NativeMidi: music volume change affects master application volume with using of "Microsoft GS" on Windows

[Wohlstand]

NativeMidi: music volume change affects master application volume with using of "Microsoft GS" on Windows

[Wohlstand]

So, to get fixed this issue you need to use the "Alternative Native MIDI for Windows" module built to make sure the MIDI volume will don't affect the application-wide volume.

[Wohlstand]

Recently I have found that there are existing a MIDI drivers are don't affecting master MIDI volume change and keeping playing music with full volume. Roland Virtual Sound Canvas and Yamaha XG drivers on Windows XP are does that.

[Wohlstand]

Recently I have re-tested this on Windows 10: this behavior is absolutely same as in the past. Workaround is still be needed.

[MyreMylar]

Quick question, as I'm not a MIDI expert and related to the above linked pygame bug.

Would changing the MIDI back-end to something open source like FluidSynth also resolve this issue for a user of SDL Mixer? Assuming those changes of yours eventually make it into the official SDL Mixer version?

[Wohlstand]

@MyreMylar, yes, this issue does NOT affects other synthesizers like FluidSynth, Timididty and these are added to MixerX exclusively: libADLMIDI and libOPNMIDI. This issue affects only the NativeMidi, happens only on Windows, happens only in a condition you will use Microsoft GS synthesizer as default MIDI synthesizer. Another way to avoid this issue is installing of a custom system-wide MIDI synthesizer (like Yamaha SyXG50).

[Wohlstand]

Because of this issue, a libADLMIDI is used in MixerX as a default system independent MIDI synthesizer.

[MyreMylar]

Thanks! That was what I was assuming.

So it sounds like the issue with windows MIDI volume affecting all sounds in pygame might resolve itself if your changes all get ported into the Official SDL Mixer that pygame uses (assuming pygame also updates to the latest SDL at that point).

[Wohlstand]

This issue happens with MSGS only and doesn't depends on Mixer itself. Therefore I told that I should to develop a workaround to completely resolve this problem and allow using of Native MIDI safely.

[rversteegen]

Recently I have found that there are existing a MIDI drivers are don't affecting master MIDI volume change and keeping playing music with full volume. Roland Virtual Sound Canvas and Yamaha XG drivers on Windows XP are does that.

I'm not sure I understand what you wrote here. Do you mean that those MIDI drivers are broken and ignore the master MIDI volume? So you think that injecting per-channel volume commands could also fix that problem too?

[Wohlstand]

Do you mean that those MIDI drivers are broken and ignore the master MIDI volume?

Microsoft GS Wavetable Synthesizer is only buggy. Yes, per-channel volume injecting should resolve this issue. Look at algorithm:

• keep the global factor 1.0...0.0 as a volume level (full or silent).
• on a moment of volume change, multiply last sent CC7 value multiplied to the factor and immediately send it to MIDI output (per every channel).
• every time CC7 is sending by MIDI stream, you should multiply it with to a factor (per every channel).
• midiOutputVolume() set to maximum since initialization.

[Wohlstand]

Anyway, current code doesn't allows to implement this workaround quickly, therefore I going to implement some sort of this to use in MixerX instead of old code: https://github.com/Wohlstand/BW_Midi_Sequencer/tree/master/examples/win32-midiOut
However, it's C++, and may looks unapproveable if the pure-C only is needed. Note that this thing is not ready yet and I still need to implement that workaround, however, with my code it looks easier to implement it.

[Wohlstand]

Okay, since ages, I desired to finally fix out this. So, meet the alternative NativeMIDI for Windows: 8277fe5

• I had to use my own MIDI sequencer to extend functionality: full seekability, loop points, XMI/MUS formats support.
• I tricked over 7'th controller and I applied the volume factor to all channels. In result, the workaround for MSGS now works.

[Wohlstand]

Anyway, until I'll rewrite the MIDI Sequencer into pure C, this update will be MixerX exclusive (I don't think the official Mixer would take the C++-coded part into project).