SCI: CASTLEBRAIN - Stereo audio flipped in hourglass puzzle

[henke37]

The audio effects that play while the hourglasses are running is played in the wrong stereo channel

[sluicebox]

This is impressive; can you elaborate? How could you tell it's on the wrong channel? Is sound a part of this puzzle? Can you attach a save game, or if it's easy to get through from the start, tell me how to get there and reproduce? Does this happen in DOSBox?

Sorry but I haven't played this game since I was a kid, though I remember loving it. Seems like a great excuse to get back into it!

I laughed out loud that you set an "hourglasses" keyword

[henke37]

It is fairly simple, two hourglasses on screen. Each plays its own sound effect when active. Pretty easy to tell by using headphones and mark one eyeballs what is intended.

The audio is not used in the puzzle at all. I don't think audio is required at all in the game.

As for how to get to it, it's accessible on the third screen of the game, the clock room, so just after the copy protection "puzzle".

And no, I have not checked with the original interpreter.

[henke37]

Save in the clock room

[ZvikaZ]

Which audio device are you using?
If it's MT32, try GM. If it's GM, try MT32.

Explanation - MIDI defines controller #7 as 'pan' (i.e., location of channel in the right/left axis). That's way stereo effects are created.

However, sadly, the pre-GM MIDI spec hasn't defined the details of this, and MT32 and GM uses different values!
GM defines 0 as most-left, and 127 as most-right; while MT32 is using 0 as most-right and 127 as most-left.

Therefore, it's expected that MT32 and GM will have reversed stereo locations, unless we'll support that in the drivers (which as far as I remember, we don't).

According to the list at ​https://en.wikipedia.org/wiki/List_of_MT-32-compatible_computer_games, Castle of Dr. Brain was composed for MT32.

Therefore, hopefully, you're using GM, and it makes sense that you'll heard the stereo flipped, and it'll be solved by changing to MT32.

[henke37]

Yup, I had it in GM mode. Switching it to MT-32 fixed the issue.

[ZvikaZ]

Good to hear that it's working as expected.

However, the interesting question, do we want to add a 'flipping' mechanism in the drivers as enhancement?
I mean that if we're using MT32/GM, while the game was intended for the other driver, to change the value to 127-orig_value.

It's not too complicated, but I'm not sure that it's "good to do", and I'm not sure that we have a definitive list of the intended driver for each game, and thus this change might cause more problems that benefit?

Or maybe add this mechanism as optional? Or will it only make our audio configuration more complicated, and it's already complicated enough?