/*
* in_jai.cpp -- read a JPEG file as-is
* by [email protected] at Sun Mar 17 20:15:25 CET 2002
*/
/* Imp: test this code with various JPEG files! */

#ifdef __GNUC__
#ifndef __clang__
#pragma implementation
#endif
#endif

#include "image.hpp"
#include "error.hpp"

#if USE_IN_JAI

#include "in_jai.hpp"
#include <string.h> /* memchr() */
#include <stdio.h>

/* --- */

class JAI: public Image::Sampled {
public:
 /** (Horiz<<4+Vert) sampling factor for the first color component. Usually
  * 0x11, but TIFF defaults to 0x22.
  */
 JAI(dimen_t wd_, dimen_t ht_, unsigned char bpc_, unsigned char cs_, slen_t flen_, slen_t SOF_offs_, unsigned char hvs_);
 virtual void copyRGBRow(char *to, dimen_t whichrow) const;
 virtual void to8();
 virtual Image::Indexed* toIndexed();
 virtual bool canGray() const;
 // virtual void setBpc(unsigned char bpc_);
 virtual Image::RGB    * toRGB(unsigned char bpc_);
 virtual Image::Gray   * toGray(unsigned char bpc_);
 virtual unsigned char minRGBBpc() const;
 virtual Image::Sampled* addAlpha(Image::Gray *al);
 void fixEOI();
};

JAI::JAI(dimen_t wd_, dimen_t ht_, unsigned char bpc_, unsigned char cs_, slen_t flen_, slen_t SOF_offs_, unsigned char hvs_) {
 param_assert(cs_<=5);
 // init(0,0,wd_,ht_,bpc_,TY_BLACKBOX,cs2cpp[cs_]);
 cs=cs_;
 bpc=8; (void)bpc_; // bpc=bpc_; /* /DCTDecode supports only BitsPerComponent==8 */
 ty=TY_BLACKBOX;
 wd=wd_;
 ht=ht_;
 cpp=cs2cpp[cs_];
 // pred=1;
 transpc=0x1000000UL; /* Dat: this means: no transparent color */
 rlen=0;
 beg=new char[len=0+flen_+0+bpc];
 rowbeg=(headp=const_cast<char*>(beg))+flen_;
 xoffs=SOF_offs_;
 trail=const_cast<char*>(beg)+len-bpc;
 const_cast<char*>(beg)[len-1]=hvs_; /* dirty place */
}

void JAI::fixEOI() {
 /* by [email protected] at Tue Jun  4 15:36:12 CEST 2002 */
 if (rowbeg[-2]!='\xFF' || rowbeg[-1]!='\xD9') {
   *rowbeg++='\xFF';
   *rowbeg++='\xD9';
 }
}

Image::Sampled* JAI::addAlpha(Image::Gray *) {
 Error::sev(Error::WARNING) << "JAI: alpha channel ignored" << (Error*)0;
 return this;
}


unsigned char JAI:: minRGBBpc() const { return bpc; }
void JAI::copyRGBRow(char*, dimen_t) const { assert(0); }
void JAI::to8() { assert(0); }
Image::Indexed* JAI::toIndexed() { return (Image::Indexed*)NULLP; }
bool JAI::canGray() const { return cs==CS_GRAYSCALE; }
Image::RGB    * JAI::toRGB(unsigned char) { assert(0); return 0; }
Image::Gray   * JAI::toGray(unsigned char) { assert(0); return 0; }

/* --- The following code is based on standard/image.c from PHP4 */

/* some defines for the different JPEG block types */
#define M_SOF0  0xC0                    /* Start Of Frame0: Baseline JPEG */
#define M_SOF1  0xC1                    /* N indicates which compression process */
#define M_SOF2  0xC2                    /* Only SOF0-SOF2 are now in common use */
#define M_SOF3  0xC3
#define M_SOF5  0xC5                    /* NB: codes C4 and CC are NOT SOF markers */
#define M_SOF6  0xC6
#define M_SOF7  0xC7
#define M_SOF9  0xC9
#define M_SOF10 0xCA
#define M_SOF11 0xCB
#define M_SOF13 0xCD
#define M_SOF14 0xCE
#define M_SOF15 0xCF
#define M_SOI   0xD8
#define M_EOI   0xD9                    /* End Of Image (end of datastream) */
#define M_SOS   0xDA                    /* Start Of Scan (begins compressed data) */
#define M_APP0  0xe0
#define M_APP1  0xe1
#define M_APP2  0xe2
#define M_APP3  0xe3
#define M_APP4  0xe4
#define M_APP5  0xe5
#define M_APP6  0xe6
#define M_APP7  0xe7
#define M_APP8  0xe8
#define M_APP9  0xe9
#define M_APP10 0xea
#define M_APP11 0xeb
#define M_APP12 0xec
#define M_APP13 0xed
#define M_APP14 0xee
#define M_APP15 0xef


#if 0
static unsigned int jai_next_marker(FILE *fp)
  /* get next marker byte from file */
{
 int c;

#if 0 /**** pts ****/
 /* skip unimportant stuff */
 c = MACRO_GETC(fp);
 while (c != 0xff) {
   if ((c = MACRO_GETC(fp)) == EOF)
     return M_EOI; /* we hit EOF */
 }
#else
 if (0xff!=(c=MACRO_GETC(fp))) return M_EOI;
#endif


 /* get marker byte, swallowing possible padding */
 do {
   if ((c = MACRO_GETC(fp)) == EOF)
     return M_EOI;    /* we hit EOF */
 } while (c == 0xff);

 return (unsigned int) c;
}
#endif

#if 0
static inline int getc_(FILE *f) { return MACRO_GETC(f); }
static inline long ftell_(FILE *f) { return ftell(f); }
template <class T>
static unsigned short jai_read2(T *fp);
template <class T>
static void jai_handle_jpeg(struct jai_gfxinfo *result, T *fp) {
#endif
/* Dat: removed templates at Tue Mar 11 19:59:16 CET 2003, because decoding
* JPEG headers isn't time-critical
*/

static inline unsigned short jai_read2(GenBuffer::Readable *fp) {
#if 0
 unsigned char a[ 2 ];
 /* just return 0 if we hit the end-of-file */
 if (fread(a,sizeof(a),1,fp) != 1) return 0;
 return (((unsigned short) a[ 0 ]) << 8) + ((unsigned short) a[ 1 ]);
#else
 int a=fp->vi_getcc(), b=fp->vi_getcc();
 /* just return 0 if we hit the end-of-file */
 return a>=0 && b>=0 ? (a<<8)+b : 0;
#endif
}

/** main loop to parse JPEG structure */
void jai_parse_jpeg(struct jai_gfxinfo *result, DecoderTeller *fp, bool must_be_baseline) {
 int c;
 unsigned int length;
 unsigned char had_adobe;

 result->bad=9; /* signal invalid return value */
 result->id_rgb=0;
 result->had_jfif=0;
 result->colortransform=127; /* no Adobe marker yet */
 // fseek(fp, 0L, SEEK_SET);    /* position file pointer on SOF */

 /* Verify JPEG header */
 /* Dat: maybe 0xFF != '\xFF' */
 if ((c=fp->vi_getcc())!=0xFF) return;
 while ((c=fp->vi_getcc())==0xFF) ;
 if (c!=M_SOI) return;

 result->bad=1;
 // fprintf(stderr, "welcome ofs=%ld\n", fp->vi_tell());
 while (1) {
  if ((c=fp->vi_getcc())!=0xFF) { result->bad=8; return; }
  while ((c=fp->vi_getcc())==0xFF) ;
  if (c==-1) { result->bad=2; return; }
  switch (c) {
   case M_SOF0: do_SOF:
     if (result->bad!=1) { result->bad=4; return; } /* only one M_SOF allowed */
     result->SOF_type=c-M_SOF0;
     result->SOF_offs=fp->vi_tell();
     // fprintf(stderr, "SOF_offs=%d\n", result->SOF_offs);
     /* handle SOFn block */
     length=jai_read2(fp);
     result->bpc = fp->vi_getcc();
     result->height = jai_read2(fp);
     result->width = jai_read2(fp);
     result->cpp = fp->vi_getcc();
     if ((length-=8)!=3U*result->cpp) return;
     if (result->bpc!=8) { result->bad=6; return; }
     if (result->cpp!=1 && result->cpp!=3 && result->cpp!=4) { result->bad=5; return; }
     assert(length>=3);
     if (result->cpp==3) {
       result->id_rgb =fp->vi_getcc()=='R';  result->hvs=fp->vi_getcc(); fp->vi_getcc();
       result->id_rgb&=fp->vi_getcc()=='G';  fp->vi_getcc(); fp->vi_getcc();
       result->id_rgb&=fp->vi_getcc()=='B';  fp->vi_getcc(); fp->vi_getcc();
     } else { length-=2; fp->vi_getcc(); result->hvs=fp->vi_getcc(); while (length--!=0) fp->vi_getcc(); }
     result->bad=2;
     break;
   case M_SOF1:
   case M_SOF2:
   case M_SOF3:
   case M_SOF5:
   case M_SOF6:
   case M_SOF7:
   case M_SOF9:
   case M_SOF10:
   case M_SOF11:
   case M_SOF13:
   case M_SOF14:
   case M_SOF15:
     if (!must_be_baseline) goto do_SOF;
     // fprintf(stderr, "SOF%u\n", marker-M_SOF0); assert(0);
     result->bad=3;
     return;
   case M_SOS: /* we are about to hit image data. We're done. Success. */
     if (result->bad==2 /* && !feof(fp)*/) { /* Dat: !feof() already guaranteed */
       if (result->cpp==1) {
         result->colorspace=Image::Sampled::CS_GRAYSCALE;
       } else if (result->cpp==3) {
         result->colorspace=Image::Sampled::CS_YCbCr;
         if (result->had_jfif!=0) ;
         else if (result->colortransform==0) result->colorspace=Image::Sampled::CS_RGB;
         else if (result->colortransform==1) ;
         else if (result->colortransform!=127) Error::sev(Error::EERROR) << "JAI: unknown ColorTransform: " << (unsigned)result->colortransform << (Error*)0;
         else if (result->id_rgb!=0) result->colorspace=Image::Sampled::CS_RGB;
         /* Imp: check for id_ycbcr */
         else Error::sev(Error::WARNING) << "JAI: assuming YCbCr color space" << (Error*)0;
       } else if (result->cpp==4) {
         result->colorspace=Image::Sampled::CS_CMYK;
         if (result->colortransform==0) ;
         else if (result->colortransform==2) result->colorspace=Image::Sampled::CS_YCCK;
         else if (result->colortransform!=127) Error::sev(Error::EERROR) << "JAI: unknown ColorTransform: " << (unsigned)result->colortransform << (Error*)0;
       } else assert(0);
       result->bad=0;
     }
     /* fall through */
   case M_EOI: /* premature EOF */
     return;
   case M_APP0: /* JFIF application-specific marker */
     length=jai_read2(fp);
     if (length==2+4+1+2+1+2+2+1+1) {
       result->had_jfif=fp->vi_getcc()=='J' && fp->vi_getcc()=='F' && fp->vi_getcc()=='I' &&
                        fp->vi_getcc()=='F' && fp->vi_getcc()==0;
       length-=7;
     } else length-=2;
     while (length--!=0) fp->vi_getcc();
     break;
   case M_APP14: /* Adobe application-specific marker */
     length=jai_read2(fp);
     if ((length-=2)==5+2+2+2+1) {
       had_adobe=fp->vi_getcc()=='A' && fp->vi_getcc()=='d' && fp->vi_getcc()=='o' &&
                 fp->vi_getcc()=='b' && fp->vi_getcc()=='e' && ((unsigned char)fp->vi_getcc())>=1;
       fp->vi_getcc(); fp->vi_getcc(); fp->vi_getcc(); fp->vi_getcc(); fp->vi_getcc();
       if (had_adobe) result->colortransform=fp->vi_getcc();
                 else fp->vi_getcc();
     } else while (length--!=0) fp->vi_getcc();
     break;
   case M_APP1:
   case M_APP2:
   case M_APP3:
   case M_APP4:
   case M_APP5:
   case M_APP6:
   case M_APP7:
   case M_APP8:
   case M_APP9:
   case M_APP10:
   case M_APP11:
   case M_APP12:
   case M_APP13:
   case M_APP15:
     /* fall through */
   default: { /* anything else isn't interesting */
     /* skip over a variable-length block; assumes proper length marker */
     unsigned short length;
     length = jai_read2(fp);
     length -= 2;        /* length includes itself */
     #if 0 /**** pts: fseek would disturb later ftell()s and feof()s */
       fseek(fp, (long) length, SEEK_CUR);  /* skip the header */
     #else
       while (length--!=0) fp->vi_getcc(); /* make feof(fp) correct */
     #endif
   }
  }
 }
}

char const*jai_errors[]={
 (char const*)NULLP,
 /*1*/ "missing SOF0 marker",
 /*2*/ "premature EOF",
 /*3*/ "not a Baseline JPEG (SOF must be SOF0)",
 /*4*/ "more SOF0 markers",
 /*5*/ "bad # components",
 /*6*/ "bad bpc",
 /*7*/ "?",
 /*8*/ "0xFF expected",
 /*9*/ "invalid JPEG header",
 // /*10*/ "not ending with EOI", /* not output by jai_handle_jpeg! */
};

static Image::Sampled *in_jai_reader(Image::Loader::UFD* ufd, SimBuffer::Flat const&) {
 // assert(0);
 struct jai_gfxinfo gi;
 Filter::UngetFILED* ufdd=(Filter::UngetFILED*)ufd;
 FILE *file_=ufdd->getFILE(/*seekable:*/true);
 jai_parse_jpeg(&gi, ufdd);
 // jai_parse_jpeg(&gi, (FILE*)file_);
 // long ftel=ftell((FILE*)file_);
 if (gi.bad!=0) Error::sev(Error::EERROR) << "JAI: " << jai_errors[gi.bad] << (Error*)0;
 // printf("ftell=%lu\n", ftell((FILE*)file_));
 fseek((FILE*)file_, 0L, 2); /* EOF */
 long flen=ftell((FILE*)file_); /* skip extra bytes after EOI. Imp: no need to do this */
 // fprintf(stderr, "flen=%lu\n", flen);
 assert(flen>2);
 rewind((FILE*)file_);
 JAI *ret=new JAI(gi.width,gi.height,gi.bpc,gi.colorspace,flen,gi.SOF_offs,gi.hvs);
 if (fread(ret->getHeadp(), flen, 1, (FILE*)file_)!=1 || ferror((FILE*)file_)) {
   ret->fixEOI();
   /* fclose((FILE*)file_); */
   Error::sev(Error::EERROR) << "JAI: IO error" << (Error*)0;
 }
 /* fclose((FILE*)file_); */
 return ret;
}

static Image::Loader::reader_t in_jai_checker(char buf[Image::Loader::MAGIC_LEN], char [Image::Loader::MAGIC_LEN], SimBuffer::Flat const& loadHints, Image::Loader::UFD* ufd) {
 if (0!=memcmp(buf, "\xff\xd8\xff", 3)
  || !(loadHints.findFirst((char const*)",jpeg-asis,",6)!=loadHints.getLength() || loadHints.findFirst((char const*)",asis,",6)!=loadHints.getLength())
    ) return 0;
 Filter::UngetFILED* ufdd=(Filter::UngetFILED*)ufd;
 ufdd->seek(0);
 Image::Loader::reader_t ret=jai_is_baseline_jpeg(ufdd) ? in_jai_reader : 0;
 ufdd->seek(0);
 return ret;
}

#if 0 /* Filter::FlatR* used by JPEGSOF0Encode::vi_write() in appliers.cpp */
static inline int getc_(Filter::FlatR *f) { return f->getcc(); }
static inline long ftell_(Filter::FlatR *f) { return f->tell(); }
void jai_parse_jpeg(struct jai_gfxinfo *result, Filter::FlatR *f) {
 jai_handle_jpeg(result, f);
}
void jai_parse_jpeg(struct jai_gfxinfo *result, FILE *f) {
 jai_handle_jpeg(result, f);
}
#endif

#if 0 /* unused */
int jai_is_baseline_jpeg(char const* filename) {
 /* by [email protected] at Tue Mar 11 20:27:56 CET 2003 */
 FILE *f=fopen(filename, "rb");
 if (!f) return -1;
 Filter::FILED filed(f, /*closep:*/true);
 return jai_is_baseline_jpeg(&filed);
}
#endif
int jai_is_baseline_jpeg(/*DecoderTeller*/Filter::UngetFILED *fp) {
 char buf[3];
 struct jai_gfxinfo gi;
 bool qfalse=(3!=fp->vi_read(buf, 3) || 0!=memcmp(buf, "\xff\xd8\xff", 3));
 fp->unread(buf, 3);
 if (qfalse) return false;
 fp->getFILE(/*seekable*/true); /* make it seekable, so the caller can seek back */
 jai_parse_jpeg(&gi, fp, /*must_be_baseline:*/false);
 fp->seek(0);
 return gi.bad!=0 ? -1 : gi.SOF_type==0;
}
#else
#define in_jai_checker (Image::Loader::checker_t)NULLP
#endif /* USE_IN_JAI */

Image::Loader in_jai_loader = { "JAI", in_jai_checker, 0 };

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.