Audio Comparison PCM with Linear Interpolation
Following on the previous topic about linear interpolation. I have improved it on the Megadrive sound chip core JT12. This core already made a x2 interpolation by default. Now I have extended it to arbitrary numbers.
This increases the sound quality of the Megadrive but for games with very poor samples the difference in sound is very large so I guess that somepeople may prefer the aliasing sound just because it was what they grew up with.
I have made the comparison with Megadrive rather than with NeoGeo as Megadrive games often have poorer quality on PCM so the difference is more obvious.
There are three samples played twice, first without interpolation and second with interpolation. What do you think?
Comments (11)
I would try comparison by using my "Mega Blaster" as it has a real YM2612 chip and a PCM Playback capability via the real chip.
I like the linear interpolation. At least that softens the harsh anti-aliasing hiss...
Prefiero el original y seguro que te has dado una paliza para la interpolación :_)
I like the improvement, but I think it should be an options, like others have said.
I agree that as a filter it should be user selectable.
Unless you’re going to pair it with a compensating EQ curve to bring the high frequencies back up, I wouldn’t do it.
I cannot bring the high frequencies up because they are not existing in the original sample! The reason we hear high frequency content is aliasing in the original PCM circuit.
I like that low-pass filter sound, makes it feel more analog. But as you note, I think many people would think it is too much.
linear interpolation is not a good strategy for upsampling. From which sampling rates to which sampling rates to you need to upsample? I do similiar things at work but for radio signals. Maybe I can give you a better proposal
Take into account that the sampling rate is unknown. Indeed, some games do not even hold a steady rate because of poor design of the sound driver (running in the Z80 CPU). So basically, the data sampling rate is anywhere from low kHz to 55kHz, with large jitter. Of course, the upsampling must be done in real time too.
Would to have an option to toggle for the existing cores :)