SineWave generates heavy amounts of ringing because of float round off errors and improper subsampling

[mlindner]

SineWave generates a lot of ringing noise by using float32 instead of float64 for its calculations.

Below is what occurs with the default SineWave.

Below is what occurs with a modified SineWave that does calculation in float64 and then converts back to float32 for the result.

I suspect there are similar issues across all sources where rounding errors is causing distortion. The distortion is very noticeable by ear.

[mlindner]

Looks like this is actually a combination of two issues.

1. There's random noise that creeps in as the float32 shifts exponent sizes (in the top image that's seen as lines in between the regular pattern of lines).
2. There's also a incorrect subsampling error which causes the significant regular spaced noise when the 48000 Hz signal is somewhere subsampled to 44100 Hz.

The bottom image was produced by both changing the sampling rate from 48000 to 44100 and also changing f32 to f64 math.

Here is what the output looks like when changing only 48000 to 44100. You can see the noise slowly creeping in over time as the exponent increments.

[mlindner]

The top case is caused by the Source implementation of SourcesQueueOutput. It constantly hits the THRESHOLD case which causes the excessive ringing. If the THRESHOLD is increased to a much larger value then the ringing is drastically reduced but still not eliminated.

[mlindner]

Closing this and splitting it into two issues.