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   DBG("executing DGifSlurp()");
  49   if (unlikely(DGifSlurp(gif) != GIF_OK))
  50     {
  51       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Gif read failed.");
  52       DGifCloseFile(gif);
  53       return 0;
  54     }
  55
  56   DBG("ImageCount=%d ColorResolution=%d SBackGroundColor=%d SColorMap=%p", gif->ImageCount, gif->SColorResolution, gif->SBackGroundColor, gif->SColorMap);
  57   if (unlikely(!gif->ImageCount))
  58     {
  59       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "There are no images in gif file.");
  60       DGifCloseFile(gif);
  61       return 0;
  62     }
  63
  64   /* Read image parameters */
  65   SavedImage *image = gif->SavedImages;
  66   if (unlikely(image->ImageDesc.Width <= 0 || image->ImageDesc.Height <= 0 ||
  67       image->ImageDesc.Width > (int)IMAGE_MAX_SIZE || image->ImageDesc.Height > (int)IMAGE_MAX_SIZE))
  68     {
  69       image_thread_err(io->thread, IMAGE_ERR_INVALID_DIMENSIONS, "Invalid gif dimensions.");
  70       DGifCloseFile(gif);
  71       return 0;
  72     }
  73   ColorMapObject *color_map = image->ImageDesc.ColorMap ? : gif->SColorMap;
  74   if (unlikely(!color_map))
  75     {
  76       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Missing palette.");
  77       DGifCloseFile(gif);
  78       return 0;
  79     }
  80   io->cols = image->ImageDesc.Width;
  81   io->rows = image->ImageDesc.Height;
  82   if (unlikely((io->number_of_colors = color_map->ColorCount) > 256))
  83     {
  84       image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Too many gif colors.");
  85       DGifCloseFile(gif);
  86       return 0;
  87     }
  88   io->flags = COLOR_SPACE_RGB | IMAGE_IO_HAS_PALETTE;
  89   /* FIXME transparent GIFs disabled */
  90 #if 0
  91   if (gif->SColorMap && !image->ImageDesc.ColorMap && (uns)gif->SBackGroundColor < (uns)color_map->ColorCount)
  92     {
  93       io->flags |= IMAGE_ALPHA | IMAGE_IO_HAS_BACKGROUND;
  94       GifColorType *background = color_map->Colors + gif->SBackGroundColor;
  95       color_make_rgb(&io->background_color, background->Red, background->Green, background->Blue);
  96     }
  97 #endif
  98
  99   /* Success */
 100   io->read_cancel = libungif_read_cancel;
 101   return 1;
 102 }
 103
 104 int
 105 libungif_read_data(struct image_io *io)
 106 {
 107   DBG("libungif_read_data()");
 108
 109   GifFileType *gif = io->read_data;
 110   SavedImage *image = gif->SavedImages;
 111
 112   /* Prepare image */
 113   struct image_io_read_data_internals rdi;
 114   if (unlikely(!image_io_read_data_prepare(&rdi, io, image->ImageDesc.Width, image->ImageDesc.Height, io->flags)))
 115     {
 116       DGifCloseFile(gif);
 117       return 0;
 118     }
 119
 120   /* Get pixels and palette */
 121   byte *pixels = (byte *)image->RasterBits;
 122   ColorMapObject *color_map = image->ImageDesc.ColorMap ? : gif->SColorMap;
 123   GifColorType *palette = color_map->Colors;
 124   uns background = (
 125   /* FIXME: transparent GIFs disabled */
 126 #if 1
 127     0 &&
 128 #endif
 129     gif->SColorMap && !image->ImageDesc.ColorMap) ? gif->SBackGroundColor : 256;
 130   byte *img_end = rdi.image->pixels + rdi.image->image_size;
 131
 132   /* Handle deinterlacing */
 133   uns dein_step, dein_next;
 134   if (image->ImageDesc.Interlace)
 135     dein_step = dein_next = rdi.image->row_size << 3;
 136   else
 137     dein_step = dein_next = rdi.image->row_size;
 138
 139   /* Convert pixels */
 140   switch (rdi.image->pixel_size)
 141     {
 142       case 1:
 143         {
 144           byte pal[256], *pal_pos = pal, *pal_end = pal + 256;
 145           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos++, palette++)
 146             *pal_pos = rgb_to_gray_func(palette->Red, palette->Green, palette->Blue);
 147           if (pal_pos != pal_end)
 148             bzero(pal_pos, pal_end - pal_pos);
 149           if (io->flags & IMAGE_IO_USE_BACKGROUND)
 150             color_put_grayscale(pal + background, &io->background_color);
 151 #         define DO_ROW_END do{ \
 152               walk_row_start += dein_step; \
 153               if (walk_row_start > img_end) \
 154                 { uns n = dein_next >> 1; walk_row_start = rdi.image->pixels + n, dein_step = dein_next; dein_next = n; } \
 155             }while(0)
 156 #         define IMAGE_WALK_PREFIX(x) walk_##x
 157 #         define IMAGE_WALK_INLINE
 158 #         define IMAGE_WALK_IMAGE (rdi.image)
 159 #         define IMAGE_WALK_UNROLL 4
 160 #         define IMAGE_WALK_COL_STEP 1
 161 #         define IMAGE_WALK_ROW_STEP 0
 162 #         define IMAGE_WALK_DO_STEP do{ *walk_pos = pal[*pixels++]; }while(0)
 163 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 164 #         include "images/image-walk.h"
 165           break;
 166         }
 167       case 2:
 168         {
 169           byte pal[256 * 2], *pal_pos = pal, *pal_end = pal + 256 * 2;
 170           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 2, palette++)
 171             {
 172               pal_pos[0] = rgb_to_gray_func(palette->Red, palette->Green, palette->Blue);
 173               pal_pos[1] = 255;
 174             }
 175           if (pal_pos != pal_end)
 176             bzero(pal_pos, pal_end - pal_pos);
 177           if (background < 256)
 178             pal[background * 2 + 1] = 0;
 179 #         define IMAGE_WALK_PREFIX(x) walk_##x
 180 #         define IMAGE_WALK_INLINE
 181 #         define IMAGE_WALK_IMAGE (rdi.image)
 182 #         define IMAGE_WALK_UNROLL 4
 183 #         define IMAGE_WALK_COL_STEP 2
 184 #         define IMAGE_WALK_ROW_STEP 0
 185 #         define IMAGE_WALK_DO_STEP do{ *(u16 *)walk_pos = ((u16 *)pal)[*pixels++]; }while(0)
 186 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 187 #         include "images/image-walk.h"
 188           break;
 189         }
 190       case 3:
 191         {
 192           byte pal[256 * 4], *pal_pos = pal, *pal_end = pal + 256 * 4;
 193           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 4, palette++)
 194             {
 195               pal_pos[0] = palette->Red;
 196               pal_pos[1] = palette->Green;
 197               pal_pos[2] = palette->Blue;
 198             }
 199           if (pal_pos != pal_end)
 200             bzero(pal_pos, pal_end - pal_pos);
 201           if (io->flags & IMAGE_IO_USE_BACKGROUND)
 202             color_put_rgb(pal + background, &io->background_color);
 203 #         define IMAGE_WALK_PREFIX(x) walk_##x
 204 #         define IMAGE_WALK_INLINE
 205 #         define IMAGE_WALK_IMAGE (rdi.image)
 206 #         define IMAGE_WALK_UNROLL 4
 207 #         define IMAGE_WALK_COL_STEP 3
 208 #         define IMAGE_WALK_ROW_STEP 0
 209 #         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)
 210 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 211 #         include "images/image-walk.h"
 212           break;
 213         }
 214       case 4:
 215         {
 216           byte pal[256 * 4], *pal_pos = pal, *pal_end = pal + 256 * 4;
 217           for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 4, palette++)
 218             {
 219               pal_pos[0] = palette->Red;
 220               pal_pos[1] = palette->Green;
 221               pal_pos[2] = palette->Blue;
 222               pal_pos[3] = 255;
 223             }
 224           if (pal_pos != pal_end)
 225             bzero(pal_pos, pal_end - pal_pos);
 226           if (background < 256)
 227             pal[background * 4 + 3] = 0;
 228 #         define IMAGE_WALK_PREFIX(x) walk_##x
 229 #         define IMAGE_WALK_INLINE
 230 #         define IMAGE_WALK_IMAGE (rdi.image)
 231 #         define IMAGE_WALK_UNROLL 4
 232 #         define IMAGE_WALK_COL_STEP 4
 233 #         define IMAGE_WALK_ROW_STEP 0
 234 #         define IMAGE_WALK_DO_STEP do{ *(u32 *)walk_pos = ((u32 *)pal)[*pixels++]; }while(0)
 235 #         define IMAGE_WALK_DO_ROW_END DO_ROW_END
 236 #         include "images/image-walk.h"
 237           break;
 238         }
 239       default:
 240         ASSERT(0);
 241     }
 242
 243   /* Destroy libungif structure */
 244   DGifCloseFile(gif);
 245
 246   /* Finish image */
 247   return image_io_read_data_finish(&rdi, io);
 248 }