Linux-audio-user August 2010

linux-audio-user@lists.linuxaudio.org

118 participants
112 discussions

by Martin Homuth-Rosemann

Beginn der weitergeleiteten Nachricht: Datum: Sun, 1 Aug 2010 12:40:14 +0200 Von: Martin Homuth-Rosemann <linuxaudio(a)cryptomys.de> An: James Morris <james(a)jwm-art.net> Betreff: Re: [LAU] Connie, an organ template for JACK Am Sat, 31 Jul 2010 23:41:52 +0100 schrieb James Morris <james(a)jwm-art.net>: > ... > Same problem as Foo YC 20, a lack of volume envelope. The clicks > resulting from sudden jumps in sample amplitude make it unusable for > me. > > Cheers, > James. Hi James, I do apply a simple envelope to the keys to reduce the awful clicking - it's done in connie_main.c in rt_process_cb(), starting at line 370: --- 8< --- // process the keys (attac/decay/release), do stop mixture if ( ++timer > tg_sample_rate / 4000 ) { // 4 kHz -> every 250us timer = 0; int *p_vol = tg_vol_key + LOWNOTE; // tg_vol_key[note] int *p_raw = midi_vol_raw + LOWNOTE; // ramp the midi volumes up/down to remove the clicking at key press/release for ( int note = LOWNOTE; note < HIGHNOTE; note++, p_vol++, p_raw++ ) { if ( *p_vol < *p_raw ) { if ( tg_percussion ) // attack immediately up to 0..256 (*p_vol) = 256 * tg_percussion; // then decay to 64 (0..48 ms) else (*p_vol) += 8; // attack quick up (2 ms) } else if ( *p_vol > *p_raw ) { (*p_vol)--; // decay/release slow down (16 ms) } } // for ( note ) ... --- 8< --- If you change the line 382 (*p_vol) += 8; // attack quick up (2 ms) to (*p_vol) ++; // attack slow up (16 ms) you'll get a slower attac. But a soft click will be leftover because your envelope is a ramp (i.e. non bandlimited frequency range and aliasing...) and it's only integer range 0..64. I chose the quick up / slow down because if you press a key the starting sound will "mask" the click and you'll get a more direct feeling - no delay between key action and playing sound. It decays more slowly because there is no "masking" (silence). Feel free to improve this part to your needs. If it's still unusable for you it willbe possible to use a more complex envelope (e.g. bandlimited step) or shorter time steps - but this will cost more cpu because at the moment the keys were calculated every 250µs only (-> sample rate 4KHz) to reduce cpu load. Ciao Martin

13 years, 8 months

Fwd: [Fluxus] Live Coding Performance in Brussels: call for participation]

by rosea grammostola

---------- Forwarded message ---------- Hi all, Our Brussels-based organization, iMAL, is partner of the *Media Facade Festival Europe* starting 27th of August in 7 cities (Helsinki, Berlin, Linz, Budapest, Madrid, Liverpool and Brussels). see: http://www.imal.org and *http://www.mediafacades.eu*<http://www.mediafacades.eu/> On the *3rd of September*, there is a *Live Coding Performance* initiated by Kibu ( *http://www.kitchenbudapest.hu/en* <http://www.kitchenbudapest.hu/en>)that should take place in every city and being live streamed so that local coders could respond to other coders inputs. see: * http://www.mediafacades.eu/node/125* <http://www.mediafacades.eu/node/125> We are still looking for live coders to take part in the Brussels node of the event. If you are interested and located in or near Brussels (Belgium, Nederland, Germany, France), *send your application* to: marie-laure(a)imal.org *before August 10th.* * * Feel free to forward this call to potential interested live coders! best, Marie-Laure Delaby project manager & coordinator iMAL- Center for digital cultures and technology http://www.imal.org +32 2 410 30 93

13 years, 8 months

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Linux-audio-user August 2010