[BUG] WinMM app cannot receive channel voice messages with channel number 2 to 16.

[m-komo]

Describe the bug
* This issue was observed with the Internal Preview (2025-02-16 Customer Preview 2 Daily).

WinMM app can receive channel voice messages with the MIDI channel number 1 only.
All channel voice messages with channel number 2 to 16 are lost.

This issue can be reproduced with both MIDI 1.0 devices and MIDI 2.0 devices regardless of the drive.

To Reproduce

1. Set the Roland UM-ONE mk2 to class-compliant mode (set the switch to "TAB") and short INPUPT and OUTPUT to loop back messages.
2. Attach the UM-ONE to PC.
3. Open midi.exe and monitor the "UM-ONE".
4. Open midi1monitor.exe and monitor the "UM-ONE".
5. Open the Pocket MIDI and choose the "UM-ONE" as an OutputPort.
6. From the "Views" menu, open "System Exclusive" window.
7. In the System Exclusive window, open the attached file (TestMIDI_AllChs.txt).
8. Click "Transmit" to send messages.

The midi1monitor.exe only receives channel 1 voice messages, even the midi.exe receives all sent messages as UMP MT2.

Expected behavior
WinMM app can receive channel voice messages with all MIDI channels.

Installer Name or Version

• [Internal Preview] Windows MIDI Services (In-Box Service) 1.0.3-preview-11.250216-1702-x64.exe
• [Internal Preview] Windows MIDI Services (SDK Runtime and Tools) 1.0.3-preview-11.250216-1702-x64.exe

Desktop (please complete the following information):

• OS: Windows 11 24H2 build 27788.1000 (Insider Cannary channel)

Device information, if this is with an external MIDI device:

• Roland UM-ONE mk2

[Psychlist1972]

Thank you. Looking at it, I can see the messages coming in in UMP are also not correct. It doesn't receive all messages, but instead is getting the same FF problem that is seen in WinMM

[Psychlist1972]

If I send from the console using UMP, and monitor from another console using UMP, the data is correct, even through there's translation to and from the device.

So the issue is with the wdmaud2.drv code, most likely, as the corruption happens coming from a WinMM app or when a WinMM app is receiving data.

[Psychlist1972]

I have a partial fix for this in the dailies. It's still dropping E0-EF (pitch bend) messages, however. I will work on that.

[Psychlist1972]

This is now fixed