//?jpgd.cpp?-?C++?class?for?JPEG?decompression.
//?Public?domain?Rich?Geldreich?
//?Last?updated?Apr.?16?2011
//?Alex?Evans:?Linear?memory?allocator?（taken?from?jpge.h）.
//
//?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?

#include?
#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（ab）?（（（a）>（b））???（a）?:?（b））
#define?JPGD_MIN（ab）?（（（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]?=?{??0181692310172432251811451219263340484134272013671421283542495657504336292215233037445158595245383139465360615447556263?};

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_501321