From: Robert J. <spa...@gm...> - 2010-05-10 21:15:04
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Hi, 2010/5/10 Pieter Barendrecht <pi...@re...>: > Wow, so many replies! Thanks guys for spending some of your time on my > problems. > > Ok, I set the Input- and Output Devices of QJackCTL to "Default" again. > My hw:0 is "HDA Intel", hw:0,0 is "AD198x Analog" and hw0,1 is "AD198x > Digital". > I increased the Periods to 3, because my Soundcard is a HDA-Intel > (According to lspci it is "Audio device: Intel Corporation 82801G (ICH7 > Family) High Definition Audio Controller (rev 02)"). > I changed the sample rate to "48000". > > However, when using Ubuntu with the non-RT kernel this still results in > many xrun messages. > By the way, when I start QJackCTL from a terminal, I get these messages: > > Suspending PulseAudio > ** (<unknown>:2883): CRITICAL **: atk_object_set_name: assertion `name ! > = NULL' failed > Just to be clear. My suggestions are just that. It's not certain they improve things, drivers improve, distros produce different errors. As for running the non-rt kernel, it may be interesting from an analysis perspective but it is likely not an option for production. > -------------------------------------------------------------------- > > Ok, on to the RT kernel. When I start QJackCTL (same settings as above) > from the terminal I get the same messages, however unlike the normal > situation, there are no xrun reports. > When I try to open the .SF2 file, the "Jack Zombified" messages appear > in the Terminal in which I started MusE. Furthermore, MusE popups a > dialog (link: http://redpanda.nl/JackZombified.png ). Last time I didn't > try the "Restart" button, but I just tried it and after this MusE is > connected to Jack again. There were no xrun messages at all :) Better. But with 512 frame buffers you should not experience this things... > > Because of this I lowered the Frames/Period (in QJackCTL) to 128 which > results in a latency of 8 msec. I don't understand this option > completely, the higher the Frames/Period the higher the precission but > the higher the latency? It's not really a question of precision. Audio programs generally work on sample-buffers. 128 means that the buffer is 128 samples long. Before the audio is sent to soundcard the buffer must be filled. So 128 samples must be produced before the soundcard will get the buffer. This means there is a small delay (latency) before the audio makes sound. It is less stressing for the computer to fill buffers as seldom as possible. So from the computers perspective big buffers are good. But if you need realtime, e.g. you want to hear what you are playing in realtime, then you want the buffers to be as small as possible. When the computer cannot keep up an xrun or zombification will occur, which is what you are experiencing.. ... which reminds me. In recent jack1 there is a parameter to disable zombification. I'm using jack2 at the moment so I can't check the parameter, -Z could that be it? It may help you. > I really need a low latency in order to record some music using the > metronome of MusE. > > Next step was to try out my Roland TD8 Drum Module with Muse. I > installed Hydrogen, and set the Input port to Jack. In MusE, I selected > the Hydrogen In port and recorded some drums using the same MIDI Device > I use for recording keyboards. What exactly are you using Hydrogen for in this scenario? Nothing wrong with using hydrogen but unless you use the sounds there are probably easier ways. > It works, however there are two issues: > > - Sometimes when recording drums, Jack "zombifies" again. After the > "Restart" button it works again, but I lose my recording... Please try and run top (or some derivative, i like htop) in a terminal at the same time as you do the playback. The zombification and drop outs seem like you are running out of CPU, but what is using all the CPU, is it really muse and jack? Don't know if you mentioned the specs of your computer, is it on the slower side? > - When recording or playing back the drums, the samples from Hydrogen > are played back but like only half of them. The sounds are very short > like they stop half way, when I click the drums in Hydrogen itself they > sound much better. Interesting... though I can't for the life of me figure out what it means. something is definitely not right... Oh, could it be that your drum-module sends note-off events and hydrogen silences the drum? There may be a setting in the drum-module to control this behaviour > > I tried to record this using my Mobile Phone, but the quality isn't > good. The first part is the MusE playback, second some random drums in > Hydrogen and again some playback in MusE. http://redpanda.nl/Test.ogg can't really tell but I'll take your word for it. > > Finally, how can I record the result of the music I created in MusE? I > tried to record the "Out" track to a WAV file, but this WAV file appears > to be empty after the recording (although its size is a couple of MBs). That should definitely work, I just tried it to be sure, works here. Please try the Audio->Bounce to file menu alternative, does it really not work? Ah, maybe you are not routing sound through MusE? You mentioned hydrogen, it sends it output directly to jack unless you configure it otherwise. I think you mentioned fluidsynth, MusE has an internal fluidsynth and I think that's the one you meant, but there are several external variants which would behave like hydrogen. > > Thanks again! > Best regards, > > Pieter > > > > > On Mon, 2010-05-10 at 16:50 +1000, Geoff Beasley wrote: >> Pieter this proves that you are running in 1/2 duplex ( playback only!) >> _____________________________________________________________________ >> >> ALSA: Cannot open PCM device alsa_pcm for capture. Falling back to >> playback-only mode >> configuring for 44100Hz, period = 512 frames (11.6 ms), buffer = 2 >> periods >> ALSA: final selected sample format for playback: 16bit little-endian >> _____________________________________________________________________ >> >> In Qjackctl select :- >> >> Interface = ( here, click the > next to the [default] box to see the actual >> names of your installed devices and select your primary soundcard.) >> >> Input device = default >> Output device = default >> Sample rate = 48000 >> Periods/Buffer = 3 (hda-intel) or 2 (most other cards) >> >> and see what happens. >> >> hth >> >> g > > > > ------------------------------------------------------------------------------ > > _______________________________________________ > Lmuse-user mailing list > Lmu...@li... > https://lists.sourceforge.net/lists/listinfo/lmuse-user > |