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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | /* Zgv v2.7 - GIF, JPEG and PBM/PGM/PPM viewer, for VGA PCs running Linux. |
| 2 | * Copyright (C) 1993-1995 Russell Marks. See README for license details. |
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| 3 | * |
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| 4 | * readjpeg.c - interface to the IJG's JPEG software, derived from |
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| 5 | * their example.c. |
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| 6 | */ |
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| 7 | |||
| 8 | #include |
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| 9 | #include |
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| 10 | #include |
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| 11 | #include |
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| 12 | #include |
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| 13 | #include |
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| 14 | #include |
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| 15 | #include "libmgfx.h" |
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| 16 | |||
| 17 | static mgfx_image_t * the_image; |
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| 18 | static FILE * global_jpeg_infile; |
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| 19 | static struct jpeg_decompress_struct cinfo; |
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| 20 | |||
| 21 | struct my_error_mgr |
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| 22 | { |
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| 23 | struct jpeg_error_mgr pub; |
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| 24 | jmp_buf setjmp_buffer; |
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| 25 | }; |
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| 26 | |||
| 27 | typedef struct my_error_mgr * my_error_ptr; |
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| 28 | |||
| 29 | static void jpegerr(char *msgtext) |
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| 30 | { |
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| 31 | } |
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| 32 | |||
| 33 | static void my_error_exit(j_common_ptr cinfo) |
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| 34 | { |
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| 35 | my_error_ptr myerr=(my_error_ptr) cinfo->err; |
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| 36 | char buf[JMSG_LENGTH_MAX]; |
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| 37 | (*cinfo->err->format_message)(cinfo,buf); |
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| 38 | jpegerr(buf); |
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| 39 | longjmp(myerr->setjmp_buffer, 1); |
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| 40 | } |
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| 41 | |||
| 42 | static void my_output_message(j_common_ptr cinfo) |
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| 43 | { |
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| 44 | } |
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| 45 | |||
| 46 | static void aborted_file_jpeg_cleanup() |
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| 47 | { |
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| 48 | jpeg_destroy_decompress(&cinfo); |
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| 49 | fclose(global_jpeg_infile); |
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| 50 | } |
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| 51 | |||
| 52 | int read_JPEG_file(FILE * in,mgfx_image_t * img) |
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| 53 | { |
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| 54 | struct my_error_mgr jerr; |
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| 55 | int row_stride; |
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| 56 | int tmp,f; |
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| 57 | unsigned char *ptr; |
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| 58 | the_image=img; |
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| 59 | if((img->pal=(byte *)malloc(768))==NULL) return(_PICERR_NOMEM); |
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| 60 | cinfo.err=jpeg_std_error(&jerr.pub); |
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| 61 | jerr.pub.error_exit=my_error_exit; |
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| 62 | jerr.pub.output_message=my_output_message; |
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| 63 | if(setjmp(jerr.setjmp_buffer)) |
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| 64 | { |
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| 65 | jpeg_destroy_decompress(&cinfo); |
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| 66 | free(img->pal); |
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| 67 | return(_PICERR_CORRUPT); |
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| 68 | } |
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| 69 | jpeg_create_decompress(&cinfo); |
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| 70 | jpeg_stdio_src(&cinfo,in); |
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| 71 | jpeg_read_header(&cinfo,TRUE); |
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| 72 | cinfo.dct_method=JDCT_FLOAT; |
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| 73 | img->bpp=24; |
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| 74 | if(cinfo.jpeg_color_space==JCS_GRAYSCALE) |
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| 75 | { |
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| 76 | cinfo.out_color_space=JCS_GRAYSCALE; |
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| 77 | cinfo.desired_number_of_colors=256; |
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| 78 | cinfo.quantize_colors=FALSE; |
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| 79 | cinfo.two_pass_quantize=FALSE; |
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| 80 | img->bpp=8; |
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| 81 | for(f=0;f<256;f++) |
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| 82 | img->pal[f]=img->pal[256+f]=img->pal[512+f]=f; |
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| 83 | } |
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| 84 | img->width=cinfo.image_width; |
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| 85 | img->height=cinfo.image_height; |
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| 86 | img->the_image=(byte *)malloc(((img->bpp+7)/8)*img->width*img->height); |
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| 87 | if(img->the_image==NULL) |
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| 88 | { |
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| 89 | jpegerr("Out of memory"); |
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| 90 | longjmp(jerr.setjmp_buffer,1); |
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| 91 | } |
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| 92 | jpeg_start_decompress(&cinfo); |
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| 93 | if(img->bpp==8 && cinfo.jpeg_color_space!=JCS_GRAYSCALE) |
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| 94 | for(f=0;f |
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| 95 | { |
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| 96 | img->pal[ f]=cinfo.colormap[0][f]; |
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| 97 | img->pal[256+f]=cinfo.colormap[1][f]; |
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| 98 | img->pal[512+f]=cinfo.colormap[2][f]; |
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| 99 | } |
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| 100 | ptr=img->the_image; |
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| 101 | row_stride=((img->bpp+7)/8)*img->width; |
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| 102 | if(img->bpp==8) |
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| 103 | while(cinfo.output_scanline |
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| 104 | { |
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| 105 | jpeg_read_scanlines(&cinfo,&ptr,1); |
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| 106 | ptr+=row_stride; |
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| 107 | } |
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| 108 | else |
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| 109 | while(cinfo.output_scanline |
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| 110 | { |
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| 111 | jpeg_read_scanlines(&cinfo,&ptr,1); |
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| 112 | for(f=0;f |
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| 113 | } |
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| 114 | jpeg_finish_decompress(&cinfo); |
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| 115 | jpeg_destroy_decompress(&cinfo); |
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| 116 | return(_PIC_OK); |
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| 117 | } |
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| 118 | |||
| 119 | static struct mgfx_image_format this_fmt_1={ |
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| 120 | "JPEG", |
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| 121 | "jpg", |
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| 122 | read_JPEG_file, |
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| 123 | NULL, |
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| 124 | }; |
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| 125 | |||
| 126 | static struct mgfx_image_format this_fmt_2={ |
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| 127 | "JPEG", |
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| 128 | "jpeg", |
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| 129 | read_JPEG_file, |
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| 130 | NULL, |
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| 131 | }; |
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| 132 | |||
| 133 | void mgfx_register_jpeg(void) |
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| 134 | { |
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| 135 | register_image_format(&this_fmt_1); |
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| 136 | register_image_format(&this_fmt_2); |
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| 137 | } |