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Remote code execution via MIDI messages

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Re: Remote code execution via MIDI messages

#71

Post by helpfulContrib »

bluGill wrote: post #62
127 wrote: post #43

Earlier quoted context omitted.

That doesn't make much sense as note on and note off messages are very simple and you can't insert arbitrary bytes with them, unless maybe you use some very particular run mode.

Note on/off are just messages. We by convention map them to notes, but note 69 is A-440 on most keyboards, but you could see note 69 and play a C instead (this is somewhat common - have the computer transpose so you can play with others who play the music in a different key - better players can do this in their head but it is not a universal skill even with great players) There is no reason you can't take a sequence…

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Re: Remote code execution via MIDI messages

#72

Post by helpfulContrib »

odiroot wrote: post #54
liotier wrote: post #7

Of course it is SysEx. SysEx is to standard MIDI what inline assembler is to Python. A world of undocumented proprietary stuff lurks within just about every MIDI device !

SysEx is awesome. I'm quite sad modern synths seem to use it less and less (Roland!!!). Though Behringer is still quite good with it. E.g. their Deepmind can be pretty much 100% programmed with it, on top of already good MIDI CC scope.

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Re: Remote code execution via MIDI messages

#73

Post by bluGill »

officeplant wrote: post #69
bluGill wrote: post #63

Earlier quoted context omitted.

Many synthesizers have limits on how many sounds they can support. Midi was originally started because 1970's (analog) synthesizers could only produce one sound and so they wanted a way to have several synthesizers connected together. Before midi was finished synthesizers (now digital) could play more than one note. Though hardware limitations (not just software) didn't support infinite notes and so until around 2000…

The companies that came together to make MIDI all had analog polysynths capable of true polyphony before the MIDI standard was even finished. (distinct osc/amp/filter outputs per note and not just paraphonic synths that shared AMP/Filter circuits between OSCs) MIDI was more about unifying the entire studio of synths, samplers, drum machines, and recording equipment. And creating interoperability between various manuf…

Right but the conversations started before then.

Re: Remote code execution via MIDI messages

#74

Post by dhosek »

dkdbejwi383 wrote: post #58
b3orn wrote: post #56

Earlier quoted context omitted.

More notes or voices playing than the player has fingers is quite common, a note doesn't stop just because you let go of the key. Sometimes you want it to ring out so most synthesizers handle that case. Some even let you configure the behaviour, for example you could reallocate the longest playing note or the closest note.

You'd still get a note off event, which would then trigger the release part of the envelope or whatever.

Sustain pedal. Not sure how it’s implemented in midi, but that’s one way to have more than ten notes playing at once. (There’s also four-hand duets and the rare but not non-existent play two adjacent white keys with one finger technique.)

Re: Remote code execution via MIDI messages

#75

Post by dhosek »

bluGill wrote: post #63
b3orn wrote: post #56

Earlier quoted context omitted.

More notes or voices playing than the player has fingers is quite common, a note doesn't stop just because you let go of the key. Sometimes you want it to ring out so most synthesizers handle that case. Some even let you configure the behaviour, for example you could reallocate the longest playing note or the closest note.

Many synthesizers have limits on how many sounds they can support. Midi was originally started because 1970's (analog) synthesizers could only produce one sound and so they wanted a way to have several synthesizers connected together. Before midi was finished synthesizers (now digital) could play more than one note. Though hardware limitations (not just software) didn't support infinite notes and so until around 2000…

It was well before 2000. Most of my gear is 1990s vintage and while some has limited polyphony, most has unlimited polyphony and doesn‘t do note stealing.

Re: Remote code execution via MIDI messages

#78

Post by kevin_thibedeau »

bluGill wrote: post #63
b3orn wrote: post #56

Earlier quoted context omitted.

More notes or voices playing than the player has fingers is quite common, a note doesn't stop just because you let go of the key. Sometimes you want it to ring out so most synthesizers handle that case. Some even let you configure the behaviour, for example you could reallocate the longest playing note or the closest note.

Many synthesizers have limits on how many sounds they can support. Midi was originally started because 1970's (analog) synthesizers could only produce one sound and so they wanted a way to have several synthesizers connected together. Before midi was finished synthesizers (now digital) could play more than one note. Though hardware limitations (not just software) didn't support infinite notes and so until around 2000…

Polyphonic analog synths existed before MIDI. Notably, the Novachord from the late 30s. For the modern era, analog 2-8 note polyphony was available by the late 70s.

Re: Remote code execution via MIDI messages

#79

Post by LegionMammal978 »

SideQuark wrote: post #77

> World’s First MIDI Shellcode There's been MIDI shell code for well over 20 years on pretty much all major platforms: https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=midi

Plenty of buffer overflows. But has anyone actually written a shellcode for those?

Re: Remote code execution via MIDI messages

#80

Post by Earw0rm »

officeplant wrote: post #69
bluGill wrote: post #63

Earlier quoted context omitted.

Many synthesizers have limits on how many sounds they can support. Midi was originally started because 1970's (analog) synthesizers could only produce one sound and so they wanted a way to have several synthesizers connected together. Before midi was finished synthesizers (now digital) could play more than one note. Though hardware limitations (not just software) didn't support infinite notes and so until around 2000…

The companies that came together to make MIDI all had analog polysynths capable of true polyphony before the MIDI standard was even finished. (distinct osc/amp/filter outputs per note and not just paraphonic synths that shared AMP/Filter circuits between OSCs) MIDI was more about unifying the entire studio of synths, samplers, drum machines, and recording equipment. And creating interoperability between various manuf…

Yep, and not forgetting that serial ports on a computer were (at the time) expensive, and the sounds most synths were capable of were.. kind of simple. So there was the motivation for stacking multiple synths up to produce bigger/richer sound, doing keyboard splits (possible on some hardware of the time but not most), as well as driving many devices from a single port.

Multi timbral synths (different sounds addressable per MIDI channel) were a later thing too, analog polysynths could play more than one voice, but very few could play more than maybe two different _sounds_ at once.

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