How do I visualize audio data?

Answer 1

You might want to look into the R language for this. I don't have very much experience with it, but it's used largely in statistical analysis/visualization scenarios. I would be surprised if they didn't have some smoothing function to get rid of the extremes like you mentioned.

And you should have no trouble importing your data into it. Not only can you read flat text files, but it's also designed to be easily extensible with C, so there is probably some kind of C# interface as well.

Answer 2

You'll likely have more than 1 sample for each pixel. For each group of samples mapped to a single pixel, you could draw a (vertical) line segment from the minimum value in the sample group to the maximum value. If you zoom in to 1 sample per pixel or less, this doesn't work anymore, and the 'nice' solution would be to display the sinc interpolated values. Because DrawLine cannot paint a single pixel, there is a small problem when the minimum and maximum are the same. In that case you could copy a single pixel image in the desired position, as in the code below:

double samplesPerPixel = (double)L / _width;
double firstSample = 0;
int endSample = firstSample + L - 1;
for (short pixel = 0; pixel < _width; pixel++)
{
    int lastSample = __min(endSample, (int)(firstSample + samplesPerPixel));
    double Y = _data[channel][(int)firstSample];
    double minY = Y;
    double maxY = Y;
    for (int sample = (int)firstSample + 1; sample <= lastSample; sample++)
    {
     Y = _data[channel][sample];
     minY = __min(Y, minY);
     maxY = __max(Y, maxY);
    }
    x = pixel + _offsetx;
    y1 = Value2Pixel(minY);
    y2 = Value2Pixel(maxY);
    if (y1 == y2)
    {
     g->DrawImageUnscaled(bm, x, y1);
    }
    else
    {
     g->DrawLine(pen, x, y1, x, y2);
    }
    firstSample += samplesPerPixel;
}

Note that Value2Pixel scales a sample value to a pixel value (in the y-direction).