modules/psionpic.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 // Psion PIC
   6
   7 #include <deark-config.h>
   8 #include <deark-private.h>
   9 DE_DECLARE_MODULE(de_module_psionpic);
  10
  11 struct plane_info_struct {
  12         i64 width, height;
  13         i64 image_pos; // absolute position in file
  14         i64 rowspan;
  15 };
  16
  17 typedef struct localctx_struct {
  18         i64 num_planes;
  19         int bw;
  20         struct plane_info_struct *plane_info; // Array of plane_info_structs
  21 } lctx;
  22
  23 static void do_read_plane_info(deark *c, lctx *d, struct plane_info_struct *pi, i64 pos)
  24 {
  25         i64 image_relative_pos;
  26         i64 image_size_in_bytes;
  27
  28         de_zeromem(pi, sizeof(struct plane_info_struct));
  29         pi->width = de_getu16le(pos+2);
  30         pi->height = de_getu16le(pos+4);
  31         image_size_in_bytes = de_getu16le(pos+6);
  32         image_relative_pos = de_getu32le(pos+8);
  33         pi->image_pos = pos + 12 + image_relative_pos;
  34         pi->rowspan = ((pi->width+15)/16)*2; // 2-byte alignment
  35
  36         de_dbg(c, "bitmap: descriptor at %d, image at %d (size %d)",
  37                 (int)pos, (int)pi->image_pos, (int)image_size_in_bytes);
  38         de_dbg_dimensions(c, pi->width, pi->height);
  39 }
  40
  41 static void do_bitmap_1plane(deark *c, lctx *d, i64 plane_num)
  42 {
  43         struct plane_info_struct *pi = &d->plane_info[plane_num];
  44
  45         de_dbg(c, "making a bilevel image from plane %d", (int)plane_num);
  46
  47         de_convert_and_write_image_bilevel2(c->infile, pi->image_pos, pi->width, pi->height,
  48                 pi->rowspan, DE_CVTF_WHITEISZERO|DE_CVTF_LSBFIRST, NULL, 0);
  49 }
  50
  51 static void do_bitmap_2planes(deark *c, lctx *d, i64 pn1, i64 pn2)
  52 {
  53         de_bitmap *img = NULL;
  54         i64 i, j;
  55         u8 n0, n1;
  56
  57         de_dbg(c, "making a grayscale image from planes %d and %d", (int)pn1, (int)pn2);
  58
  59         // TODO: Support -padpix (need samples with width not a multiple of 16)
  60         img = de_bitmap_create(c, d->plane_info[pn1].width, d->plane_info[pn1].height, 1);
  61
  62         for(j=0; j<d->plane_info[pn1].height; j++) {
  63                 for(i=0; i<d->plane_info[pn1].width; i++) {
  64                         n0 = de_get_bits_symbol_lsb(c->infile, 1, d->plane_info[pn1].image_pos + j*d->plane_info[pn1].rowspan, i);
  65                         n1 = de_get_bits_symbol_lsb(c->infile, 1, d->plane_info[pn2].image_pos + j*d->plane_info[pn2].rowspan, i);
  66                         de_bitmap_setpixel_gray(img, i, j, (3-(n0*2+n1))*85);
  67                 }
  68         }
  69         de_bitmap_write_to_file(img, NULL, 0);
  70
  71         de_bitmap_destroy(img);
  72 }
  73
  74 static int could_be_2bit(lctx *d, int startpos)
  75 {
  76         i64 i;
  77         if( (d->num_planes - startpos)%2 != 0) {
  78                 // Not an even number of bitmaps.
  79                 return 0;
  80         }
  81         for(i=startpos; i<d->num_planes; i+=2) {
  82                 if(d->plane_info[i].width!=d->plane_info[i+1].width ||
  83                         d->plane_info[i].height!=d->plane_info[i+1].height)
  84                 {
  85                         // Bitmaps aren't the same size.
  86                         return 0;
  87                 }
  88         }
  89         return 1;
  90 }
  91
  92 #define PPIC_FMT_1_1  1
  93 #define PPIC_FMT_1_2  2
  94 #define PPIC_FMT_2_2  3
  95
  96 // This detection logic is just a wild guess. Copy it at your own risk.
  97 static int detect_format(deark *c, lctx *d)
  98 {
  99         if(d->bw)
 100                 return PPIC_FMT_1_1;
 101
 102         if(d->num_planes>=3 &&
 103                 d->plane_info[0].width==24 && d->plane_info[0].height==24 &&
 104                 d->plane_info[1].width==48 && d->plane_info[1].height==48 &&
 105                 could_be_2bit(d, 1))
 106         {
 107                 return PPIC_FMT_1_2;
 108         }
 109
 110         if(d->num_planes>=1 &&
 111                 d->plane_info[0].width==24 && d->plane_info[0].height==24)
 112         {
 113                 return PPIC_FMT_1_1;
 114         }
 115
 116         if(d->num_planes>=2 && could_be_2bit(d, 0)) {
 117                 return PPIC_FMT_2_2;
 118         }
 119
 120         return PPIC_FMT_1_1;
 121 }
 122
 123 static void de_run_psionpic(deark *c, de_module_params *mparams)
 124 {
 125         lctx *d = NULL;
 126         i64 i;
 127         int format;
 128         const char *s;
 129
 130         d = de_malloc(c, sizeof(lctx));
 131
 132         s = de_get_ext_option(c, "psionpic:bw");
 133         if(s) {
 134                 d->bw = 1;
 135         }
 136
 137         d->num_planes = de_getu16le(6);
 138         de_dbg(c, "number of planes/bitmaps: %d", (int)d->num_planes);
 139
 140         // After the 8-byte header are [num_images] 12-byte bitmap descriptors.
 141         d->plane_info = de_mallocarray(c, d->num_planes, sizeof(struct plane_info_struct));
 142         for(i=0; i<d->num_planes; i++) {
 143                 do_read_plane_info(c, d, &d->plane_info[i], 8+12*i);
 144         }
 145
 146         // The PIC format seems like it was intended to store an arbitrary
 147         // number of bilevel images, but some of them are clearly planes that
 148         // are intended to be combined to form an image. I don't know for sure
 149         // how I'm supposed to do that.
 150
 151         format = detect_format(c, d);
 152
 153         switch(format) {
 154         case PPIC_FMT_2_2:
 155                 for(i=0; i+1<d->num_planes; i+=2) {
 156                         do_bitmap_2planes(c, d, i, i+1);
 157                 }
 158                 break;
 159         case PPIC_FMT_1_2:
 160                 do_bitmap_1plane(c, d, 0);
 161                 for(i=1; i+1<d->num_planes; i+=2) {
 162                         do_bitmap_2planes(c, d, i, i+1);
 163                 }
 164                 break;
 165         default:
 166                 for(i=0; i<d->num_planes; i++) {
 167                         do_bitmap_1plane(c, d, i);
 168                 }
 169         }
 170
 171         de_free(c, d->plane_info);
 172         de_free(c, d);
 173 }
 174
 175 static int de_identify_psionpic(deark *c)
 176 {
 177         if(!dbuf_memcmp(c->infile, 0, "PIC\xdc\x30\x30", 6))
 178                 return 100;
 179         return 0;
 180 }
 181
 182 static void de_help_psionpic(deark *c)
 183 {
 184         de_msg(c, "-opt psionpic:bw : Do not try to detect grayscale images");
 185 }
 186
 187 void de_module_psionpic(deark *c, struct deark_module_info *mi)
 188 {
 189         mi->id = "psionpic";
 190         mi->desc = "Psion PIC, a.k.a. EPOC PIC";
 191         mi->run_fn = de_run_psionpic;
 192         mi->identify_fn = de_identify_psionpic;
 193         mi->help_fn = de_help_psionpic;
 194 }