Emulation Audio Questions

[iamdarkyoshi]

So I am running dolphin so I can play mario kart DD (GameCube) and I want it to use my 5.1 surround sound. It has the option to use a Dolby decoder if I use openAL audio, so I selected that, selected the Dolby decoder, and now it only plays on my center channel. What gives? Any ideas? Stereo is for noobs.

[Mr.McMister]

The GameCube used Dolby Pro Logic 2 for surround sound. It matrixes 4 channels into a regular stereo signal(center is generated as the difference between L and R and LFE is generated as well) where the receiver can then separate the channels back out again if set to Dolby PLII mode. If your receiver does not support Dolby PLII you cannot get surround.

[iamdarkyoshi]

The GameCube used Dolby Pro Logic 2 for surround sound. It matrixes 4 channels into a regular stereo signal(center is generated as the difference between L and R and LFE is generated as well) where the receiver can then separate the channels back out again if set to Dolby PLII mode. If your receiver does not support Dolby PLII you cannot get surround.

I am using the onboard 5.1 soundcard of my PC. All other games work with surround sound, perhaps the emulator is not correctly decoding the sound to play on my PC's soundcard?

[Mr.McMister]

I am using the onboard 5.1 soundcard of my PC. All other games work with surround sound, perhaps the emulator is not correctly decoding the sound to play on my PC's soundcard?

Are you running each speaker directly from your sound card or do you have a surround receiver? If you are running to a receiver first turn on Dolby Pro Logic II. If you are running the speakers directly of the sound card then there is no method as of yet to achieve surround with this setup.

The GameCube and wii's soundchip is only capable of outputing a stereo signal and dolphin as a result of accurate emulation is only capable of this as well. Dolby PLII is a way of cheating this limitation by matrixing the audio of the other channels into that stereo signal in an analog fashion. Because of this you need something capable of separating out this analog mix such as a surround receiver with Dolby PLII.

[iamdarkyoshi]

Are you running each speaker directly from your sound card or do you have a surround receiver? If you are running to a receiver first turn on Dolby Pro Logic II. If you are running the speakers directly of the sound card then there is no method as of yet to achieve surround with this setup.

The GameCube and wii's soundchip is only capable of outputing a stereo signal and dolphin as a result of accurate emulation is only capable of this as well. Dolby PLII is a way of cheating this limitation by matrixing the audio of the other channels into that stereo signal in an analog fashion. Because of this you need something capable of separating out this analog mix such as a surround receiver with Dolby PLII.

Interesting. When I go to the game's setting to test the different options, the left, center, and right channels play sound, but nothing from the rear. Mario's voice fades in and cuts out as he says "Surround Sound" (because it starts at left rear and goes to left front, center, right front, and then right rear) but the odd thing is that the center channel plays sound, something that setting it to stereo does NOT do...

[Mr.McMister]

Interesting. When I go to the game's setting to test the different options, the left, center, and right channels play sound, but nothing from the rear. Mario's voice fades in and cuts out as he says "Surround Sound" (because it starts at left rear and goes to left front, center, right front, and then right rear) but the odd thing is that the center channel plays sound, something that setting it to stereo does NOT do...

I just checked into things and I did see that dolphin has begun to implement a Dolby PLII decoder on the OpenAL backend. This runs as an extra process on top of the regular emulation and is currently very buggy. Essentially it's running in software what is normally done in hardware on a surround receiver. This will take a fair amount of extra CPU power on top of the regular emulation. You can try the latest nightly builds, but I wouldn't keep your hopes up. In the mean time if you want working surround you'll need to use the method with a Dolby PLII capable receiver(setting dolphin to stereo output, the game to surround, and setting the receiver to PLII mode.)

Sorry, it had been a while since I last checked into dolphin's experimental features.