| # Live video input from display class. |
| |
| import gl |
| import GL |
| |
| # The live video input class. |
| # Only instantiate this if have_video is true! |
| |
| class DisplayVideoIn: |
| |
| # Initialize an instance. Arguments: |
| # vw, vh: size of the video window data to be captured. |
| # position defaults to 0, 0 but can be set later |
| def __init__(self, pktmax, vw, vh, type): |
| self.pktmax = pktmax |
| self.realwidth, self.realheight = vw, vh |
| if type <> 'rgb': |
| raise 'Incorrent video data type', type |
| self.type = type |
| self.width = vw |
| self.height = vh |
| # |
| # Open dummy window |
| # |
| gl.foreground() |
| gl.noport() |
| self.wid = gl.winopen('DisplayVideoIn') |
| |
| self.x0 = 0 |
| self.x1 = self.x0 + self.width - 1 |
| self.y0 = 0 |
| self.y1 = self.y0 + self.height - 1 |
| # Compute # full lines per packet |
| self.lpp = pktmax / self.linewidth() |
| if self.lpp <= 0: |
| raise 'No lines in packet', self.linewidth() |
| self.pktsize = self.lpp*self.linewidth() |
| self.data = None |
| self.old_data = None |
| self.dataoffset = 0 |
| self.lpos = 0 |
| self.hints = 0 |
| |
| # Change the size of the video being displayed. |
| |
| def resizevideo(self, vw, vh): |
| self.width = vw |
| self.height = vh |
| self.x1 = self.x0 + self.width - 1 |
| self.y1 = self.y0 + self.height - 1 |
| |
| def positionvideo(self, x, y): |
| self.x0 = x |
| self.y0 = y |
| self.x1 = self.x0 + self.width - 1 |
| self.y1 = self.y0 + self.height - 1 |
| |
| # Remove an instance. |
| # This turns off continuous capture. |
| |
| def close(self): |
| gl.winclose(self.wid) |
| |
| # Get the length in bytes of a video line |
| def linewidth(self): |
| return self.width*4 |
| |
| # Get the next video packet. |
| # This returns (lpos, data) where: |
| # - lpos is the line position |
| # - data is a piece of data |
| # The dimensions of data are: |
| # - pixel depth = 1 byte |
| # - scan line width = self.width (the vw argument to __init__()) |
| # - number of scan lines = self.lpp (PKTMAX / vw) |
| |
| def getnextpacket(self): |
| if not self.data or self.dataoffset >= len(self.data): |
| self.old_data = self.data |
| self.data = gl.readdisplay(self.x0, self.y0, \ |
| self.x1, self.y1, self.hints) |
| self.dataoffset = 0 |
| self.lpos = 0 |
| data = self.data[self.dataoffset:self.dataoffset+self.pktsize] |
| while self.old_data and \ |
| self.dataoffset+self.pktsize < len(self.data): |
| odata = self.old_data[self.dataoffset: \ |
| self.dataoffset+self.pktsize] |
| if odata <> data: |
| break |
| print 'skip', self.lpos |
| self.lpos = self.lpos + self.lpp |
| self.dataoffset = self.dataoffset + self.pktsize |
| data = self.data[self.dataoffset:\ |
| self.dataoffset+self.pktsize] |
| lpos = self.lpos |
| self.dataoffset = self.dataoffset + self.pktsize |
| self.lpos = self.lpos + self.lpp |
| return lpos, data |