Re: [LAD] Real-time plotting of audio/ oscilloscope.

How do the other scopes work? If you really want to get a good image of a waveform on a screen then you might want to totally divorce the sampling rate from the screen drawing: To actually see a waveform and how it develops then you really need the scope to sync to it. The way the oscilloscopes worked was a detection level at which to start painting (positive edge zero crossing for example but other levels are equally acceptable) and a delay time before searching again (blanking period, more or less). After that you have the scan rate at which the analogue signal was painted over the tube but for your waveforms just scan at the sample rate. Forget drawing every sample as a pixel/line, just scan through the audio data to find your sync point then render the next (eg) 500 samples into your favorite kind of bitmap and request it be displayed/flushed. If you do this 20 times per second, ie, find your sync point every 50ms then you will get a pretty good image of how a waveform develops over time. All the rest of the audio data can be dumped unceremoniously to /dev/null. The sample rate is not that relevent, making the rendered image have some form of consistency is and you will not get that if you simply attempt to render every sample. Regards, nick. "we have to make sure the old choice [Windows] doesn't disappear”. Jim Wong, president of IT products, Acer _________________________________________________________________ Hotmail: Trusted email with powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969