📄 qc-mjpeg.c
字号:
/* fourth stage */ block[0] = (x7 + x1) >> 8; block[1] = (x3 + x2) >> 8; block[2] = (x0 + x4) >> 8; block[3] = (x8 + x6) >> 8; block[4] = (x8 - x6) >> 8; block[5] = (x0 - x4) >> 8; block[6] = (x3 - x2) >> 8; block[7] = (x7 - x1) >> 8;}/* }}} *//* {{{ [fold] qc_mjpeg_idct_col(s16 *block) *//* column (vertical) IDCT * * 7 pi 1 * dst[8*k] = sum c[l] * src[8*l] * cos ( -- * ( k + - ) * l ) * l=0 8 2 * * where: c[0] = 1/1024 * c[1..7] = (1/1024)*sqrt (2) */static void inline qc_mjpeg_idct_col(s16 *block){ int x0, x1, x2, x3, x4, x5, x6, x7, x8; /* shortcut */ x1 = block [8*4] << 8; x2 = block [8*6]; x3 = block [8*2]; x4 = block [8*1]; x5 = block [8*7]; x6 = block [8*5]; x7 = block [8*3];#if 0 if (! (x1 | x2 | x3 | x4 | x5 | x6 | x7 )) { block[8*0] = block[8*1] = block[8*2] = block[8*3] = block[8*4] = block[8*5] = block[8*6] = block[8*7] = (block[8*0] + 32) >> 6; return; }#endif x0 = (block[8*0] << 8) + 8192; /* first stage */ x8 = W7 * (x4 + x5) + 4; x4 = (x8 + (W1 - W7) * x4) >> 3; x5 = (x8 - (W1 + W7) * x5) >> 3; x8 = W3 * (x6 + x7) + 4; x6 = (x8 - (W3 - W5) * x6) >> 3; x7 = (x8 - (W3 + W5) * x7) >> 3; /* second stage */ x8 = x0 + x1; x0 -= x1; x1 = W6 * (x3 + x2) + 4; x2 = (x1 - (W2 + W6) * x2) >> 3; x3 = (x1 + (W2 - W6) * x3) >> 3; x1 = x4 + x6; x4 -= x6; x6 = x5 + x7; x5 -= x7; /* third stage */ x7 = x8 + x3; x8 -= x3; x3 = x0 + x2; x0 -= x2; x2 = (181 * (x4 + x5) + 128) >> 8; x4 = (181 * (x4 - x5) + 128) >> 8; /* fourth stage */ block[8*0] = (x7 + x1) >> 14; block[8*1] = (x3 + x2) >> 14; block[8*2] = (x0 + x4) >> 14; block[8*3] = (x8 + x6) >> 14; block[8*4] = (x8 - x6) >> 14; block[8*5] = (x0 - x4) >> 14; block[8*6] = (x3 - x2) >> 14; block[8*7] = (x7 - x1) >> 14;}/* }}} *//* {{{ [fold] qc_mjpeg_idct(s16 *block, u8 *dest, int stride) *//* Inverse discrete cosine transform block, store result to dest */static void qc_mjpeg_idct(s16 *block, u8 *dest, int stride){ int i; if (qcdebug&QC_DEBUGLOGIC) PDEBUG("qc_mjpeg_idct(block=%p,dest=%p,stride=%i)",block,dest,stride); for (i=0; i<8; i++) qc_mjpeg_idct_row(block + 8*i); for (i=0; i<8; i++) qc_mjpeg_idct_col(block + i); i = 8; do { /* The original code used lookup-tables instead of explicit * comparisons (as CLIP is doing here). However, sometimes * the values pointed outside the LUT which caused problems * in the kernel driver. Thus, the LUTs are removed here. */ dest[0] = CLIP(block[0],0,255); dest[1] = CLIP(block[1],0,255); dest[2] = CLIP(block[2],0,255); dest[3] = CLIP(block[3],0,255); dest[4] = CLIP(block[4],0,255); dest[5] = CLIP(block[5],0,255); dest[6] = CLIP(block[6],0,255); dest[7] = CLIP(block[7],0,255); dest += stride; block += 8; } while (--i);}/* }}} *//* }}} *//* {{{ [fold] **** MJPEG decoding: bitstream processing (structures and macros) * *//* the idea is taken from zlib, but the bits are ordered the other way, so * I modified the code. * Variables: * p points to next unread byte in stream. * k number of bits read but not processed. * b contains the read but not processed bits in the k most significant bits. */struct bitstream { u32 b; u8 *p; u8 *end; int k;};#define GETWORD(p) ((p)[0] << 8 | (p)[1])#define NEEDBITS(b,k,p) \ do { \ if ((k) > 0) { \ (b) |= GETWORD(p) << (k); \ (p) += 2; \ (k) -= 16; \ } \ } while(0)#define DUMPBITS(b,k,j) do { (k) += (j); (b) <<= (j); } while (0)#define BITVALUE(b,j) ((b)>>(32-(j)))/* }}} *//* {{{ [fold] **** qc_mjpeg_lvc: MJPEG decoding: variable length code decoding **************** *//* {{{ [fold] u8 shiftTables[18][64] */static const u8 shiftTables[18][64] = { {2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 }, {2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2 }, {2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2 }, {2,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3 }, {2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3, 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3 }, {2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, 3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4 }, {2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4 }, {2,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5 }, {2,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6, 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6 }, {2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2 }, {2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3 }, {2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3, 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3 }, {2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, 3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4 }, {2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4 }, {2,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5 }, {2,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5, 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5 }, {2,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, 5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6 }, {2,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 },};/* }}} *//* {{{ [fold] u8 shiftTblIndex[] */static const u8 shiftTblIndex[] = { 8, 17, 8, 16, 7, 16, 7, 15, 6, 15, 6, 14, 5, 14, 5, 13, 4, 13, 4, 12, 3, 12, 3, 11, 2, 11, 2, 10, 1, 9, 0, 9};/* }}} *//* {{{ [fold] s16 scaleTable[64] */static const s16 scaleTable[64] = { 8192, 16704, 16704, 17733, 17032, 17733, 18204, 18081, 18081, 18204, 18724, 18561, 19195, 18561, 18724, 19265, 19091, 19704, 19704, 19091, 19265, 21406, 19642, 20267, 20228, 20267, 19642, 21406, 22725, 21826, 20852, 20805, 20805, 20852, 21826, 22725, 23170, 23170, 21406, 21399, 21406, 23170, 23170, 24597, 23785, 22017, 22017, 23785, 24597, 25250, 24464, 22653, 24464, 25250, 25971, 25171, 25171, 25971, 26722, 27969, 26722, 29691, 29691, 31520};/* }}} *//* {{{ [fold] u8 scan_norm[64] */static const u8 scan_norm[64] = { /* Octals */ 000, 001, 010, 020, 011, 002, 003, 012, 021, 030, 040, 031, 022, 013, 004, 005, 014, 023, 032, 041, 050, 060, 051, 042, 033, 024, 015, 006, 007, 016, 025, 034, 043, 052, 061, 070, 071, 062, 053, 044, 035, 026, 017, 027, 036, 045, 054, 063, 072, 073, 064, 055, 046, 037, 047, 056, 065, 074, 075, 066, 057, 067, 076, 077};/* }}} *//* {{{ [fold] hufftable[960] */struct hufftable_entry { s16 value; u8 bits; u8 skip;};static const struct hufftable_entry hufftable[960] = { /* first level entries */ { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { 1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { -1, 3, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { 2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { -2, 4, 1 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 32767, 4, 255 }, { 1, 5, 2 }, { 1, 5, 2 }, { 1, 5, 2 }, { 1, 5, 2 }, { 1, 5, 2 }, { 1, 5, 2 }, { 1, 5, 2 }, { 1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { -1, 5, 2 }, { 3, 5, 1 }, { 3, 5, 1 }, { 3, 5, 1 }, { 3, 5, 1 }, { 3, 5, 1 }, { 3, 5, 1 }, { 3, 5, 1 }, { 3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { -3, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { 4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { -4, 5, 1 }, { 1, 6, 3 }, { 1, 6, 3 }, { 1, 6, 3 }, { 1, 6, 3 }, { -1, 6, 3 }, { -1, 6, 3 }, { -1, 6, 3 }, { -1, 6, 3 }, { 2, 6, 2 }, { 2, 6, 2 }, { 2, 6, 2 }, { 2, 6, 2 }, { -2, 6, 2 }, { -2, 6, 2 }, { -2, 6, 2 }, { -2, 6, 2 }, { 5, 6, 1 }, { 5, 6, 1 }, { 5, 6, 1 }, { 5, 6, 1 }, { -5, 6, 1 }, { -5, 6, 1 }, { -5, 6, 1 }, { -5, 6, 1 }, { 6, 6, 1 }, { 6, 6, 1 }, { 6, 6, 1 }, { 6, 6, 1 }, { -6, 6, 1 }, { -6, 6, 1 }, { -6, 6, 1 }, { -6, 6, 1 }, { 1, 7, 4 }, { 1, 7, 4 }, { -1, 7, 4 }, { -1, 7, 4 }, { 1, 7, 5 }, { 1, 7, 5 }, { -1, 7, 5 }, { -1, 7, 5 }, { 7, 7, 1 }, { 7, 7, 1 }, { -7, 7, 1 }, { -7, 7, 1 }, { 8, 7, 1 }, { 8, 7, 1 }, { -8, 7, 1 }, { -8, 7, 1 }, { 1, 8, 6 }, { -1, 8, 6 }, { 1, 8, 7 }, { -1, 8, 7 }, { 2, 8, 3 }, { -2, 8, 3 }, { 3, 8, 2 }, { -3, 8, 2 }, { 4, 8, 2 }, { -4, 8, 2 }, { 9, 8, 1 }, { -9, 8, 1 }, { 10, 8, 1 }, { -10, 8, 1 }, { 11, 8, 1 }, { -11, 8, 1 }, { 256, 9, 99 }, { 258, 9, 99 }, { 260, 9, 99 }, { 262, 9, 99 }, { 264, 9, 99 }, { 266, 9, 99 }, { 268, 9, 99 }, { 270, 9, 99 }, { 272, 9, 99 }, { 274, 9, 99 }, { 276, 9, 99 }, { 278, 9, 99 }, { 280, 9, 99 }, { 282, 9, 99 }, { 284, 9, 99 }, { 286, 9, 99 }, { 288, 10, 99 }, { 292, 10, 99 }, { 296, 10, 99 }, { 300, 10, 99 }, { 304, 10, 99 }, { 308, 10, 99 }, { 312, 10, 99 }, { 316, 10, 99 }, { 320, 11, 99 }, { 328, 11, 99 }, { 336, 12, 99 }, { 352, 13, 99 }, { 384, 13, 99 }, { 416, 13, 99 }, { 448, 16, 99 }, { 704, 16, 99 }, /* indirect entries */ { 1, 9, 8 }, { -1, 9, 8 }, { 1, 9, 9 }, { -1, 9, 9 }, { 1, 9, 10 }, { -1, 9, 10 }, { 1, 9, 11 }, { -1, 9, 11 }, { 2, 9, 4 },⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -