On Thu, 17 Jun 2010 00:29:44 -0400 Jeremy <[email protected]> wrote:
> Hi, > > When I'm programming, I find it immensely helpful to be able to plot audio > data at different points in its processing, for debugging, and to test new > ideas. > > Essentially I want an oscilloscope, which plots each chunk of 1024 samples. > > I've tried using libplot, but it seems too slow. It's causing constant > xruns, even when I only plot every 5th sample. > > I thought that maybe libplot was too abstract, and that I needed to draw the > pixels on the screen directly. I tried using SDL, but it caused excessive > xruns also. Simply setting 48000 pixels per second was enough to cause the > flow of xruns. This is *not* erasing the screen, just drawing the points. > I'd expect that erasing the screen is the slow part, but apparently not. How did you write your SDL program? Don't use any Setpixel functions. Draw your pixels to a memory buffer/surface with the same pixel format as the screen and flip that to the screen. Or try OpenGL. Use GL Arrays if glBegin()/glEnd() is too slow. The hardware shouldn't be a bottleneck if you don't use a system older than 10 years or so. If you use OpenGL, you need an accelerated driver of course, else it's useless. _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
