Re: [hatari-devel] MIDI support for Windows & OSX (with PortMidi)

[Simon Iten <itensimon@xxxxxxxxx>]

> On 4 Oct 2017, at 00:29, Simon Iten <itensimon@xxxxxxxxx> wrote:
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> 
> 
> 
>> On 4 Oct 2017, at 00:13, Eero Tamminen <oak@xxxxxxxxxxxxxx> wrote:
>> 
>> Hi,
>> 
>> On 10/03/2017 11:57 PM, Simon Iten wrote:
>>> does or how does portmidi change the way midi is presented to a usb-midi converter?
>>> or in other words, why does portmidi on osx behave differently (“better” in my case) then linux with the standard none portmidi method?
>> 
>> PortMidi sends whole MIDI packages while the other one outputs the data byte-by-byte.
>> 
>> Which device drivers you use on Linux and which on OSX?
>> 
> on osx i use the motu drivers from the support page they have. on linux there is no firmware needed, but i seem to remember the device is not fully class compliant. (a hack of the device id is necesarry). but it works out of the box on my linux system. 
>> 
>>> this is with the same atari software, same synth and same interface. driver issue on linux? (fastlane-usb motu, not fully class compliant)
>> 
>> Are you using the same version of Hatari?
>> 
>> You can build Hatari also on Linux with portmidi to compare, whether they still behave the same, i.e. is the issue in the OS / driver level.
>> 
>> 
> i am using a non portmidi version on linux.
> 
> does the github version have portmidi for linux already. or do i have to apply the patch?
> 
> i will try to test this further.
sorry not GitHub...
>> 	- Eero
>> 
>>>> On 3 Oct 2017, at 22:10, Nicolas Pomarède <npomarede@xxxxxxxxxxxx> wrote:
>>>> 
>>>> Le 03/10/2017 à 21:26, David Savinkoff a écrit :
>>>>> ----- Eero Tamminen wrote:
>>>>>> PS. Jari has also some questions about jitter he's seeing in MIDI output:
>>>>>> 	http://www.atari-forum.com/viewtopic.php?f=51&t=32344
>>>>> As a MIDI jitter testing experiment, try the following sound options:
>>>>> --sound-buffer-size 10
>>>>> --sound-sync true
>>>>> These options affect emulation rate, and may improve the jitter.
>>>> 
>>>> Hi
>>>> 
>>>> I'm not sure this would help ; for midi output, you'd want as realtime possible behaviour, which I think is better achieved when emulation speed is not audio driven but using usleep in the main loop.
>>>> In that case if MFP expects a timer to last 1.39 sec for example under STF, then Hatari should take also exactly 1.39 sec.
>>>> 
>>>> Plus, MIDI programs don't necessarily use the YM2149 chip, so you would have no audio data to sync with (except playing empty audio buffers).
>>>> 
>>>> Put another way, I have more trust in usleep precision in that case than in syncing with an audio driver whose latency might vary depending on output sample rate or buffers size :)
>>>> 
>>>> Nicolas
>>>> 
>>>> 
>> 
>> 
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