Right Audio channel output starts ever so slightly later

pce-devel / mednafenPceDev

Managed Mednafen Git repo with relevant fixes in support of the PCE (Developer) Community.

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Right Audio channel output starts ever so slightly later #61

Open pceDev16 opened 2 years ago

pceDev16 commented 2 years ago

Comparing the output of MDFourier in the latest 240PTestSuite from @artemio he noticed that the Right Audio channel is starting 0.000625 miliseconds later. This is happening in both our builds and the baseline vanilla Mednafen

pceDev16 commented 2 years ago

Some more info from digging into this a bit more:

@artemio has also seen this on a single physical DUO-R out of a sample of 10 and we know that the original author also used a Duo to set up the emulation nature of the PCE modules so perhaps they had a similar "run" of DUO's that exhibited this issue?
This issue is not exhibiting on physical SuperGrafx units

pceDev16 commented 2 years ago

The delay appears to be exactly 5 cycles of an 8khz waveform

dshadoff commented 2 years ago

5 cycles of an 8KHz waveform would be 0.625 milliseconds (or 0.000625 seconds).... is this what you meant above ? (rather than "0.000625 milliseconds)

dshadoff commented 3 months ago

@pceDev16 , which of the various audio outputs is being compared here - CD ? PSG ? ADPCM ?

And just to be clear, are you saying that SOME real hardware is also exhibiting this behaviour ? If true, I would like to try to understand what the variation is between chipsets (but maybe I misunderstood what was written above ?)