Re: [Line6linux-devel] (no subject)

[Stefan H. <ste...@gm...>]

On Wed, May 1, 2013 at 9:33 PM, Andrej Kruták <de...@an...> wrote:
> On Wed, May 1, 2013 at 7:30 PM, Stefan Hajnoczi <ste...@gm...> wrote:
>>
>> On Wed, May 1, 2013 at 11:11 AM, Andrej Kruták <de...@an...> wrote:
>> > As I said, I don't know much about MIDI, so it's hard to tell for me, if
>> > the
>> > messages in X3 (bean) resemble it at all. What's your plan if it's
>> > different, is the userspace (planned t be) flexible enough? How is the
>> > profile uploading/downloading handled with the XT?
>>
>> Userspace should support multiple devices in a data-driven way -
>> adding support for a new device should (mostly) mean populating a
>> table of MIDI messages.
>>
> So in case there's no real MIDI in the device, you expect it to be somehow
> emulated by the driver, right? But for example the volume is send from X3 as
> a float number, while in MIDI (after a short look) it seems to be just an
> unsigned char....

No, MIDI is not emulated by the driver.  In some cases the driver
spies on MIDI traffic or generates MIDI messages internally, but it
doesn't process MIDI messages and convert them into Line6-specific I/O
operations.

MIDI is extensible and you can send arbitrary data over it (may
involve a 7-bit encoding).  Line6 uses a custom MIDI mapping and
parameters can be floats, fixed-point, etc.

Can you explain what you mean regarding volume sent as a float?  Do
you have a traffic capture?

>> Don't expect anything close to the Line6 Editor working yet.
>> Personally, I care about a solid PCM and MIDI driver, but I don't care
>> so much about a Line6 Editor.  If someone invests the time then I'm
>> sure it would be doable in a couple of months.
>>
>
> For me, it'd be enough to just dump all the settings, put (some of) them
> back through some sys file, for example (or ioctl). According to the USB
> comm, it seems it's easily doable. Editing would be nice, I saw there's some
> work around that done already - but as yuo say, someone has to have time for
> it... :)

Dumping the device is easy on the HD300, maybe it's the same on yours.

The device has a MIDI dump option available in an options menu.  You
can select whether to dump just the current patch or all patches.

When you activate MIDI dump the device sends all the patches over
MIDI.  On your computer you can use amidi(1) to save this to file.

Later you use amidi(1) to send the sysex back to the device, restoring
the patch(es).

If you don't enjoy using amidi(1) I bet some of the graphical DAWs or
MIDI tools under Linux also support storing/loading sysex dumps.

Stefan