#include "jpg.h" #define ERR_NO_SOI 1 #define ERR_NOT_8BIT 2 #define ERR_HEIGHT_MISMATCH 3 #define ERR_WIDTH_MISMATCH 4 #define ERR_BAD_WIDTH_OR_HEIGHT 5 #define ERR_TOO_MANY_COMPPS 6 #define ERR_ILLEGAL_HV 7 #define ERR_QUANT_TABLE_SELECTOR 8 #define ERR_NOT_YCBCR_221111 9 #define ERR_UNKNOWN_CID_IN_SCAN 10 #define ERR_NOT_SEQUENTIAL_DCT 11 #define ERR_WRONG_MARKER 12 #define ERR_NO_EOI 13 #define ERR_BAD_TABLES 14 #define ERR_DEPTH_MISMATCH 15 #define ISHIFT 11 #define IFIX(a) ((int)((a) * (1 << ISHIFT) + .5)) #define IMULT(a, b) (((a) * (b)) >> ISHIFT) #define ITOINT(a) ((a) >> ISHIFT) #ifndef __P # define __P(x) x #endif /* special markers */ #define M_BADHUFF -1 #define M_EOF 0x80 struct in { unsigned int bits; int left; int marker; void *data; }; /*********************************/ struct dec_hufftbl; struct enc_hufftbl; union hufftblp { struct dec_hufftbl *dhuff; struct enc_hufftbl *ehuff; }; struct scan { int dc; /* old dc value */ union hufftblp hudc; union hufftblp huac; int next; /* when to switch to next scan */ int cid; /* component id */ int hv; /* horiz/vert, copied from comp */ int tq; /* quant tbl, copied from comp */ }; /*********************************/ #define DECBITS 8 /* seems to be the optimum */ struct dec_hufftbl { int maxcode[17]; int valptr[16]; unsigned char vals[256]; unsigned int llvals[1 << DECBITS]; }; struct jpeg_decdata { int dcts[6 * 64 + 16]; int out[64 * 6]; int dquant[3][64]; }; static void decode_mcus __P((struct in *, int *, int, struct scan *, int *)); static void dec_makehuff __P((struct dec_hufftbl *, int *, unsigned char *)); static void setinput __P((struct in *)); /*********************************/ #undef PREC #define PREC int static void idctqtab __P((unsigned char *, PREC *)); static void idct __P((int *, int *, PREC *, PREC, int)); static void scaleidctqtab __P((PREC *, PREC)); /*********************************/ static void initcol __P((PREC[][64])); static void col221111(int *out, unsigned char *pic, int width, int bits); static unsigned char tmp_img[16*16*4]; /* 16 x 16, 32 bit color */ /*********************************/ #define M_SOI 0xd8 #define M_APP0 0xe0 #define M_DQT 0xdb #define M_SOF0 0xc0 #define M_DHT 0xc4 #define M_DRI 0xdd #define M_SOS 0xda #define M_RST0 0xd0 #define M_EOI 0xd9 #define M_COM 0xfe static unsigned char *datap; static struct jpeg_decdata decdata; static void memset(void *p, int c, int n) { unsigned char *x = p; while(n--) *x++ = c; } static int getbyte(void) { return *datap++; } static int getword(void) { int c1, c2; c1 = *datap; c2 = datap[1]; datap += 2; return c1 << 8 | c2; } struct comp { int cid; int hv; int tq; }; #define MAXCOMP 4 struct jpginfo { int nc; /* number of components */ int ns; /* number of scans */ int dri; /* restart interval */ }; static struct jpginfo info; static struct comp comps[MAXCOMP]; static struct scan dscans[MAXCOMP]; static unsigned char quant[4][64]; static struct dec_hufftbl dhuff[4]; #define dec_huffdc (dhuff + 0) #define dec_huffac (dhuff + 2) static struct in in; static int readtables(int till) { int m, l, i, j, lq, pq, tq; int tc, th, tt; for (;;) { if (getbyte() != 0xff) return -1; if ((m = getbyte()) == till) break; switch (m) { case 0xc2: return 0; case M_DQT: lq = getword(); while (lq > 2) { pq = getbyte(); tq = pq & 15; if (tq > 3) return -1; pq >>= 4; if (pq != 0) return -1; for (i = 0; i < 64; i++) quant[tq][i] = getbyte(); lq -= 64 + 1; } break; case M_DHT: l = getword(); while (l > 2) { int hufflen[16], k; unsigned char huffvals[256]; tc = getbyte(); th = tc & 15; tc >>= 4; tt = tc * 2 + th; if (tc > 1 || th > 1) return -1; for (i = 0; i < 16; i++) hufflen[i] = getbyte(); l -= 1 + 16; k = 0; for (i = 0; i < 16; i++) { for (j = 0; j < hufflen[i]; j++) huffvals[k++] = getbyte(); l -= hufflen[i]; } dec_makehuff(dhuff + tt, hufflen, huffvals); } break; case M_DRI: l = getword(); info.dri = getword(); break; default: l = getword(); while (l-- > 2) getbyte(); break; } } return 0; } static void dec_initscans(void) { int i; for (i = 0; i < info.ns; i++) dscans[i].dc = 0; } int jpeg_decode(unsigned char *buf, unsigned char *pic, int x0, int x1, int y0, int y1, int color_bits) { int i, j, m, tac, tdc; int mcusx, mcusy, mx, my; int max[6]; int width, height; int mx0, mx1, my0, my1; datap = buf; if (getbyte() != 0xff) return ERR_NO_SOI; if (getbyte() != M_SOI) return ERR_NO_SOI; if (readtables(M_SOF0)) return ERR_BAD_TABLES; if(info.dri) return ERR_WRONG_MARKER; getword(); i = getbyte(); if (i != 8) return ERR_NOT_8BIT; height = getword(); width = getword(); info.nc = getbyte(); if (info.nc > MAXCOMP) return ERR_TOO_MANY_COMPPS; for (i = 0; i < info.nc; i++) { int h, v; comps[i].cid = getbyte(); comps[i].hv = getbyte(); v = comps[i].hv & 15; h = comps[i].hv >> 4; comps[i].tq = getbyte(); if (h > 3 || v > 3) return ERR_ILLEGAL_HV; if (comps[i].tq > 3) return ERR_QUANT_TABLE_SELECTOR; } if (readtables(M_SOS)) return ERR_BAD_TABLES; getword(); info.ns = getbyte(); if (info.ns != 3) return ERR_NOT_YCBCR_221111; for (i = 0; i < 3; i++) { dscans[i].cid = getbyte(); tdc = getbyte(); tac = tdc & 15; tdc >>= 4; if (tdc > 1 || tac > 1) return ERR_QUANT_TABLE_SELECTOR; for (j = 0; j < info.nc; j++) if (comps[j].cid == dscans[i].cid) break; if (j == info.nc) return ERR_UNKNOWN_CID_IN_SCAN; dscans[i].hv = comps[j].hv; dscans[i].tq = comps[j].tq; dscans[i].hudc.dhuff = dec_huffdc + tdc; dscans[i].huac.dhuff = dec_huffac + tac; } i = getbyte(); j = getbyte(); m = getbyte(); if (i != 0 || j != 63 || m != 0) return ERR_NOT_SEQUENTIAL_DCT; if (dscans[0].cid != 1 || dscans[1].cid != 2 || dscans[2].cid != 3) return ERR_NOT_YCBCR_221111; if (dscans[0].hv != 0x22 || dscans[1].hv != 0x11 || dscans[2].hv != 0x11) return ERR_NOT_YCBCR_221111; mcusx = (width + 15) >> 4; mcusy = (height + 15) >> 4; mx0 = x0 >> 4; my0 = y0 >> 4; /* inclusive! */ mx1 = ((x1 + 15) >> 4) - 1; my1 = ((y1 + 15) >> 4) - 1; if(my1 < mcusy) mcusy = my1 + 1; idctqtab(quant[dscans[0].tq], decdata.dquant[0]); idctqtab(quant[dscans[1].tq], decdata.dquant[1]); idctqtab(quant[dscans[2].tq], decdata.dquant[2]); initcol(decdata.dquant); setinput(&in); dec_initscans(); dscans[0].next = 6 - 4; dscans[1].next = 6 - 4 - 1; dscans[2].next = 6 - 4 - 1 - 1; /* 411 encoding */ for (my = 0; my < mcusy; my++) { for (mx = 0; mx < mcusx; mx++) { decode_mcus(&in, decdata.dcts, 6, dscans, max); if( my >= my0 && my <= my1 && mx >= mx0 && mx <= mx1 ) { int i0, i1, j0, j1, yofs; idct(decdata.dcts, decdata.out, decdata.dquant[0], IFIX(128.5), max[0]); idct(decdata.dcts + 64, decdata.out + 64, decdata.dquant[0], IFIX(128.5), max[1]); idct(decdata.dcts + 128, decdata.out + 128, decdata.dquant[0], IFIX(128.5), max[2]); idct(decdata.dcts + 192, decdata.out + 192, decdata.dquant[0], IFIX(128.5), max[3]); idct(decdata.dcts + 256, decdata.out + 256, decdata.dquant[1], IFIX(0.5), max[4]); idct(decdata.dcts + 320, decdata.out + 320, decdata.dquant[2], IFIX(0.5), max[5]); // color_bits * 2: actually 16 * (color_bits / 8) col221111(decdata.out, tmp_img, color_bits * 2, color_bits); j0 = my == my0 ? y0 - 16 * my : 0; j1 = my == my1 ? y1 - 16 * my : 16; for(j = j0; j < j1; j++) { yofs = (16 * my - y0 + j) * (x1 - x0); i0 = mx == mx0 ? x0 - 16 * mx : 0; i1 = mx == mx1 ? x1 - 16 * mx : 16; switch(color_bits) { case 8: for(i = i0; i < i1; i++) { *((unsigned char *) pic + 16 * mx - x0 + i + yofs) = *((unsigned char *) tmp_img + 16 * j + i); } break; case 16: for(i = i0; i < i1; i++) { *((unsigned short *) pic + 16 * mx - x0 + i + yofs) = *((unsigned short *) tmp_img + 16 * j + i); } break; case 32: for(i = i0; i < i1; i++) { *((unsigned *) pic + 16 * mx - x0 + i + yofs) = *((unsigned *) tmp_img + 16 * j + i); } break; } } } } } return 0; } /****************************************************************/ /************** huffman decoder ***************/ /****************************************************************/ static int fillbits __P((struct in *, int, unsigned int)); static int dec_rec2 __P((struct in *, struct dec_hufftbl *, int *, int, int)); static void setinput(in) struct in *in; { in->left = 0; in->bits = 0; in->marker = 0; } static int fillbits(in, le, bi) struct in *in; int le; unsigned int bi; { int b, m; if (in->marker) { if (le <= 16) in->bits = bi << 16, le += 16; return le; } while (le <= 24) { b = getbyte(); if (b == 0xff && (m = getbyte()) != 0) { in->marker = m; if (le <= 16) bi = bi << 16, le += 16; break; } bi = bi << 8 | b; le += 8; } in->bits = bi; /* tmp... 2 return values needed */ return le; } #define LEBI_DCL int le, bi #define LEBI_GET(in) (le = in->left, bi = in->bits) #define LEBI_PUT(in) (in->left = le, in->bits = bi) #define GETBITS(in, n) ( \ (le < (n) ? le = fillbits(in, le, bi), bi = in->bits : 0), \ (le -= (n)), \ bi >> le & ((1 << (n)) - 1) \ ) #define UNGETBITS(in, n) ( \ le += (n) \ ) static int dec_rec2(in, hu, runp, c, i) struct in *in; struct dec_hufftbl *hu; int *runp; int c, i; { LEBI_DCL; LEBI_GET(in); if (i) { UNGETBITS(in, i & 127); *runp = i >> 8 & 15; i >>= 16; } else { for (i = DECBITS; (c = ((c << 1) | GETBITS(in, 1))) >= (hu->maxcode[i]); i++); if (i >= 16) { in->marker = M_BADHUFF; return 0; } i = hu->vals[hu->valptr[i] + c - hu->maxcode[i - 1] * 2]; *runp = i >> 4; i &= 15; } if (i == 0) { /* sigh, 0xf0 is 11 bit */ LEBI_PUT(in); return 0; } /* receive part */ c = GETBITS(in, i); if (c < (1 << (i - 1))) c += (-1 << i) + 1; LEBI_PUT(in); return c; } #define DEC_REC(in, hu, r, i) ( \ r = GETBITS(in, DECBITS), \ i = hu->llvals[r], \ i & 128 ? \ ( \ UNGETBITS(in, i & 127), \ r = i >> 8 & 15, \ i >> 16 \ ) \ : \ ( \ LEBI_PUT(in), \ i = dec_rec2(in, hu, &r, r, i), \ LEBI_GET(in), \ i \ ) \ ) static void decode_mcus(in, dct, n, sc, maxp) struct in *in; int *dct; int n; struct scan *sc; int *maxp; { struct dec_hufftbl *hu; int i, r, t; LEBI_DCL; memset(dct, 0, n * 64 * sizeof(*dct)); LEBI_GET(in); while (n-- > 0) { hu = sc->hudc.dhuff; *dct++ = (sc->dc += DEC_REC(in, hu, r, t)); hu = sc->huac.dhuff; i = 63; while (i > 0) { t = DEC_REC(in, hu, r, t); if (t == 0 && r == 0) { dct += i; break; } dct += r; *dct++ = t; i -= r + 1; } *maxp++ = 64 - i; if (n == sc->next) sc++; } LEBI_PUT(in); } static void dec_makehuff(hu, hufflen, huffvals) struct dec_hufftbl *hu; int *hufflen; unsigned char *huffvals; { int code, k, i, j, d, x, c, v; for (i = 0; i < (1 << DECBITS); i++) hu->llvals[i] = 0; /* * llvals layout: * * value v already known, run r, backup u bits: * vvvvvvvvvvvvvvvv 0000 rrrr 1 uuuuuuu * value unknown, size b bits, run r, backup u bits: * 000000000000bbbb 0000 rrrr 0 uuuuuuu * value and size unknown: * 0000000000000000 0000 0000 0 0000000 */ code = 0; k = 0; for (i = 0; i < 16; i++, code <<= 1) { /* sizes */ hu->valptr[i] = k; for (j = 0; j < hufflen[i]; j++) { hu->vals[k] = *huffvals++; if (i < DECBITS) { c = code << (DECBITS - 1 - i); v = hu->vals[k] & 0x0f; /* size */ for (d = 1 << (DECBITS - 1 - i); --d >= 0;) { if (v + i < DECBITS) { /* both fit in table */ x = d >> (DECBITS - 1 - v - i); if (v && x < (1 << (v - 1))) x += (-1 << v) + 1; x = x << 16 | (hu-> vals[k] & 0xf0) << 4 | (DECBITS - (i + 1 + v)) | 128; } else x = v << 16 | (hu-> vals[k] & 0xf0) << 4 | (DECBITS - (i + 1)); hu->llvals[c | d] = x; } } code++; k++; } hu->maxcode[i] = code; } hu->maxcode[16] = 0x20000; /* always terminate decode */ } /****************************************************************/ /************** idct ***************/ /****************************************************************/ #define ONE ((PREC)IFIX(1.)) #define S2 ((PREC)IFIX(0.382683432)) #define C2 ((PREC)IFIX(0.923879532)) #define C4 ((PREC)IFIX(0.707106781)) #define S22 ((PREC)IFIX(2 * 0.382683432)) #define C22 ((PREC)IFIX(2 * 0.923879532)) #define IC4 ((PREC)IFIX(1 / 0.707106781)) #define C3IC1 ((PREC)IFIX(0.847759065)) /* c3/c1 */ #define C5IC1 ((PREC)IFIX(0.566454497)) /* c5/c1 */ #define C7IC1 ((PREC)IFIX(0.198912367)) /* c7/c1 */ #define XPP(a,b) (t = a + b, b = a - b, a = t) #define XMP(a,b) (t = a - b, b = a + b, a = t) #define XPM(a,b) (t = a + b, b = b - a, a = t) #define ROT(a,b,s,c) ( t = IMULT(a + b, s), \ a = IMULT(a, c - s) + t, \ b = IMULT(b, c + s) - t) #define IDCT \ ( \ XPP(t0, t1), \ XMP(t2, t3), \ t2 = IMULT(t2, IC4) - t3, \ XPP(t0, t3), \ XPP(t1, t2), \ XMP(t4, t7), \ XPP(t5, t6), \ XMP(t5, t7), \ t5 = IMULT(t5, IC4), \ ROT(t4, t6, S22, C22),\ t6 -= t7, \ t5 -= t6, \ t4 -= t5, \ XPP(t0, t7), \ XPP(t1, t6), \ XPP(t2, t5), \ XPP(t3, t4) \ ) static unsigned char zig2[64] = { 0, 2, 3, 9, 10, 20, 21, 35, 14, 16, 25, 31, 39, 46, 50, 57, 5, 7, 12, 18, 23, 33, 37, 48, 27, 29, 41, 44, 52, 55, 59, 62, 15, 26, 30, 40, 45, 51, 56, 58, 1, 4, 8, 11, 19, 22, 34, 36, 28, 42, 43, 53, 54, 60, 61, 63, 6, 13, 17, 24, 32, 38, 47, 49 }; void idct(in, out, quant, off, max) int *in; int *out; PREC *quant; PREC off; int max; { PREC t0, t1, t2, t3, t4, t5, t6, t7, t; PREC tmp[64], *tmpp; int i, j; unsigned char *zig2p; t0 = off; if (max == 1) { t0 += in[0] * quant[0]; for (i = 0; i < 64; i++) out[i] = ITOINT(t0); return; } zig2p = zig2; tmpp = tmp; for (i = 0; i < 8; i++) { j = *zig2p++; t0 += in[j] * quant[j]; j = *zig2p++; t5 = in[j] * quant[j]; j = *zig2p++; t2 = in[j] * quant[j]; j = *zig2p++; t7 = in[j] * quant[j]; j = *zig2p++; t1 = in[j] * quant[j]; j = *zig2p++; t4 = in[j] * quant[j]; j = *zig2p++; t3 = in[j] * quant[j]; j = *zig2p++; t6 = in[j] * quant[j]; IDCT; tmpp[0 * 8] = t0; tmpp[1 * 8] = t1; tmpp[2 * 8] = t2; tmpp[3 * 8] = t3; tmpp[4 * 8] = t4; tmpp[5 * 8] = t5; tmpp[6 * 8] = t6; tmpp[7 * 8] = t7; tmpp++; t0 = 0; } for (i = 0; i < 8; i++) { t0 = tmp[8 * i + 0]; t1 = tmp[8 * i + 1]; t2 = tmp[8 * i + 2]; t3 = tmp[8 * i + 3]; t4 = tmp[8 * i + 4]; t5 = tmp[8 * i + 5]; t6 = tmp[8 * i + 6]; t7 = tmp[8 * i + 7]; IDCT; out[8 * i + 0] = ITOINT(t0); out[8 * i + 1] = ITOINT(t1); out[8 * i + 2] = ITOINT(t2); out[8 * i + 3] = ITOINT(t3); out[8 * i + 4] = ITOINT(t4); out[8 * i + 5] = ITOINT(t5); out[8 * i + 6] = ITOINT(t6); out[8 * i + 7] = ITOINT(t7); } } static unsigned char zig[64] = { 0, 1, 5, 6, 14, 15, 27, 28, 2, 4, 7, 13, 16, 26, 29, 42, 3, 8, 12, 17, 25, 30, 41, 43, 9, 11, 18, 24, 31, 40, 44, 53, 10, 19, 23, 32, 39, 45, 52, 54, 20, 22, 33, 38, 46, 51, 55, 60, 21, 34, 37, 47, 50, 56, 59, 61, 35, 36, 48, 49, 57, 58, 62, 63 }; static PREC aaidct[8] = { IFIX(0.3535533906), IFIX(0.4903926402), IFIX(0.4619397663), IFIX(0.4157348062), IFIX(0.3535533906), IFIX(0.2777851165), IFIX(0.1913417162), IFIX(0.0975451610) }; static void idctqtab(qin, qout) unsigned char *qin; PREC *qout; { int i, j; for (i = 0; i < 8; i++) for (j = 0; j < 8; j++) qout[zig[i * 8 + j]] = qin[zig[i * 8 + j]] * IMULT(aaidct[i], aaidct[j]); } static void scaleidctqtab(q, sc) PREC *q; PREC sc; { int i; for (i = 0; i < 64; i++) q[i] = IMULT(q[i], sc); } /****************************************************************/ /************** color decoder ***************/ /****************************************************************/ /* * YCbCr Color transformation: * * y:0..255 Cb:-128..127 Cr:-128..127 * * R = Y + 1.40200 * Cr * G = Y - 0.34414 * Cb - 0.71414 * Cr * B = Y + 1.77200 * Cb * * => * Cr *= 1.40200; * Cb *= 1.77200; * Cg = 0.19421 * Cb + .50937 * Cr; * R = Y + Cr; * G = Y - Cg; * B = Y + Cb; * * => * Cg = (50 * Cb + 130 * Cr + 128) >> 8; */ static void initcol(q) PREC q[][64]; { scaleidctqtab(q[1], IFIX(1.77200)); scaleidctqtab(q[2], IFIX(1.40200)); } /* This is optimized for the stupid sun SUNWspro compiler. */ #define STORECLAMP(a,x) \ ( \ (a) = (x), \ (unsigned int)(x) >= 256 ? \ ((a) = (x) < 0 ? 0 : 255) \ : \ 0 \ ) #define CLAMP(x) ((unsigned int)(x) >= 256 ? ((x) < 0 ? 0 : 255) : (x)) #define CBCRCG(xin) \ ( \ cb = outc[0 + xin], \ cr = outc[64 + xin], \ cg = (50 * cb + 130 * cr + 128) >> 8 \ ) #define PIC(yin, xin, p, xout) \ ( \ y = outy[(yin) * 8 + xin], \ STORECLAMP(p[(xout) * 4 + 0], y + cb), \ STORECLAMP(p[(xout) * 4 + 1], y - cg), \ STORECLAMP(p[(xout) * 4 + 2], y + cr) \ ) #define PIC221111x(xin, xin_4, xin_3) \ ( \ CBCRCG(xin), \ PIC(xin_4 + 0, xin_3 + 0, pic0, xin * 2 + 0), \ PIC(xin_4 + 0, xin_3 + 1, pic0, xin * 2 + 1), \ PIC(xin_4 + 1, xin_3 + 0, pic1, xin * 2 + 0), \ PIC(xin_4 + 1, xin_3 + 1, pic1, xin * 2 + 1) \ ) #define PIC_16(yin, xin, p, xout, add) \ ( \ y = outy[(yin) * 8 + xin], \ *(unsigned short *) (p + (xout) * 2) = store_16(CLAMP(y + cr), CLAMP(y - cg), CLAMP(y + cb), add) \ ) #define PIC221111_16x(xin, xin_4, xin_3) \ ( \ CBCRCG(xin), \ PIC_16(xin_4 + 0, xin_3 + 0, pic0, xin * 2 + 0, 3 * 0x55), \ PIC_16(xin_4 + 0, xin_3 + 1, pic0, xin * 2 + 1, 0 * 0x55), \ PIC_16(xin_4 + 1, xin_3 + 0, pic1, xin * 2 + 0, 1 * 0x55), \ PIC_16(xin_4 + 1, xin_3 + 1, pic1, xin * 2 + 1, 2 * 0x55) \ ) #define PIC_8(yin, xin, p, xout, add) \ ( \ y = outy[(yin) * 8 + xin], \ p[(xout)] = store_8(CLAMP(y + cr), CLAMP(y - cg), CLAMP(y + cb), add) \ ) #define PIC221111_8x(xin, xin_4, xin_3) \ ( \ CBCRCG(xin), \ PIC_8(xin_4 + 0, xin_3 + 0, pic0, xin * 2 + 0, 3 * 0x55), \ PIC_8(xin_4 + 0, xin_3 + 1, pic0, xin * 2 + 1, 0 * 0x55), \ PIC_8(xin_4 + 1, xin_3 + 0, pic1, xin * 2 + 0, 1 * 0x55), \ PIC_8(xin_4 + 1, xin_3 + 1, pic1, xin * 2 + 1, 2 * 0x55) \ ) static unsigned store_16(unsigned r, unsigned g, unsigned b, unsigned add) { unsigned rgb; rgb = (((r << 5) - r + add) >> 8) << 11; rgb += (((g << 6) - g + add) >> 8) << 5; rgb += ((b << 5) - b + add) >> 8; return rgb; } static unsigned store_8(unsigned r, unsigned g, unsigned b, unsigned add) { unsigned rgb; #if 0 r = ((r << 2) - r + add) >> 8; g = ((g << 3) - g + add) >> 8; b = ((b << 3) - b + add) >> 8; rgb = (r << 6) + (g << 3) + b; #endif rgb = (((r << 2) - r + add) >> 8) << 6; rgb += (((g << 3) - g + add) >> 8) << 3; rgb += ((b << 3) - b + add) >> 8; return rgb; } static void col221111(int *out, unsigned char *pic, int width, int bits) { int i, j, k, k_4, k_3; unsigned char *pic0, *pic1; int *outy, *outc; int cr, cg, cb, y; pic0 = pic; pic1 = pic + width; outy = out; outc = out + 64 * 4; for(i = 2; i > 0; i--) { for(j = 4; j > 0; j--) { for(k = 0; k < 8; k++) { k_4 = (k >> 2) << 3; k_3 = (k & 3) << 1; switch(bits) { case 8: PIC221111_8x(k, k_4, k_3); break; case 16: PIC221111_16x(k, k_4, k_3); break; case 32: PIC221111x(k, k_4, k_3); break; } } outc += 8; outy += 16; pic0 += 2 * width; pic1 += 2 * width; } outy += 64 * 2 - 16 * 4; } } /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ unsigned jpeg_get_size(unsigned char *buf) { unsigned u; datap = buf; getbyte(); getbyte(); if(readtables(M_SOF0)) return 0; getword(); getbyte(); u = getword() << 16; u += getword(); return u; }