[CM] Fwd: Linux/Midi Test

[lieven moors]

And another thing, when selecting high priority,
I do hear sound initially, but it is totally fucked up (timingwise), and 
the process gets killed
finally by the watchdog.

lieven moors wrote:
> I tried the test program with a suprising result.
> The timing sounds rock solid, with normal permissions, and with a 
> duration of 62.5 ms.
>
> P.S.
> When I selected realtime permission, the process was killed by 
> das_watchdog, and I heard nothing.
> (das_watchdog guards for realtime processes that block the system)
>
> William Andrew Burnson wrote:
>> Here is my test program to play back notes in a single JUCE thread to 
>> help detect jitter:
>> http://williamburnson.com/midi-test.tar.gz
>>
>> To use it, follow INSTRUCTIONS (basically, drop 
>> juce_amalgamated.cpp/h into the folder and type make)
>>
>> I tried using snd_seq_drain_output and I didn't notice any difference...
>>
>> ---- Original message ----
>>  
>>> Date: Tue, 11 Aug 2009 15:43:31 +0200 (CEST)
>>> From: "Kjetil S. Matheussen" <k.s.matheussen at notam02.no>  Subject: 
>>> Re: [CM] Fwd: Linux/Midi Test  To: lieven moors <lievenmoors at gmail.com>
>>> Cc: Heinrich Taube <taube at uiuc.edu>, cmdist at ccrma.Stanford.EDU, 
>>> Andrew Burnson <burnson2 at uiuc.edu>
>>>
>>>
>>>
>>> On Tue, 11 Aug 2009, lieven moors wrote:
>>>
>>>    
>>>> I think I might know what the problem is with Juce. I had a look at 
>>>> the
>>>> Juce code myself,
>>>> and it looks like sendMessageNow() is not calling the
>>>> snd_seq_drain_output().
>>>>       
>>> For what its worth, the one time I've written code which sends
>>> midi via alsa, the code calls snd_seq_drain_output as last
>>> operation. I don't remember what I did back then, but this
>>> could definitely be the problem. It sounds likely, at least.
>>>
>>>
>>> static void alsaseq_PutMidi(
>>>                 struct MidiLink *midilink,
>>>                 uint32_t msg
>>>                 )
>>> {
>>>   unsigned int d3=(msg>>8)&0xff;
>>>   unsigned int d2=(msg>>16)&0xff;
>>>   unsigned int d1=(msg>>24)&0xff;
>>>
>>>   unsigned char buffer[3]={d1,d2,d3};
>>>   snd_seq_event_t ev;
>>>   snd_midi_event_t *midi_ev;
>>>   snd_midi_event_new( 10, &midi_ev );
>>>
>>>   snd_seq_ev_clear( &ev );
>>>   snd_midi_event_encode(midi_ev,
>>>             buffer,
>>>             3,
>>>             &ev);
>>>   snd_midi_event_free( midi_ev );
>>>
>>>   snd_seq_ev_set_source(&ev,midilink->port);
>>>   snd_seq_ev_set_subs(&ev);
>>>
>>>   snd_seq_ev_schedule_tick( &ev, radium_queue, 1, 1);
>>>
>>>   snd_seq_event_output(radium_seq, &ev);
>>>
>>>   snd_seq_drain_output(radium_seq);
>>>
>>> }
>>>
>>>     
>>
>>   
>
>