| // jpgd.cpp - C++ class for JPEG decompression. |
| // Public domain, Rich Geldreich <richgel99@gmail.com> |
| // Alex Evans: Linear memory allocator (taken from jpge.h). |
| // v1.04, May. 19, 2012: Code tweaks to fix VS2008 static code analysis warnings (all looked harmless) |
| // |
| // Supports progressive and baseline sequential JPEG image files, and the most common chroma subsampling factors: Y, H1V1, H2V1, H1V2, and H2V2. |
| // |
| // Chroma upsampling quality: H2V2 is upsampled in the frequency domain, H2V1 and H1V2 are upsampled using point sampling. |
| // Chroma upsampling reference: "Fast Scheme for Image Size Change in the Compressed Domain" |
| // http://vision.ai.uiuc.edu/~dugad/research/dct/index.html |
| |
| #include "jpgd.h" |
| #include <string.h> |
| |
| #include <assert.h> |
| #define JPGD_ASSERT(x) assert(x) |
| |
| #ifdef _MSC_VER |
| #pragma warning (disable : 4611) // warning C4611: interaction between '_setjmp' and C++ object destruction is non-portable |
| #endif |
| |
| // Set to 1 to enable freq. domain chroma upsampling on images using H2V2 subsampling (0=faster nearest neighbor sampling). |
| // This is slower, but results in higher quality on images with highly saturated colors. |
| #define JPGD_SUPPORT_FREQ_DOMAIN_UPSAMPLING 1 |
| |
| #define JPGD_TRUE (1) |
| #define JPGD_FALSE (0) |
| |
| #define JPGD_MAX(a,b) (((a)>(b)) ? (a) : (b)) |
| #define JPGD_MIN(a,b) (((a)<(b)) ? (a) : (b)) |
| |
| namespace jpgd { |
| |
| static inline void *jpgd_malloc(size_t nSize) { return malloc(nSize); } |
| static inline void jpgd_free(void *p) { free(p); } |
| |
| // DCT coefficients are stored in this sequence. |
| static int g_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 }; |
| |
| enum JPEG_MARKER |
| { |
| M_SOF0 = 0xC0, M_SOF1 = 0xC1, M_SOF2 = 0xC2, M_SOF3 = 0xC3, M_SOF5 = 0xC5, M_SOF6 = 0xC6, M_SOF7 = 0xC7, M_JPG = 0xC8, |
| M_SOF9 = 0xC9, M_SOF10 = 0xCA, M_SOF11 = 0xCB, M_SOF13 = 0xCD, M_SOF14 = 0xCE, M_SOF15 = 0xCF, M_DHT = 0xC4, M_DAC = 0xCC, |
| M_RST0 = 0xD0, M_RST1 = 0xD1, M_RST2 = 0xD2, M_RST3 = 0xD3, M_RST4 = 0xD4, M_RST5 = 0xD5, M_RST6 = 0xD6, M_RST7 = 0xD7, |
| M_SOI = 0xD8, M_EOI = 0xD9, M_SOS = 0xDA, M_DQT = 0xDB, M_DNL = 0xDC, M_DRI = 0xDD, M_DHP = 0xDE, M_EXP = 0xDF, |
| M_APP0 = 0xE0, M_APP15 = 0xEF, M_JPG0 = 0xF0, M_JPG13 = 0xFD, M_COM = 0xFE, M_TEM = 0x01, M_ERROR = 0x100, RST0 = 0xD0 |
| }; |
| |
| enum JPEG_SUBSAMPLING { JPGD_GRAYSCALE = 0, JPGD_YH1V1, JPGD_YH2V1, JPGD_YH1V2, JPGD_YH2V2 }; |
| |
| #define CONST_BITS 13 |
| #define PASS1_BITS 2 |
| #define SCALEDONE ((int32)1) |
| |
| #define FIX_0_298631336 ((int32)2446) /* FIX(0.298631336) */ |
| #define FIX_0_390180644 ((int32)3196) /* FIX(0.390180644) */ |
| #define FIX_0_541196100 ((int32)4433) /* FIX(0.541196100) */ |
| #define FIX_0_765366865 ((int32)6270) /* FIX(0.765366865) */ |
| #define FIX_0_899976223 ((int32)7373) /* FIX(0.899976223) */ |
| #define FIX_1_175875602 ((int32)9633) /* FIX(1.175875602) */ |
| #define FIX_1_501321110 ((int32)12299) /* FIX(1.501321110) */ |
| #define FIX_1_847759065 ((int32)15137) /* FIX(1.847759065) */ |
| #define FIX_1_961570560 ((int32)16069) /* FIX(1.961570560) */ |
| #define FIX_2_053119869 ((int32)16819) /* FIX(2.053119869) */ |
| #define FIX_2_562915447 ((int32)20995) /* FIX(2.562915447) */ |
| #define FIX_3_072711026 ((int32)25172) /* FIX(3.072711026) */ |
| |
| #define DESCALE(x,n) (((x) + (SCALEDONE << ((n)-1))) >> (n)) |
| #define DESCALE_ZEROSHIFT(x,n) (((x) + (128 << (n)) + (SCALEDONE << ((n)-1))) >> (n)) |
| |
| #define MULTIPLY(var, cnst) ((var) * (cnst)) |
| |
| #define CLAMP(i) ((static_cast<uint>(i) > 255) ? (((~i) >> 31) & 0xFF) : (i)) |
| |
| static const char *err_reason; |
| |
| // Compiler creates a fast path 1D IDCT for X non-zero columns |
| template <int NONZERO_COLS> |
| struct Row |
| { |
| static void idct(int* pTemp, const jpgd_block_t* pSrc) |
| { |
| // ACCESS_COL() will be optimized at compile time to either an array access, or 0. |
| #define ACCESS_COL(x) (((x) < NONZERO_COLS) ? (int)pSrc[x] : 0) |
| |
| const int z2 = ACCESS_COL(2), z3 = ACCESS_COL(6); |
| |
| const int z1 = MULTIPLY(z2 + z3, FIX_0_541196100); |
| const int tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065); |
| const int tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); |
| |
| const int tmp0 = (ACCESS_COL(0) + ACCESS_COL(4)) << CONST_BITS; |
| const int tmp1 = (ACCESS_COL(0) - ACCESS_COL(4)) << CONST_BITS; |
| |
| const int tmp10 = tmp0 + tmp3, tmp13 = tmp0 - tmp3, tmp11 = tmp1 + tmp2, tmp12 = tmp1 - tmp2; |
| |
| const int atmp0 = ACCESS_COL(7), atmp1 = ACCESS_COL(5), atmp2 = ACCESS_COL(3), atmp3 = ACCESS_COL(1); |
| |
| const int bz1 = atmp0 + atmp3, bz2 = atmp1 + atmp2, bz3 = atmp0 + atmp2, bz4 = atmp1 + atmp3; |
| const int bz5 = MULTIPLY(bz3 + bz4, FIX_1_175875602); |
| |
| const int az1 = MULTIPLY(bz1, - FIX_0_899976223); |
| const int az2 = MULTIPLY(bz2, - FIX_2_562915447); |
| const int az3 = MULTIPLY(bz3, - FIX_1_961570560) + bz5; |
| const int az4 = MULTIPLY(bz4, - FIX_0_390180644) + bz5; |
| |
| const int btmp0 = MULTIPLY(atmp0, FIX_0_298631336) + az1 + az3; |
| const int btmp1 = MULTIPLY(atmp1, FIX_2_053119869) + az2 + az4; |
| const int btmp2 = MULTIPLY(atmp2, FIX_3_072711026) + az2 + az3; |
| const int btmp3 = MULTIPLY(atmp3, FIX_1_501321110) + az1 + az4; |
| |
| pTemp[0] = DESCALE(tmp10 + btmp3, CONST_BITS-PASS1_BITS); |
| pTemp[7] = DESCALE(tmp10 - btmp3, CONST_BITS-PASS1_BITS); |
| pTemp[1] = DESCALE(tmp11 + btmp2, CONST_BITS-PASS1_BITS); |
| pTemp[6] = DESCALE(tmp11 - btmp2, CONST_BITS-PASS1_BITS); |
| pTemp[2] = DESCALE(tmp12 + btmp1, CONST_BITS-PASS1_BITS); |
| pTemp[5] = DESCALE(tmp12 - btmp1, CONST_BITS-PASS1_BITS); |
| pTemp[3] = DESCALE(tmp13 + btmp0, CONST_BITS-PASS1_BITS); |
| pTemp[4] = DESCALE(tmp13 - btmp0, CONST_BITS-PASS1_BITS); |
| } |
| }; |
| |
| template <> |
| struct Row<0> |
| { |
| static void idct(int* pTemp, const jpgd_block_t* pSrc) |
| { |
| #ifdef _MSC_VER |
| pTemp; pSrc; |
| #endif |
| } |
| }; |
| |
| template <> |
| struct Row<1> |
| { |
| static void idct(int* pTemp, const jpgd_block_t* pSrc) |
| { |
| const int dcval = (pSrc[0] << PASS1_BITS); |
| |
| pTemp[0] = dcval; |
| pTemp[1] = dcval; |
| pTemp[2] = dcval; |
| pTemp[3] = dcval; |
| pTemp[4] = dcval; |
| pTemp[5] = dcval; |
| pTemp[6] = dcval; |
| pTemp[7] = dcval; |
| } |
| }; |
| |
| // Compiler creates a fast path 1D IDCT for X non-zero rows |
| template <int NONZERO_ROWS> |
| struct Col |
| { |
| static void idct(uint8* pDst_ptr, const int* pTemp) |
| { |
| // ACCESS_ROW() will be optimized at compile time to either an array access, or 0. |
| #define ACCESS_ROW(x) (((x) < NONZERO_ROWS) ? pTemp[x * 8] : 0) |
| |
| const int z2 = ACCESS_ROW(2); |
| const int z3 = ACCESS_ROW(6); |
| |
| const int z1 = MULTIPLY(z2 + z3, FIX_0_541196100); |
| const int tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065); |
| const int tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); |
| |
| const int tmp0 = (ACCESS_ROW(0) + ACCESS_ROW(4)) << CONST_BITS; |
| const int tmp1 = (ACCESS_ROW(0) - ACCESS_ROW(4)) << CONST_BITS; |
| |
| const int tmp10 = tmp0 + tmp3, tmp13 = tmp0 - tmp3, tmp11 = tmp1 + tmp2, tmp12 = tmp1 - tmp2; |
| |
| const int atmp0 = ACCESS_ROW(7), atmp1 = ACCESS_ROW(5), atmp2 = ACCESS_ROW(3), atmp3 = ACCESS_ROW(1); |
| |
| const int bz1 = atmp0 + atmp3, bz2 = atmp1 + atmp2, bz3 = atmp0 + atmp2, bz4 = atmp1 + atmp3; |
| const int bz5 = MULTIPLY(bz3 + bz4, FIX_1_175875602); |
| |
| const int az1 = MULTIPLY(bz1, - FIX_0_899976223); |
| const int az2 = MULTIPLY(bz2, - FIX_2_562915447); |
| const int az3 = MULTIPLY(bz3, - FIX_1_961570560) + bz5; |
| const int az4 = MULTIPLY(bz4, - FIX_0_390180644) + bz5; |
| |
| const int btmp0 = MULTIPLY(atmp0, FIX_0_298631336) + az1 + az3; |
| const int btmp1 = MULTIPLY(atmp1, FIX_2_053119869) + az2 + az4; |
| const int btmp2 = MULTIPLY(atmp2, FIX_3_072711026) + az2 + az3; |
| const int btmp3 = MULTIPLY(atmp3, FIX_1_501321110) + az1 + az4; |
| |
| int i = DESCALE_ZEROSHIFT(tmp10 + btmp3, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*0] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp10 - btmp3, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*7] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp11 + btmp2, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*1] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp11 - btmp2, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*6] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp12 + btmp1, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*2] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp12 - btmp1, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*5] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp13 + btmp0, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*3] = (uint8)CLAMP(i); |
| |
| i = DESCALE_ZEROSHIFT(tmp13 - btmp0, CONST_BITS+PASS1_BITS+3); |
| pDst_ptr[8*4] = (uint8)CLAMP(i); |
| } |
| }; |
| |
| template <> |
| struct Col<1> |
| { |
| static void idct(uint8* pDst_ptr, const int* pTemp) |
| { |
| int dcval = DESCALE_ZEROSHIFT(pTemp[0], PASS1_BITS+3); |
| const uint8 dcval_clamped = (uint8)CLAMP(dcval); |
| pDst_ptr[0*8] = dcval_clamped; |
| pDst_ptr[1*8] = dcval_clamped; |
| pDst_ptr[2*8] = dcval_clamped; |
| pDst_ptr[3*8] = dcval_clamped; |
| pDst_ptr[4*8] = dcval_clamped; |
| pDst_ptr[5*8] = dcval_clamped; |
| pDst_ptr[6*8] = dcval_clamped; |
| pDst_ptr[7*8] = dcval_clamped; |
| } |
| }; |
| |
| static const uint8 s_idct_row_table[] = |
| { |
| 1,0,0,0,0,0,0,0, 2,0,0,0,0,0,0,0, 2,1,0,0,0,0,0,0, 2,1,1,0,0,0,0,0, 2,2,1,0,0,0,0,0, 3,2,1,0,0,0,0,0, 4,2,1,0,0,0,0,0, 4,3,1,0,0,0,0,0, |
| 4,3,2,0,0,0,0,0, 4,3,2,1,0,0,0,0, 4,3,2,1,1,0,0,0, 4,3,2,2,1,0,0,0, 4,3,3,2,1,0,0,0, 4,4,3,2,1,0,0,0, 5,4,3,2,1,0,0,0, 6,4,3,2,1,0,0,0, |
| 6,5,3,2,1,0,0,0, 6,5,4,2,1,0,0,0, 6,5,4,3,1,0,0,0, 6,5,4,3,2,0,0,0, 6,5,4,3,2,1,0,0, 6,5,4,3,2,1,1,0, 6,5,4,3,2,2,1,0, 6,5,4,3,3,2,1,0, |
| 6,5,4,4,3,2,1,0, 6,5,5,4,3,2,1,0, 6,6,5,4,3,2,1,0, 7,6,5,4,3,2,1,0, 8,6,5,4,3,2,1,0, 8,7,5,4,3,2,1,0, 8,7,6,4,3,2,1,0, 8,7,6,5,3,2,1,0, |
| 8,7,6,5,4,2,1,0, 8,7,6,5,4,3,1,0, 8,7,6,5,4,3,2,0, 8,7,6,5,4,3,2,1, 8,7,6,5,4,3,2,2, 8,7,6,5,4,3,3,2, 8,7,6,5,4,4,3,2, 8,7,6,5,5,4,3,2, |
| 8,7,6,6,5,4,3,2, 8,7,7,6,5,4,3,2, 8,8,7,6,5,4,3,2, 8,8,8,6,5,4,3,2, 8,8,8,7,5,4,3,2, 8,8,8,7,6,4,3,2, 8,8,8,7,6,5,3,2, 8,8,8,7,6,5,4,2, |
| 8,8,8,7,6,5,4,3, 8,8,8,7,6,5,4,4, 8,8,8,7,6,5,5,4, 8,8,8,7,6,6,5,4, 8,8,8,7,7,6,5,4, 8,8,8,8,7,6,5,4, 8,8,8,8,8,6,5,4, 8,8,8,8,8,7,5,4, |
| 8,8,8,8,8,7,6,4, 8,8,8,8,8,7,6,5, 8,8,8,8,8,7,6,6, 8,8,8,8,8,7,7,6, 8,8,8,8,8,8,7,6, 8,8,8,8,8,8,8,6, 8,8,8,8,8,8,8,7, 8,8,8,8,8,8,8,8, |
| }; |
| |
| static const uint8 s_idct_col_table[] = { 1, 1, 2, 3, 3, 3, 3, 3, 3, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8 }; |
| |
| void idct(const jpgd_block_t* pSrc_ptr, uint8* pDst_ptr, int block_max_zag) |
| { |
| JPGD_ASSERT(block_max_zag >= 1); |
| JPGD_ASSERT(block_max_zag <= 64); |
| |
| if (block_max_zag <= 1) |
| { |
| int k = ((pSrc_ptr[0] + 4) >> 3) + 128; |
| k = CLAMP(k); |
| k = k | (k<<8); |
| k = k | (k<<16); |
| |
| for (int i = 8; i > 0; i--) |
| { |
| *(int*)&pDst_ptr[0] = k; |
| *(int*)&pDst_ptr[4] = k; |
| pDst_ptr += 8; |
| } |
| return; |
| } |
| |
| int temp[64]; |
| |
| const jpgd_block_t* pSrc = pSrc_ptr; |
| int* pTemp = temp; |
| |
| const uint8* pRow_tab = &s_idct_row_table[(block_max_zag - 1) * 8]; |
| int i; |
| for (i = 8; i > 0; i--, pRow_tab++) |
| { |
| switch (*pRow_tab) |
| { |
| case 0: Row<0>::idct(pTemp, pSrc); break; |
| case 1: Row<1>::idct(pTemp, pSrc); break; |
| case 2: Row<2>::idct(pTemp, pSrc); break; |
| case 3: Row<3>::idct(pTemp, pSrc); break; |
| case 4: Row<4>::idct(pTemp, pSrc); break; |
| case 5: Row<5>::idct(pTemp, pSrc); break; |
| case 6: Row<6>::idct(pTemp, pSrc); break; |
| case 7: Row<7>::idct(pTemp, pSrc); break; |
| case 8: Row<8>::idct(pTemp, pSrc); break; |
| } |
| |
| pSrc += 8; |
| pTemp += 8; |
| } |
| |
| pTemp = temp; |
| |
| const int nonzero_rows = s_idct_col_table[block_max_zag - 1]; |
| for (i = 8; i > 0; i--) |
| { |
| switch (nonzero_rows) |
| { |
| case 1: Col<1>::idct(pDst_ptr, pTemp); break; |
| case 2: Col<2>::idct(pDst_ptr, pTemp); break; |
| case 3: Col<3>::idct(pDst_ptr, pTemp); break; |
| case 4: Col<4>::idct(pDst_ptr, pTemp); break; |
| case 5: Col<5>::idct(pDst_ptr, pTemp); break; |
| case 6: Col<6>::idct(pDst_ptr, pTemp); break; |
| case 7: Col<7>::idct(pDst_ptr, pTemp); break; |
| case 8: Col<8>::idct(pDst_ptr, pTemp); break; |
| } |
| |
| pTemp++; |
| pDst_ptr++; |
| } |
| } |
| |
| void idct_4x4(const jpgd_block_t* pSrc_ptr, uint8* pDst_ptr) |
| { |
| int temp[64]; |
| int* pTemp = temp; |
| const jpgd_block_t* pSrc = pSrc_ptr; |
| |
| for (int i = 4; i > 0; i--) |
| { |
| Row<4>::idct(pTemp, pSrc); |
| pSrc += 8; |
| pTemp += 8; |
| } |
| |
| pTemp = temp; |
| for (int i = 8; i > 0; i--) |
| { |
| Col<4>::idct(pDst_ptr, pTemp); |
| pTemp++; |
| pDst_ptr++; |
| } |
| } |
| |
| // Retrieve one character from the input stream. |
| inline uint jpeg_decoder::get_char() |
| { |
| // Any bytes remaining in buffer? |
| if (!m_in_buf_left) |
| { |
| // Try to get more bytes. |
| prep_in_buffer(); |
| // Still nothing to get? |
| if (!m_in_buf_left) |
| { |
| // Pad the end of the stream with 0xFF 0xD9 (EOI marker) |
| int t = m_tem_flag; |
| m_tem_flag ^= 1; |
| if (t) |
| return 0xD9; |
| else |
| return 0xFF; |
| } |
| } |
| |
| uint c = *m_pIn_buf_ofs++; |
| m_in_buf_left--; |
| |
| return c; |
| } |
| |
| // Same as previous method, except can indicate if the character is a pad character or not. |
| inline uint jpeg_decoder::get_char(bool *pPadding_flag) |
| { |
| if (!m_in_buf_left) |
| { |
| prep_in_buffer(); |
| if (!m_in_buf_left) |
| { |
| *pPadding_flag = true; |
| int t = m_tem_flag; |
| m_tem_flag ^= 1; |
| if (t) |
| return 0xD9; |
| else |
| return 0xFF; |
| } |
| } |
| |
| *pPadding_flag = false; |
| |
| uint c = *m_pIn_buf_ofs++; |
| m_in_buf_left--; |
| |
| return c; |
| } |
| |
| // Inserts a previously retrieved character back into the input buffer. |
| inline void jpeg_decoder::stuff_char(uint8 q) |
| { |
| *(--m_pIn_buf_ofs) = q; |
| m_in_buf_left++; |
| } |
| |
| // Retrieves one character from the input stream, but does not read past markers. Will continue to return 0xFF when a marker is encountered. |
| inline uint8 jpeg_decoder::get_octet() |
| { |
| bool padding_flag; |
| int c = get_char(&padding_flag); |
| |
| if (c == 0xFF) |
| { |
| if (padding_flag) |
| return 0xFF; |
| |
| c = get_char(&padding_flag); |
| if (padding_flag) |
| { |
| stuff_char(0xFF); |
| return 0xFF; |
| } |
| |
| if (c == 0x00) |
| return 0xFF; |
| else |
| { |
| stuff_char(static_cast<uint8>(c)); |
| stuff_char(0xFF); |
| return 0xFF; |
| } |
| } |
| |
| return static_cast<uint8>(c); |
| } |
| |
| // Retrieves a variable number of bits from the input stream. Does not recognize markers. |
| inline uint jpeg_decoder::get_bits(int num_bits) |
| { |
| if (!num_bits) |
| return 0; |
| |
| uint i = m_bit_buf >> (32 - num_bits); |
| |
| if ((m_bits_left -= num_bits) <= 0) |
| { |
| m_bit_buf <<= (num_bits += m_bits_left); |
| |
| uint c1 = get_char(); |
| uint c2 = get_char(); |
| m_bit_buf = (m_bit_buf & 0xFFFF0000) | (c1 << 8) | c2; |
| |
| m_bit_buf <<= -m_bits_left; |
| |
| m_bits_left += 16; |
| |
| JPGD_ASSERT(m_bits_left >= 0); |
| } |
| else |
| m_bit_buf <<= num_bits; |
| |
| return i; |
| } |
| |
| // Retrieves a variable number of bits from the input stream. Markers will not be read into the input bit buffer. Instead, an infinite number of all 1's will be returned when a marker is encountered. |
| inline uint jpeg_decoder::get_bits_no_markers(int num_bits) |
| { |
| if (!num_bits) |
| return 0; |
| |
| uint i = m_bit_buf >> (32 - num_bits); |
| |
| if ((m_bits_left -= num_bits) <= 0) |
| { |
| m_bit_buf <<= (num_bits += m_bits_left); |
| |
| if ((m_in_buf_left < 2) || (m_pIn_buf_ofs[0] == 0xFF) || (m_pIn_buf_ofs[1] == 0xFF)) |
| { |
| uint c1 = get_octet(); |
| uint c2 = get_octet(); |
| m_bit_buf |= (c1 << 8) | c2; |
| } |
| else |
| { |
| m_bit_buf |= ((uint)m_pIn_buf_ofs[0] << 8) | m_pIn_buf_ofs[1]; |
| m_in_buf_left -= 2; |
| m_pIn_buf_ofs += 2; |
| } |
| |
| m_bit_buf <<= -m_bits_left; |
| |
| m_bits_left += 16; |
| |
| JPGD_ASSERT(m_bits_left >= 0); |
| } |
| else |
| m_bit_buf <<= num_bits; |
| |
| return i; |
| } |
| |
| // Decodes a Huffman encoded symbol. |
| inline int jpeg_decoder::huff_decode(huff_tables *pH) |
| { |
| int symbol; |
| |
| // Check first 8-bits: do we have a complete symbol? |
| if ((symbol = pH->look_up[m_bit_buf >> 24]) < 0) |
| { |
| // Decode more bits, use a tree traversal to find symbol. |
| int ofs = 23; |
| do |
| { |
| symbol = pH->tree[-(int)(symbol + ((m_bit_buf >> ofs) & 1))]; |
| ofs--; |
| } while (symbol < 0); |
| |
| get_bits_no_markers(8 + (23 - ofs)); |
| } |
| else |
| get_bits_no_markers(pH->code_size[symbol]); |
| |
| return symbol; |
| } |
| |
| // Decodes a Huffman encoded symbol. |
| inline int jpeg_decoder::huff_decode(huff_tables *pH, int& extra_bits) |
| { |
| int symbol; |
| |
| // Check first 8-bits: do we have a complete symbol? |
| if ((symbol = pH->look_up2[m_bit_buf >> 24]) < 0) |
| { |
| // Use a tree traversal to find symbol. |
| int ofs = 23; |
| do |
| { |
| symbol = pH->tree[-(int)(symbol + ((m_bit_buf >> ofs) & 1))]; |
| ofs--; |
| } while (symbol < 0); |
| |
| get_bits_no_markers(8 + (23 - ofs)); |
| |
| extra_bits = get_bits_no_markers(symbol & 0xF); |
| } |
| else |
| { |
| JPGD_ASSERT(((symbol >> 8) & 31) == pH->code_size[symbol & 255] + ((symbol & 0x8000) ? (symbol & 15) : 0)); |
| |
| if (symbol & 0x8000) |
| { |
| get_bits_no_markers((symbol >> 8) & 31); |
| extra_bits = symbol >> 16; |
| } |
| else |
| { |
| int code_size = (symbol >> 8) & 31; |
| int num_extra_bits = symbol & 0xF; |
| int bits = code_size + num_extra_bits; |
| if (bits <= (m_bits_left + 16)) |
| extra_bits = get_bits_no_markers(bits) & ((1 << num_extra_bits) - 1); |
| else |
| { |
| get_bits_no_markers(code_size); |
| extra_bits = get_bits_no_markers(num_extra_bits); |
| } |
| } |
| |
| symbol &= 0xFF; |
| } |
| |
| return symbol; |
| } |
| |
| // Tables and macro used to fully decode the DPCM differences. |
| static const int s_extend_test[16] = { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 }; |
| static const int s_extend_offset[16] = { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1, ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1, ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1, ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 }; |
| static const int s_extend_mask[] = { 0, (1<<0), (1<<1), (1<<2), (1<<3), (1<<4), (1<<5), (1<<6), (1<<7), (1<<8), (1<<9), (1<<10), (1<<11), (1<<12), (1<<13), (1<<14), (1<<15), (1<<16) }; |
| // The logical AND's in this macro are to shut up static code analysis (aren't really necessary - couldn't find another way to do this) |
| #define JPGD_HUFF_EXTEND(x, s) (((x) < s_extend_test[s & 15]) ? ((x) + s_extend_offset[s & 15]) : (x)) |
| |
| // Clamps a value between 0-255. |
| inline uint8 jpeg_decoder::clamp(int i) |
| { |
| if (static_cast<uint>(i) > 255) |
| i = (((~i) >> 31) & 0xFF); |
| |
| return static_cast<uint8>(i); |
| } |
| |
| namespace DCT_Upsample |
| { |
| struct Matrix44 |
| { |
| typedef int Element_Type; |
| enum { NUM_ROWS = 4, NUM_COLS = 4 }; |
| |
| Element_Type v[NUM_ROWS][NUM_COLS]; |
| |
| inline int rows() const { return NUM_ROWS; } |
| inline int cols() const { return NUM_COLS; } |
| |
| inline const Element_Type & at(int r, int c) const { return v[r][c]; } |
| inline Element_Type & at(int r, int c) { return v[r][c]; } |
| |
| inline Matrix44() { } |
| |
| inline Matrix44& operator += (const Matrix44& a) |
| { |
| for (int r = 0; r < NUM_ROWS; r++) |
| { |
| at(r, 0) += a.at(r, 0); |
| at(r, 1) += a.at(r, 1); |
| at(r, 2) += a.at(r, 2); |
| at(r, 3) += a.at(r, 3); |
| } |
| return *this; |
| } |
| |
| inline Matrix44& operator -= (const Matrix44& a) |
| { |
| for (int r = 0; r < NUM_ROWS; r++) |
| { |
| at(r, 0) -= a.at(r, 0); |
| at(r, 1) -= a.at(r, 1); |
| at(r, 2) -= a.at(r, 2); |
| at(r, 3) -= a.at(r, 3); |
| } |
| return *this; |
| } |
| |
| friend inline Matrix44 operator + (const Matrix44& a, const Matrix44& b) |
| { |
| Matrix44 ret; |
| for (int r = 0; r < NUM_ROWS; r++) |
| { |
| ret.at(r, 0) = a.at(r, 0) + b.at(r, 0); |
| ret.at(r, 1) = a.at(r, 1) + b.at(r, 1); |
| ret.at(r, 2) = a.at(r, 2) + b.at(r, 2); |
| ret.at(r, 3) = a.at(r, 3) + b.at(r, 3); |
| } |
| return ret; |
| } |
| |
| friend inline Matrix44 operator - (const Matrix44& a, const Matrix44& b) |
| { |
| Matrix44 ret; |
| for (int r = 0; r < NUM_ROWS; r++) |
| { |
| ret.at(r, 0) = a.at(r, 0) - b.at(r, 0); |
| ret.at(r, 1) = a.at(r, 1) - b.at(r, 1); |
| ret.at(r, 2) = a.at(r, 2) - b.at(r, 2); |
| ret.at(r, 3) = a.at(r, 3) - b.at(r, 3); |
| } |
| return ret; |
| } |
| |
| static inline void add_and_store(jpgd_block_t* pDst, const Matrix44& a, const Matrix44& b) |
| { |
| for (int r = 0; r < 4; r++) |
| { |
| pDst[0*8 + r] = static_cast<jpgd_block_t>(a.at(r, 0) + b.at(r, 0)); |
| pDst[1*8 + r] = static_cast<jpgd_block_t>(a.at(r, 1) + b.at(r, 1)); |
| pDst[2*8 + r] = static_cast<jpgd_block_t>(a.at(r, 2) + b.at(r, 2)); |
| pDst[3*8 + r] = static_cast<jpgd_block_t>(a.at(r, 3) + b.at(r, 3)); |
| } |
| } |
| |
| static inline void sub_and_store(jpgd_block_t* pDst, const Matrix44& a, const Matrix44& b) |
| { |
| for (int r = 0; r < 4; r++) |
| { |
| pDst[0*8 + r] = static_cast<jpgd_block_t>(a.at(r, 0) - b.at(r, 0)); |
| pDst[1*8 + r] = static_cast<jpgd_block_t>(a.at(r, 1) - b.at(r, 1)); |
| pDst[2*8 + r] = static_cast<jpgd_block_t>(a.at(r, 2) - b.at(r, 2)); |
| pDst[3*8 + r] = static_cast<jpgd_block_t>(a.at(r, 3) - b.at(r, 3)); |
| } |
| } |
| }; |
| |
| const int FRACT_BITS = 10; |
| const int SCALE = 1 << FRACT_BITS; |
| |
| typedef int Temp_Type; |
| #define D(i) (((i) + (SCALE >> 1)) >> FRACT_BITS) |
| #define F(i) ((int)((i) * SCALE + .5f)) |
| |
| // Any decent C++ compiler will optimize this at compile time to a 0, or an array access. |
| #define AT(c, r) ((((c)>=NUM_COLS)||((r)>=NUM_ROWS)) ? 0 : pSrc[(c)+(r)*8]) |
| |
| // NUM_ROWS/NUM_COLS = # of non-zero rows/cols in input matrix |
| template<int NUM_ROWS, int NUM_COLS> |
| struct P_Q |
| { |
| static void calc(Matrix44& P, Matrix44& Q, const jpgd_block_t* pSrc) |
| { |
| // 4x8 = 4x8 times 8x8, matrix 0 is constant |
| const Temp_Type X000 = AT(0, 0); |
| const Temp_Type X001 = AT(0, 1); |
| const Temp_Type X002 = AT(0, 2); |
| const Temp_Type X003 = AT(0, 3); |
| const Temp_Type X004 = AT(0, 4); |
| const Temp_Type X005 = AT(0, 5); |
| const Temp_Type X006 = AT(0, 6); |
| const Temp_Type X007 = AT(0, 7); |
| const Temp_Type X010 = D(F(0.415735f) * AT(1, 0) + F(0.791065f) * AT(3, 0) + F(-0.352443f) * AT(5, 0) + F(0.277785f) * AT(7, 0)); |
| const Temp_Type X011 = D(F(0.415735f) * AT(1, 1) + F(0.791065f) * AT(3, 1) + F(-0.352443f) * AT(5, 1) + F(0.277785f) * AT(7, 1)); |
| const Temp_Type X012 = D(F(0.415735f) * AT(1, 2) + F(0.791065f) * AT(3, 2) + F(-0.352443f) * AT(5, 2) + F(0.277785f) * AT(7, 2)); |
| const Temp_Type X013 = D(F(0.415735f) * AT(1, 3) + F(0.791065f) * AT(3, 3) + F(-0.352443f) * AT(5, 3) + F(0.277785f) * AT(7, 3)); |
| const Temp_Type X014 = D(F(0.415735f) * AT(1, 4) + F(0.791065f) * AT(3, 4) + F(-0.352443f) * AT(5, 4) + F(0.277785f) * AT(7, 4)); |
| const Temp_Type X015 = D(F(0.415735f) * AT(1, 5) + F(0.791065f) * AT(3, 5) + F(-0.352443f) * AT(5, 5) + F(0.277785f) * AT(7, 5)); |
| const Temp_Type X016 = D(F(0.415735f) * AT(1, 6) + F(0.791065f) * AT(3, 6) + F(-0.352443f) * AT(5, 6) + F(0.277785f) * AT(7, 6)); |
| const Temp_Type X017 = D(F(0.415735f) * AT(1, 7) + F(0.791065f) * AT(3, 7) + F(-0.352443f) * AT(5, 7) + F(0.277785f) * AT(7, 7)); |
| const Temp_Type X020 = AT(4, 0); |
| const Temp_Type X021 = AT(4, 1); |
| const Temp_Type X022 = AT(4, 2); |
| const Temp_Type X023 = AT(4, 3); |
| const Temp_Type X024 = AT(4, 4); |
| const Temp_Type X025 = AT(4, 5); |
| const Temp_Type X026 = AT(4, 6); |
| const Temp_Type X027 = AT(4, 7); |
| const Temp_Type X030 = D(F(0.022887f) * AT(1, 0) + F(-0.097545f) * AT(3, 0) + F(0.490393f) * AT(5, 0) + F(0.865723f) * AT(7, 0)); |
| const Temp_Type X031 = D(F(0.022887f) * AT(1, 1) + F(-0.097545f) * AT(3, 1) + F(0.490393f) * AT(5, 1) + F(0.865723f) * AT(7, 1)); |
| const Temp_Type X032 = D(F(0.022887f) * AT(1, 2) + F(-0.097545f) * AT(3, 2) + F(0.490393f) * AT(5, 2) + F(0.865723f) * AT(7, 2)); |
| const Temp_Type X033 = D(F(0.022887f) * AT(1, 3) + F(-0.097545f) * AT(3, 3) + F(0.490393f) * AT(5, 3) + F(0.865723f) * AT(7, 3)); |
| const Temp_Type X034 = D(F(0.022887f) * AT(1, 4) + F(-0.097545f) * AT(3, 4) + F(0.490393f) * AT(5, 4) + F(0.865723f) * AT(7, 4)); |
| const Temp_Type X035 = D(F(0.022887f) * AT(1, 5) + F(-0.097545f) * AT(3, 5) + F(0.490393f) * AT(5, 5) + F(0.865723f) * AT(7, 5)); |
| const Temp_Type X036 = D(F(0.022887f) * AT(1, 6) + F(-0.097545f) * AT(3, 6) + F(0.490393f) * AT(5, 6) + F(0.865723f) * AT(7, 6)); |
| const Temp_Type X037 = D(F(0.022887f) * AT(1, 7) + F(-0.097545f) * AT(3, 7) + F(0.490393f) * AT(5, 7) + F(0.865723f) * AT(7, 7)); |
| |
| // 4x4 = 4x8 times 8x4, matrix 1 is constant |
| P.at(0, 0) = X000; |
| P.at(0, 1) = D(X001 * F(0.415735f) + X003 * F(0.791065f) + X005 * F(-0.352443f) + X007 * F(0.277785f)); |
| P.at(0, 2) = X004; |
| P.at(0, 3) = D(X001 * F(0.022887f) + X003 * F(-0.097545f) + X005 * F(0.490393f) + X007 * F(0.865723f)); |
| P.at(1, 0) = X010; |
| P.at(1, 1) = D(X011 * F(0.415735f) + X013 * F(0.791065f) + X015 * F(-0.352443f) + X017 * F(0.277785f)); |
| P.at(1, 2) = X014; |
| P.at(1, 3) = D(X011 * F(0.022887f) + X013 * F(-0.097545f) + X015 * F(0.490393f) + X017 * F(0.865723f)); |
| P.at(2, 0) = X020; |
| P.at(2, 1) = D(X021 * F(0.415735f) + X023 * F(0.791065f) + X025 * F(-0.352443f) + X027 * F(0.277785f)); |
| P.at(2, 2) = X024; |
| P.at(2, 3) = D(X021 * F(0.022887f) + X023 * F(-0.097545f) + X025 * F(0.490393f) + X027 * F(0.865723f)); |
| P.at(3, 0) = X030; |
| P.at(3, 1) = D(X031 * F(0.415735f) + X033 * F(0.791065f) + X035 * F(-0.352443f) + X037 * F(0.277785f)); |
| P.at(3, 2) = X034; |
| P.at(3, 3) = D(X031 * F(0.022887f) + X033 * F(-0.097545f) + X035 * F(0.490393f) + X037 * F(0.865723f)); |
| // 40 muls 24 adds |
| |
| // 4x4 = 4x8 times 8x4, matrix 1 is constant |
| Q.at(0, 0) = D(X001 * F(0.906127f) + X003 * F(-0.318190f) + X005 * F(0.212608f) + X007 * F(-0.180240f)); |
| Q.at(0, 1) = X002; |
| Q.at(0, 2) = D(X001 * F(-0.074658f) + X003 * F(0.513280f) + X005 * F(0.768178f) + X007 * F(-0.375330f)); |
| Q.at(0, 3) = X006; |
| Q.at(1, 0) = D(X011 * F(0.906127f) + X013 * F(-0.318190f) + X015 * F(0.212608f) + X017 * F(-0.180240f)); |
| Q.at(1, 1) = X012; |
| Q.at(1, 2) = D(X011 * F(-0.074658f) + X013 * F(0.513280f) + X015 * F(0.768178f) + X017 * F(-0.375330f)); |
| Q.at(1, 3) = X016; |
| Q.at(2, 0) = D(X021 * F(0.906127f) + X023 * F(-0.318190f) + X025 * F(0.212608f) + X027 * F(-0.180240f)); |
| Q.at(2, 1) = X022; |
| Q.at(2, 2) = D(X021 * F(-0.074658f) + X023 * F(0.513280f) + X025 * F(0.768178f) + X027 * F(-0.375330f)); |
| Q.at(2, 3) = X026; |
| Q.at(3, 0) = D(X031 * F(0.906127f) + X033 * F(-0.318190f) + X035 * F(0.212608f) + X037 * F(-0.180240f)); |
| Q.at(3, 1) = X032; |
| Q.at(3, 2) = D(X031 * F(-0.074658f) + X033 * F(0.513280f) + X035 * F(0.768178f) + X037 * F(-0.375330f)); |
| Q.at(3, 3) = X036; |
| // 40 muls 24 adds |
| } |
| }; |
| |
| template<int NUM_ROWS, int NUM_COLS> |
| struct R_S |
| { |
| static void calc(Matrix44& R, Matrix44& S, const jpgd_block_t* pSrc) |
| { |
| // 4x8 = 4x8 times 8x8, matrix 0 is constant |
| const Temp_Type X100 = D(F(0.906127f) * AT(1, 0) + F(-0.318190f) * AT(3, 0) + F(0.212608f) * AT(5, 0) + F(-0.180240f) * AT(7, 0)); |
| const Temp_Type X101 = D(F(0.906127f) * AT(1, 1) + F(-0.318190f) * AT(3, 1) + F(0.212608f) * AT(5, 1) + F(-0.180240f) * AT(7, 1)); |
| const Temp_Type X102 = D(F(0.906127f) * AT(1, 2) + F(-0.318190f) * AT(3, 2) + F(0.212608f) * AT(5, 2) + F(-0.180240f) * AT(7, 2)); |
| const Temp_Type X103 = D(F(0.906127f) * AT(1, 3) + F(-0.318190f) * AT(3, 3) + F(0.212608f) * AT(5, 3) + F(-0.180240f) * AT(7, 3)); |
| const Temp_Type X104 = D(F(0.906127f) * AT(1, 4) + F(-0.318190f) * AT(3, 4) + F(0.212608f) * AT(5, 4) + F(-0.180240f) * AT(7, 4)); |
| const Temp_Type X105 = D(F(0.906127f) * AT(1, 5) + F(-0.318190f) * AT(3, 5) + F(0.212608f) * AT(5, 5) + F(-0.180240f) * AT(7, 5)); |
| const Temp_Type X106 = D(F(0.906127f) * AT(1, 6) + F(-0.318190f) * AT(3, 6) + F(0.212608f) * AT(5, 6) + F(-0.180240f) * AT(7, 6)); |
| const Temp_Type X107 = D(F(0.906127f) * AT(1, 7) + F(-0.318190f) * AT(3, 7) + F(0.212608f) * AT(5, 7) + F(-0.180240f) * AT(7, 7)); |
| const Temp_Type X110 = AT(2, 0); |
| const Temp_Type X111 = AT(2, 1); |
| const Temp_Type X112 = AT(2, 2); |
| const Temp_Type X113 = AT(2, 3); |
| const Temp_Type X114 = AT(2, 4); |
| const Temp_Type X115 = AT(2, 5); |
| const Temp_Type X116 = AT(2, 6); |
| const Temp_Type X117 = AT(2, 7); |
| const Temp_Type X120 = D(F(-0.074658f) * AT(1, 0) + F(0.513280f) * AT(3, 0) + F(0.768178f) * AT(5, 0) + F(-0.375330f) * AT(7, 0)); |
| const Temp_Type X121 = D(F(-0.074658f) * AT(1, 1) + F(0.513280f) * AT(3, 1) + F(0.768178f) * AT(5, 1) + F(-0.375330f) * AT(7, 1)); |
| const Temp_Type X122 = D(F(-0.074658f) * AT(1, 2) + F(0.513280f) * AT(3, 2) + F(0.768178f) * AT(5, 2) + F(-0.375330f) * AT(7, 2)); |
| const Temp_Type X123 = D(F(-0.074658f) * AT(1, 3) + F(0.513280f) * AT(3, 3) + F(0.768178f) * AT(5, 3) + F(-0.375330f) * AT(7, 3)); |
| const Temp_Type X124 = D(F(-0.074658f) * AT(1, 4) + F(0.513280f) * AT(3, 4) + F(0.768178f) * AT(5, 4) + F(-0.375330f) * AT(7, 4)); |
| const Temp_Type X125 = D(F(-0.074658f) * AT(1, 5) + F(0.513280f) * AT(3, 5) + F(0.768178f) * AT(5, 5) + F(-0.375330f) * AT(7, 5)); |
| const Temp_Type X126 = D(F(-0.074658f) * AT(1, 6) + F(0.513280f) * AT(3, 6) + F(0.768178f) * AT(5, 6) + F(-0.375330f) * AT(7, 6)); |
| const Temp_Type X127 = D(F(-0.074658f) * AT(1, 7) + F(0.513280f) * AT(3, 7) + F(0.768178f) * AT(5, 7) + F(-0.375330f) * AT(7, 7)); |
| const Temp_Type X130 = AT(6, 0); |
| const Temp_Type X131 = AT(6, 1); |
| const Temp_Type X132 = AT(6, 2); |
| const Temp_Type X133 = AT(6, 3); |
| const Temp_Type X134 = AT(6, 4); |
| const Temp_Type X135 = AT(6, 5); |
| const Temp_Type X136 = AT(6, 6); |
| const Temp_Type X137 = AT(6, 7); |
| // 80 muls 48 adds |
| |
| // 4x4 = 4x8 times 8x4, matrix 1 is constant |
| R.at(0, 0) = X100; |
| R.at(0, 1) = D(X101 * F(0.415735f) + X103 * F(0.791065f) + X105 * F(-0.352443f) + X107 * F(0.277785f)); |
| R.at(0, 2) = X104; |
| R.at(0, 3) = D(X101 * F(0.022887f) + X103 * F(-0.097545f) + X105 * F(0.490393f) + X107 * F(0.865723f)); |
| R.at(1, 0) = X110; |
| R.at(1, 1) = D(X111 * F(0.415735f) + X113 * F(0.791065f) + X115 * F(-0.352443f) + X117 * F(0.277785f)); |
| R.at(1, 2) = X114; |
| R.at(1, 3) = D(X111 * F(0.022887f) + X113 * F(-0.097545f) + X115 * F(0.490393f) + X117 * F(0.865723f)); |
| R.at(2, 0) = X120; |
| R.at(2, 1) = D(X121 * F(0.415735f) + X123 * F(0.791065f) + X125 * F(-0.352443f) + X127 * F(0.277785f)); |
| R.at(2, 2) = X124; |
| R.at(2, 3) = D(X121 * F(0.022887f) + X123 * F(-0.097545f) + X125 * F(0.490393f) + X127 * F(0.865723f)); |
| R.at(3, 0) = X130; |
| R.at(3, 1) = D(X131 * F(0.415735f) + X133 * F(0.791065f) + X135 * F(-0.352443f) + X137 * F(0.277785f)); |
| R.at(3, 2) = X134; |
| R.at(3, 3) = D(X131 * F(0.022887f) + X133 * F(-0.097545f) + X135 * F(0.490393f) + X137 * F(0.865723f)); |
| // 40 muls 24 adds |
| // 4x4 = 4x8 times 8x4, matrix 1 is constant |
| S.at(0, 0) = D(X101 * F(0.906127f) + X103 * F(-0.318190f) + X105 * F(0.212608f) + X107 * F(-0.180240f)); |
| S.at(0, 1) = X102; |
| S.at(0, 2) = D(X101 * F(-0.074658f) + X103 * F(0.513280f) + X105 * F(0.768178f) + X107 * F(-0.375330f)); |
| S.at(0, 3) = X106; |
| S.at(1, 0) = D(X111 * F(0.906127f) + X113 * F(-0.318190f) + X115 * F(0.212608f) + X117 * F(-0.180240f)); |
| S.at(1, 1) = X112; |
| S.at(1, 2) = D(X111 * F(-0.074658f) + X113 * F(0.513280f) + X115 * F(0.768178f) + X117 * F(-0.375330f)); |
| S.at(1, 3) = X116; |
| S.at(2, 0) = D(X121 * F(0.906127f) + X123 * F(-0.318190f) + X125 * F(0.212608f) + X127 * F(-0.180240f)); |
| S.at(2, 1) = X122; |
| S.at(2, 2) = D(X121 * F(-0.074658f) + X123 * F(0.513280f) + X125 * F(0.768178f) + X127 * F(-0.375330f)); |
| S.at(2, 3) = X126; |
| S.at(3, 0) = D(X131 * F(0.906127f) + X133 * F(-0.318190f) + X135 * F(0.212608f) + X137 * F(-0.180240f)); |
| S.at(3, 1) = X132; |
| S.at(3, 2) = D(X131 * F(-0.074658f) + X133 * F(0.513280f) + X135 * F(0.768178f) + X137 * F(-0.375330f)); |
| S.at(3, 3) = X136; |
| // 40 muls 24 adds |
| } |
| }; |
| } // end namespace DCT_Upsample |
| |
| // Unconditionally frees all allocated m_blocks. |
| void jpeg_decoder::free_all_blocks() |
| { |
| m_pStream = NULL; |
| for (mem_block *b = m_pMem_blocks; b; ) |
| { |
| mem_block *n = b->m_pNext; |
| jpgd_free(b); |
| b = n; |
| } |
| m_pMem_blocks = NULL; |
| } |
| |
| // This method handles all errors. It will never return. |
| // It could easily be changed to use C++ exceptions. |
| JPGD_NORETURN void jpeg_decoder::stop_decoding(jpgd_status status) |
| { |
| m_error_code = status; |
| free_all_blocks(); |
| longjmp(m_jmp_state, status); |
| } |
| |
| void *jpeg_decoder::alloc(size_t nSize, bool zero) |
| { |
| nSize = (JPGD_MAX(nSize, 1) + 3) & ~3; |
| char *rv = NULL; |
| for (mem_block *b = m_pMem_blocks; b; b = b->m_pNext) |
| { |
| if ((b->m_used_count + nSize) <= b->m_size) |
| { |
| rv = b->m_data + b->m_used_count; |
| b->m_used_count += nSize; |
| break; |
| } |
| } |
| if (!rv) |
| { |
| int capacity = JPGD_MAX(32768 - 256, (nSize + 2047) & ~2047); |
| mem_block *b = (mem_block*)jpgd_malloc(sizeof(mem_block) + capacity); |
| if (!b) { stop_decoding(JPGD_NOTENOUGHMEM); } |
| b->m_pNext = m_pMem_blocks; m_pMem_blocks = b; |
| b->m_used_count = nSize; |
| b->m_size = capacity; |
| rv = b->m_data; |
| } |
| if (zero) memset(rv, 0, nSize); |
| return rv; |
| } |
| |
| void jpeg_decoder::word_clear(void *p, uint16 c, uint n) |
| { |
| uint8 *pD = (uint8*)p; |
| const uint8 l = c & 0xFF, h = (c >> 8) & 0xFF; |
| while (n) |
| { |
| pD[0] = l; pD[1] = h; pD += 2; |
| n--; |
| } |
| } |
| |
| // Refill the input buffer. |
| // This method will sit in a loop until (A) the buffer is full or (B) |
| // the stream's read() method reports and end of file condition. |
| void jpeg_decoder::prep_in_buffer() |
| { |
| m_in_buf_left = 0; |
| m_pIn_buf_ofs = m_in_buf; |
| |
| if (m_eof_flag) |
| return; |
| |
| do |
| { |
| int bytes_read = m_pStream->read(m_in_buf + m_in_buf_left, JPGD_IN_BUF_SIZE - m_in_buf_left, &m_eof_flag); |
| if (bytes_read == -1) |
| stop_decoding(JPGD_STREAM_READ); |
| |
| m_in_buf_left += bytes_read; |
| } while ((m_in_buf_left < JPGD_IN_BUF_SIZE) && (!m_eof_flag)); |
| |
| m_total_bytes_read += m_in_buf_left; |
| |
| // Pad the end of the block with M_EOI (prevents the decompressor from going off the rails if the stream is invalid). |
| // (This dates way back to when this decompressor was written in C/asm, and the all-asm Huffman decoder did some fancy things to increase perf.) |
| word_clear(m_pIn_buf_ofs + m_in_buf_left, 0xD9FF, 64); |
| } |
| |
| // Read a Huffman code table. |
| void jpeg_decoder::read_dht_marker() |
| { |
| int i, index, count; |
| uint8 huff_num[17]; |
| uint8 huff_val[256]; |
| |
| uint num_left = get_bits(16); |
| |
| if (num_left < 2) |
| stop_decoding(JPGD_BAD_DHT_MARKER); |
| |
| num_left -= 2; |
| |
| while (num_left) |
| { |
| index = get_bits(8); |
| |
| huff_num[0] = 0; |
| |
| count = 0; |
| |
| for (i = 1; i <= 16; i++) |
| { |
| huff_num[i] = static_cast<uint8>(get_bits(8)); |
| count += huff_num[i]; |
| } |
| |
| if (count > 255) |
| stop_decoding(JPGD_BAD_DHT_COUNTS); |
| |
| for (i = 0; i < count; i++) |
| huff_val[i] = static_cast<uint8>(get_bits(8)); |
| |
| i = 1 + 16 + count; |
| |
| if (num_left < (uint)i) |
| stop_decoding(JPGD_BAD_DHT_MARKER); |
| |
| num_left -= i; |
| |
| if ((index & 0x10) > 0x10) |
| stop_decoding(JPGD_BAD_DHT_INDEX); |
| |
| index = (index & 0x0F) + ((index & 0x10) >> 4) * (JPGD_MAX_HUFF_TABLES >> 1); |
| |
| if (index >= JPGD_MAX_HUFF_TABLES) |
| stop_decoding(JPGD_BAD_DHT_INDEX); |
| |
| if (!m_huff_num[index]) |
| m_huff_num[index] = (uint8 *)alloc(17); |
| |
| if (!m_huff_val[index]) |
| m_huff_val[index] = (uint8 *)alloc(256); |
| |
| m_huff_ac[index] = (index & 0x10) != 0; |
| memcpy(m_huff_num[index], huff_num, 17); |
| memcpy(m_huff_val[index], huff_val, 256); |
| } |
| } |
| |
| // Read a quantization table. |
| void jpeg_decoder::read_dqt_marker() |
| { |
| int n, i, prec; |
| uint num_left; |
| uint temp; |
| |
| num_left = get_bits(16); |
| |
| if (num_left < 2) |
| stop_decoding(JPGD_BAD_DQT_MARKER); |
| |
| num_left -= 2; |
| |
| while (num_left) |
| { |
| n = get_bits(8); |
| prec = n >> 4; |
| n &= 0x0F; |
| |
| if (n >= JPGD_MAX_QUANT_TABLES) |
| stop_decoding(JPGD_BAD_DQT_TABLE); |
| |
| if (!m_quant[n]) |
| m_quant[n] = (jpgd_quant_t *)alloc(64 * sizeof(jpgd_quant_t)); |
| |
| // read quantization entries, in zag order |
| for (i = 0; i < 64; i++) |
| { |
| temp = get_bits(8); |
| |
| if (prec) |
| temp = (temp << 8) + get_bits(8); |
| |
| m_quant[n][i] = static_cast<jpgd_quant_t>(temp); |
| } |
| |
| i = 64 + 1; |
| |
| if (prec) |
| i += 64; |
| |
| if (num_left < (uint)i) |
| stop_decoding(JPGD_BAD_DQT_LENGTH); |
| |
| num_left -= i; |
| } |
| } |
| |
| // Read the start of frame (SOF) marker. |
| void jpeg_decoder::read_sof_marker() |
| { |
| int i; |
| uint num_left; |
| |
| num_left = get_bits(16); |
| |
| if (get_bits(8) != 8) /* precision: sorry, only 8-bit precision is supported right now */ |
| stop_decoding(JPGD_BAD_PRECISION); |
| |
| m_image_y_size = get_bits(16); |
| |
| if ((m_image_y_size < 1) || (m_image_y_size > JPGD_MAX_HEIGHT)) |
| stop_decoding(JPGD_BAD_HEIGHT); |
| |
| m_image_x_size = get_bits(16); |
| |
| if ((m_image_x_size < 1) || (m_image_x_size > JPGD_MAX_WIDTH)) |
| stop_decoding(JPGD_BAD_WIDTH); |
| |
| m_comps_in_frame = get_bits(8); |
| |
| if (m_comps_in_frame > JPGD_MAX_COMPONENTS) |
| stop_decoding(JPGD_TOO_MANY_COMPONENTS); |
| |
| if (num_left != (uint)(m_comps_in_frame * 3 + 8)) |
| stop_decoding(JPGD_BAD_SOF_LENGTH); |
| |
| for (i = 0; i < m_comps_in_frame; i++) |
| { |
| m_comp_ident[i] = get_bits(8); |
| m_comp_h_samp[i] = get_bits(4); |
| m_comp_v_samp[i] = get_bits(4); |
| m_comp_quant[i] = get_bits(8); |
| } |
| } |
| |
| // Used to skip unrecognized markers. |
| void jpeg_decoder::skip_variable_marker() |
| { |
| uint num_left; |
| |
| num_left = get_bits(16); |
| |
| if (num_left < 2) |
| stop_decoding(JPGD_BAD_VARIABLE_MARKER); |
| |
| num_left -= 2; |
| |
| while (num_left) |
| { |
| get_bits(8); |
| num_left--; |
| } |
| } |
| |
| // Read a define restart interval (DRI) marker. |
| void jpeg_decoder::read_dri_marker() |
| { |
| if (get_bits(16) != 4) |
| stop_decoding(JPGD_BAD_DRI_LENGTH); |
| |
| m_restart_interval = get_bits(16); |
| } |
| |
| // Read a start of scan (SOS) marker. |
| void jpeg_decoder::read_sos_marker() |
| { |
| uint num_left; |
| int i, ci, n, c, cc; |
| |
| num_left = get_bits(16); |
| |
| n = get_bits(8); |
| |
| m_comps_in_scan = n; |
| |
| num_left -= 3; |
| |
| if ( (num_left != (uint)(n * 2 + 3)) || (n < 1) || (n > JPGD_MAX_COMPS_IN_SCAN) ) |
| stop_decoding(JPGD_BAD_SOS_LENGTH); |
| |
| for (i = 0; i < n; i++) |
| { |
| cc = get_bits(8); |
| c = get_bits(8); |
| num_left -= 2; |
| |
| for (ci = 0; ci < m_comps_in_frame; ci++) |
| if (cc == m_comp_ident[ci]) |
| break; |
| |
| if (ci >= m_comps_in_frame) |
| stop_decoding(JPGD_BAD_SOS_COMP_ID); |
| |
| m_comp_list[i] = ci; |
| m_comp_dc_tab[ci] = (c >> 4) & 15; |
| m_comp_ac_tab[ci] = (c & 15) + (JPGD_MAX_HUFF_TABLES >> 1); |
| } |
| |
| m_spectral_start = get_bits(8); |
| m_spectral_end = get_bits(8); |
| m_successive_high = get_bits(4); |
| m_successive_low = get_bits(4); |
| |
| if (!m_progressive_flag) |
| { |
| m_spectral_start = 0; |
| m_spectral_end = 63; |
| } |
| |
| num_left -= 3; |
| |
| while (num_left) /* read past whatever is num_left */ |
| { |
| get_bits(8); |
| num_left--; |
| } |
| } |
| |
| // Finds the next marker. |
| int jpeg_decoder::next_marker() |
| { |
| uint c, bytes; |
| |
| bytes = 0; |
| |
| do |
| { |
| do |
| { |
| bytes++; |
| c = get_bits(8); |
| } while (c != 0xFF); |
| |
| do |
| { |
| c = get_bits(8); |
| } while (c == 0xFF); |
| |
| } while (c == 0); |
| |
| // If bytes > 0 here, there where extra bytes before the marker (not good). |
| |
| return c; |
| } |
| |
| // Process markers. Returns when an SOFx, SOI, EOI, or SOS marker is |
| // encountered. |
| int jpeg_decoder::process_markers() |
| { |
| int c; |
| |
| for ( ; ; ) |
| { |
| c = next_marker(); |
| |
| switch (c) |
| { |
| case M_SOF0: |
| case M_SOF1: |
| case M_SOF2: |
| case M_SOF3: |
| case M_SOF5: |
| case M_SOF6: |
| case M_SOF7: |
| // case M_JPG: |
| case M_SOF9: |
| case M_SOF10: |
| case M_SOF11: |
| case M_SOF13: |
| case M_SOF14: |
| case M_SOF15: |
| case M_SOI: |
| case M_EOI: |
| case M_SOS: |
| { |
| return c; |
| } |
| case M_DHT: |
| { |
| read_dht_marker(); |
| break; |
| } |
| // No arithmitic support - dumb patents! |
| case M_DAC: |
| { |
| stop_decoding(JPGD_NO_ARITHMITIC_SUPPORT); |
| break; |
| } |
| case M_DQT: |
| { |
| read_dqt_marker(); |
| break; |
| } |
| case M_DRI: |
| { |
| read_dri_marker(); |
| break; |
| } |
| //case M_APP0: /* no need to read the JFIF marker */ |
| |
| case M_JPG: |
| case M_RST0: /* no parameters */ |
| case M_RST1: |
| case M_RST2: |
| case M_RST3: |
| case M_RST4: |
| case M_RST5: |
| case M_RST6: |
| case M_RST7: |
| case M_TEM: |
| { |
| stop_decoding(JPGD_UNEXPECTED_MARKER); |
| break; |
| } |
| default: /* must be DNL, DHP, EXP, APPn, JPGn, COM, or RESn or APP0 */ |
| { |
| skip_variable_marker(); |
| break; |
| } |
| } |
| } |
| } |
| |
| // Finds the start of image (SOI) marker. |
| // This code is rather defensive: it only checks the first 512 bytes to avoid |
| // false positives. |
| void jpeg_decoder::locate_soi_marker() |
| { |
| uint lastchar, thischar; |
| uint bytesleft; |
| |
| lastchar = get_bits(8); |
| |
| thischar = get_bits(8); |
| |
| /* ok if it's a normal JPEG file without a special header */ |
| |
| if ((lastchar == 0xFF) && (thischar == M_SOI)) |
| return; |
| |
| bytesleft = 4096; //512; |
| |
| for ( ; ; ) |
| { |
| if (--bytesleft == 0) |
| stop_decoding(JPGD_NOT_JPEG); |
| |
| lastchar = thischar; |
| |
| thischar = get_bits(8); |
| |
| if (lastchar == 0xFF) |
| { |
| if (thischar == M_SOI) |
| break; |
| else if (thischar == M_EOI) // get_bits will keep returning M_EOI if we read past the end |
| stop_decoding(JPGD_NOT_JPEG); |
| } |
| } |
| |
| // Check the next character after marker: if it's not 0xFF, it can't be the start of the next marker, so the file is bad. |
| thischar = (m_bit_buf >> 24) & 0xFF; |
| |
| if (thischar != 0xFF) |
| stop_decoding(JPGD_NOT_JPEG); |
| } |
| |
| // Find a start of frame (SOF) marker. |
| void jpeg_decoder::locate_sof_marker() |
| { |
| locate_soi_marker(); |
| |
| int c = process_markers(); |
| |
| switch (c) |
| { |
| case M_SOF2: |
| m_progressive_flag = JPGD_TRUE; |
| case M_SOF0: /* baseline DCT */ |
| case M_SOF1: /* extended sequential DCT */ |
| { |
| read_sof_marker(); |
| break; |
| } |
| case M_SOF9: /* Arithmitic coding */ |
| { |
| stop_decoding(JPGD_NO_ARITHMITIC_SUPPORT); |
| break; |
| } |
| default: |
| { |
| stop_decoding(JPGD_UNSUPPORTED_MARKER); |
| break; |
| } |
| } |
| } |
| |
| // Find a start of scan (SOS) marker. |
| int jpeg_decoder::locate_sos_marker() |
| { |
| int c; |
| |
| c = process_markers(); |
| |
| if (c == M_EOI) |
| return JPGD_FALSE; |
| else if (c != M_SOS) |
| stop_decoding(JPGD_UNEXPECTED_MARKER); |
| |
| read_sos_marker(); |
| |
| return JPGD_TRUE; |
| } |
| |
| // Reset everything to default/uninitialized state. |
| void jpeg_decoder::init(jpeg_decoder_stream *pStream) |
| { |
| m_pMem_blocks = NULL; |
| m_error_code = JPGD_SUCCESS; |
| m_ready_flag = false; |
| m_image_x_size = m_image_y_size = 0; |
| m_pStream = pStream; |
| m_progressive_flag = JPGD_FALSE; |
| |
| memset(m_huff_ac, 0, sizeof(m_huff_ac)); |
| memset(m_huff_num, 0, sizeof(m_huff_num)); |
| memset(m_huff_val, 0, sizeof(m_huff_val)); |
| memset(m_quant, 0, sizeof(m_quant)); |
| |
| m_scan_type = 0; |
| m_comps_in_frame = 0; |
| |
| memset(m_comp_h_samp, 0, sizeof(m_comp_h_samp)); |
| memset(m_comp_v_samp, 0, sizeof(m_comp_v_samp)); |
| memset(m_comp_quant, 0, sizeof(m_comp_quant)); |
| memset(m_comp_ident, 0, sizeof(m_comp_ident)); |
| memset(m_comp_h_blocks, 0, sizeof(m_comp_h_blocks)); |
| memset(m_comp_v_blocks, 0, sizeof(m_comp_v_blocks)); |
| |
| m_comps_in_scan = 0; |
| memset(m_comp_list, 0, sizeof(m_comp_list)); |
| memset(m_comp_dc_tab, 0, sizeof(m_comp_dc_tab)); |
| memset(m_comp_ac_tab, 0, sizeof(m_comp_ac_tab)); |
| |
| m_spectral_start = 0; |
| m_spectral_end = 0; |
| m_successive_low = 0; |
| m_successive_high = 0; |
| m_max_mcu_x_size = 0; |
| m_max_mcu_y_size = 0; |
| m_blocks_per_mcu = 0; |
| m_max_blocks_per_row = 0; |
| m_mcus_per_row = 0; |
| m_mcus_per_col = 0; |
| m_expanded_blocks_per_component = 0; |
| m_expanded_blocks_per_mcu = 0; |
| m_expanded_blocks_per_row = 0; |
| m_freq_domain_chroma_upsample = false; |
| |
| memset(m_mcu_org, 0, sizeof(m_mcu_org)); |
| |
| m_total_lines_left = 0; |
| m_mcu_lines_left = 0; |
| m_real_dest_bytes_per_scan_line = 0; |
| m_dest_bytes_per_scan_line = 0; |
| m_dest_bytes_per_pixel = 0; |
| |
| memset(m_pHuff_tabs, 0, sizeof(m_pHuff_tabs)); |
| |
| memset(m_dc_coeffs, 0, sizeof(m_dc_coeffs)); |
| memset(m_ac_coeffs, 0, sizeof(m_ac_coeffs)); |
| memset(m_block_y_mcu, 0, sizeof(m_block_y_mcu)); |
| |
| m_eob_run = 0; |
| |
| memset(m_block_y_mcu, 0, sizeof(m_block_y_mcu)); |
| |
| m_pIn_buf_ofs = m_in_buf; |
| m_in_buf_left = 0; |
| m_eof_flag = false; |
| m_tem_flag = 0; |
| |
| memset(m_in_buf_pad_start, 0, sizeof(m_in_buf_pad_start)); |
| memset(m_in_buf, 0, sizeof(m_in_buf)); |
| memset(m_in_buf_pad_end, 0, sizeof(m_in_buf_pad_end)); |
| |
| m_restart_interval = 0; |
| m_restarts_left = 0; |
| m_next_restart_num = 0; |
| |
| m_max_mcus_per_row = 0; |
| m_max_blocks_per_mcu = 0; |
| m_max_mcus_per_col = 0; |
| |
| memset(m_last_dc_val, 0, sizeof(m_last_dc_val)); |
| m_pMCU_coefficients = NULL; |
| m_pSample_buf = NULL; |
| |
| m_total_bytes_read = 0; |
| |
| m_pScan_line_0 = NULL; |
| m_pScan_line_1 = NULL; |
| |
| // Ready the input buffer. |
| prep_in_buffer(); |
| |
| // Prime the bit buffer. |
| m_bits_left = 16; |
| m_bit_buf = 0; |
| |
| get_bits(16); |
| get_bits(16); |
| |
| for (int i = 0; i < JPGD_MAX_BLOCKS_PER_MCU; i++) |
| m_mcu_block_max_zag[i] = 64; |
| } |
| |
| #define SCALEBITS 16 |
| #define ONE_HALF ((int) 1 << (SCALEBITS-1)) |
| #define FIX(x) ((int) ((x) * (1L<<SCALEBITS) + 0.5f)) |
| |
| // Create a few tables that allow us to quickly convert YCbCr to RGB. |
| void jpeg_decoder::create_look_ups() |
| { |
| for (int i = 0; i <= 255; i++) |
| { |
| int k = i - 128; |
| m_crr[i] = ( FIX(1.40200f) * k + ONE_HALF) >> SCALEBITS; |
| m_cbb[i] = ( FIX(1.77200f) * k + ONE_HALF) >> SCALEBITS; |
| m_crg[i] = (-FIX(0.71414f)) * k; |
| m_cbg[i] = (-FIX(0.34414f)) * k + ONE_HALF; |
| } |
| } |
| |
| // This method throws back into the stream any bytes that where read |
| // into the bit buffer during initial marker scanning. |
| void jpeg_decoder::fix_in_buffer() |
| { |
| // In case any 0xFF's where pulled into the buffer during marker scanning. |
| JPGD_ASSERT((m_bits_left & 7) == 0); |
| |
| if (m_bits_left == 16) |
| stuff_char( (uint8)(m_bit_buf & 0xFF)); |
| |
| if (m_bits_left >= 8) |
| stuff_char( (uint8)((m_bit_buf >> 8) & 0xFF)); |
| |
| stuff_char((uint8)((m_bit_buf >> 16) & 0xFF)); |
| stuff_char((uint8)((m_bit_buf >> 24) & 0xFF)); |
| |
| m_bits_left = 16; |
| get_bits_no_markers(16); |
| get_bits_no_markers(16); |
| } |
| |
| void jpeg_decoder::transform_mcu(int mcu_row) |
| { |
| jpgd_block_t* pSrc_ptr = m_pMCU_coefficients; |
| uint8* pDst_ptr = m_pSample_buf + mcu_row * m_blocks_per_mcu * 64; |
| |
| for (int mcu_block = 0; mcu_block < m_blocks_per_mcu; mcu_block++) |
| { |
| idct(pSrc_ptr, pDst_ptr, m_mcu_block_max_zag[mcu_block]); |
| pSrc_ptr += 64; |
| pDst_ptr += 64; |
| } |
| } |
| |
| static const uint8 s_max_rc[64] = |
| { |
| 17, 18, 34, 50, 50, 51, 52, 52, 52, 68, 84, 84, 84, 84, 85, 86, 86, 86, 86, 86, |
| 102, 118, 118, 118, 118, 118, 118, 119, 120, 120, 120, 120, 120, 120, 120, 136, |
| 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, |
| 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136 |
| }; |
| |
| void jpeg_decoder::transform_mcu_expand(int mcu_row) |
| { |
| jpgd_block_t* pSrc_ptr = m_pMCU_coefficients; |
| uint8* pDst_ptr = m_pSample_buf + mcu_row * m_expanded_blocks_per_mcu * 64; |
| |
| // Y IDCT |
| int mcu_block; |
| for (mcu_block = 0; mcu_block < m_expanded_blocks_per_component; mcu_block++) |
| { |
| idct(pSrc_ptr, pDst_ptr, m_mcu_block_max_zag[mcu_block]); |
| pSrc_ptr += 64; |
| pDst_ptr += 64; |
| } |
| |
| // Chroma IDCT, with upsampling |
| jpgd_block_t temp_block[64]; |
| |
| for (int i = 0; i < 2; i++) |
| { |
| DCT_Upsample::Matrix44 P, Q, R, S; |
| |
| JPGD_ASSERT(m_mcu_block_max_zag[mcu_block] >= 1); |
| JPGD_ASSERT(m_mcu_block_max_zag[mcu_block] <= 64); |
| |
| int max_zag = m_mcu_block_max_zag[mcu_block++] - 1; |
| if (max_zag <= 0) max_zag = 0; // should never happen, only here to shut up static analysis |
| switch (s_max_rc[max_zag]) |
| { |
| case 1*16+1: |
| DCT_Upsample::P_Q<1, 1>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<1, 1>::calc(R, S, pSrc_ptr); |
| break; |
| case 1*16+2: |
| DCT_Upsample::P_Q<1, 2>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<1, 2>::calc(R, S, pSrc_ptr); |
| break; |
| case 2*16+2: |
| DCT_Upsample::P_Q<2, 2>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<2, 2>::calc(R, S, pSrc_ptr); |
| break; |
| case 3*16+2: |
| DCT_Upsample::P_Q<3, 2>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<3, 2>::calc(R, S, pSrc_ptr); |
| break; |
| case 3*16+3: |
| DCT_Upsample::P_Q<3, 3>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<3, 3>::calc(R, S, pSrc_ptr); |
| break; |
| case 3*16+4: |
| DCT_Upsample::P_Q<3, 4>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<3, 4>::calc(R, S, pSrc_ptr); |
| break; |
| case 4*16+4: |
| DCT_Upsample::P_Q<4, 4>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<4, 4>::calc(R, S, pSrc_ptr); |
| break; |
| case 5*16+4: |
| DCT_Upsample::P_Q<5, 4>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<5, 4>::calc(R, S, pSrc_ptr); |
| break; |
| case 5*16+5: |
| DCT_Upsample::P_Q<5, 5>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<5, 5>::calc(R, S, pSrc_ptr); |
| break; |
| case 5*16+6: |
| DCT_Upsample::P_Q<5, 6>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<5, 6>::calc(R, S, pSrc_ptr); |
| break; |
| case 6*16+6: |
| DCT_Upsample::P_Q<6, 6>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<6, 6>::calc(R, S, pSrc_ptr); |
| break; |
| case 7*16+6: |
| DCT_Upsample::P_Q<7, 6>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<7, 6>::calc(R, S, pSrc_ptr); |
| break; |
| case 7*16+7: |
| DCT_Upsample::P_Q<7, 7>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<7, 7>::calc(R, S, pSrc_ptr); |
| break; |
| case 7*16+8: |
| DCT_Upsample::P_Q<7, 8>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<7, 8>::calc(R, S, pSrc_ptr); |
| break; |
| case 8*16+8: |
| DCT_Upsample::P_Q<8, 8>::calc(P, Q, pSrc_ptr); |
| DCT_Upsample::R_S<8, 8>::calc(R, S, pSrc_ptr); |
| break; |
| default: |
| JPGD_ASSERT(false); |
| } |
| |
| DCT_Upsample::Matrix44 a(P + Q); P -= Q; |
| DCT_Upsample::Matrix44& b = P; |
| DCT_Upsample::Matrix44 c(R + S); R -= S; |
| DCT_Upsample::Matrix44& d = R; |
| |
| DCT_Upsample::Matrix44::add_and_store(temp_block, a, c); |
| idct_4x4(temp_block, pDst_ptr); |
| pDst_ptr += 64; |
| |
| DCT_Upsample::Matrix44::sub_and_store(temp_block, a, c); |
| idct_4x4(temp_block, pDst_ptr); |
| pDst_ptr += 64; |
| |
| DCT_Upsample::Matrix44::add_and_store(temp_block, b, d); |
| idct_4x4(temp_block, pDst_ptr); |
| pDst_ptr += 64; |
| |
| DCT_Upsample::Matrix44::sub_and_store(temp_block, b, d); |
| idct_4x4(temp_block, pDst_ptr); |
| pDst_ptr += 64; |
| |
| pSrc_ptr += 64; |
| } |
| } |
| |
| // Loads and dequantizes the next row of (already decoded) coefficients. |
| // Progressive images only. |
| void jpeg_decoder::load_next_row() |
| { |
| int i; |
| jpgd_block_t *p; |
| jpgd_quant_t *q; |
| int mcu_row, mcu_block, row_block = 0; |
| int component_num, component_id; |
| int block_x_mcu[JPGD_MAX_COMPONENTS]; |
| |
| memset(block_x_mcu, 0, JPGD_MAX_COMPONENTS * sizeof(int)); |
| |
| for (mcu_row = 0; mcu_row < m_mcus_per_row; mcu_row++) |
| { |
| int block_x_mcu_ofs = 0, block_y_mcu_ofs = 0; |
| |
| for (mcu_block = 0; mcu_block < m_blocks_per_mcu; mcu_block++) |
| { |
| component_id = m_mcu_org[mcu_block]; |
| q = m_quant[m_comp_quant[component_id]]; |
| |
| p = m_pMCU_coefficients + 64 * mcu_block; |
| |
| jpgd_block_t* pAC = coeff_buf_getp(m_ac_coeffs[component_id], block_x_mcu[component_id] + block_x_mcu_ofs, m_block_y_mcu[component_id] + block_y_mcu_ofs); |
| jpgd_block_t* pDC = coeff_buf_getp(m_dc_coeffs[component_id], block_x_mcu[component_id] + block_x_mcu_ofs, m_block_y_mcu[component_id] + block_y_mcu_ofs); |
| p[0] = pDC[0]; |
| memcpy(&p[1], &pAC[1], 63 * sizeof(jpgd_block_t)); |
| |
| for (i = 63; i > 0; i--) |
| if (p[g_ZAG[i]]) |
| break; |
| |
| m_mcu_block_max_zag[mcu_block] = i + 1; |
| |
| for ( ; i >= 0; i--) |
| if (p[g_ZAG[i]]) |
| p[g_ZAG[i]] = static_cast<jpgd_block_t>(p[g_ZAG[i]] * q[i]); |
| |
| row_block++; |
| |
| if (m_comps_in_scan == 1) |
| block_x_mcu[component_id]++; |
| else |
| { |
| if (++block_x_mcu_ofs == m_comp_h_samp[component_id]) |
| { |
| block_x_mcu_ofs = 0; |
| |
| if (++block_y_mcu_ofs == m_comp_v_samp[component_id]) |
| { |
| block_y_mcu_ofs = 0; |
| |
| block_x_mcu[component_id] += m_comp_h_samp[component_id]; |
| } |
| } |
| } |
| } |
| |
| if (m_freq_domain_chroma_upsample) |
| transform_mcu_expand(mcu_row); |
| else |
| transform_mcu(mcu_row); |
| } |
| |
| if (m_comps_in_scan == 1) |
| m_block_y_mcu[m_comp_list[0]]++; |
| else |
| { |
| for (component_num = 0; component_num < m_comps_in_scan; component_num++) |
| { |
| component_id = m_comp_list[component_num]; |
| |
| m_block_y_mcu[component_id] += m_comp_v_samp[component_id]; |
| } |
| } |
| } |
| |
| // Restart interval processing. |
| void jpeg_decoder::process_restart() |
| { |
| int i; |
| int c = 0; |
| |
| // Align to a byte boundry |
| // FIXME: Is this really necessary? get_bits_no_markers() never reads in markers! |
| //get_bits_no_markers(m_bits_left & 7); |
| |
| // Let's scan a little bit to find the marker, but not _too_ far. |
| // 1536 is a "fudge factor" that determines how much to scan. |
| for (i = 1536; i > 0; i--) |
| if (get_char() == 0xFF) |
| break; |
| |
| if (i == 0) |
| stop_decoding(JPGD_BAD_RESTART_MARKER); |
| |
| for ( ; i > 0; i--) |
| if ((c = get_char()) != 0xFF) |
| break; |
| |
| if (i == 0) |
| stop_decoding(JPGD_BAD_RESTART_MARKER); |
| |
| // Is it the expected marker? If not, something bad happened. |
| if (c != (m_next_restart_num + M_RST0)) |
| stop_decoding(JPGD_BAD_RESTART_MARKER); |
| |
| // Reset each component's DC prediction values. |
| memset(&m_last_dc_val, 0, m_comps_in_frame * sizeof(uint)); |
| |
| m_eob_run = 0; |
| |
| m_restarts_left = m_restart_interval; |
| |
| m_next_restart_num = (m_next_restart_num + 1) & 7; |
| |
| // Get the bit buffer going again... |
| |
| m_bits_left = 16; |
| get_bits_no_markers(16); |
| get_bits_no_markers(16); |
| } |
| |
| static inline int dequantize_ac(int c, int q) { c *= q; return c; } |
| |
| // Decodes and dequantizes the next row of coefficients. |
| void jpeg_decoder::decode_next_row() |
| { |
| int row_block = 0; |
| |
| for (int mcu_row = 0; mcu_row < m_mcus_per_row; mcu_row++) |
| { |
| if ((m_restart_interval) && (m_restarts_left == 0)) |
| process_restart(); |
| |
| jpgd_block_t* p = m_pMCU_coefficients; |
| for (int mcu_block = 0; mcu_block < m_blocks_per_mcu; mcu_block++, p += 64) |
| { |
| int component_id = m_mcu_org[mcu_block]; |
| jpgd_quant_t* q = m_quant[m_comp_quant[component_id]]; |
| |
| int r, s; |
| s = huff_decode(m_pHuff_tabs[m_comp_dc_tab[component_id]], r); |
| s = JPGD_HUFF_EXTEND(r, s); |
| |
| m_last_dc_val[component_id] = (s += m_last_dc_val[component_id]); |
| |
| p[0] = static_cast<jpgd_block_t>(s * q[0]); |
| |
| int prev_num_set = m_mcu_block_max_zag[mcu_block]; |
| |
| huff_tables *pH = m_pHuff_tabs[m_comp_ac_tab[component_id]]; |
| |
| int k; |
| for (k = 1; k < 64; k++) |
| { |
| int extra_bits; |
| s = huff_decode(pH, extra_bits); |
| |
| r = s >> 4; |
| s &= 15; |
| |
| if (s) |
| { |
| if (r) |
| { |
| if ((k + r) > 63) |
| stop_decoding(JPGD_DECODE_ERROR); |
| |
| if (k < prev_num_set) |
| { |
| int n = JPGD_MIN(r, prev_num_set - k); |
| int kt = k; |
| while (n--) |
| p[g_ZAG[kt++]] = 0; |
| } |
| |
| k += r; |
| } |
| |
| s = JPGD_HUFF_EXTEND(extra_bits, s); |
| |
| JPGD_ASSERT(k < 64); |
| |
| p[g_ZAG[k]] = static_cast<jpgd_block_t>(dequantize_ac(s, q[k])); //s * q[k]; |
| } |
| else |
| { |
| if (r == 15) |
| { |
| if ((k + 16) > 64) |
| stop_decoding(JPGD_DECODE_ERROR); |
| |
| if (k < prev_num_set) |
| { |
| int n = JPGD_MIN(16, prev_num_set - k); |
| int kt = k; |
| while (n--) |
| { |
| JPGD_ASSERT(kt <= 63); |
| p[g_ZAG[kt++]] = 0; |
| } |
| } |
| |
| k += 16 - 1; // - 1 because the loop counter is k |
| JPGD_ASSERT(p[g_ZAG[k]] == 0); |
| } |
| else |
| break; |
| } |
| } |
| |
| if (k < prev_num_set) |
| { |
| int kt = k; |
| while (kt < prev_num_set) |
| p[g_ZAG[kt++]] = 0; |
| } |
| |
| m_mcu_block_max_zag[mcu_block] = k; |
| |
| row_block++; |
| } |
| |
| if (m_freq_domain_chroma_upsample) |
| transform_mcu_expand(mcu_row); |
| else |
| transform_mcu(mcu_row); |
| |
| m_restarts_left--; |
| } |
| } |
| |
| // YCbCr H1V1 (1x1:1:1, 3 m_blocks per MCU) to RGB |
| void jpeg_decoder::H1V1Convert() |
| { |
| int row = m_max_mcu_y_size - m_mcu_lines_left; |
| uint8 *d = m_pScan_line_0; |
| uint8 *s = m_pSample_buf + row * 8; |
| |
| for (int i = m_max_mcus_per_row; i > 0; i--) |
| { |
| for (int j = 0; j < 8; j++) |
| { |
| int y = s[j]; |
| int cb = s[64+j]; |
| int cr = s[128+j]; |
| |
| d[0] = clamp(y + m_crr[cr]); |
| d[1] = clamp(y + ((m_crg[cr] + m_cbg[cb]) >> 16)); |
| d[2] = clamp(y + m_cbb[cb]); |
| d[3] = 255; |
| |
| d += 4; |
| } |
| |
| s += 64*3; |
| } |
| } |
| |
| // YCbCr H2V1 (2x1:1:1, 4 m_blocks per MCU) to RGB |
| void jpeg_decoder::H2V1Convert() |
| { |
| int row = m_max_mcu_y_size - m_mcu_lines_left; |
| uint8 *d0 = m_pScan_line_0; |
| uint8 *y = m_pSample_buf + row * 8; |
| uint8 *c = m_pSample_buf + 2*64 + row * 8; |
| |
| for (int i = m_max_mcus_per_row; i > 0; i--) |
| { |
| for (int l = 0; l < 2; l++) |
| { |
| for (int j = 0; j < 4; j++) |
| { |
| int cb = c[0]; |
| int cr = c[64]; |
| |
| int rc = m_crr[cr]; |
| int gc = ((m_crg[cr] + m_cbg[cb]) >> 16); |
| int bc = m_cbb[cb]; |
| |
| int yy = y[j<<1]; |
| d0[0] = clamp(yy+rc); |
| d0[1] = clamp(yy+gc); |
| d0[2] = clamp(yy+bc); |
| d0[3] = 255; |
| |
| yy = y[(j<<1)+1]; |
| d0[4] = clamp(yy+rc); |
| d0[5] = clamp(yy+gc); |
| d0[6] = clamp(yy+bc); |
| d0[7] = 255; |
| |
| d0 += 8; |
| |
| c++; |
| } |
| y += 64; |
| } |
| |
| y += 64*4 - 64*2; |
| c += 64*4 - 8; |
| } |
| } |
| |
| // YCbCr H2V1 (1x2:1:1, 4 m_blocks per MCU) to RGB |
| void jpeg_decoder::H1V2Convert() |
| { |
| int row = m_max_mcu_y_size - m_mcu_lines_left; |
| uint8 *d0 = m_pScan_line_0; |
| uint8 *d1 = m_pScan_line_1; |
| uint8 *y; |
| uint8 *c; |
| |
| if (row < 8) |
| y = m_pSample_buf + row * 8; |
| else |
| y = m_pSample_buf + 64*1 + (row & 7) * 8; |
| |
| c = m_pSample_buf + 64*2 + (row >> 1) * 8; |
| |
| for (int i = m_max_mcus_per_row; i > 0; i--) |
| { |
| for (int j = 0; j < 8; j++) |
| { |
| int cb = c[0+j]; |
| int cr = c[64+j]; |
| |
| int rc = m_crr[cr]; |
| int gc = ((m_crg[cr] + m_cbg[cb]) >> 16); |
| int bc = m_cbb[cb]; |
| |
| int yy = y[j]; |
| d0[0] = clamp(yy+rc); |
| d0[1] = clamp(yy+gc); |
| d0[2] = clamp(yy+bc); |
| d0[3] = 255; |
| |
| yy = y[8+j]; |
| d1[0] = clamp(yy+rc); |
| d1[1] = clamp(yy+gc); |
| d1[2] = clamp(yy+bc); |
| d1[3] = 255; |
| |
| d0 += 4; |
| d1 += 4; |
| } |
| |
| y += 64*4; |
| c += 64*4; |
| } |
| } |
| |
| // YCbCr H2V2 (2x2:1:1, 6 m_blocks per MCU) to RGB |
| void jpeg_decoder::H2V2Convert() |
| { |
| int row = m_max_mcu_y_size - m_mcu_lines_left; |
| uint8 *d0 = m_pScan_line_0; |
| uint8 *d1 = m_pScan_line_1; |
| uint8 *y; |
| uint8 *c; |
| |
| if (row < 8) |
| y = m_pSample_buf + row * 8; |
| else |
| y = m_pSample_buf + 64*2 + (row & 7) * 8; |
| |
| c = m_pSample_buf + 64*4 + (row >> 1) * 8; |
| |
| for (int i = m_max_mcus_per_row; i > 0; i--) |
| { |
| for (int l = 0; l < 2; l++) |
| { |
| for (int j = 0; j < 8; j += 2) |
| { |
| int cb = c[0]; |
| int cr = c[64]; |
| |
| int rc = m_crr[cr]; |
| int gc = ((m_crg[cr] + m_cbg[cb]) >> 16); |
| int bc = m_cbb[cb]; |
| |
| int yy = y[j]; |
| d0[0] = clamp(yy+rc); |
| d0[1] = clamp(yy+gc); |
| d0[2] = clamp(yy+bc); |
| d0[3] = 255; |
| |
| yy = y[j+1]; |
| d0[4] = clamp(yy+rc); |
| d0[5] = clamp(yy+gc); |
| d0[6] = clamp(yy+bc); |
| d0[7] = 255; |
| |
| yy = y[j+8]; |
| d1[0] = clamp(yy+rc); |
| d1[1] = clamp(yy+gc); |
| d1[2] = clamp(yy+bc); |
| d1[3] = 255; |
| |
| yy = y[j+8+1]; |
| d1[4] = clamp(yy+rc); |
| d1[5] = clamp(yy+gc); |
| d1[6] = clamp(yy+bc); |
| d1[7] = 255; |
| |
| d0 += 8; |
| d1 += 8; |
| |
| c++; |
| } |
| y += 64; |
| } |
| |
| y += 64*6 - 64*2; |
| c += 64*6 - 8; |
| } |
| } |
| |
| // Y (1 block per MCU) to 8-bit grayscale |
| void jpeg_decoder::gray_convert() |
| { |
| int row = m_max_mcu_y_size - m_mcu_lines_left; |
| uint8 *d = m_pScan_line_0; |
| uint8 *s = m_pSample_buf + row * 8; |
| |
| for (int i = m_max_mcus_per_row; i > 0; i--) |
| { |
| *(uint *)d = *(uint *)s; |
| *(uint *)(&d[4]) = *(uint *)(&s[4]); |
| |
| s += 64; |
| d += 8; |
| } |
| } |
| |
| void jpeg_decoder::expanded_convert() |
| { |
| int row = m_max_mcu_y_size - m_mcu_lines_left; |
| |
| uint8* Py = m_pSample_buf + (row / 8) * 64 * m_comp_h_samp[0] + (row & 7) * 8; |
| |
| uint8* d = m_pScan_line_0; |
| |
| for (int i = m_max_mcus_per_row; i > 0; i--) |
| { |
| for (int k = 0; k < m_max_mcu_x_size; k += 8) |
| { |
| const int Y_ofs = k * 8; |
| const int Cb_ofs = Y_ofs + 64 * m_expanded_blocks_per_component; |
| const int Cr_ofs = Y_ofs + 64 * m_expanded_blocks_per_component * 2; |
| for (int j = 0; j < 8; j++) |
| { |
| int y = Py[Y_ofs + j]; |
| int cb = Py[Cb_ofs + j]; |
| int cr = Py[Cr_ofs + j]; |
| |
| d[0] = clamp(y + m_crr[cr]); |
| d[1] = clamp(y + ((m_crg[cr] + m_cbg[cb]) >> 16)); |
| d[2] = clamp(y + m_cbb[cb]); |
| d[3] = 255; |
| |
| d += 4; |
| } |
| } |
| |
| Py += 64 * m_expanded_blocks_per_mcu; |
| } |
| } |
| |
| // Find end of image (EOI) marker, so we can return to the user the exact size of the input stream. |
| void jpeg_decoder::find_eoi() |
| { |
| if (!m_progressive_flag) |
| { |
| // Attempt to read the EOI marker. |
| //get_bits_no_markers(m_bits_left & 7); |
| |
| // Prime the bit buffer |
| m_bits_left = 16; |
| get_bits(16); |
| get_bits(16); |
| |
| // The next marker _should_ be EOI |
| process_markers(); |
| } |
| |
| m_total_bytes_read -= m_in_buf_left; |
| } |
| |
| int jpeg_decoder::decode(const void** pScan_line, uint* pScan_line_len) |
| { |
| if ((m_error_code) || (!m_ready_flag)) |
| return JPGD_FAILED; |
| |
| if (m_total_lines_left == 0) |
| return JPGD_DONE; |
| |
| if (m_mcu_lines_left == 0) |
| { |
| if (setjmp(m_jmp_state)) |
| return JPGD_FAILED; |
| |
| if (m_progressive_flag) |
| load_next_row(); |
| else |
| decode_next_row(); |
| |
| // Find the EOI marker if that was the last row. |
| if (m_total_lines_left <= m_max_mcu_y_size) |
| find_eoi(); |
| |
| m_mcu_lines_left = m_max_mcu_y_size; |
| } |
| |
| if (m_freq_domain_chroma_upsample) |
| { |
| expanded_convert(); |
| *pScan_line = m_pScan_line_0; |
| } |
| else |
| { |
| switch (m_scan_type) |
| { |
| case JPGD_YH2V2: |
| { |
| if ((m_mcu_lines_left & 1) == 0) |
| { |
| H2V2Convert(); |
| *pScan_line = m_pScan_line_0; |
| } |
| else |
| *pScan_line = m_pScan_line_1; |
| |
| break; |
| } |
| case JPGD_YH2V1: |
| { |
| H2V1Convert(); |
| *pScan_line = m_pScan_line_0; |
| break; |
| } |
| case JPGD_YH1V2: |
| { |
| if ((m_mcu_lines_left & 1) == 0) |
| { |
| H1V2Convert(); |
| *pScan_line = m_pScan_line_0; |
| } |
| else |
| *pScan_line = m_pScan_line_1; |
| |
| break; |
| } |
| case JPGD_YH1V1: |
| { |
| H1V1Convert(); |
| *pScan_line = m_pScan_line_0; |
| break; |
| } |
| case JPGD_GRAYSCALE: |
| { |
| gray_convert(); |
| *pScan_line = m_pScan_line_0; |
| |
| break; |
| } |
| } |
| } |
| |
| *pScan_line_len = m_real_dest_bytes_per_scan_line; |
| |
| m_mcu_lines_left--; |
| m_total_lines_left--; |
| |
| return JPGD_SUCCESS; |
| } |
| |
| // Creates the tables needed for efficient Huffman decoding. |
| void jpeg_decoder::make_huff_table(int index, huff_tables *pH) |
| { |
| int p, i, l, si; |
| uint8 huffsize[257]; |
| uint huffcode[257]; |
| uint code; |
| uint subtree; |
| int code_size; |
| int lastp; |
| int nextfreeentry; |
| int currententry; |
| |
| pH->ac_table = m_huff_ac[index] != 0; |
| |
| p = 0; |
| |
| for (l = 1; l <= 16; l++) |
| { |
| for (i = 1; i <= m_huff_num[index][l]; i++) |
| { |
| JPGD_ASSERT(p < 257); |
| huffsize[p++] = static_cast<uint8>(l); |
| } |
| } |
| |
| huffsize[p] = 0; |
| |
| lastp = p; |
| |
| code = 0; |
| si = huffsize[0]; |
| p = 0; |
| |
| while (huffsize[p]) |
| { |
| while (huffsize[p] == si) |
| { |
| JPGD_ASSERT(p < 257); |
| huffcode[p++] = code; |
| code++; |
| } |
| |
| code <<= 1; |
| si++; |
| } |
| |
| memset(pH->look_up, 0, sizeof(pH->look_up)); |
| memset(pH->look_up2, 0, sizeof(pH->look_up2)); |
| memset(pH->tree, 0, sizeof(pH->tree)); |
| memset(pH->code_size, 0, sizeof(pH->code_size)); |
| |
| nextfreeentry = -1; |
| |
| p = 0; |
| |
| while (p < lastp) |
| { |
| i = m_huff_val[index][p]; |
| code = huffcode[p]; |
| code_size = huffsize[p]; |
| |
| pH->code_size[i] = static_cast<uint8>(code_size); |
| |
| if (code_size <= 8) |
| { |
| code <<= (8 - code_size); |
| |
| for (l = 1 << (8 - code_size); l > 0; l--) |
| { |
| JPGD_ASSERT(i < 256); |
| |
| pH->look_up[code] = i; |
| |
| bool has_extrabits = false; |
| int extra_bits = 0; |
| int num_extra_bits = i & 15; |
| |
| int bits_to_fetch = code_size; |
| if (num_extra_bits) |
| { |
| int total_codesize = code_size + num_extra_bits; |
| if (total_codesize <= 8) |
| { |
| has_extrabits = true; |
| extra_bits = ((1 << num_extra_bits) - 1) & (code >> (8 - total_codesize)); |
| JPGD_ASSERT(extra_bits <= 0x7FFF); |
| bits_to_fetch += num_extra_bits; |
| } |
| } |
| |
| if (!has_extrabits) |
| pH->look_up2[code] = i | (bits_to_fetch << 8); |
| else |
| pH->look_up2[code] = i | 0x8000 | (extra_bits << 16) | (bits_to_fetch << 8); |
| |
| code++; |
| } |
| } |
| else |
| { |
| subtree = (code >> (code_size - 8)) & 0xFF; |
| |
| currententry = pH->look_up[subtree]; |
| |
| if (currententry == 0) |
| { |
| pH->look_up[subtree] = currententry = nextfreeentry; |
| pH->look_up2[subtree] = currententry = nextfreeentry; |
| |
| nextfreeentry -= 2; |
| } |
| |
| code <<= (16 - (code_size - 8)); |
| |
| for (l = code_size; l > 9; l--) |
| { |
| if ((code & 0x8000) == 0) |
| currententry--; |
| |
| if (pH->tree[-currententry - 1] == 0) |
| { |
| pH->tree[-currententry - 1] = nextfreeentry; |
| |
| currententry = nextfreeentry; |
| |
| nextfreeentry -= 2; |
| } |
| else |
| currententry = pH->tree[-currententry - 1]; |
| |
| code <<= 1; |
| } |
| |
| if ((code & 0x8000) == 0) |
| currententry--; |
| |
| pH->tree[-currententry - 1] = i; |
| } |
| |
| p++; |
| } |
| } |
| |
| // Verifies the quantization tables needed for this scan are available. |
| void jpeg_decoder::check_quant_tables() |
| { |
| for (int i = 0; i < m_comps_in_scan; i++) |
| if (m_quant[m_comp_quant[m_comp_list[i]]] == NULL) |
| stop_decoding(JPGD_UNDEFINED_QUANT_TABLE); |
| } |
| |
| // Verifies that all the Huffman tables needed for this scan are available. |
| void jpeg_decoder::check_huff_tables() |
| { |
| for (int i = 0; i < m_comps_in_scan; i++) |
| { |
| if ((m_spectral_start == 0) && (m_huff_num[m_comp_dc_tab[m_comp_list[i]]] == NULL)) |
| stop_decoding(JPGD_UNDEFINED_HUFF_TABLE); |
| |
| if ((m_spectral_end > 0) && (m_huff_num[m_comp_ac_tab[m_comp_list[i]]] == NULL)) |
| stop_decoding(JPGD_UNDEFINED_HUFF_TABLE); |
| } |
| |
| for (int i = 0; i < JPGD_MAX_HUFF_TABLES; i++) |
| if (m_huff_num[i]) |
| { |
| if (!m_pHuff_tabs[i]) |
| m_pHuff_tabs[i] = (huff_tables *)alloc(sizeof(huff_tables)); |
| |
| make_huff_table(i, m_pHuff_tabs[i]); |
| } |
| } |
| |
| // Determines the component order inside each MCU. |
| // Also calcs how many MCU's are on each row, etc. |
| void jpeg_decoder::calc_mcu_block_order() |
| { |
| int component_num, component_id; |
| int max_h_samp = 0, max_v_samp = 0; |
| |
| for (component_id = 0; component_id < m_comps_in_frame; component_id++) |
| { |
| if (m_comp_h_samp[component_id] > max_h_samp) |
| max_h_samp = m_comp_h_samp[component_id]; |
| |
| if (m_comp_v_samp[component_id] > max_v_samp) |
| max_v_samp = m_comp_v_samp[component_id]; |
| } |
| |
| for (component_id = 0; component_id < m_comps_in_frame; component_id++) |
| { |
| m_comp_h_blocks[component_id] = ((((m_image_x_size * m_comp_h_samp[component_id]) + (max_h_samp - 1)) / max_h_samp) + 7) / 8; |
| m_comp_v_blocks[component_id] = ((((m_image_y_size * m_comp_v_samp[component_id]) + (max_v_samp - 1)) / max_v_samp) + 7) / 8; |
| } |
| |
| if (m_comps_in_scan == 1) |
| { |
| m_mcus_per_row = m_comp_h_blocks[m_comp_list[0]]; |
| m_mcus_per_col = m_comp_v_blocks[m_comp_list[0]]; |
| } |
| else |
| { |
| m_mcus_per_row = (((m_image_x_size + 7) / 8) + (max_h_samp - 1)) / max_h_samp; |
| m_mcus_per_col = (((m_image_y_size + 7) / 8) + (max_v_samp - 1)) / max_v_samp; |
| } |
| |
| if (m_comps_in_scan == 1) |
| { |
| m_mcu_org[0] = m_comp_list[0]; |
| |
| m_blocks_per_mcu = 1; |
| } |
| else |
| { |
| m_blocks_per_mcu = 0; |
| |
| for (component_num = 0; component_num < m_comps_in_scan; component_num++) |
| { |
| int num_blocks; |
| |
| component_id = m_comp_list[component_num]; |
| |
| num_blocks = m_comp_h_samp[component_id] * m_comp_v_samp[component_id]; |
| |
| while (num_blocks--) |
| m_mcu_org[m_blocks_per_mcu++] = component_id; |
| } |
| } |
| } |
| |
| // Starts a new scan. |
| int jpeg_decoder::init_scan() |
| { |
| if (!locate_sos_marker()) |
| return JPGD_FALSE; |
| |
| calc_mcu_block_order(); |
| |
| check_huff_tables(); |
| |
| check_quant_tables(); |
| |
| memset(m_last_dc_val, 0, m_comps_in_frame * sizeof(uint)); |
| |
| m_eob_run = 0; |
| |
| if (m_restart_interval) |
| { |
| m_restarts_left = m_restart_interval; |
| m_next_restart_num = 0; |
| } |
| |
| fix_in_buffer(); |
| |
| return JPGD_TRUE; |
| } |
| |
| // Starts a frame. Determines if the number of components or sampling factors |
| // are supported. |
| void jpeg_decoder::init_frame() |
| { |
| int i; |
| |
| if (m_comps_in_frame == 1) |
| { |
| if ((m_comp_h_samp[0] != 1) || (m_comp_v_samp[0] != 1)) |
| stop_decoding(JPGD_UNSUPPORTED_SAMP_FACTORS); |
| |
| m_scan_type = JPGD_GRAYSCALE; |
| m_max_blocks_per_mcu = 1; |
| m_max_mcu_x_size = 8; |
| m_max_mcu_y_size = 8; |
| } |
| else if (m_comps_in_frame == 3) |
| { |
| if ( ((m_comp_h_samp[1] != 1) || (m_comp_v_samp[1] != 1)) || |
| ((m_comp_h_samp[2] != 1) || (m_comp_v_samp[2] != 1)) ) |
| stop_decoding(JPGD_UNSUPPORTED_SAMP_FACTORS); |
| |
| if ((m_comp_h_samp[0] == 1) && (m_comp_v_samp[0] == 1)) |
| { |
| m_scan_type = JPGD_YH1V1; |
| |
| m_max_blocks_per_mcu = 3; |
| m_max_mcu_x_size = 8; |
| m_max_mcu_y_size = 8; |
| } |
| else if ((m_comp_h_samp[0] == 2) && (m_comp_v_samp[0] == 1)) |
| { |
| m_scan_type = JPGD_YH2V1; |
| m_max_blocks_per_mcu = 4; |
| m_max_mcu_x_size = 16; |
| m_max_mcu_y_size = 8; |
| } |
| else if ((m_comp_h_samp[0] == 1) && (m_comp_v_samp[0] == 2)) |
| { |
| m_scan_type = JPGD_YH1V2; |
| m_max_blocks_per_mcu = 4; |
| m_max_mcu_x_size = 8; |
| m_max_mcu_y_size = 16; |
| } |
| else if ((m_comp_h_samp[0] == 2) && (m_comp_v_samp[0] == 2)) |
| { |
| m_scan_type = JPGD_YH2V2; |
| m_max_blocks_per_mcu = 6; |
| m_max_mcu_x_size = 16; |
| m_max_mcu_y_size = 16; |
| } |
| else |
| stop_decoding(JPGD_UNSUPPORTED_SAMP_FACTORS); |
| } |
| else |
| stop_decoding(JPGD_UNSUPPORTED_COLORSPACE); |
| |
| m_max_mcus_per_row = (m_image_x_size + (m_max_mcu_x_size - 1)) / m_max_mcu_x_size; |
| m_max_mcus_per_col = (m_image_y_size + (m_max_mcu_y_size - 1)) / m_max_mcu_y_size; |
| |
| // These values are for the *destination* pixels: after conversion. |
| if (m_scan_type == JPGD_GRAYSCALE) |
| m_dest_bytes_per_pixel = 1; |
| else |
| m_dest_bytes_per_pixel = 4; |
| |
| m_dest_bytes_per_scan_line = ((m_image_x_size + 15) & 0xFFF0) * m_dest_bytes_per_pixel; |
| |
| m_real_dest_bytes_per_scan_line = (m_image_x_size * m_dest_bytes_per_pixel); |
| |
| // Initialize two scan line buffers. |
| m_pScan_line_0 = (uint8 *)alloc(m_dest_bytes_per_scan_line, true); |
| if ((m_scan_type == JPGD_YH1V2) || (m_scan_type == JPGD_YH2V2)) |
| m_pScan_line_1 = (uint8 *)alloc(m_dest_bytes_per_scan_line, true); |
| |
| m_max_blocks_per_row = m_max_mcus_per_row * m_max_blocks_per_mcu; |
| |
| // Should never happen |
| if (m_max_blocks_per_row > JPGD_MAX_BLOCKS_PER_ROW) |
| stop_decoding(JPGD_ASSERTION_ERROR); |
| |
| // Allocate the coefficient buffer, enough for one MCU |
| m_pMCU_coefficients = (jpgd_block_t*)alloc(m_max_blocks_per_mcu * 64 * sizeof(jpgd_block_t)); |
| |
| for (i = 0; i < m_max_blocks_per_mcu; i++) |
| m_mcu_block_max_zag[i] = 64; |
| |
| m_expanded_blocks_per_component = m_comp_h_samp[0] * m_comp_v_samp[0]; |
| m_expanded_blocks_per_mcu = m_expanded_blocks_per_component * m_comps_in_frame; |
| m_expanded_blocks_per_row = m_max_mcus_per_row * m_expanded_blocks_per_mcu; |
| // Freq. domain chroma upsampling is only supported for H2V2 subsampling factor (the most common one I've seen). |
| m_freq_domain_chroma_upsample = false; |
| #if JPGD_SUPPORT_FREQ_DOMAIN_UPSAMPLING |
| m_freq_domain_chroma_upsample = (m_expanded_blocks_per_mcu == 4*3); |
| #endif |
| |
| if (m_freq_domain_chroma_upsample) |
| m_pSample_buf = (uint8 *)alloc(m_expanded_blocks_per_row * 64); |
| else |
| m_pSample_buf = (uint8 *)alloc(m_max_blocks_per_row * 64); |
| |
| m_total_lines_left = m_image_y_size; |
| |
| m_mcu_lines_left = 0; |
| |
| create_look_ups(); |
| } |
| |
| // The coeff_buf series of methods originally stored the coefficients |
| // into a "virtual" file which was located in EMS, XMS, or a disk file. A cache |
| // was used to make this process more efficient. Now, we can store the entire |
| // thing in RAM. |
| jpeg_decoder::coeff_buf* jpeg_decoder::coeff_buf_open(int block_num_x, int block_num_y, int block_len_x, int block_len_y) |
| { |
| coeff_buf* cb = (coeff_buf*)alloc(sizeof(coeff_buf)); |
| |
| cb->block_num_x = block_num_x; |
| cb->block_num_y = block_num_y; |
| cb->block_len_x = block_len_x; |
| cb->block_len_y = block_len_y; |
| cb->block_size = (block_len_x * block_len_y) * sizeof(jpgd_block_t); |
| cb->pData = (uint8 *)alloc(cb->block_size * block_num_x * block_num_y, true); |
| return cb; |
| } |
| |
| inline jpgd_block_t *jpeg_decoder::coeff_buf_getp(coeff_buf *cb, int block_x, int block_y) |
| { |
| JPGD_ASSERT((block_x < cb->block_num_x) && (block_y < cb->block_num_y)); |
| return (jpgd_block_t *)(cb->pData + block_x * cb->block_size + block_y * (cb->block_size * cb->block_num_x)); |
| } |
| |
| // The following methods decode the various types of m_blocks encountered |
| // in progressively encoded images. |
| void jpeg_decoder::decode_block_dc_first(jpeg_decoder *pD, int component_id, int block_x, int block_y) |
| { |
| int s, r; |
| jpgd_block_t *p = pD->coeff_buf_getp(pD->m_dc_coeffs[component_id], block_x, block_y); |
| |
| if ((s = pD->huff_decode(pD->m_pHuff_tabs[pD->m_comp_dc_tab[component_id]])) != 0) |
| { |
| r = pD->get_bits_no_markers(s); |
| s = JPGD_HUFF_EXTEND(r, s); |
| } |
| |
| pD->m_last_dc_val[component_id] = (s += pD->m_last_dc_val[component_id]); |
| |
| p[0] = static_cast<jpgd_block_t>(s << pD->m_successive_low); |
| } |
| |
| void jpeg_decoder::decode_block_dc_refine(jpeg_decoder *pD, int component_id, int block_x, int block_y) |
| { |
| if (pD->get_bits_no_markers(1)) |
| { |
| jpgd_block_t *p = pD->coeff_buf_getp(pD->m_dc_coeffs[component_id], block_x, block_y); |
| |
| p[0] |= (1 << pD->m_successive_low); |
| } |
| } |
| |
| void jpeg_decoder::decode_block_ac_first(jpeg_decoder *pD, int component_id, int block_x, int block_y) |
| { |
| int k, s, r; |
| |
| if (pD->m_eob_run) |
| { |
| pD->m_eob_run--; |
| return; |
| } |
| |
| jpgd_block_t *p = pD->coeff_buf_getp(pD->m_ac_coeffs[component_id], block_x, block_y); |
| |
| for (k = pD->m_spectral_start; k <= pD->m_spectral_end; k++) |
| { |
| s = pD->huff_decode(pD->m_pHuff_tabs[pD->m_comp_ac_tab[component_id]]); |
| |
| r = s >> 4; |
| s &= 15; |
| |
| if (s) |
| { |
| if ((k += r) > 63) |
| pD->stop_decoding(JPGD_DECODE_ERROR); |
| |
| r = pD->get_bits_no_markers(s); |
| s = JPGD_HUFF_EXTEND(r, s); |
| |
| p[g_ZAG[k]] = static_cast<jpgd_block_t>(s << pD->m_successive_low); |
| } |
| else |
| { |
| if (r == 15) |
| { |
| if ((k += 15) > 63) |
| pD->stop_decoding(JPGD_DECODE_ERROR); |
| } |
| else |
| { |
| pD->m_eob_run = 1 << r; |
| |
| if (r) |
| pD->m_eob_run += pD->get_bits_no_markers(r); |
| |
| pD->m_eob_run--; |
| |
| break; |
| } |
| } |
| } |
| } |
| |
| void jpeg_decoder::decode_block_ac_refine(jpeg_decoder *pD, int component_id, int block_x, int block_y) |
| { |
| int s, k, r; |
| int p1 = 1 << pD->m_successive_low; |
| int m1 = (-1) << pD->m_successive_low; |
| jpgd_block_t *p = pD->coeff_buf_getp(pD->m_ac_coeffs[component_id], block_x, block_y); |
| |
| JPGD_ASSERT(pD->m_spectral_end <= 63); |
| |
| k = pD->m_spectral_start; |
| |
| if (pD->m_eob_run == 0) |
| { |
| for ( ; k <= pD->m_spectral_end; k++) |
| { |
| s = pD->huff_decode(pD->m_pHuff_tabs[pD->m_comp_ac_tab[component_id]]); |
| |
| r = s >> 4; |
| s &= 15; |
| |
| if (s) |
| { |
| if (s != 1) |
| pD->stop_decoding(JPGD_DECODE_ERROR); |
| |
| if (pD->get_bits_no_markers(1)) |
| s = p1; |
| else |
| s = m1; |
| } |
| else |
| { |
| if (r != 15) |
| { |
| pD->m_eob_run = 1 << r; |
| |
| if (r) |
| pD->m_eob_run += pD->get_bits_no_markers(r); |
| |
| break; |
| } |
| } |
| |
| do |
| { |
| jpgd_block_t *this_coef = p + g_ZAG[k & 63]; |
| |
| if (*this_coef != 0) |
| { |
| if (pD->get_bits_no_markers(1)) |
| { |
| if ((*this_coef & p1) == 0) |
| { |
| if (*this_coef >= 0) |
| *this_coef = static_cast<jpgd_block_t>(*this_coef + p1); |
| else |
| *this_coef = static_cast<jpgd_block_t>(*this_coef + m1); |
| } |
| } |
| } |
| else |
| { |
| if (--r < 0) |
| break; |
| } |
| |
| k++; |
| |
| } while (k <= pD->m_spectral_end); |
| |
| if ((s) && (k < 64)) |
| { |
| p[g_ZAG[k]] = static_cast<jpgd_block_t>(s); |
| } |
| } |
| } |
| |
| if (pD->m_eob_run > 0) |
| { |
| for ( ; k <= pD->m_spectral_end; k++) |
| { |
| jpgd_block_t *this_coef = p + g_ZAG[k & 63]; // logical AND to shut up static code analysis |
| |
| if (*this_coef != 0) |
| { |
| if (pD->get_bits_no_markers(1)) |
| { |
| if ((*this_coef & p1) == 0) |
| { |
| if (*this_coef >= 0) |
| *this_coef = static_cast<jpgd_block_t>(*this_coef + p1); |
| else |
| *this_coef = static_cast<jpgd_block_t>(*this_coef + m1); |
| } |
| } |
| } |
| } |
| |
| pD->m_eob_run--; |
| } |
| } |
| |
| // Decode a scan in a progressively encoded image. |
| void jpeg_decoder::decode_scan(pDecode_block_func decode_block_func) |
| { |
| int mcu_row, mcu_col, mcu_block; |
| int block_x_mcu[JPGD_MAX_COMPONENTS], m_block_y_mcu[JPGD_MAX_COMPONENTS]; |
| |
| memset(m_block_y_mcu, 0, sizeof(m_block_y_mcu)); |
| |
| for (mcu_col = 0; mcu_col < m_mcus_per_col; mcu_col++) |
| { |
| int component_num, component_id; |
| |
| memset(block_x_mcu, 0, sizeof(block_x_mcu)); |
| |
| for (mcu_row = 0; mcu_row < m_mcus_per_row; mcu_row++) |
| { |
| int block_x_mcu_ofs = 0, block_y_mcu_ofs = 0; |
| |
| if ((m_restart_interval) && (m_restarts_left == 0)) |
| process_restart(); |
| |
| for (mcu_block = 0; mcu_block < m_blocks_per_mcu; mcu_block++) |
| { |
| component_id = m_mcu_org[mcu_block]; |
| |
| decode_block_func(this, component_id, block_x_mcu[component_id] + block_x_mcu_ofs, m_block_y_mcu[component_id] + block_y_mcu_ofs); |
| |
| if (m_comps_in_scan == 1) |
| block_x_mcu[component_id]++; |
| else |
| { |
| if (++block_x_mcu_ofs == m_comp_h_samp[component_id]) |
| { |
| block_x_mcu_ofs = 0; |
| |
| if (++block_y_mcu_ofs == m_comp_v_samp[component_id]) |
| { |
| block_y_mcu_ofs = 0; |
| block_x_mcu[component_id] += m_comp_h_samp[component_id]; |
| } |
| } |
| } |
| } |
| |
| m_restarts_left--; |
| } |
| |
| if (m_comps_in_scan == 1) |
| m_block_y_mcu[m_comp_list[0]]++; |
| else |
| { |
| for (component_num = 0; component_num < m_comps_in_scan; component_num++) |
| { |
| component_id = m_comp_list[component_num]; |
| m_block_y_mcu[component_id] += m_comp_v_samp[component_id]; |
| } |
| } |
| } |
| } |
| |
| // Decode a progressively encoded image. |
| void jpeg_decoder::init_progressive() |
| { |
| int i; |
| |
| if (m_comps_in_frame == 4) |
| stop_decoding(JPGD_UNSUPPORTED_COLORSPACE); |
| |
| // Allocate the coefficient buffers. |
| for (i = 0; i < m_comps_in_frame; i++) |
| { |
| m_dc_coeffs[i] = coeff_buf_open(m_max_mcus_per_row * m_comp_h_samp[i], m_max_mcus_per_col * m_comp_v_samp[i], 1, 1); |
| m_ac_coeffs[i] = coeff_buf_open(m_max_mcus_per_row * m_comp_h_samp[i], m_max_mcus_per_col * m_comp_v_samp[i], 8, 8); |
| } |
| |
| for ( ; ; ) |
| { |
| int dc_only_scan, refinement_scan; |
| pDecode_block_func decode_block_func; |
| |
| if (!init_scan()) |
| break; |
| |
| dc_only_scan = (m_spectral_start == 0); |
| refinement_scan = (m_successive_high != 0); |
| |
| if ((m_spectral_start > m_spectral_end) || (m_spectral_end > 63)) |
| stop_decoding(JPGD_BAD_SOS_SPECTRAL); |
| |
| if (dc_only_scan) |
| { |
| if (m_spectral_end) |
| stop_decoding(JPGD_BAD_SOS_SPECTRAL); |
| } |
| else if (m_comps_in_scan != 1) /* AC scans can only contain one component */ |
| stop_decoding(JPGD_BAD_SOS_SPECTRAL); |
| |
| if ((refinement_scan) && (m_successive_low != m_successive_high - 1)) |
| stop_decoding(JPGD_BAD_SOS_SUCCESSIVE); |
| |
| if (dc_only_scan) |
| { |
| if (refinement_scan) |
| decode_block_func = decode_block_dc_refine; |
| else |
| decode_block_func = decode_block_dc_first; |
| } |
| else |
| { |
| if (refinement_scan) |
| decode_block_func = decode_block_ac_refine; |
| else |
| decode_block_func = decode_block_ac_first; |
| } |
| |
| decode_scan(decode_block_func); |
| |
| m_bits_left = 16; |
| get_bits(16); |
| get_bits(16); |
| } |
| |
| m_comps_in_scan = m_comps_in_frame; |
| |
| for (i = 0; i < m_comps_in_frame; i++) |
| m_comp_list[i] = i; |
| |
| calc_mcu_block_order(); |
| } |
| |
| void jpeg_decoder::init_sequential() |
| { |
| if (!init_scan()) |
| stop_decoding(JPGD_UNEXPECTED_MARKER); |
| } |
| |
| void jpeg_decoder::decode_start() |
| { |
| init_frame(); |
| |
| if (m_progressive_flag) |
| init_progressive(); |
| else |
| init_sequential(); |
| } |
| |
| void jpeg_decoder::decode_init(jpeg_decoder_stream *pStream) |
| { |
| init(pStream); |
| locate_sof_marker(); |
| } |
| |
| jpeg_decoder::jpeg_decoder(jpeg_decoder_stream *pStream) |
| { |
| if (setjmp(m_jmp_state)) |
| return; |
| decode_init(pStream); |
| } |
| |
| int jpeg_decoder::begin_decoding() |
| { |
| if (m_ready_flag) |
| return JPGD_SUCCESS; |
| |
| if (m_error_code) |
| return JPGD_FAILED; |
| |
| if (setjmp(m_jmp_state)) |
| return JPGD_FAILED; |
| |
| decode_start(); |
| |
| m_ready_flag = true; |
| |
| return JPGD_SUCCESS; |
| } |
| |
| jpeg_decoder::~jpeg_decoder() |
| { |
| free_all_blocks(); |
| } |
| |
| jpeg_decoder_file_stream::jpeg_decoder_file_stream() |
| { |
| m_pFile = NULL; |
| m_eof_flag = false; |
| m_error_flag = false; |
| } |
| |
| void jpeg_decoder_file_stream::close() |
| { |
| if (m_pFile) |
| { |
| fclose(m_pFile); |
| m_pFile = NULL; |
| } |
| |
| m_eof_flag = false; |
| m_error_flag = false; |
| } |
| |
| jpeg_decoder_file_stream::~jpeg_decoder_file_stream() |
| { |
| close(); |
| } |
| |
| bool jpeg_decoder_file_stream::open(const char *Pfilename) |
| { |
| close(); |
| |
| m_eof_flag = false; |
| m_error_flag = false; |
| |
| #if defined(_MSC_VER) |
| m_pFile = NULL; |
| fopen_s(&m_pFile, Pfilename, "rb"); |
| #else |
| m_pFile = fopen(Pfilename, "rb"); |
| #endif |
| return m_pFile != NULL; |
| } |
| |
| int jpeg_decoder_file_stream::read(uint8 *pBuf, int max_bytes_to_read, bool *pEOF_flag) |
| { |
| if (!m_pFile) |
| return -1; |
| |
| if (m_eof_flag) |
| { |
| *pEOF_flag = true; |
| return 0; |
| } |
| |
| if (m_error_flag) |
| return -1; |
| |
| int bytes_read = static_cast<int>(fread(pBuf, 1, max_bytes_to_read, m_pFile)); |
| if (bytes_read < max_bytes_to_read) |
| { |
| if (ferror(m_pFile)) |
| { |
| m_error_flag = true; |
| return -1; |
| } |
| |
| m_eof_flag = true; |
| *pEOF_flag = true; |
| } |
| |
| return bytes_read; |
| } |
| |
| bool jpeg_decoder_mem_stream::open(const uint8 *pSrc_data, uint size) |
| { |
| close(); |
| m_pSrc_data = pSrc_data; |
| m_ofs = 0; |
| m_size = size; |
| return true; |
| } |
| |
| int jpeg_decoder_mem_stream::read(uint8 *pBuf, int max_bytes_to_read, bool *pEOF_flag) |
| { |
| *pEOF_flag = false; |
| |
| if (!m_pSrc_data) |
| return -1; |
| |
| uint bytes_remaining = m_size - m_ofs; |
| if ((uint)max_bytes_to_read > bytes_remaining) |
| { |
| max_bytes_to_read = bytes_remaining; |
| *pEOF_flag = true; |
| } |
| |
| memcpy(pBuf, m_pSrc_data + m_ofs, max_bytes_to_read); |
| m_ofs += max_bytes_to_read; |
| |
| return max_bytes_to_read; |
| } |
| |
| unsigned char *decompress_jpeg_image_from_stream(jpeg_decoder_stream *pStream, int *width, int *height, int *actual_comps, int req_comps) |
| { |
| if (!actual_comps) { |
| err_reason = "no actual_comps"; |
| return NULL; |
| } |
| *actual_comps = 0; |
| |
| if (!pStream) { |
| err_reason = "stream == NULL"; |
| return NULL; |
| } |
| if (!width) { |
| err_reason = "width == NULL"; |
| return NULL; |
| } |
| if (!height) { |
| err_reason = "height == NULL"; |
| return NULL; |
| } |
| |
| if ((req_comps != 1) && (req_comps != 3) && (req_comps != 4)) { |
| err_reason = "req_comps not 1, 3 or 4"; |
| return NULL; |
| } |
| |
| jpeg_decoder decoder(pStream); |
| if (decoder.get_error_code() != JPGD_SUCCESS) { |
| err_reason = "decoder init failed for stream"; |
| return NULL; |
| } |
| |
| const int image_width = decoder.get_width(), image_height = decoder.get_height(); |
| *width = image_width; |
| *height = image_height; |
| *actual_comps = decoder.get_num_components(); |
| |
| if (decoder.begin_decoding() != JPGD_SUCCESS) { |
| err_reason = "begin decoding failed"; |
| return NULL; |
| } |
| |
| const int dst_bpl = image_width * req_comps; |
| |
| uint8 *pImage_data = (uint8*)jpgd_malloc(dst_bpl * image_height); |
| if (!pImage_data) { |
| err_reason = "image data == NULL"; |
| return NULL; |
| } |
| |
| for (int y = 0; y < image_height; y++) |
| { |
| const uint8* pScan_line; |
| uint scan_line_len; |
| if (decoder.decode((const void**)&pScan_line, &scan_line_len) != JPGD_SUCCESS) |
| { |
| jpgd_free(pImage_data); |
| err_reason = "line scanning failed"; |
| return NULL; |
| } |
| |
| uint8 *pDst = pImage_data + y * dst_bpl; |
| |
| if (((req_comps == 1) && (decoder.get_num_components() == 1)) || ((req_comps == 4) && (decoder.get_num_components() == 3))) |
| memcpy(pDst, pScan_line, dst_bpl); |
| else if (decoder.get_num_components() == 1) |
| { |
| if (req_comps == 3) |
| { |
| for (int x = 0; x < image_width; x++) |
| { |
| uint8 luma = pScan_line[x]; |
| pDst[0] = luma; |
| pDst[1] = luma; |
| pDst[2] = luma; |
| pDst += 3; |
| } |
| } |
| else |
| { |
| for (int x = 0; x < image_width; x++) |
| { |
| uint8 luma = pScan_line[x]; |
| pDst[0] = luma; |
| pDst[1] = luma; |
| pDst[2] = luma; |
| pDst[3] = 255; |
| pDst += 4; |
| } |
| } |
| } |
| else if (decoder.get_num_components() == 3) |
| { |
| if (req_comps == 1) |
| { |
| const int YR = 19595, YG = 38470, YB = 7471; |
| for (int x = 0; x < image_width; x++) |
| { |
| int r = pScan_line[x*4+0]; |
| int g = pScan_line[x*4+1]; |
| int b = pScan_line[x*4+2]; |
| *pDst++ = static_cast<uint8>((r * YR + g * YG + b * YB + 32768) >> 16); |
| } |
| } |
| else |
| { |
| for (int x = 0; x < image_width; x++) |
| { |
| pDst[0] = pScan_line[x*4+0]; |
| pDst[1] = pScan_line[x*4+1]; |
| pDst[2] = pScan_line[x*4+2]; |
| pDst += 3; |
| } |
| } |
| } |
| } |
| |
| return pImage_data; |
| } |
| |
| const char *failure_reason(void) |
| { |
| return err_reason; |
| } |
| |
| unsigned char *decompress_jpeg_image_from_memory(const unsigned char *pSrc_data, int src_data_size, int *width, int *height, int *actual_comps, int req_comps) |
| { |
| jpgd::jpeg_decoder_mem_stream mem_stream(pSrc_data, src_data_size); |
| return decompress_jpeg_image_from_stream(&mem_stream, width, height, actual_comps, req_comps); |
| } |
| |
| unsigned char *decompress_jpeg_image_from_file(const char *pSrc_filename, int *width, int *height, int *actual_comps, int req_comps) |
| { |
| jpgd::jpeg_decoder_file_stream file_stream; |
| if (!file_stream.open(pSrc_filename)) |
| return NULL; |
| return decompress_jpeg_image_from_stream(&file_stream, width, height, actual_comps, req_comps); |
| } |
| |
| } // namespace jpgd |
