FRAME* fg_grab_read( FRAMEGRABBER* fg )
{
FRAME* fr = frame_new( fg->window.width,
fg->window.height,
fg->picture.palette );
read( fg->fd,
fr->data,
frame_get_size( fr ) );
return fr;
}
FRAME* frame_new( int width, int height, int format )
{
FRAME* fr = malloc( sizeof( FRAME ) );
fr->width = width;
fr->height = height;
fr->format = format;
fr->size = frame_get_size( fr );
fr->data = malloc( fr->size );
return fr;
}
FRAME* fg_grab_frame( FRAMEGRABBER* fg, FRAME* fr )
{
int capture_frame = fg->cur_frame + 1;
//----------------------
// Very first time only
//----------------------
if ( fg->mbuf.frames > 1 && fg->cur_frame == -1 )
{
fg->cur_frame = 1;
// Set up capture parameters
fg->mmap.format = fg->picture.palette;
fg->mmap.frame = fg->cur_frame;
fg->mmap.width = fg->window.width;
fg->mmap.height = fg->window.height;
// Start capture
if ( ioctl( fg->fd, VIDIOCMCAPTURE, &(fg->mmap) ) < 0 )
{
perror( "fg_grab(): failed to capture frame" );
return NULL;
}
}
//----------------------------
// Start capturing next frame
//----------------------------
// Wrap counter
if ( capture_frame >= fg->mbuf.frames )
{
capture_frame = 0;
}
// Set up capture parameters
fg->mmap.format = fg->picture.palette;
fg->mmap.frame = capture_frame;
fg->mmap.width = fg->window.width;
fg->mmap.height = fg->window.height;
// Start capture
if ( ioctl( fg->fd, VIDIOCMCAPTURE, &(fg->mmap) ) < 0 )
{
perror( "fg_grab(): failed to capture frame" );
return NULL;
}
//--------------------
// Save current frame
//--------------------
// Wait for end of frame
if ( ioctl( fg->fd, VIDIOCSYNC, &(fg->cur_frame) ) < 0 )
{
perror( "fg_grab(): failed to sync frame" );
return NULL;
}
// Save video buffer into our own memory
memcpy( fr->data,
fg->mb_map + fg->mbuf.offsets[fg->cur_frame],
frame_get_size( fr ) );
// Move along to the next one
fg->cur_frame = capture_frame;
return fr;
}
