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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 | } |