aboutsummaryrefslogtreecommitdiffhomepage
path: root/libmpdemux/demux_gif.c
blob: ddd11f757b9f8ca8653c751520498b05fec2ba34 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/*
	GIF file parser for MPlayer
	by Joey Parrish
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "config.h"

#include "mp_msg.h"
#include "help_mp.h"

#include "stream.h"
#include "demuxer.h"
#include "stheader.h"

#include <gif_lib.h>
static int current_pts = 0;
static unsigned char *pallete = NULL;

#define GIF_SIGNATURE (('G' << 16) | ('I' << 8) | 'F')

#ifndef HAVE_GIF_TVT_HACK
// not supported by certain versions of the library
int my_read_gif(GifFileType *gif, uint8_t *buf, int len) {
  return stream_read(gif->UserData, buf, len);
}
#endif
  
static int gif_check_file(demuxer_t *demuxer)
{
  if (stream_read_int24(demuxer->stream) == GIF_SIGNATURE)
    return DEMUXER_TYPE_GIF;
  return 0;
}

static int demux_gif_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds)
{
  GifFileType *gif = (GifFileType *)demuxer->priv;
  GifRecordType type = UNDEFINED_RECORD_TYPE;
  int len = 0;
  demux_packet_t *dp = NULL;
  ColorMapObject *effective_map = NULL;
  char *buf = NULL;

  while (type != IMAGE_DESC_RECORD_TYPE) {
    if (DGifGetRecordType(gif, &type) == GIF_ERROR) {
      PrintGifError();
      return 0; // oops
    }
    if (type == TERMINATE_RECORD_TYPE)
      return 0; // eof
    if (type == SCREEN_DESC_RECORD_TYPE) {
      if (DGifGetScreenDesc(gif) == GIF_ERROR) {
        PrintGifError();
        return 0; // oops
      }
    }
    if (type == EXTENSION_RECORD_TYPE) {
      int code;
      unsigned char *p = NULL;
      if (DGifGetExtension(gif, &code, &p) == GIF_ERROR) {
        PrintGifError();
        return 0; // oops
      }
      if (code == 0xF9) {
        int frametime = 0;
        if (p[0] == 4) // is the length correct?
          frametime = (p[1] << 8) | p[2]; // set the time, centiseconds
        current_pts += frametime;
      } else if ((code == 0xFE) && (verbose)) { // comment extension
	// print iff verbose
	printf("GIF comment: ");
        while (p != NULL) {
          int length = p[0];
	  char *comments = p + 1;
	  comments[length] = 0;
	  printf("%s", comments);
          if (DGifGetExtensionNext(gif, &p) == GIF_ERROR) {
            PrintGifError();
            return 0; // oops
          }
	}
	printf("\n");
      }
      while (p != NULL) {
        if (DGifGetExtensionNext(gif, &p) == GIF_ERROR) {
          PrintGifError();
          return 0; // oops
        }
      }
    }
  }
  
  if (DGifGetImageDesc(gif) == GIF_ERROR) {
    PrintGifError();
    return 0; // oops
  }

  len = gif->Image.Width * gif->Image.Height;
  dp = new_demux_packet(len);
  buf = malloc(len);
  memset(buf, 0, len);
  memset(dp->buffer, 0, len);
  
  if (DGifGetLine(gif, buf, len) == GIF_ERROR) {
    PrintGifError();
    return 0; // oops
  }

  effective_map = gif->Image.ColorMap;
  if (effective_map == NULL) effective_map = gif->SColorMap;

  {
    int y;

    // copy the pallete
    for (y = 0; y < 256; y++) {
	pallete[(y * 4) + 0] = effective_map->Colors[y].Blue;
	pallete[(y * 4) + 1] = effective_map->Colors[y].Green;
	pallete[(y * 4) + 2] = effective_map->Colors[y].Red;
	pallete[(y * 4) + 3] = 0;
    }

    for (y = 0; y < gif->Image.Height; y++) {
      unsigned char *drow = dp->buffer;
      unsigned char *gbuf = buf + (y * gif->Image.Width);

      drow += gif->Image.Width * (y + gif->Image.Top);
      drow += gif->Image.Left;

      memcpy(drow, gbuf, gif->Image.Width);
    }
  }

  free(buf);

  demuxer->video->dpos++;
  dp->pts = ((float)current_pts) / 100;
  dp->pos = stream_tell(demuxer->stream);
  ds_add_packet(demuxer->video, dp);

  return 1;
}

static demuxer_t* demux_open_gif(demuxer_t* demuxer)
{
  sh_video_t *sh_video = NULL;
  GifFileType *gif = NULL;

  current_pts = 0;
  demuxer->seekable = 0; // FIXME

  // go back to the beginning
  stream_seek(demuxer->stream,demuxer->stream->start_pos);

#ifdef HAVE_GIF_TVT_HACK
  // without the TVT functionality of libungif, a hard seek must be
  // done to the beginning of the file.  this is because libgif is
  // unable to use mplayer's cache, and without this lseek libgif will
  // not read from the beginning of the file and the command will fail.
  // with this hack enabled, you will lose the ability to stream a GIF.
  lseek(demuxer->stream->fd, 0, SEEK_SET);
  gif = DGifOpenFileHandle(demuxer->stream->fd);
#else
  gif = DGifOpen(demuxer->stream, my_read_gif);
#endif
  if (!gif) {
    PrintGifError();
    return NULL;
  }

  // create a new video stream header
  sh_video = new_sh_video(demuxer, 0);

  // make sure the demuxer knows about the new video stream header
  // (even though new_sh_video() ought to take care of it)
  demuxer->video->sh = sh_video;

  // make sure that the video demuxer stream header knows about its
  // parent video demuxer stream (this is getting wacky), or else
  // video_read_properties() will choke
  sh_video->ds = demuxer->video;

  sh_video->disp_w = gif->SWidth;
  sh_video->disp_h = gif->SHeight;

  sh_video->format = mmioFOURCC(8, 'R', 'G', 'B');
  
  sh_video->fps = 5.0f;
  sh_video->frametime = 1.0f / sh_video->fps;
  
  sh_video->bih = malloc(sizeof(BITMAPINFOHEADER) + (256 * 4));
  sh_video->bih->biCompression = sh_video->format;
  sh_video->bih->biBitCount = 8;
  sh_video->bih->biPlanes = 2;
  pallete = (unsigned char *)(sh_video->bih + 1);
  
  demuxer->priv = gif;

  return demuxer;
}

static void demux_close_gif(demuxer_t* demuxer)
{
  GifFileType *gif = (GifFileType *)demuxer->priv;

  if(!gif)
    return;

  if (DGifCloseFile(gif) == GIF_ERROR)
    PrintGifError();
  
  demuxer->stream->fd = 0;
  demuxer->priv = NULL;
}


demuxer_desc_t demuxer_desc_gif = {
  "GIF demuxer",
  "gif",
  "GIF",
  "Joey Parrish",
  "",
  DEMUXER_TYPE_GIF,
  0, // unsafe autodetect
  gif_check_file,
  demux_gif_fill_buffer,
  demux_open_gif,
  demux_close_gif,
  NULL,
  NULL
};