libmpdemux/demux_bmp.c

   1 /*
   2     BMP file parser for the MPlayer program
   3     by Mike Melanson
   4 */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9
  10 #include "config.h"
  11 #include "mp_msg.h"
  12 #include "help_mp.h"
  13
  14 #include "stream.h"
  15 #include "demuxer.h"
  16 #include "stheader.h"
  17
  18 typedef struct {
  19   int image_size;
  20   int image_offset;
  21 } bmp_image_t;
  22
  23 // Check if a file is a BMP file depending on whether starts with 'BM'
  24 int bmp_check_file(demuxer_t *demuxer)
  25 {
  26   if (stream_read_word(demuxer->stream) == (('B' << 8) | 'M'))
  27     return 1;
  28   else
  29     return 0;
  30 }
  31
  32 // return value:
  33 //     0 = EOF or no stream found
  34 //     1 = successfully read a packet
  35 int demux_bmp_fill_buffer(demuxer_t *demuxer)
  36 {
  37   bmp_image_t *bmp_image = (bmp_image_t *)demuxer->priv;
  38
  39   stream_reset(demuxer->stream);
  40   stream_seek(demuxer->stream, bmp_image->image_offset);
  41   ds_read_packet(demuxer->video, demuxer->stream, bmp_image->image_size,
  42     0, bmp_image->image_offset, 1);
  43
  44   return 1;
  45 }
  46
  47 demuxer_t* demux_open_bmp(demuxer_t* demuxer)
  48 {
  49   sh_video_t *sh_video = NULL;
  50   unsigned int filesize;
  51   unsigned int data_offset;
  52   bmp_image_t *bmp_image;
  53
  54   // go back to the beginning
  55   stream_reset(demuxer->stream);
  56   stream_seek(demuxer->stream, 2);
  57   filesize = stream_read_dword_le(demuxer->stream);
  58   stream_skip(demuxer->stream, 4);
  59   data_offset = stream_read_word_le(demuxer->stream);
  60   stream_skip(demuxer->stream, 2);
  61
  62   // create a new video stream header
  63   sh_video = new_sh_video(demuxer, 0);
  64
  65   // make sure the demuxer knows about the new video stream header
  66   demuxer->video->sh = sh_video;
  67
  68   // make sure that the video demuxer stream header knows about its
  69   // parent video demuxer stream
  70   sh_video->ds = demuxer->video;
  71
  72   // load the BITMAPINFOHEADER
  73   // allocate size and take the palette table into account
  74   sh_video->bih = (BITMAPINFOHEADER *)malloc(data_offset - 12);
  75   sh_video->bih->biSize = stream_read_dword_le(demuxer->stream);
  76   sh_video->bih->biWidth = stream_read_dword_le(demuxer->stream);
  77   sh_video->bih->biHeight = stream_read_dword_le(demuxer->stream);
  78   sh_video->bih->biPlanes = stream_read_word_le(demuxer->stream);
  79   sh_video->bih->biBitCount = stream_read_word_le(demuxer->stream);
  80   sh_video->bih->biCompression = stream_read_dword_le(demuxer->stream);
  81   sh_video->bih->biSizeImage = stream_read_dword_le(demuxer->stream);
  82   sh_video->bih->biXPelsPerMeter = stream_read_dword_le(demuxer->stream);
  83   sh_video->bih->biYPelsPerMeter = stream_read_dword_le(demuxer->stream);
  84   sh_video->bih->biClrUsed = stream_read_dword_le(demuxer->stream);
  85   sh_video->bih->biClrImportant = stream_read_dword_le(demuxer->stream);
  86   // fetch the palette
  87   stream_read(demuxer->stream, (unsigned char *)(sh_video->bih) + 40,
  88     sh_video->bih->biClrUsed * 4);
  89
  90   // load the data
  91   bmp_image = (bmp_image_t *)malloc(sizeof(bmp_image_t));
  92   bmp_image->image_size = filesize - data_offset;
  93   bmp_image->image_offset = data_offset;
  94
  95   // custom fourcc for internal MPlayer use
  96   sh_video->format = sh_video->bih->biCompression;
  97
  98   sh_video->disp_w = sh_video->bih->biWidth;
  99   sh_video->disp_h = sh_video->bih->biHeight;
 100
 101   // get the speed
 102   sh_video->fps = 2;
 103   sh_video->frametime = 1 / sh_video->fps;
 104
 105   demuxer->priv = bmp_image;
 106
 107   return demuxer;
 108 }
 109
 110 void demux_close_bmp(demuxer_t* demuxer) {
 111   bmp_image_t *bmp_image = demuxer->priv;
 112
 113   if(!bmp_image)
 114     return;
 115   free(bmp_image);
 116 }