I'm not sure what it would be without seeing the error output, but there is a way around that. camera.list_cameras() will return a list of the cameras plugged into the computer. If the list is empty, you know it found no cameras. You could use it as follows:
camlist = camera.list_cameras() if len(cameras) > 0: cam = camera.Camera(camlist[0]) Nirav On Mon, Apr 20, 2009 at 9:46 AM, Alexandre Quessy <[email protected]> wrote: > Hello René, > We save frames in lists. You can take a frame either by pressing space > bar, or using an intervalometer. (for timelapses) The right region of > the display shows the resulting animation in a loop. (for now) The > left region shows the current video input, plus an optional onion skin > of the last recorded frame. A screen shot will be online soon. > > By the way, there is an other bug. With V4L2, if there is no camera > plugged-in, sometimes, I get a null pointer error and it says "Pygame > parachute", or something. And then it crashes. I have heard it's v4l2 > that is a bit flaky, but that some higher-level wrapper, such as > Gstreamer, make sure things don't crash when using v4l2. Of course, > bugs are not reproducable when you need them.... (so that I could > copy-paste the output here) > > a > > > > 2009/4/19 René Dudfield <[email protected]>: >> looks pretty cool :) >> >> How does it work? >> >> I imagine you can take snapshots, and then do playbacks? Or can you do a >> video recording too? So in video mode, it'd take snapshots at a given frame >> rate. >> >> Are there any screen shots? >> >> >> >> >> On Sat, Apr 18, 2009 at 12:54 PM, Alexandre Quessy <[email protected]> >> wrote: >>> >>> Problem solved !! >>> Thanks a lot Nirav. >>> >>> If you want to try toonloop, you can checkout the code and run it. >>> The installation instructions for Ubuntu are in here : >>> http://code.google.com/p/toonloop/source/browse/trunk/doc/INSTALL.txt >>> >>> Try ./toonloop.py --help for startup flags, and press "h" while it is >>> running for instructions. >>> It needs a valid pygame camera, of course. >>> See http://toonloop.com for more informations. >>> We need beta testers too. And I think this is a wonderful application >>> of pygame.camera. >>> >>> a >>> >>> 2009/4/17 Nirav Patel <[email protected]>: >>> > Also, forgot to mention this, but thanks for using the camera module! >>> > It has yet to experience widespread use, so this kind of beta testing >>> > is great to get it ready for the next pygame release. >>> > >>> > Nirav >>> > >>> > On Fri, Apr 17, 2009 at 11:17 AM, Nirav Patel <[email protected]> >>> > wrote: >>> >> Ah yes, this seems to be a bug in both JPEG saving and in the camera >>> >> module. Fun stuff. >>> >> >>> >> The JPEG assumes that any 24 bit surface is going to be in the exact >>> >> color order that it expects. Which is fine, except that the default >>> >> color order for a 24 bit Surface is not that. >>> >> >>> >> This also led me to find a bug in the camera module though, where if >>> >> you are using a 24 bit surface, it will assume you want the default >>> >> color order, regardless of if you hand it a Surface to use that has a >>> >> different color order. >>> >> >>> >> I commited the one line fix for JPEG, which just does an additional >>> >> check to see if it needs to create a new surface or not. Please test >>> >> it if you can. The fix for the camera module may take longer, as I >>> >> need to rethink some assumptions, though in the vast majority of use >>> >> cases, users should not be effected. >>> >> >>> >> Nirav >>> >> >>> >> On Fri, Apr 17, 2009 at 9:48 AM, René Dudfield <[email protected]> >>> >> wrote: >>> >>> Hi, >>> >>> >>> >>> can you please let me know the result of: >>> >>> >>> >>> cam_surf = X >>> >>> normal_surf = pygame.Surface((1,1)) >>> >>> surfs = cam_surf, normal_surf >>> >>> >>> >>> for s in surfs: >>> >>> print s.get_losses(), s.get_masks(), s.get_shifts() >>> >>> >>> >>> I think maybe the jpeg saving code isn't respecting one of those. >>> >>> Actually... don't worry, I'm pretty sure that's the cause of it. >>> >>> Will fix >>> >>> soon. >>> >>> >>> >>> cheers, >>> >>> >>> >>> >>> >>> >>> >>> On Fri, Apr 17, 2009 at 11:14 PM, Alexandre Quessy >>> >>> <[email protected]> >>> >>> wrote: >>> >>>> >>> >>>> Hello Pygame people, >>> >>>> This is my first post on this list, and more might follow since I am >>> >>>> using pygame for ToonLoop, a stop motion software. The new >>> >>>> pygame.camera module works for me and this is very good job. Thanks >>> >>>> for contributing that ! >>> >>>> >>> >>>> I think I found a bug ! Hopefully it is only my code that is wrong >>> >>>> and >>> >>>> this is easy to fix. >>> >>>> >>> >>>> When I save a Pygame surface that I obtained using pygame.camera to a >>> >>>> JPEG using pygame.image.save, the colors are messed up. It looks like >>> >>>> the red and blue channels are interchanged. Thus, maybe my surface is >>> >>>> RBG, whereas pygame.image expects RGB. A camera image doesn't contain >>> >>>> any alpha channel usually. >>> >>>> >>> >>>> When I display the surface as a pygame sprite the colors are OK. >>> >>>> When I display the surface as an OpenGL texture the colors are OK. >>> >>>> (using tostring(surface, "RGBX", True)) >>> >>>> When I save the surface as an other format such as PNG or BMP the >>> >>>> colors >>> >>>> are OK. >>> >>>> When I use a surface obtained by loading a JPG image, the colors are >>> >>>> OK. >>> >>>> The bug only occurs when I save a surface obtained using the >>> >>>> pygame.camera module. >>> >>>> It consistently happened on 3 Linux computers. >>> >>>> >>> >>>> I use Pygame compiled from today's SVN with Python 2.5.2 on Ubuntu >>> >>>> GNU/Linux 8.10 using a V4L2 device. (a WinTV card) >>> >>>> >>> >>>> A short code snippet to reproduce the bug: >>> >>>> http://rafb.net/p/gccaJG37.html >>> >>>> >>> >>>> A JPEG to see how the output looks like : >>> >>>> http://toonloop.com/static/tmp/image_color_test_out.jpg >>> >>>> A correct image in an other format to compare : >>> >>>> http://toonloop.com/static/tmp/image_color_test_out.png >>> >>>> >>> >>>> If you want to download the code and the test image I use : >>> >>>> http://toonloop.com/static/tmp/bug_color_jpeg.tar.gz >>> >>>> I also convert the colorbars.jpg files to surface and back to a JPG >>> >>>> file for comparison. It works flawlessly. >>> >>>> >>> >>>> -- >>> >>>> Alexandre Quessy >>> >>>> http://alexandre.quessy.net/ >>> >>> >>> >>> >>> >> >>> > >>> >>> >>> >>> -- >>> Alexandre Quessy >>> http://alexandre.quessy.net/ >> >> > > > > -- > Alexandre Quessy > http://alexandre.quessy.net/ >
