--- /dev/null
+// 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))
+
+// 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++)
+ 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)
+ {
+ 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)
+ return NULL;
+ *actual_comps = 0;
+
+ if ((!pStream) || (!width) || (!height) || (!req_comps))
+ return NULL;
+
+ if ((req_comps != 1) && (req_comps != 3) && (req_comps != 4))
+ return NULL;
+
+ jpeg_decoder decoder(pStream);
+ if (decoder.get_error_code() != JPGD_SUCCESS)
+ 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)
+ return NULL;
+
+ const int dst_bpl = image_width * req_comps;
+
+ uint8 *pImage_data = (uint8*)jpgd_malloc(dst_bpl * image_height);
+ if (!pImage_data)
+ 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);
+ return NULL;
+ }
+
+ uint8 *pDst = pImage_data + y * dst_bpl;
+
+#if 1
+ //Return as BGRA
+ if ((req_comps == 4) && (decoder.get_num_components() == 3)) {
+ for (int x = 0; x < image_width; x++)
+ {
+ pDst[0] = pScan_line[x*4+2];
+ pDst[1] = pScan_line[x*4+1];
+ pDst[2] = pScan_line[x*4+0];
+ pDst[3] = 255;
+ pDst += 4;
+ }
+ } else
+#endif
+ 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;
+}
+
+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
projects / platform / core / graphics / tizenvg.git / commitdiff