opencv/samples/swig_python/capture-cam.py

#! /usr/bin/env python

import sys

# import the necessary things for OpenCV
from opencv import cv
from opencv import highgui

# the codec existing in cvcapp.cpp,
# need to have a better way to specify them in the future
# WARNING: I have see only MPEG1VIDEO working on my computer
H263 = 0x33363255
H263I = 0x33363249
MSMPEG4V3 = 0x33564944
MPEG4 = 0x58564944
MSMPEG4V2 = 0x3234504D
MJPEG = 0x47504A4D
MPEG1VIDEO = 0x314D4950
AC3 = 0x2000
MP2 = 0x50
FLV1 = 0x31564C46

#############################################################################
# so, here is the main part of the program

if __name__ == '__main__':

    # a small welcome
    print "OpenCV Python capture video"

    # first, create the necessary window
    highgui.cvNamedWindow ('Camera', highgui.CV_WINDOW_AUTOSIZE)

    # move the new window to a better place
    highgui.cvMoveWindow ('Camera', 10, 10)

    try:
        # try to get the device number from the command line
        device = int (sys.argv [1])

        # got it ! so remove it from the arguments
        del sys.argv [1]
    except (IndexError, ValueError):
        # no device number on the command line, assume we want the 1st device
        device = 0

    if len (sys.argv) == 1:
        # no argument on the command line, try to use the camera
        capture = highgui.cvCreateCameraCapture (device)
    else:
        # we have an argument on the command line,
        # we can assume this is a file name, so open it
        capture = highgui.cvCreateFileCapture (sys.argv [1])            

    # check that capture device is OK
    if not capture:
        print "Error opening capture device"
        sys.exit (1)

    # capture the 1st frame to get some propertie on it
    frame = highgui.cvQueryFrame (capture)

    # get size of the frame
    frame_size = cv.cvGetSize (frame)

    # get the frame rate of the capture device
    fps = highgui.cvGetCaptureProperty (capture, highgui.CV_CAP_PROP_FPS)
    if fps == 0:
        # no fps getted, so set it to 30 by default
        fps = 30

    # create the writer
    writer = highgui.cvCreateVideoWriter ("captured.mpg", MPEG1VIDEO,
                                          fps, frame_size, True)

    # check the writer is OK
    if not writer:
        print "Error opening writer"
        sys.exit (1)
        
    while 1:
        # do forever

        # 1. capture the current image
        frame = highgui.cvQueryFrame (capture)
        if frame is None:
            # no image captured... end the processing
            break

        # write the frame to the output file
        highgui.cvWriteFrame (writer, frame)

        # display the frames to have a visual output
        highgui.cvShowImage ('Camera', frame)

        # handle events
        k = highgui.cvWaitKey (5)

        if k % 0x100 == 27:
            # user has press the ESC key, so exit
            break

    # end working with the writer
    # not working at this time... Need to implement some typemaps...
    # but exiting without calling it is OK in this simple application
    #highgui.cvReleaseVideoWriter (writer)