mirrors/dolphin-emulator
1
0
Fork 0
mirror of https://github.com/dolphin-emu/dolphin.git synced 2025-04-24 06:14:54 +00:00
Code Issues Projects Releases Packages Wiki Activity

IOS/USB: Try to fix the Wii Speak Channel record/playback feature

Browse source
This commit is contained in:
Sepalani 2024-05-12 12:58:53 +04:00
parent 045545a9b9
commit e4fd94b24b
1 changed files with 23 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
Source/Core/Core/IOS/USB/Emulated/WiiSpeak.cpp
View file

@ -190,16 +190,35 @@ int WiiSpeak::SubmitTransfer(std::unique_ptr<IsoMessage> cmd)
break;
}
// Anything more causes the visual cue to not appear.
// Anything less is more choppy audio.
// Transferring too slow causes the visual cue to not appear,
// while transferring too fast results in more choppy audio.
DEBUG_LOG_FMT(IOS_USB,
"Wii Speak isochronous transfer: length={:04x} endpoint={:02x} num_packets={:02x}",
cmd->length, cmd->endpoint, cmd->num_packets);
// According to the Wii Speak specs on wiibrew, it's "USB 2.0 Full-speed Device Module",
// so the length of a single frame should be 1 ms.
// TODO: Find a proper way to compute the transfer timing.
const u32 transfer_timing = 2500; // 2.5 ms
//
// Monster Hunter 3 and the Wii Speak Channel use cmd->length=0x100, allowing 256/2 samples
// (i.e. 128 samples in 16-bit mono) per frame transfer. The Microphone class is using cubeb
// configured with a sample rate of 8000.
//
// Based on these numbers, here are some theoretical speeds:
// - fastest transfer speed would be 8000 samples in 63 ms (i.e. 8000 * 1/128 = 62.5)
// * using a timing of 1 ms per frame of 128 samples
// * here cubeb sample rate is the bottleneck
// - slowest transfer speed would be 8000 samples in 1000 ms (i.e. 128 * 1000/8000 = 16)
// * using a timing of 16 ms per frame of 128 samples
// * matching cubeb sampling rate
//
// A decent timing would be 16ms. However, it seems that the Wii Speak Channel record feature is
// broken if the timing is less than 32ms and that the record playback is broken when around 34ms
// and above. Monster Hunter 3 doesn't seem affected by this timing issue.
//
// TODO: Investigate and ensure that's the proper way to fix it.
// Maybe it's related to the Wii DSP and its stereo/mono mode?
// If so, what would be the impact of using DSP LLE/HLE in mono/stereo?
const u32 transfer_timing = 32000;
cmd->ScheduleTransferCompletion(IPC_SUCCESS, transfer_timing);
return IPC_SUCCESS;
}