag ? s_std_lum_quant
: s_std_croma_quant);
m_out_buf_left = JPGE_OUT_BUF_SIZE;
m_pOut_buf = m_out_buf;
if (m_params.m_two_pass_flag) {
clear_obj(m_huff_count);
first_pass_init();
} else {
memcpy(m_huff_bits[0 + 0], s_dc_lum_bits, 17);
memcpy(m_huff_val[0 + 0], s_dc_lum_val, DC_LUM_CODES);
memcpy(m_huff_bits[2 + 0], s_ac_lum_bits, 17);
memcpy(m_huff_val[2 + 0], s_ac_lum_val, AC_LUM_CODES);
memcpy(m_huff_bits[0 + 1], s_dc_chroma_bits, 17);
memcpy(m_huff_val[0 + 1], s_dc_chroma_val, DC_CHROMA_CODES);
memcpy(m_huff_bits[2 + 1], s_ac_chroma_bits, 17);
memcpy(m_huff_val[2 + 1], s_ac_chroma_val, AC_CHROMA_CODES);
if (!second_pass_init())
return false; // in effect, skip over the first pass
}
return m_all_stream_writes_succeeded;
}
void jpeg_encoder::load_block_8_8_grey(int x) {
uint8 *pSrc;
sample_array_t *pDst = m_sample_array;
x <<= 3;
for (int i = 0; i < 8; i++, pDst += 8) {
pSrc = m_mcu_lines[i] + x;
pDst[0] = pSrc[0] - 128;
pDst[1] = pSrc[1] - 128;
pDst[2] = pSrc[2] - 128;
pDst[3] = pSrc[3] - 128;
pDst[4] = pSrc[4] - 128;
pDst[5] = pSrc[5] - 128;
pDst[6] = pSrc[6] - 128;
pDst[7] = pSrc[7] - 128;
}
}
void jpeg_encoder::load_block_8_8(int x, int y, int c) {
uint8 *pSrc;
sample_array_t *pDst = m_sample_array;
x = (x * (8 * 3)) + c;
y <<= 3;
for (int i = 0; i < 8; i++, pDst += 8) {
pSrc = m_mcu_lines[y + i] + x;
pDst[0] = pSrc[0 * 3] - 128;
pDst[1] = pSrc[1 * 3] - 128;
pDst[2] = pSrc[2 * 3] - 128;
pDst[3] = pSrc[3 * 3] - 128;
pDst[4] = pSrc[4 * 3] - 128;
pDst[5] = pSrc[5 * 3] - 128;
pDst[6] = pSrc[6 * 3] - 128;
pDst[7] = pSrc[7 * 3] - 128;
}
}
void jpeg_encoder::load_block_16_8(int x, int c) {
uint8 *pSrc1, *pSrc2;
sample_array_t *pDst = m_sample_array;
x = (x * (16 * 3)) + c;
int a = 0, b = 2;
for (int i = 0; i < 16; i += 2, pDst += 8) {
pSrc1 = m_mcu_lines[i + 0] + x;
pSrc2 = m_mcu_lines[i + 1] + x;
pDst[0] =
((pSrc1[0 * 3] + pSrc1[1 * 3] + pSrc2[0 * 3] + pSrc2[1 * 3] + a) >> 2) -
128;
pDst[1] =
((pSrc1[2 * 3] + pSrc1[3 * 3] + pSrc2[2 * 3] + pSrc2[3 * 3] + b) >> 2) -
128;
pDst[2] =
((pSrc1[4 * 3] + pSrc1[5 * 3] + pSrc2[4 * 3] + pSrc2[5 * 3] + a) >> 2) -
128;
pDst[3] =
((pSrc1[6 * 3] + pSrc1[7 * 3] + pSrc2[6 * 3] + pSrc2[7 * 3] + b) >> 2) -
128;
pDst[4] =
((pSrc1[8 * 3] + pSrc1[9 * 3] + pSrc2[8 * 3] + pSrc2[9 * 3] + a) >> 2) -
128;
pDst[5] =
((pSrc1[10 * 3] + pSrc1[11 * 3] + pSrc2[10 * 3] + pSrc2[11 * 3] + b) >>
2) -
128;
pDst[6] =
((pSrc1[12 * 3] + pSrc1[13 * 3] + pSrc2[12 * 3] + pSrc2[13 * 3] + a) >>
2) -
128;
pDst[7] =
((pSrc1[14 * 3] + pSrc1[15 * 3] + pSrc2[14 * 3] + pSrc2[15 * 3] + b) >>
2) -
128;
int temp = a;
a = b;
b = temp;
}
}
void jpeg_encoder::load_block_16_8_8(int x, int c) {
uint8 *pSrc1;
sample_array_t *pDst = m_sample_array;
x = (x * (16 * 3)) + c;
for (int i = 0; i < 8; i++, pDst += 8) {
pSrc1 = m_mcu_lines[i + 0] + x;
pDst[0] = ((pSrc1[0 * 3] + pSrc1[1 * 3]) >> 1) - 128;
pDst[1] = ((pSrc1[2 * 3] + pSrc1[3 * 3]) >> 1) - 128;
pDst[2] = ((pSrc1[4 * 3] + pSrc1[5 * 3]) >> 1) - 128;
pDst[3] = ((pSrc1[6 * 3] + pSrc1[7 * 3]) >> 1) - 128;
pDst[4] = ((pSrc1[8 * 3] + pSrc1[9 * 3]) >> 1) - 128;
pDst[5] = ((pSrc1[10 * 3] + pSrc1[11 * 3]) >> 1) - 128;
pDst[6] = ((pSrc1[12 * 3] + pSrc1[13 * 3]) >> 1) - 128;
pDst[7] = ((pSrc1[14 * 3] + pSrc1[15 * 3]) >> 1) - 128;
}
}
void jpeg_encoder::load_quantized_coefficients(int component_num) {
int32 *q = m_quantization_tables[component_num > 0];
int16 *pDst = m_coefficient_array;
for (int i = 0; i < 64; i++) {
sample_array_t j = m_sample_array[s_zag[i]];
if (j < 0) {
if ((j = -j + (*q >> 1)) < *q)
*pDst++ = 0;
else
*pDst++ = static_cast<int16>(-(j / *q));
} else {
if ((j = j + (*q >> 1)) < *q)
*pDst++ = 0;
else
*pDst++ = static_cast<int16>((j / *q));
}
q++;
}
}
void jpeg_encoder::flush_output_buffer() {
if (m_out_buf_left != JPGE_OUT_BUF_SIZE)
m_all_stream_writes_succeeded =
m_all_stream_writes_succeeded &&
m_pStream->put_buf(m_out_buf, JPGE_OUT_BUF_SIZE - m_out_buf_left);
m_pOut_buf = m_out_buf;
m_out_buf_left = JPGE_OUT_BUF_SIZE;
}
void jpeg_encoder::put_bits(uint bits, uint len) {
m_bit_buffer |= ((uint32)bits << (24 - (m_bits_in += len)));
while (m_bits_in >= 8) {
uint8 c;
#define JPGE_PUT_BYTE(c) \
{ \
*m_pOut_buf++ = (c); \
if (--m_out_buf_left == 0) \
flush_output_buffer(); \
}
JPGE_PUT_BYTE(c = (uint8)((m_bit_buffer >> 16) & 0xFF));
if (c == 0xFF)
JPGE_PUT_BYTE(0);
m_bit_buffer <<= 8;
m_bits_in -= 8;
}
}
void jpeg_encoder::code_coefficients_pass_one(int component_num) {
if (component_num >= 3)
return; // just to shut up static analysis
int i, run_len, nbits, temp1;
int16 *src = m_coefficient_array;
uint32 *dc_count = component_num ? m_huff_count[0 + 1] : m_huff_count[0 + 0],
*ac_count = component_num ? m_huff_count[2 + 1] : m_huff_count[2 + 0];
temp1 = src[0] - m_last_dc_val[component_num];
m_last_dc_val[component_num] = src[0];
if (temp1 < 0)
temp1 = -temp1;
nbits = 0;
while (temp1) {
nbits++;
temp1 >>= 1;
}
dc_count[nbits]++;
for (run_len = 0, i = 1; i < 64; i++) {
if ((temp1 = m_coefficient_array[i]) == 0)
run_len++;
else {
while (run_len >= 16) {
ac_count[0xF0]++;
run_len -= 16;
}
if (temp1 < 0)
temp1 = -temp1;
nbits = 1;
while (temp1 >>= 1)
nbits++;
ac_count[(run_len << 4) + nbits]++;
run_len = 0;
}
}
if (run_len)
ac_count[0]++;
}
void jpeg_encoder::code_coefficients_pass_two(int component_num) {
int i, j, run_len, nbits, temp1, temp2;
int16 *pSrc = m_coefficient_array;
uint *codes[2];
uint8 *code_sizes[2];
if (component_num == 0) {
codes[0] = m_huff_codes[0 + 0];
codes[1] = m_huff_codes[2 + 0];
code_sizes[0] = m_huff_code_sizes[0 + 0];
code_sizes[1] = m_huff_code_sizes[2 + 0];
} else {
codes[0] = m_huff_codes[0 + 1];
codes[1] = m_huff_codes[2 + 1];
code_sizes[0] = m_huff_code_sizes[0 + 1];
code_sizes[1] = m_huff_code_sizes[2 + 1];
}
temp1 = temp2 = pSrc[0] - m_last_dc_val[component_num];
m_last_dc_val[component_num] = pSrc[0];
if (temp1 < 0) {
temp1 = -temp1;
temp2--;
}
nbits = 0;
while (temp1) {
nbits++;
temp1 >>= 1;
}
put_bits(codes[0][nbits], code_sizes[0][nbits]);
if (nbits)
put_bits(temp2 & ((1 << nbits) - 1), nbits);
for (run_len = 0, i = 1; i < 64; i++) {
if ((temp1 = m_coefficient_array[i]) == 0)
run_len++;
else {
while (run_len >= 16) {
put_bits(codes[1][0xF0], code_sizes[1][0xF0]);
run_len -= 16;
}
if ((temp2 = temp1) < 0) {
temp1 = -temp1;
temp2--;
}
nbits = 1;
while (temp1 >>= 1)
nbits++;
j = (run_len << 4) + nbits;
put_bits(codes[1][j], code_sizes[1][j]);
put_bits(temp2 & ((1 << nbits) - 1), nbits);
run_len = 0;
}
}
if (run_len)
put_bits(codes[1][0], code_sizes[1][0]);
}
void jpeg_encoder::code_block(int component_num) {
DCT2D(m_sample_array);
load_quantized_coefficients(component_num);
if (m_pass_num == 1)
code_coefficients_pass_one(component_num);
else
code_coefficients_pass_two(component_num);
}
void jpeg_encoder::process_mcu_row() {
if (m_num_components == 1) {
for (int i = 0; i < m_mcus_per_row; i++) {
load_block_8_8_grey(i);
code_block(0);
}
} else if ((m_comp_h_samp[0] == 1) && (m_comp_v_samp[0] == 1)) {
for (int i = 0; i < m_mcus_per_row; i++) {
load_block_8_8(i, 0, 0);
code_block(0);
load_block_8_8(i, 0, 1);
code_block(1);
load_block_8_8(i, 0, 2);
code_block(2);
}
} else if ((m_comp_h_samp[0] == 2) && (m_comp_v_samp[0] == 1)) {
for (int i = 0; i < m_mcus_per_row; i++) {
load_block_8_8(i * 2 + 0, 0, 0);
code_block(0);
load_block_8_8(i * 2 + 1, 0, 0);
code_block(0);
load_block_16_8_8(i, 1);
code_block(1);
load_block_16_8_8(i, 2);
code_block(2);
}
} else if ((m_comp_h_samp[0] == 2) && (m_comp_v_samp[0] == 2)) {
for (int i = 0; i < m_mcus_per_row; i++) {
load_block_8_8(i * 2 + 0, 0, 0);
code_block(0);
load_block_8_8(i * 2 + 1, 0, 0);
code_block(0);
load_block_8_8(i * 2 + 0, 1, 0);
code_block(0);
load_block_8_8(i * 2 + 1, 1, 0);
code_block(0);
load_block_16_8(i, 1);
code_block(1);
load_block_16_8(i, 2);
code_block(2);
}
}
}
bool jpeg_encoder::terminate_pass_one() {
optimize_huffman_table(0 + 0, DC_LUM_CODES);
optimize_huffman_table(2 + 0, AC_LUM_CODES);
if (m_num_components > 1) {
optimize_huffman_table(0 + 1, DC_CHROMA_CODES);
optimize_huffman_table(2 + 1, AC_CHROMA_CODES);
}
return second_pass_init();
}
bool jpeg_encoder::terminate_pass_two() {
put_bits(0x7F, 7);
flush_output_buffer();
emit_marker(M_EOI);
m_pass_num++; // purposely bump up m_pass_num, for debugging
return true;
}
bool jpeg_encoder::process_end_of_image() {
if (m_mcu_y_ofs) {
if (m_mcu_y_ofs < 16) // check here just to shut up static analysis
{
for (int i = m_mcu_y_ofs; i < m_mcu_y; i++)
memcpy(m_mcu_lines[i], m_mcu_lines[m_mcu_y_ofs - 1], m_image_bpl_mcu);
}
process_mcu_row();
}
if (m_pass_num == 1)
return terminate_pass_one();
else
return terminate_pass_two();
}
void jpeg_encoder::load_mcu(const void *pSrc) {
const uint8 *Psrc = reinterpret_cast<const uint8 *>(pSrc);