[CM] Fwd: Linux/Midi Test

[lieven moors]

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);
>>
>> }
>>
>>     
>
>