On Sat, Jul 8, 2017 at 10:32 PM, Daniel Schürmann <dasch...@mixxx.org>
> I share Be's concerns about TinyCC compiler. On one hand it is available
> in the Ubuntu repos, on the other hand it is "not recommended for
> production use" in the explaining text.
> But that is not a big problem. For me it makes no difference if we dynamic
> ling a device.so file generated from TinyCC or GCC.
> GCC is available by default and calling it from ctlra or manual should not
> a big issue. We most likely cannot rely on TinyCC for Windows anyway.
> I think we have to distinguish between two areas of device depended code.
> 1. The driver part, which presents the controller in a generic way like it
> already happens with midi controllers
> 2. The application mapping, to adapt application features to controller
> If I get it right, ctlra aims to cover only 1.
Ctlra exposes generic events. These must be interpreted by the application
in *some* way - it can be C code, XML, JS, or whatever. But *somehow* the
event need to be bound to a ControlProxy in Mixxx yes.
Even if we have a ctlra controller in Mixxx, we need to adapt the signals
> to Mixxx Control Objects using xml or js files.
Why XML or JS? I see many more options, and just because we have existing
infrastructure for a similar case doesn't mean its always the correct
> The other point of view is the knowledge out there among audio artists.
> Here are two stats sources:
All this tells me is that "more" people are programming - logical thinking.
If we present easy-to-use functions in plain C, I'm sure any JS developer
will be able to understand it. Its about making the problem easy to
understand and achieve your goals with, more than choosing tools some might
have experience with. Aka: lets focus on solving the problem in the easiest
way, not trying to use the "easiest" or "most used" tools.
<snip points about out-of-process and OSC>
No comment, I see neither of those as a good solution for this particular
> > 2. If a user wanted to replace a precompiled mapping that came with
> > Mixxx with one they made or got online, what would that process go like?
> Would the user need to install TCC? Would we have to include TCC in Mixxx?
> Mixxx should already have access to a C compiler, if we decide to go the C
> way. The other option would be to share pre-compiled *.so files.
> But they are not cross platform and can contain a trojan.
Lets move away from the dynamically compiled code for Mixxx. Given the
problem, maybe TCC isn't the best fit. It served me well in developing
complex mappings - as a developer. Perhaps its not the best for users, and
that's OK. Lets find a better solution for novice / casual users who don't
want to compile anything.
> > 3. The programming language. It is a lot easier to find someone who
> > for a small project, than it is to find someone who knows C. For people
> > with minimal or no prior programming experience, higher level languages
> > are much easier to learn.
> likewise C, you cannot instantly start over to hack up your driver.
> You need a lot of reading and probably reverse engineering, which is
> probably harder than adopt a sample script of a partly unknown language
Good point - and I don't expect anybody to "just pop up" and start hacking
a driver from zero-experience.
> IMHO the success of Ctlra depends to a high degree to the numberer of
> supported popular controllers. If we manage to push this number up, all the
> technical issues are secondary.
Yes, agreed. Enabling cool features (screens!!) and such might sway some
people to consider using Ctlra too - lets see!
> If we fail, Ctlra is just another controller interface to support.
Heh - that's one of my favorites. Thanks for that :)
> Kind regards,
> Am 08.07.2017 um 22:00 schrieb Be:
>> Thanks for taking up this project! Reading your proposal on the wiki
>> page, the way you intend to integrate into Mixx's ControllerManager and
>> Controller classes makes more sense now.
>> The big question I am wondering about is the process of creating the
>> mappings from Ctlra events to Mixxx's state. Your idea to use TCC is
>> interesting and I think it's no problem for a proof-of-concept, but I am
>> doubtful it would be a good way to integrate Ctrla support into
>> applications for several reasons:
>> 1. Is it possible for a controller mapping to crash the application? That
>> should not happen under any circumstance.
>> 2. If a user wanted to replace a precompiled mapping that came with Mixxx
>> with one they made or got online, what would that process go like? Would
>> the user need to install TCC? Would we have to include TCC in Mixxx?
>> 3. The programming language. It is a lot easier to find someone who knows
>> project, than it is to find someone who knows C. For people with minimal or
>> no prior programming experience, higher level languages are much easier to
>> 4. Mixxx, and other applications, already have systems for supporting
>> MIDI controllers. Like Mixxx, some of these applications already have their
>> own scripting environments. Maintaining code and documentation for separate
>> ways for mappings to interact with the application would be a burden for
>> the application developers. For controller mapping developers, their
>> experience would be totally different depending on whether they were
>> mapping a MIDI controller or a Ctlra supported controller. This would be a
>> barrier to sharing knowledge and code between people mapping MIDI
>> controllers and Ctlra supported controllers.
>> 5. TCC is unmaintained. The last release was 4 years ago. If we found
>> issues with it, it would probably be upon us to fix them. I for one would
>> much rather spend my time working on Mixxx than a C compiler.
>> So, I think it would make more sense to expose Ctlra to Mixxx's existing
>> two capabilities added for this to work:
>> would be called when particular Ctlra events are passed to Mixxx.
>> 2. Scripts would need to have a way to send output messages to Ctlra.
>> There should be a way to freeze/unfreeze the sending of output messages so
>> many outputs could be updated simultaneously in a single HID packet.
>> I have written a proposal for how to do this with MIDI:
>> It would be great if we could create JS APIs that are almost identical
>> for MIDI and Ctlra.
>> On 07/06/2017 04:57 PM, Harry van Haaren wrote:
>>> Hi All,
>>> First of all - this is my first post to the Mixxx-devel list, so a brief
>>> intro is in order;
>>> I'm Harry van Haaren, developer of the OpenAV audio software, bit of a
>>> music/tech/linux head :)
>>> I've recently been working on improving controller support in Linux
>>> audio land, in particular
>>> what I call "modern USB HID" controller devices (think DJ controllers
>>> like Akai/NI/Abletons range).
>>> I've developed the Ctlra library as OpenAV, which provides access to
>>> these hardware devices
>>> on Linux. The library allows hotplug and various other "advanced"
>>> features like accessing
>>> screens on devices.
>>> I'd like to integrate Ctlra into Mixxx - to provide access to hardware
>>> currently not available
>>> to Linux users, and also to provide hotplug support to those
>>> controllers. I've created a blueprint
>>> on Launchpad, and written an introduction on Ctlra and how I propose
>>> to integrate it in Mixxx.
>>> Finally, there is a documentation page on what Ctlra itself achieves
>>> here, and the source is here.
>>> If you have an interest in hotplug of controllers, controller support or
>>> hardware on Linux,
>>> do have a read of the wiki page and others, and I'd appreciate your
>>> input on the ideas!
>>> Thanks for all your efforts on Mixxx so far, onwards and upwards!
>>> -Harry of OpenAV
>>>  https://blueprints.launchpad.net/mixxx/+spec/ctlra-controlle
>>>  https://www.mixxx.org/wiki/doku.php/ctlra_support
>>>  http://openavproductions.com/doc/ctlra.html
>>>  https://github.com/openAVproductions/openAV-ctlra
>>> Check out the vibrant tech community on one of the world's most
>>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>>> Get Mixxx, the #1 Free MP3 DJ Mixing software Today
>>> Mixxx-devel mailing list
>> Check out the vibrant tech community on one of the world's most
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>> Get Mixxx, the #1 Free MP3 DJ Mixing software Today
>> Mixxx-devel mailing list
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> Get Mixxx, the #1 Free MP3 DJ Mixing software Today
> Mixxx-devel mailing list
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