// Draw the waveform in a graphics
// TODO: handle other bit depths than 16 bit.
private void DrawWaveform(Graphics g, AudioBlock block)
{
PCMFormatInfo format = this.audio.getPCMFormat();
if (format.getBitDepth() != 16)
{
throw new Exception("Cannot deal with bitdepth others than 16.");
}
ushort channels = format.getNumberOfChannels();
ushort frameSize = format.getBlockAlign();
int samplesPerPixel = (int)Math.Ceiling(this.audio.getPCMLength() / (float)frameSize / Width * channels);
int bytesPerPixel = samplesPerPixel * frameSize / channels;
byte[] bytes = new byte[bytesPerPixel];
short[] samples = new short[samplesPerPixel];
System.IO.Stream au = this.audio.getAudioData();
for (int x = 0; x < Width; ++x)
{
int read = au.Read(bytes, 0, bytesPerPixel);
Buffer.BlockCopy(bytes, 0, samples, 0, read);
DrawChannel(g, block.Highlighted ? block.Colors.WaveformChannelSelectedPen :
channels == 1 ? block.Colors.WaveformMonoPen : block.Colors.WaveformChannel1Pen,
samples, x, read, frameSize, 0, channels);
if (channels == 2)
{
DrawChannel(g, block.Selected ? block.Colors.WaveformChannelSelectedPen : block.Colors.WaveformChannel2Pen,
samples, x, read, frameSize, 1, channels);
}
}
au.Close();
}
