modules/jovianvi.c

   1 // This file is part of Deark.
   2 // Copyright (C) 2016 Jason Summers
   3 // See the file COPYING for terms of use.
   4
   5 // Jovian Logic VI (.vi)
   6
   7 #include <deark-config.h>
   8 #include <deark-private.h>
   9 DE_DECLARE_MODULE(de_module_jovianvi);
  10
  11 typedef struct localctx_struct {
  12         u8 imgtype;
  13         u8 pal_code;
  14         i64 npwidth, h;
  15         i64 pdwidth;
  16         i64 bitdepth;
  17         i64 bits_alloc;
  18         i64 rowspan;
  19         i64 palpos;
  20         i64 bitspos;
  21         i64 pal_first_entry_idx;
  22         i64 num_pal_colors;
  23         u32 pal[256];
  24 } lctx;
  25
  26 static void do_read_palette(deark *c, lctx *d)
  27 {
  28         i64 k, z;
  29         i64 idx;
  30         u8 b1[3];
  31         u8 b2[3];
  32
  33         de_dbg(c, "palette at %d", (int)d->palpos);
  34         de_dbg_indent(c, 1);
  35
  36         for(k=0; k<d->num_pal_colors; k++) {
  37                 idx = d->pal_first_entry_idx + k;
  38                 if(idx > 255) break;
  39
  40                 de_read(b1, d->palpos + 3*k, 3);
  41                 for(z=0; z<3; z++) {
  42                         if(d->pal_code==0) {
  43                                 b2[z] = de_scale_63_to_255(b1[z]); // 6-bit palette samples
  44                         }
  45                         else {
  46                                 b2[z] = b1[z]; // 8-bit palette samples
  47                         }
  48                 }
  49
  50                 d->pal[idx] = DE_MAKE_RGB(b2[0],b2[1],b2[2]);
  51
  52                 if(d->pal_code==0) {
  53                         char tmps[64];
  54                         de_snprintf(tmps, sizeof(tmps), "(%2d,%2d,%2d) "DE_CHAR_RIGHTARROW" ",
  55                                 (int)b1[0], (int)b1[1], (int)b1[2]);
  56                         de_dbg_pal_entry2(c, k, d->pal[idx], tmps, NULL, NULL);
  57                 }
  58                 else {
  59                         de_dbg_pal_entry(c, k, d->pal[idx]);
  60                 }
  61         }
  62
  63         de_dbg_indent(c, -1);
  64 }
  65
  66 static void do_convert_grayscale(deark *c, lctx *d, de_bitmap *img)
  67 {
  68         int i, j;
  69         u8 v;
  70
  71         if(d->bitdepth==1) {
  72                 de_convert_image_bilevel(c->infile, d->bitspos, d->rowspan, img, 0);
  73                 goto done;
  74         }
  75
  76         for(j=0; j<d->h; j++) {
  77                 for(i=0; i<d->pdwidth; i++) {
  78                         v = de_get_bits_symbol(c->infile, d->bits_alloc, d->bitspos + j*d->rowspan, i);
  79                         if(d->bitdepth==4) v *= 17;
  80                         else if(d->bitdepth==6) {
  81                                 if(v<=63) v = de_scale_63_to_255(v);
  82                                 else v=0;
  83                         }
  84                         de_bitmap_setpixel_gray(img, i, j, v);
  85                 }
  86         }
  87
  88 done:
  89         ;
  90 }
  91
  92 static void do_convert_rgb(deark *c, lctx *d, de_bitmap *img)
  93 {
  94         i64 i, j;
  95         u32 clr;
  96         u8 b0, b1;
  97
  98         for(j=0; j<d->h; j++) {
  99                 for(i=0; i<d->pdwidth; i++) {
 100                         if(d->bitdepth==16) {
 101                                 b0 = de_getbyte(d->bitspos + j*d->rowspan + i*2);
 102                                 b1 = de_getbyte(d->bitspos + j*d->rowspan + i*2 + 1);
 103                                 clr = (((u32)b1)<<8) | b0;
 104                                 clr = de_rgb565_to_888(clr);
 105                         }
 106                         else {
 107                                 clr = dbuf_getRGB(c->infile, d->bitspos+j*d->rowspan+i*3, 0);
 108                         }
 109                         de_bitmap_setpixel_rgb(img, i, j, clr);
 110                 }
 111         }
 112 }
 113
 114 static void de_run_jovianvi(deark *c, de_module_params *mparams)
 115 {
 116         lctx *d = NULL;
 117         de_bitmap *img = NULL;
 118         int has_palette = 0;
 119         int is_grayscale = 0;
 120         const char *imgtypename;
 121
 122         // Warning: This decoder is based on reverse engineering, and may be
 123         // incorrect or incomplete.
 124
 125         d = de_malloc(c, sizeof(lctx));
 126
 127         d->imgtype = de_getbyte(2);
 128         de_dbg(c, "image type: 0x%02x", (unsigned int)d->imgtype);
 129
 130         switch(d->imgtype) {
 131         case 0x10:
 132                 d->bitdepth = 16;
 133                 break;
 134         case 0x11:
 135                 d->bitdepth = 24;
 136                 break;
 137         case 0x20:
 138                 d->bitdepth = 4;
 139                 is_grayscale = 1;
 140                 break;
 141         case 0x21:
 142                 d->bitdepth = 6;
 143                 is_grayscale = 1;
 144                 break;
 145         case 0x22:
 146                 d->bitdepth = 8;
 147                 is_grayscale = 1;
 148                 break;
 149         case 0x23:
 150                 d->bitdepth = 1;
 151                 is_grayscale = 1;
 152                 break;
 153         case 0x30:
 154                 d->bitdepth = 8;
 155                 has_palette = 1;
 156                 break;
 157         case 0x31:
 158                 d->bitdepth = 4;
 159                 has_palette = 1;
 160                 break;
 161         default:
 162                 de_err(c, "Unknown VI image type: 0x%02x", (unsigned int)d->imgtype);
 163                 goto done;
 164         }
 165
 166         if(d->bitdepth==6)
 167                 d->bits_alloc = 8;
 168         else
 169                 d->bits_alloc = d->bitdepth;
 170
 171         de_dbg_indent(c, 1);
 172
 173         if(is_grayscale) imgtypename="grayscale";
 174         else if(has_palette) imgtypename="palette color";
 175         else imgtypename="RGB";
 176         de_dbg(c, "%d bits/pixel, %s", (int)d->bitdepth, imgtypename);
 177         de_dbg_indent(c, -1);
 178         if(is_grayscale && (d->bitdepth!=1 && d->bitdepth!=4 && d->bitdepth!=6 && d->bitdepth!=8)) {
 179                 de_err(c, "This type of VI image is not supported");
 180                 goto done;
 181         }
 182
 183         d->npwidth = de_getu16le(3);
 184         d->h = de_getu16le(5);
 185         de_dbg_dimensions(c, d->npwidth, d->h);
 186         if(!de_good_image_dimensions(c, d->npwidth, d->h)) goto done;
 187
 188         if(has_palette) {
 189                 d->pal_code = de_getbyte(9);
 190                 de_dbg(c, "palette code: 0x%02x", (unsigned int)d->pal_code);
 191
 192                 d->pal_first_entry_idx = (i64)de_getbyte(10);
 193                 d->num_pal_colors =  (i64)de_getbyte(11);
 194                 if(d->num_pal_colors==0)
 195                         d->num_pal_colors = 256;
 196                 de_dbg(c, "index of first palette color: %d", (int)d->pal_first_entry_idx);
 197                 de_dbg(c, "number of palette colors: %d", (int)d->num_pal_colors);
 198         }
 199
 200         d->palpos = de_getu16le(12);
 201         d->bitspos = de_getu16le(14);
 202
 203         // Read palette, if applicable
 204         if(has_palette) {
 205                 do_read_palette(c, d);
 206         }
 207
 208         // Convert the image
 209         de_dbg(c, "bitmap at %d", (int)d->bitspos);
 210         d->rowspan = (d->npwidth*d->bits_alloc + 7)/8;
 211         // Note that a partial pixel's worth of padding is possible in some cases, but
 212         // it's not worth the trouble to make -padpix support it.
 213         d->pdwidth = (d->rowspan*8)/(d->bits_alloc);
 214
 215         img = de_bitmap_create2(c, d->npwidth, d->pdwidth, d->h, is_grayscale?1:3);
 216         if(has_palette) {
 217                 de_convert_image_paletted(c->infile, d->bitspos, d->bitdepth, d->rowspan, d->pal, img, 0);
 218         }
 219         else if(is_grayscale) {
 220                 do_convert_grayscale(c, d, img);
 221         }
 222         else {
 223                 do_convert_rgb(c, d, img);
 224         }
 225         de_bitmap_write_to_file(img, NULL, 0);
 226
 227 done:
 228         de_bitmap_destroy(img);
 229         de_free(c, d);
 230 }
 231
 232 static int de_identify_jovianvi(deark *c)
 233 {
 234         u8 t;
 235
 236         if(dbuf_memcmp(c->infile, 0, "VI", 2)) return 0;
 237         t = de_getbyte(2);
 238         if((t>=0x10 && t<=0x11) ||
 239                 (t>=0x20 && t<=0x23) ||
 240                 (t>=0x30 && t<=0x31))
 241         {
 242                 return 100;
 243         }
 244         return 0;
 245 }
 246
 247 void de_module_jovianvi(deark *c, struct deark_module_info *mi)
 248 {
 249         mi->id = "jovianvi";
 250         mi->desc = "Jovian Logic VI";
 251         mi->run_fn = de_run_jovianvi;
 252         mi->identify_fn = de_identify_jovianvi;
 253 }