USB MIDI?

@Rick Murray:

Is this how RISC OS works, or how USB works? I really can’t see the point of an interface with irregular externally-sourced input being set up as a “request some data” model. That seems akin to ringing the doorbell without bothering to look to see if the lights are on…

You raise a very good question. I don’t know the answer. If Jeffrey Lee, DavidS, the guys from ROOL, or anyone else, knows: please speak up! I bet Dan Ellis would know…

I imagine Maestro is belting out all the notes at 127 velocity, no?

Maestro is a tad smarter than that – it takes the velocity from the configured loudness (which, okay, is usually “loud”) and then tweaks it slightly.

IF First% xtraVol=1.01 ELSE xtraVol=1.0 :REM a little dynamics. stress 1st beat in bar very slightly

and:

packed% = (MIDIChannel%(C%)-1) OR (note%<<8) OR INT(xtraVol*(Volume%(Volumes%(C%)))<<16)

There are many things I would like to do to Maestro (on the fly volume changes and sustain pedal up/down being the main two); however I don’t have the time and I’m not sure if it could easily be extended to support this.

Adding dynamics (drawing ‘hairpins’ would certainly be a bonus) and sustain would be brilliant! Perhaps tidying up the way the notes are presented, such as joining together quavers (and quicker notes) too.
I would be willing to donate to the coffee/beer fund if this was set up as a bounty.

Also, http://youtu.be/thSI3VqEizg – (:

I tried mucking about with the registrations as it was playing on the Electone;

Adding […] Perhaps tidying up […]

:-)

Please don’t get your hopes up for me doing it anytime soon. A have way too little free time as it is. :-(

I see you have a PC (from the first video, looks like some sort of netbook). Take a look at http://musescore.org/ (for Windows, OS X, Linux) and you’ll see what I am currently using. ;-)

Also, http://youtu.be/thSI3VqEizg – (:

Was that one of the demo tracks? I don’t remember anything that long or complicated. Sounds nice, though.

Have you tried playing with the volume options for the MIDI channels? As an ugly/rough hack, it might be possible to do loud/quiet by splitting the music across two staves (one for quiet, one for loud). Far from ideal, but… in lieu of a better way…

Hi Rick,

I’m still planning to attempt some sort of Record / Playback thing. I just have not had a lot of time lately. I took another look at your miditest program this morning and reckon that I best build a working knowledge of pointers and indirection before I go much further!

Does anybody have a copy of the Acorn MIDI module (ie as on the epic-wide User IO/MIDI podule, etc) they could send me? I’d like to poke around it.

I have an Acorn MIDI podule… so I should have the module… somewhere… probably in the loft.

Mark me down as source of last resort.

Rick, doesn’t Liquid Silicon stil have MIDI Support, wich includes the latest MIDI module?
http://liquid-productions.org.uk/index.php/liquid-silicon-shop

Rick, doesn’t Liquid Silicon stilhave MIDI Support, wich includes the latest MIDI module? http://liquid-productions.org.uk/index.php/liquid-silicon-shop

Been there, tried that (last night, actually).

“Due to the very small Acorn/RISC OS market and the increasing costs involved in running a web shop, we have decided to close the online ordering facility and post any stock we have available on ebay. For anything not listed yet, we can take payment by Paypal – please contact us for details.”

And eBay… Zero items to list.

http://liquid-productions.org.uk/index.php/contact-us ?

MIDI Support is e-mailed to you, so it probably made on demand.

Before we start – it’s an alpha version. Probably FULL of bugs and quirks.

Basically – it is a clone of the Acorn MIDI module, only it talks USB. ;-)

http://www.heyrick.co.uk/random/usbmidi_alpha.zip
[update – new version, see below]

There are two test programs included. One is a version of my midi diagnostics converted to use the module instead (well, it just calls MIDI_RxByte a load of times) and the other plays the bass line of “(Dear) You” over and over.

Please note the following before attempting to use:

• THE BIGGIE – data read is blocking. This means if your keyboard is not outputting data, RISC OS will hang waiting for it. Thankfully most keyboards ought to spit out regular clock ticks and active sense messages; but it is something to keep in mind if you use a USB to MIDI dongle with nothing connected to the MIDI end.
  This is, I should add, with “noblocking” specified in the USB option and a further call to OS_Args to do it the ioctl way. Oh, the joys of RISC OS’ USB…
  This is for the Pi, might you. The Beagle is likely to do something completely different, like burst into flames…….. :-/

• Currently works with only one port, which is detected as the module starts. The module can detect devices being removed, but not yet those being inserted. Thus: connect your keyboard and then run the module; and if you disconnect and reconnect the MIDI device, use *RMReInit MIDI to force it to find the MIDI hardware.

• The MIDI_RxCommand SWI does not work. It is late, I couldn’t be bothered coding it, I’m tired.

• There is no support for the MIDI parser/player that Acorn’s offered. As such, all MIDI commands are placed into the buffer. The module does not act upon a single one.

• There is no support for the scheduled MIDI stuff either. If you want it timed, use Sound_QSchedule (or whatever it is) like !Maestro does. ;-)

• Passing port number -1 (for first available) is not currently supported.

A brief note about the data read method. When the module starts, if there is a MIDI device, it will set up callbacks every 10cs to read from the MIDI device. The data will be parsed and copied into a 1024 byte buffer. When this buffer fills up, reading from USB will stop, and data may be lost. The buffer is not circular, data reading will be paused until such time as the content of the RX buffer has been read, upon which time the pointers will be reset and the callback for reading will be restarted.
As long as a MIDI device “polls” frequently enough, there should be no problem here, as it takes about 5 seconds to fill the buffer when the module starts up.
[note – I think there’s a bug – I don’t think flushing the buffer restart reception; so you’d be best to loop on byte read until it’s all been read]

Things I learned today (aka random rants):

• Isn’t it nice how you can ask the USB subsystem to do something and it’ll do something else. I never noticed earlier as the midi display program I wrote before was single-tasking so a blocking GBPB would not have shown up.

• There’s a bug somewhere in RISC OS that after an undefined event, attempts to call the command handler in the C module will cause an abort. Rebooting and loading the same module works fine. I’m not going to bother reporting this as I have nothing concrete to say, you might as well cast runes…

• Why is it CallEvery can be used to set a ticker, but RemoveTickerEvent doesn’t remove it? I traced my code, CallEvery is called only once. RemoveTicker is called only once, with the same address and workspace pointer. And, yet, my veneer handler keeps on getting called.
  [workaround – remove the CallEvery code and instead fire off CallAfter’s when needed; less aesthetically pleasing, but it works]

• Making mistakes in module level code usually stiffs the machine. Indeed, I’ve had all sorts of bizarre stuff today, like can’t open endpoint? well, that’s an automatic red card for you. And a FileCore in use for good measure. Jeez, I’ve not seen that since RISC OS 2! My favourite, however, is the one where the mouse still works but the pointer is frozen to a random place on the screen.

• Those who read my blog (er, if anybody) will know that my Livebox’s WiFi kept dying of the heat (all 28C of it!), that Orange replaced it with a new Livebox that… let’s just say that hitting it and forcing it to crash might just be enough to get it to have its WiFi work. I have an older box here, but it keeps grinding to a halt (as in, 5K/sec if I’m lucky). Orange guy says on the forum “please try a full reset” and I say “did you not bother reading my messages? did that yesterday. oh, and does orange bother to test their equipment or was this somebody else’s customer return?”. I received an email with a code in it, a replacement should be available for collection on Thursday…

• I’m on summer holiday for three weeks (yay!) but the weather is less impressive and I don’t feel “good”. I don’t feel ill, exactly, just lethargic and tired. Like the whole world is a massive pile of “Meh” and I’m losing interest.

End note:

I don’t know if or when I will do more work on this module. I did it mainly for legacy stuff to have a way to talk to MIDI devices on newer hardware plus to have MIDI support on the Beagle/Pi/etc with a known existing API, but I would ideally like to create something with a cleaner and simpler interface than that supplied by Acorn’s module. Suggestions and ideas welcome.

If I should have some time this weekend, I’ll get my keyboard from the attic and try a little. But not sure.

Many thanks.

New version of the MIDI module. Works on the Pi with, and without, Colin’s updated USB driver.

http://www.heyrick.co.uk/random/usbmidi_alpha2.zip

No new functionality, other than “this one works”. ;-)

Also…

I have written a 24 page user guide. I’ve just hacked it to sort-of reflect the current status of the module. It is a PDF file, 106Kb.

http://www.heyrick.co.uk/random/usb-midi-0-01-user-guide-preliminary.pdf

Just out of interest – is there a repository of Maestro format music anywhere? Anything more than the generic demo tunes?

Just sent you a zipped file of Maestro tunes that I picked up somewhere to your website email address. I think they are public domain/freeware. I don’t know of any repository of Maestro tunes.

Thanks, Peter. Looking forward to it.

Just a note for all – if your machine freezes up while using the MIDI module, it likely has not crashed, but is instead waiting on data. Just unplug your MIDI dongle and RISC OS will come back to life.

And don’t forget to report the problem to me! ;-)

New version of the MIDI module.

http://www.heyrick.co.uk/random/usbmidi_alpha3.zip

Updated user guide:

http://www.heyrick.co.uk/random/usb-midi-0-01-user-guide-preliminary.pdf

What’s new:

• Fixed a dumb bug – was copying USBMIDI packets to the buffer. D’oh! Now it strips them down to pure MIDI data.
• Module now uses DADPrint for debugging – so I made a number of corrections/optimisations.
• Now ‘polls’ for data using a smart algorithm. While there is data, it will check every 5cs or 10cs (depending on whether last call returned something). If there is still no data, it will check every second. If there is still no data after 30s, it will check every 10s. The logic – no need to check every 5cs if there’s nothing to see. And if data becomes available, normal checking speeds will resume.
• Fixed bug of extraneous tickers being set up, causing the callback to be called too frequently.
• MIDI_TxNoteOn now replies with R0 set to -1 if selected MIDI device is invalid (not connected etc).
• MIDI_RxCommand implemented – but note that it will search for the next valid MIDI command (so if you MIDI_RxByte a “Note On”) and then call MIDI_RxCommand, the two parameter bytes of the Note On would be ignored. It is recommended to use EITHER RxByte or RxCommand, but not both.
• Should now raise events and service calls as documented, with the exception of “USB device connected”.

Limitations:

• Does not ‘see’ devices connected. You’ll need to RMReInit the module to get it to see a connected device.
• Does not support multiple ports. Port 0 is the first device found, end of.
• Pretty much zero support for SysEx packets at this time.
• Other stuff. ;-)

At any rate, this is a better version of (USB)MIDI that is now a fair bit more usable. I was annoying Mom with the many Maestro tunes Peter sent me… Awww, Mooooooom! You did watch Cagney and Lacey, right? and Argh! How could you not remember Treasure Hunt! Hehehe…

New version of the MIDI module.

http://www.heyrick.co.uk/random/usbmidi_alpha4.zip

Same user guide, if you don’t already have it:

http://www.heyrick.co.uk/random/usb-midi-0-01-user-guide-preliminary.pdf

What’s new:

• Now sets error flag correctly if no device found at start.
• Fixed the non-blocking code (it got broken somewhere along the way) so the module now works on the Beagle. ☺
• Now detects MIDI device insertion. Only one port/device is supported, but it can be disconnected and reconnected at will. No need to restart the module to ‘see’ it.

Tested with:

• RaspberryPi, self-built RISC OS 5.21 of 5th August, generic USB MIDI dongle, Roland E-16.
• Beagle xM, old RISC OS 5.19 from around September last year I think, same MIDI stuff as above.

I am not planning any extra work on this for the time being (asides from bug fixes) because the next step is multiple devices which is a big job. I have one week of my holiday left, so I’d like to enjoy that before the grind resumes…

…anyway, apart from SysEx support, the module should now do most of what I wanted it to do. More will follow, just not imminently, okay? :-)

Does anybody use this? Comments?

The next thing I’d be interested in finding is sequencing software for RISC OS – even if an old project, I could have a crack at converting/updating it? Any thoughts?

Well, I’ve had good play about with it.. seems to work well. :)

Used an unmodified !Maestro to play several of the example files..

MIDIWorks2 checks for Acorn MIDI version 3.14 before even attempting run and then having tweaked the check it just complains about 32bit as I’m playing about with this on the Pi. shrugs Hadn’t attempted MidiWorks before now.

Worth buying a copy of aemulor to try it out?

Craig

Anyone tried MelIDI? Cos that rocks :)

• http://www.melidi.co.uk

Worth buying a copy of aemulor to try it out?

Might have passed my evaluation period for the Pi demo (been busy with other things), but I am running RISC OS 5.21 of around 5th August 2013 – sources downloaded then, built myself.

Loading aemulorpro_demo, it is 50:50 whether it will run or stiff the machine. If it runs, it will make the mouse pointer vanish and will then stiff the machine the moment I do anything, at all, with Aemulor. If I place it in the predesktop startup, the machine will stiff at startup, and given the Pi doesn’t see it’s keyboard at early boot, there is frantic pressing of Esc to get in before Aemulor is run.

Is this a known problem?

Anyone tried MelIDI? Cos that rocks :)

• http://www.melidi.co.uk
  

I’ve never used any MIDI software, but the MelIDI author, Stephen Borrill went on to set up Precedence Technologies. I’m not sure if MelIDI was 32-bitted.

And lo, I find this forum thread :-)

MelIDI was 32-bitted back in 2006 in conjunction with Liquid Silicon (Alan gave me a few pointers (pun not intended) and did testing). Unfortunately, real-life got in the way and it all fell dormant.

However, I’m now looking at open-sourcing MelIDI and it’s pretty much ready to go. I’ve only got a RISCOS 3.71 RiscPC in regular use, but I do want it to run on the RPi too (which I also have). I bought a USB MIDI adaptor, so I’m hunting for a MIDISupport compatible backend driver. I also need to check on the distribution status of the newer frontend MIDI and MIDISupport modules.

I may well have many other questions later, my knowledge is a bit rusty :-)