Is the left and right channels of cd audio reversed?

[liuszuping]

Hello everyone, has anyone tested whether the left and right channels of the hu/cd game are reversed? I think the left and right channels of the cd game seem to be reversed? Is this a core problem?

[12characters]

Why do you think the channels are reversed? Have you confirmed that there is the same issue in more than one Turbografx game and no issue for other cores? (To rule out that it is not a bug in the game or that your speakers are connected wrong.)

When I check the sound using the 240p test suite hucard rom, the left and right audio channels plays correctly. There could be a specific issue with CD audio but I doubt it.

[dshadoff]

We have had a lively discussion on the discord server about this issue.

240P Suite only shows left/right for PSG output; CD output is a separate thing which is mixed with PSG, so it's not as straightforward as it appears.

A quick test was assembled, and I did verify that the VU meters (visual display of volume) on the CD player on the System Card were showing activity on the wrong channels. Not just that, but Mednafen has the exact same problem with its CD player.

But so far, I haven't got confirmation from anybody else that the actual sound is wrong.
(Complicating matters is the fact that HDMI, SPDIF and analog outputs should all be the same, but the original poster is saying that their board is maybe not wired in the standard way...)

This is still being investigated.
Also, I have requested Artemio to add Left/Right specific tests in 240P Suite to help validate other cores and emulators.

[Stupid Dufus]

Using a track from Dracula X I recorded audio from (1) SuperGrafx with Turbo Everdrive Pro->EDFX for stereo audio and (2) MiSTer analog out from TG16CD core

Other than some difference in volume, the wave forms appear to be the same.
(1) https://www.dropbox.com/scl/fi/2yh3lczs ... 9umf0&dl=0
(2) https://www.dropbox.com/scl/fi/0tq5kdgd ... zock0&dl=0

Is this enough to confirm, or does a different test need to be done?

[dshadoff]

Thanks, but that’s not really what’s at issue, and TurboEverdrive just throws another variable in the mix.
There is a test audio CD in the GitHub issue, and Artemio is going to confirm what a different discord user already told me - whether the “Left” channel on CD is being properly routed to the left speaker (and right to right) for HDMI, SPDIF, and analog… on an official board. I’ve already got one user who has confirmed HDMI and SPDIF, but this is different than the original poster (who may or may not have a board based on the official design). I’d check myself, but my MiSTer isn’t connected to a stereo.

[aberu]

Both SCART and Saturn-type cables have been known to get the Left and Right audio signals swapped, so also good to confirm with the user regarding their cable type.