images/io-libungif.c

   1 /*
   2  *      Image Library -- libungif
   3  *
   4  *      (c) 2006 Pavel Charvat <pchar@ucw.cz>
   5  *
   6  *      This software may be freely distributed and used according to the terms
   7  *      of the GNU Lesser General Public License.
   8  */
   9
  10 #undef LOCAL_DEBUG
  11
  12 #include "lib/lib.h"
  13 #include "lib/mempool.h"
  14 #include "lib/fastbuf.h"
  15 #include "images/images.h"
  16 #include "images/color.h"
  17 #include "images/io-main.h"
  18 #include <gif_lib.h>
  19
  20 static int
  21 libungif_read_func(GifFileType *gif, GifByteType *ptr, int len)
  22 {
  23   DBG("libungif_read_func(len=%d)", len);
  24   return bread((struct fastbuf *)gif->UserData, (byte *)ptr, len);
  25 }
  26
  27 static void
  28 libungif_read_cancel(struct image_io *io)
  29 {
  30   DBG("libungif_read_cancel()");
  31
  32   DGifCloseFile(io->read_data);
  33 }
  34
  35 int
  36 libungif_read_header(struct image_io *io)
  37 {
  38   DBG("libungif_read_header()");
  39
  40   /* Create libungif structure */
  41   GifFileType *gif;
  42   if (unlikely(!(gif = io->read_data = DGifOpen(io->fastbuf, libungif_read_func))))
  43     {
  44       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libungif structure.");
  45       return 0;
  46     }
  47
  48   if (unlikely(DGifSlurp(gif) != GIF_OK))
  49     {
  50       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Gif read failed.");
  51       DGifCloseFile(gif);
  52       return 0;
  53     }
  54
  55   if (unlikely(!gif->ImageCount))
  56     {
  57       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "There are no images in gif file.");
  58       DGifCloseFile(gif);
  59       return 0;
  60     }
  61
  62   /* Read image parameters */
  63   SavedImage *image = gif->SavedImages;
  64   if (unlikely(image->ImageDesc.Width <= 0 || image->ImageDesc.Height <= 0 ||
  65       image->ImageDesc.Width > (int)IMAGE_MAX_SIZE || image->ImageDesc.Height > (int)IMAGE_MAX_SIZE))
  66     {
  67       image_thread_err(io->thread, IMAGE_ERR_INVALID_DIMENSIONS, "Invalid gif dimensions.");
  68       DGifCloseFile(gif);
  69       return 0;
  70     }
  71   ColorMapObject *color_map = image->ImageDesc.ColorMap ? : gif->SColorMap;
  72   if (unlikely(!color_map))
  73     {
  74       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Missing palette.");
  75       DGifCloseFile(gif);
  76       return 0;
  77     }
  78   io->cols = image->ImageDesc.Width;
  79   io->rows = image->ImageDesc.Height;
  80   if (unlikely((io->number_of_colors = color_map->ColorCount) > 256))
  81     {
  82       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Too many gif colors.");
  83       DGifCloseFile(gif);
  84       return 0;
  85     }
  86   io->flags = COLOR_SPACE_RGB | IMAGE_IO_HAS_PALETTE;
  87   if ((uns)gif->SBackGroundColor < (uns)color_map->ColorCount)
  88     {
  89       io->flags |= IMAGE_ALPHA | IMAGE_IO_HAS_BACKGROUND;
  90       GifColorType *background = color_map->Colors + gif->SBackGroundColor;
  91       color_make_rgb(&io->background_color, background->Red, background->Green, background->Blue);
  92     }
  93
  94   /* Success */
  95   io->read_cancel = libungif_read_cancel;
  96   return 1;
  97 }
  98
  99 int
 100 libungif_read_data(struct image_io *io)
 101 {
 102   DBG("libungif_read_data()");
 103
 104   GifFileType *gif = io->read_data;
 105   SavedImage *image = gif->SavedImages;
 106
 107   /* Prepare image */
 108   struct image_io_read_data_internals rdi;
 109   if (unlikely(!image_io_read_data_prepare(&rdi, io, image->ImageDesc.Width, image->ImageDesc.Height, io->flags)))
 110     {
 111       DGifCloseFile(gif);
 112       return 0;
 113     }
 114
 115   /* Get pixels and palette */
 116   byte *pixels = (byte *)image->RasterBits;
 117   ColorMapObject *color_map = image->ImageDesc.ColorMap ? : gif->SColorMap;
 118   GifColorType *palette = color_map->Colors;
 119   uns background = gif->SBackGroundColor;
 120   byte *img_end = rdi.image->pixels + rdi.image->image_size;
 121
 122   /* Handle deinterlacing */
 123   uns dein_step, dein_next;
 124   if (image->ImageDesc.Interlace)
 125     dein_step = dein_next = rdi.image->row_size << 3;
 126   else
 127     dein_step = dein_next = rdi.image->row_size;
 128
 129   /* Convert pixels */
 130   switch (rdi.image->pixel_size)
 131     {
 132       case 1:
 133         {
 134           byte pal[256], *pal_pos = pal, *pal_end = pal + 256;
 135           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos++, palette++)
 136             *pal_pos = rgb_to_gray_func(palette->Red, palette->Green, palette->Blue);
 137           if (pal_pos != pal_end)
 138             bzero(pal_pos, pal_end - pal_pos);
 139           if (io->flags & IMAGE_IO_USE_BACKGROUND)
 140             color_put_grayscale(pal + background, &io->background_color);
 141 #         define DO_ROW_END do{ \
 142               walk_row_start += dein_step; \
 143               if (walk_row_start > img_end) \
 144                 { uns n = dein_next >> 1; walk_row_start = rdi.image->pixels + n, dein_step = dein_next; dein_next = n; } \
 145             }while(0)
 146 #         define IMAGE_WALK_PREFIX(x) walk_##x
 147 #         define IMAGE_WALK_INLINE
 148 #         define IMAGE_WALK_IMAGE (rdi.image)
 149 #         define IMAGE_WALK_UNROLL 4
 150 #         define IMAGE_WALK_COL_STEP 1
 151 #         define IMAGE_WALK_ROW_STEP 0
 152 #         define IMAGE_WALK_DO_STEP do{ *walk_pos = pal[*pixels++]; }while(0)
 153 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 154 #         include "images/image-walk.h"
 155           break;
 156         }
 157       case 2:
 158         {
 159           byte pal[256 * 2], *pal_pos = pal, *pal_end = pal + 256 * 2;
 160           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 2, palette++)
 161             {
 162               pal_pos[0] = rgb_to_gray_func(palette->Red, palette->Green, palette->Blue);
 163               pal_pos[1] = 255;
 164             }
 165           if (pal_pos != pal_end)
 166             bzero(pal_pos, pal_end - pal_pos);
 167           if (background < 256)
 168             pal[background * 2 + 1] = 0;
 169 #         define IMAGE_WALK_PREFIX(x) walk_##x
 170 #         define IMAGE_WALK_INLINE
 171 #         define IMAGE_WALK_IMAGE (rdi.image)
 172 #         define IMAGE_WALK_UNROLL 4
 173 #         define IMAGE_WALK_COL_STEP 2
 174 #         define IMAGE_WALK_ROW_STEP 0
 175 #         define IMAGE_WALK_DO_STEP do{ *(u16 *)walk_pos = ((u16 *)pal)[*pixels++]; }while(0)
 176 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 177 #         include "images/image-walk.h"
 178           break;
 179         }
 180       case 3:
 181         {
 182           byte pal[256 * 4], *pal_pos = pal, *pal_end = pal + 256 * 4;
 183           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 4, palette++)
 184             {
 185               pal_pos[0] = palette->Red;
 186               pal_pos[1] = palette->Green;
 187               pal_pos[2] = palette->Blue;
 188             }
 189           if (pal_pos != pal_end)
 190             bzero(pal_pos, pal_end - pal_pos);
 191           if (io->flags & IMAGE_IO_USE_BACKGROUND)
 192             color_put_rgb(pal + background, &io->background_color);
 193 #         define IMAGE_WALK_PREFIX(x) walk_##x
 194 #         define IMAGE_WALK_INLINE
 195 #         define IMAGE_WALK_IMAGE (rdi.image)
 196 #         define IMAGE_WALK_UNROLL 4
 197 #         define IMAGE_WALK_COL_STEP 3
 198 #         define IMAGE_WALK_ROW_STEP 0
 199 #         define IMAGE_WALK_DO_STEP do{ byte *p = pal + 4 * (*pixels++); walk_pos[0] = p[0]; walk_pos[1] = p[1]; walk_pos[2] = p[2]; }while(0)
 200 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 201 #         include "images/image-walk.h"
 202           break;
 203         }
 204       case 4:
 205         {
 206           byte pal[256 * 4], *pal_pos = pal, *pal_end = pal + 256 * 4;
 207           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 4, palette++)
 208             {
 209               pal_pos[0] = palette->Red;
 210               pal_pos[1] = palette->Green;
 211               pal_pos[2] = palette->Blue;
 212               pal_pos[3] = 255;
 213             }
 214           if (pal_pos != pal_end)
 215             bzero(pal_pos, pal_end - pal_pos);
 216           if (background < 256)
 217             pal[background * 4 + 3] = 0;
 218 #         define IMAGE_WALK_PREFIX(x) walk_##x
 219 #         define IMAGE_WALK_INLINE
 220 #         define IMAGE_WALK_IMAGE (rdi.image)
 221 #         define IMAGE_WALK_UNROLL 4
 222 #         define IMAGE_WALK_COL_STEP 4
 223 #         define IMAGE_WALK_ROW_STEP 0
 224 #         define IMAGE_WALK_DO_STEP do{ *(u32 *)walk_pos = ((u32 *)pal)[*pixels++]; }while(0)
 225 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 226 #         include "images/image-walk.h"
 227           break;
 228         }
 229       default:
 230         ASSERT(0);
 231     }
 232
 233   /* Destroy libungif structure */
 234   DGifCloseFile(gif);
 235
 236   /* Finish image */
 237   return image_io_read_data_finish(&rdi, io);
 238 }