Which CD format(s) should be used for emulators on the Wii?

[DominoBright]

After reading in the WiiStation thread about problems with CHD files, due to the Wii having little power and RAM for decompressing them, I've been thinking about what disc formats should be used for Genesis Plus GX and RetroArch's PCE-FAST. I'm currently using OGG+ISO for those, though I'll admit that I don't know if OGG also needs a lot of power to be used.

My understanding of the formats:

OGG+ISO uses very little space when much of the disc contains audio, but OGG is a lossy format and there are a lot of files.
CHD might perform better if it doesn't use LZMA compression (which it does by default), but it's still a workout for the Wii.
CHDs using a new Zstandard compression should help the Wii a lot, but it's a matter of both if and when emulators will support it.
BIN+CUE may allow for the best performance, assuming your storage can handle it.

 

[ssjkakaroto]

After reading in the WiiStation thread about problems with CHD files, due to the Wii having little power and RAM for decompressing them, I've been thinking about what disc formats should be used, not just for WiiStation but for Genesis Plus GX and RetroArch's PCE-FAST. I'm currently using OGG+ISO for the latter two, though I'll admit that I don't know if OGG also needs a lot of power to be used.

My understanding of the formats:

OGG+ISO uses very little space when much of the disc contains audio, but OGG is a lossy format and there are a lot of files.
CHD might perform better if it doesn't use LZMA compression (which it does by default), but it's still a workout for the Wii.
CHDs using a new Zstandard compression should help the Wii a lot, but it's a matter of both if and when emulators will support it.
BIN+CUE may allow for the best performance, assuming your storage can handle it.

IMHO: BIN+CUE (until you are sure the game runs 100%) > CHD (Zstd+FLAC when libchdr gets updated) > CHD (Zlib+FLAC)
FLAC is very resource-friendly, there's really no need for OGG+ISO (never heard of this combo, isn't it OGG+BIN?), because if you really want to go the lossy route, lossywav is available (https://hydrogenaud.io/index.php/topic,112649) which you can use to convert to FLAC.

 

[DominoBright]

I checked out the lossyWAV stuff and found the binCueMinimizer program. The CHDs it makes at Setting 2 are an excellent middleground between ISO+OGG and lossless CHD that I'll be happy to take, so thanks for letting me know about that!

That said, it doesn't have options to disable LZMA compression or use a sound quality higher than extraportable. While the former can be fixed by having CHDMAN change it to BIN+CUE and then to a CHD with the right parameters while retaining the converted audio, the latter isn't as easy to deal with.

 

[ChibiMofo]

Correction: FLAC is no more resource intensive to decode than OGG. If you want it to actually use fewer CPU cycles, use uncompressed WAV. Yes, that takes nearly three times more space, but it does not have to be decompressed, as FLAC clearly does.

 

[ssjkakaroto]

I checked out the lossyWAV stuff and found the binCueMinimizer program.

That's quite interesting, I've never heard of it before. Too bad it hasn't been updated in a long time, but you can create a regular CHD with it that uses lossyWAV (FLAC) + LZMA and then use the latest CHDMAN to convert it to FLAC + Zstd with the "copy" command.