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arnaud-neny / rePlayer

another multi-formats music player
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V2 decoding has glitches #11

Open hyvarinenjm opened 10 months ago

hyvarinenjm commented 10 months ago

Good job creating the emulator for the Farbrausch V2 asm synth. Unfortunately it seems to produce slightly different output from the original 32-bit assembler version. Normally that is inaudible, but at least https://modland.com/pub/modules/V2/Oskar%20Pedersen/q.e.d.v2m produces bad glitches. First bad one is at time stamp 0:35, second at 0:40.

arnaud-neny commented 10 months ago

I can't here the glitches myself, but what I'm suspecting is the decoding is to slow for you (so the wave output ring buffer is not filled in time). The x86 emulation I've done is very slow and I'll need at some point to optimze it (or cache the ouput). Can you try to export as wav to see if it's a performance issue?

hyvarinenjm commented 10 months ago

Sorry, I should have mentioned that I had already verified it to be a decoding issue. I exported the output to WAV and played that, the glitches remain. They are also visible in audio editor. The first glitch I reported for example shows a sudden discontinuity in sample values on the left channel: https://i.imgur.com/Ur0MMaL.png Causes a visible spike on the spectrum display: https://i.imgur.com/KgTC3Jk.png

arnaud-neny commented 10 months ago

It's going to be tricky to find this issue. I'll try to do a runtime compare between the original x86 with my version when I find some spare time.