select_file_type (j_compress_ptr cinfo, FILE * infile)
{
int c;
if (is_targa) {
#ifdef TARGA_SUPPORTED
return jinit_read_targa(cinfo);
#else
ERREXIT(cinfo, JERR_TGA_NOTCOMP);
#endif
}
if ((c = getc(infile)) == EOF)
ERREXIT(cinfo, JERR_INPUT_EMPTY);
if (ungetc(c, infile) == EOF)
ERREXIT(cinfo, JERR_UNGETC_FAILED);
switch (c) {
#ifdef BMP_SUPPORTED
case 'B':
return jinit_read_bmp(cinfo);
#endif
#ifdef GIF_SUPPORTED
case 'G':
return jinit_read_gif(cinfo);
#endif
#ifdef PPM_SUPPORTED
case 'P':
return jinit_read_ppm(cinfo);
#endif
#ifdef RLE_SUPPORTED
case 'R':
return jinit_read_rle(cinfo);
#endif
#ifdef TARGA_SUPPORTED
case 0x00:
return jinit_read_targa(cinfo);
#endif
default:
ERREXIT(cinfo, JERR_UNKNOWN_FORMAT);
break;
}
return NULL; /* suppress compiler warnings */
}
int loadbmp(char *filename, unsigned char **buf, int *w, int *h,
int dstpf, int bottomup)
{
int retval=0, dstps, srcpf, tempc;
struct jpeg_compress_struct cinfo;
struct my_error_mgr jerr;
cjpeg_source_ptr src;
FILE *file=NULL;
if(!filename || !buf || !w || !h || dstpf<0 || dstpf>=TJ_NUMPF)
_throw("loadbmp(): Invalid argument");
if((file=fopen(filename, "rb"))==NULL)
_throwunix("loadbmp(): Cannot open input file");
cinfo.err=jpeg_std_error(&jerr.pub);
jerr.pub.error_exit=my_error_exit;
jerr.pub.output_message=my_output_message;
if(setjmp(jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error. */
retval=-1; goto bailout;
}
jpeg_create_compress(&cinfo);
if((tempc=getc(file))<0 || ungetc(tempc, file)==EOF)
_throwunix("loadbmp(): Could not read input file")
else if(tempc==EOF) _throw("loadbmp(): Input file contains no data");
if(tempc=='B')
{
if((src=jinit_read_bmp(&cinfo))==NULL)
_throw("loadbmp(): Could not initialize bitmap loader");
}
else if(tempc=='P')
{
if((src=jinit_read_ppm(&cinfo))==NULL)
_throw("loadbmp(): Could not initialize bitmap loader");
}
else _throw("loadbmp(): Unsupported file type");
src->input_file=file;
(*src->start_input)(&cinfo, src);
(*cinfo.mem->realize_virt_arrays)((j_common_ptr)&cinfo);
*w=cinfo.image_width; *h=cinfo.image_height;
if(cinfo.input_components==1 && cinfo.in_color_space==JCS_RGB)
srcpf=TJPF_GRAY;
else srcpf=TJPF_RGB;
dstps=tjPixelSize[dstpf];
if((*buf=(unsigned char *)malloc((*w)*(*h)*dstps))==NULL)
_throw("loadbmp(): Memory allocation failure");
while(cinfo.next_scanline<cinfo.image_height)
{
int i, nlines=(*src->get_pixel_rows)(&cinfo, src);
for(i=0; i<nlines; i++)
{
unsigned char *outbuf; int row;
row=cinfo.next_scanline+i;
if(bottomup) outbuf=&(*buf)[((*h)-row-1)*(*w)*dstps];
else outbuf=&(*buf)[row*(*w)*dstps];
pixelconvert(src->buffer[i], srcpf, 0, outbuf, dstpf, bottomup, *w,
nlines);
}
cinfo.next_scanline+=nlines;
}
(*src->finish_input)(&cinfo, src);
bailout:
jpeg_destroy_compress(&cinfo);
if(file) fclose(file);
if(retval<0 && buf && *buf) {free(*buf); *buf=NULL;}
return retval;
}
