Linux-audio-dev

linux-audio-dev@lists.linuxaudio.org

2 participants
7447 discussions

by Ralf Mardorf

I once did a MIDI extension for SpeechBasic to program a real time MIDI sound sampler on BASIC for the C64, for example $1810 LDA $DEO6 $1813 LSR $1814 BCC $1810 $1816 LDA $DE07; read MIDI event byte, usually followed by RTS This are 6 bytes of code, to get a MIDI data byte from the UART. I did an experiment by the signature that makes Adrian going wild. Some lines for a signature are spam and I do agree. How many lines of code are used by ALSA MIDI to do the same? Lets say not per USB, but PCI. I wonder if MIDI on Linux could become better and if audio could need less resources when for Linux audio and MIDI, the concept might vary to the usual Linux concept. Some very elaborate Mac and Win audio apps do not need much resources or much bytes. I hope at least one person would understand that I'm not nagging. I try to understand Linux code, but it's very long and hard to understand, not comparable with the 4 lines above or even not comparable to longer code for professional Atari sequencers. Is there really a reason, I might not understand, to make Linux audio that complicated? Please, I guess some will write that I'm the only one having issues with ALSA MIDI and JACK, but c'mon ;) ... Cheers! Ralf PS: Latest ALSA MIDI latency tests fortunately did show that USB most times is useless, see also the 64 Studio lists archives, but PCI MIDI most times seems to be very good. Perhaps, if you should agree, there could be an advice on Linux audio web sides to prefer PCI MIDI.

14 years, 3 months

MIDI jitter - Today for 4 of 4 tests my USB device did pass all tests with success

by Ralf Mardorf

On Mon, 2010-07-05 at 10:15 +0200, Ralf Mardorf wrote: > -------- Forwarded Message -------- > From: Ralf Mardorf <ralf.mardorf(a)alice-dsl.net> > To: Clemens Ladisch <clemens(a)ladisch.de> > Cc: Linux Audio Developers <linux-audio-dev(a)lists.linuxaudio.org> > Subject: MIDI jitter - Today for 4 of 4 tests my USB device did pass all > tests with success > Date: Mon, 05 Jul 2010 10:14:21 +0200 > I'm very sceptic regarding to the ALSA MIDI latency test, OTOH the PATA > might have caused 7 ms and IIRC 19 ms too and visually interpretation > might mistake because it's hard to find the start of waveforms in the > noise. I guess (don't know), that 7 ms and 19 ms are caused by a broken HDD, but when I did the visually test the HDD wasn't broken, I did it a long time ago. So the visually test around 4 ms and ALSA MIDI latency test around 4 ms from today might be correct results for my computer and at least when I got 4 ms for the visually test, the audible result was unusable for music, anyway, I still have got some hope. To be continued ASAP.

14 years, 3 months

Re: [LAD] [Fwd: Re: No nagging, a serious question]

by Ralf Mardorf

On Sun, 2010-07-04 at 22:14 +0100, Dan Mills wrote: > You could probably hack a multi serial port card to do multiple midi > ports (Change the rock to give a suitable divider for 31250 baud > (4MHz?), add current loop interfaces)... If one is fine with programming on Linux ;).

14 years, 3 months

How to find out if denormals are zero?

by Stefan Westerfeld

Hi! I am trying to fix a problem in beast, where an algorithm (subnormal cancellation and the associated unit test) will work on "normal" computers, but not on AMD64, because denormals are treated as zero on this platform with the compiler options we are using (-ffast-math and others). So ideally I need a snippet of code (maybe assembler) that will just return whether the processor/platform will have subnormals, like on x86, or not, like on AMD64, by querying the processor status registers. Is there some code around for this? Cu... Stefan -- Stefan Westerfeld, Hamburg/Germany, http://space.twc.de/~stefan

14 years, 3 months

pointer to python/numpy audio code

by fons＠kokkinizita.net

Hello all, A few days ago someone posted a pointer to some python/numpy audio related code. I wanted to keep this message and have a look at it later, but my fingers were too quick... And I don't find that message in the archives (it could be on LAU as well). If anyone still has that message, please send me a copy ! TIA, -- FA O tu, che porte, correndo si ? E guerra e morte !

14 years, 3 months

Re: [LAD] [Vala] Vala: JACK Audio Binding

by Harry Van Haaren

Cheers for the reply & the commit! Its a help anyway, I was at 12 errors, now down to 6 errors. (+ 5 warnings). All the errors seem to be of the same kind. (Something due to accessing array[2] ?) I've never written a .vapi and dont really understand all the fancy tricks you do... So best job is probably to post the error output after running the command.. command: valac --pkg jack main.vala // my main.vala is just a single printf statement, no JACK code jack.vapi:48.36-48.44: error: syntax error, no expression allowed between array brackets public int get_aliases(ref string[2] aliases); ^^^^^^^^^ jack.vapi:48.36-48.44: error: syntax error, no expression allowed between array brackets public int get_aliases(ref string[2] aliases); ^^^^^^^^^ jack.vapi:270.41-270.47: error: syntax error, no expression allowed between array brackets public void get_read_vector(ref Data[2] vec); ^^^^^^^ jack.vapi:270.41-270.47: error: syntax error, no expression allowed between array brackets public void get_read_vector(ref Data[2] vec); ^^^^^^^ jack.vapi:271.42-271.48: error: syntax error, no expression allowed between array brackets public void get_write_vector(ref Data[2] vec); ^^^^^^^ jack.vapi:271.42-271.48: error: syntax error, no expression allowed between array brackets public void get_write_vector(ref Data[2] vec); ^^^^^^^ On Sat, Jun 26, 2010 at 10:25 PM, alberto colombo <vala(a)albx79.it> wrote: > Hello, > > I created a bug to track progress on Jack bindings: > https://bugzilla.gnome.org/show_bug.cgi?id=576777. I have just committed > the latest version I had on my HD (dated November 2009), which should > fix quite a few bugs compared to the version in that email. > > Please note that I didn't have the means or the time to test all the > bindings, therefore expect some memory errors on some functions I > haven't used. It gives plenty of warning now (it should be updated for > vala 0.9), but it should compile. > > Also, the binding are for version 0.116. If you need features from > 0.118, they'll have to be added. > > Regards > Alberto > > On Sat, 2010-06-26 at 16:04 +0100, Harry Van Haaren wrote: > > Hey all, > > > > I'm learning Vala at the moment, primarily with the intention to develop > > apps > > which support JACK audio output. I'm gonna work towards GStreamer based > > audio routing, and JACK Transport to Start/Stop my app. > > > > For the while, I hope to have a play around with JACK using Vala. So I > went > > looking for bindings and found the following: > > http://www.mail-archive.com/vala-list@gnome.org/msg02266.html > > > > I've read the replies, installed Jack.vapi into /usr/share/vala/vapi > > but I cant seem to get rid of some certain errors whenever I compile. > > > > Are others using this binding successfully? > > Any tips / info I should know about when using Jack & Vala? > > Cheers, -Harry > > _______________________________________________ > > vala-list mailing list > > vala-list(a)gnome.org > > http://mail.gnome.org/mailman/listinfo/vala-list > > >

14 years, 3 months

Vala: JACK Audio Binding

by Harry Van Haaren

Hey all, I'm learning Vala at the moment, primarily with the intention to develop apps which support JACK audio output. I'm gonna work towards GStreamer based audio routing, and JACK Transport to Start/Stop my app. For the while, I hope to have a play around with JACK using Vala. So I went looking for bindings and found the following: http://www.mail-archive.com/vala-list@gnome.org/msg02266.html I've read the replies, installed Jack.vapi into /usr/share/vala/vapi but I cant seem to get rid of some certain errors whenever I compile. Are others using this binding successfully? Any tips / info I should know about when using Jack & Vala? Cheers, -Harry

14 years, 3 months

basic MIDI note-on/note-off questions

by James Morris

Hi, I keep getting surprised at some of the most basic problems I run into... This time, processing order. 1) Notes of zero duration? Are these legal MIDI? Do I send a note-on with simultaneous note-off? Or should they simply be ignored? 2) note x ending simultaneously with note y beginning For example, a sequence of eighth notes, each an eighth in duration. As far as processing of these events goes, which should be processed first? Cheers, James.

14 years, 3 months

Jack latency handling (Re: Software for recording digital audio?)

by Kjetil S. Matheussen

Robin Gareus: > > > > 0.49 has this feature implemented. Use the "-jt" option. > > > > It should be sample sync, > > Almost. It does not yet compensate for port-latency. It is important for > both effects that introduce latency as well as to keep physical I/O in > sync with apps. > > see jack_port_get_latency() and jack_port_get_total_latency() > at http://jackaudio.org/files/docs/html/group__PortFunctions.html > Thanks for the info! I also wonder, does jack compansate for latency when it mixes the outputs from ports (i.e. when several output ports are connected to a jack_capture port), so that the sound is in sync? > > but I'm not sure whether the last > > block (the one that received a stop message from jack transport) > > should be recorded? For now it's recorded. If that's wrong, > > I'll fix it in the next release. > > While it's safe to just record it, i don't think it should be. > http://jackaudio.org/files/docs/html/group__TransportControl.html reads: > > jack_transport_stop() [..] takes effect on the _next_ process cycle. > > jack_transport_query() [..] If called from the process thread, pos > corresponds to the first frame of the _current_ cycle and the state > returned is valid for the entire cycle. > > IOW: As soon as the app sees a stopped transport in the process loop it > is exactly at, or already a bit later than the actual end. > Thank you very much. This also confirms what I though was most likely.

14 years, 3 months

Re: [LAD] Software for recording digital audio?

by Kjetil S. Matheussen

On Wed, 23 Jun 2010, Kjetil S. Matheussen wrote: > > Andrew C: >> >> Wow, thanks for the replies guys! >> >> Of the software mentioned here, my biggest wish is for syncability with >> JACK >> transport, so I can send the output of one of the linuxsampler instruments >> to the recording software, hit the play button from inside Rosegarden and >> have a perfectly synced audio copy of one particular instrument output >> which >> I can then drop back into the sequencer timeline and continue with another >> section of the song, thereby freeing up system resources. >> >> Of course, this rules out jack_capture I'm afraid! >> > > Sorry, I got this feature request about 4 years ago, but haven't > implemented it. It should only be about 10-20 extra lines of > code. I'll do it very soon. > 0.49 has this feature implemented. Use the "-jt" option. It should be sample sync, but I'm not sure whether the last block (the one that received a stop message from jack transport) should be recorded? For now it's recorded. If that's wrong, I'll fix it in the next release.

14 years, 3 months

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Linux-audio-dev