libmpdemux/demux_gif.c

   1 /*
   2         GIF file parser for MPlayer
   3         by Joey Parrish
   4 */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9
  10 #include "config.h"
  11
  12 #ifdef HAVE_GIF
  13
  14 #include "mp_msg.h"
  15 #include "help_mp.h"
  16
  17 #include "stream.h"
  18 #include "demuxer.h"
  19 #include "stheader.h"
  20
  21 #include <gif_lib.h>
  22 static int current_pts = 0;
  23 static unsigned char *pallete = NULL;
  24
  25 #define GIF_SIGNATURE (('G' << 16) | ('I' << 8) | 'F')
  26
  27 #ifndef HAVE_GIF_TVT_HACK
  28 // not supported by certain versions of the library
  29 int my_read_gif(GifFileType *gif, uint8_t *buf, int len) {
  30   return stream_read(gif->UserData, buf, len);
  31 }
  32 #endif
  33
  34 static int gif_check_file(demuxer_t *demuxer)
  35 {
  36   if (stream_read_int24(demuxer->stream) == GIF_SIGNATURE)
  37     return DEMUXER_TYPE_GIF;
  38   return 0;
  39 }
  40
  41 static int demux_gif_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds)
  42 {
  43   GifFileType *gif = (GifFileType *)demuxer->priv;
  44   sh_video_t *sh_video = (sh_video_t *)demuxer->video->sh;
  45   GifRecordType type = UNDEFINED_RECORD_TYPE;
  46   int len = 0;
  47   demux_packet_t *dp = NULL;
  48   ColorMapObject *effective_map = NULL;
  49   char *buf = NULL;
  50
  51   while (type != IMAGE_DESC_RECORD_TYPE) {
  52     if (DGifGetRecordType(gif, &type) == GIF_ERROR) {
  53       PrintGifError();
  54       return 0; // oops
  55     }
  56     if (type == TERMINATE_RECORD_TYPE)
  57       return 0; // eof
  58     if (type == SCREEN_DESC_RECORD_TYPE) {
  59       if (DGifGetScreenDesc(gif) == GIF_ERROR) {
  60         PrintGifError();
  61         return 0; // oops
  62       }
  63     }
  64     if (type == EXTENSION_RECORD_TYPE) {
  65       int code;
  66       unsigned char *p = NULL;
  67       if (DGifGetExtension(gif, &code, &p) == GIF_ERROR) {
  68         PrintGifError();
  69         return 0; // oops
  70       }
  71       if (code == 0xF9) {
  72         int frametime = 0;
  73         if (p[0] == 4) // is the length correct?
  74           frametime = (p[1] << 8) | p[2]; // set the time, centiseconds
  75         current_pts += frametime;
  76       } else if ((code == 0xFE) && (verbose)) { // comment extension
  77         // print iff verbose
  78         printf("GIF comment: ");
  79         while (p != NULL) {
  80           int length = p[0];
  81           char *comments = p + 1;
  82           comments[length] = 0;
  83           printf("%s", comments);
  84           if (DGifGetExtensionNext(gif, &p) == GIF_ERROR) {
  85             PrintGifError();
  86             return 0; // oops
  87           }
  88         }
  89         printf("\n");
  90       }
  91       while (p != NULL) {
  92         if (DGifGetExtensionNext(gif, &p) == GIF_ERROR) {
  93           PrintGifError();
  94           return 0; // oops
  95         }
  96       }
  97     }
  98   }
  99
 100   if (DGifGetImageDesc(gif) == GIF_ERROR) {
 101     PrintGifError();
 102     return 0; // oops
 103   }
 104
 105   len = gif->Image.Width * gif->Image.Height;
 106   dp = new_demux_packet(len);
 107   buf = malloc(len);
 108   memset(buf, 0, len);
 109   memset(dp->buffer, 0, len);
 110
 111   if (DGifGetLine(gif, buf, len) == GIF_ERROR) {
 112     PrintGifError();
 113     return 0; // oops
 114   }
 115
 116   effective_map = gif->Image.ColorMap;
 117   if (effective_map == NULL) effective_map = gif->SColorMap;
 118
 119   {
 120     int y;
 121
 122     // copy the pallete
 123     for (y = 0; y < 256; y++) {
 124         pallete[(y * 4) + 0] = effective_map->Colors[y].Blue;
 125         pallete[(y * 4) + 1] = effective_map->Colors[y].Green;
 126         pallete[(y * 4) + 2] = effective_map->Colors[y].Red;
 127         pallete[(y * 4) + 3] = 0;
 128     }
 129
 130     for (y = 0; y < gif->Image.Height; y++) {
 131       unsigned char *drow = dp->buffer;
 132       unsigned char *gbuf = buf + (y * gif->Image.Width);
 133
 134       drow += gif->Image.Width * (y + gif->Image.Top);
 135       drow += gif->Image.Left;
 136
 137       memcpy(drow, gbuf, gif->Image.Width);
 138     }
 139   }
 140
 141   free(buf);
 142
 143   demuxer->video->dpos++;
 144   dp->pts = ((float)current_pts) / 100;
 145   dp->pos = stream_tell(demuxer->stream);
 146   ds_add_packet(demuxer->video, dp);
 147
 148   return 1;
 149 }
 150
 151 static demuxer_t* demux_open_gif(demuxer_t* demuxer)
 152 {
 153   sh_video_t *sh_video = NULL;
 154   GifFileType *gif = NULL;
 155
 156   current_pts = 0;
 157   demuxer->seekable = 0; // FIXME
 158
 159   // go back to the beginning
 160   stream_seek(demuxer->stream,demuxer->stream->start_pos);
 161
 162 #ifdef HAVE_GIF_TVT_HACK
 163   // without the TVT functionality of libungif, a hard seek must be
 164   // done to the beginning of the file.  this is because libgif is
 165   // unable to use mplayer's cache, and without this lseek libgif will
 166   // not read from the beginning of the file and the command will fail.
 167   // with this hack enabled, you will lose the ability to stream a GIF.
 168   lseek(demuxer->stream->fd, 0, SEEK_SET);
 169   gif = DGifOpenFileHandle(demuxer->stream->fd);
 170 #else
 171   gif = DGifOpen(demuxer->stream, my_read_gif);
 172 #endif
 173   if (!gif) {
 174     PrintGifError();
 175     return NULL;
 176   }
 177
 178   // create a new video stream header
 179   sh_video = new_sh_video(demuxer, 0);
 180
 181   // make sure the demuxer knows about the new video stream header
 182   // (even though new_sh_video() ought to take care of it)
 183   demuxer->video->sh = sh_video;
 184
 185   // make sure that the video demuxer stream header knows about its
 186   // parent video demuxer stream (this is getting wacky), or else
 187   // video_read_properties() will choke
 188   sh_video->ds = demuxer->video;
 189
 190   sh_video->disp_w = gif->SWidth;
 191   sh_video->disp_h = gif->SHeight;
 192
 193   sh_video->format = mmioFOURCC(8, 'R', 'G', 'B');
 194
 195   sh_video->fps = 5.0f;
 196   sh_video->frametime = 1.0f / sh_video->fps;
 197
 198   sh_video->bih = malloc(sizeof(BITMAPINFOHEADER) + (256 * 4));
 199   sh_video->bih->biCompression = sh_video->format;
 200   sh_video->bih->biBitCount = 8;
 201   sh_video->bih->biPlanes = 2;
 202   pallete = (unsigned char *)(sh_video->bih + 1);
 203
 204   demuxer->priv = gif;
 205
 206   return demuxer;
 207 }
 208
 209 static void demux_close_gif(demuxer_t* demuxer)
 210 {
 211   GifFileType *gif = (GifFileType *)demuxer->priv;
 212
 213   if(!gif)
 214     return;
 215
 216   if (DGifCloseFile(gif) == GIF_ERROR)
 217     PrintGifError();
 218
 219   demuxer->stream->fd = 0;
 220   demuxer->priv = NULL;
 221 }
 222
 223
 224 demuxer_desc_t demuxer_desc_gif = {
 225   "GIF demuxer",
 226   "gif",
 227   "GIF",
 228   "Joey Parrish",
 229   "",
 230   DEMUXER_TYPE_GIF,
 231   0, // unsafe autodetect
 232   gif_check_file,
 233   demux_gif_fill_buffer,
 234   demux_open_gif,
 235   demux_close_gif,
 236   NULL,
 237   NULL
 238 };
 239
 240 #endif /* HAVE_GIF */