From: Tobiasz K. <un...@gm...> - 2010-05-16 10:55:44
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Hi, I'am a LMMS 0.4.6 user under Ubuntu Studio 9.10 AMD-64 There is a problem with volume automation - at very low sounds it causes some clicks. Here is my track, you should hear it at the beginning when the bass is fading-in (it is a really low sound - better use headphones): http://www.mediafire.com/?jn2zdmnzign. Here is the source file if you want to see it: http://www.mediafire.com/?hjn4mjm31d4. Hope that helps improving LMMS :) You guys are doing great job! -- Tobiasz 'unfa' Karoń |
From: Paul G. <dr...@gm...> - 2010-05-28 19:32:39
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I wonder how most DAWs handle this. LMMS only performs automation once, before each buffer is processed. for pre-recorded automation (and automation track) it is theoretically possible to do it sample-exact, since the values are known in advance. For live tweaking, I dont know what to do.. -Paul 2010/5/17 Louigi Verona <lou...@gm...>: > I have reported clicking on low values as well. Would be good if it is > fixed. > > I also tried doing rapid volume changes, like with an LFO, and it would also > generate crackling. > I dunno if its the same issue. > > Louigi. > > ------------------------------------------------------------------------------ > > > _______________________________________________ > LMMS-devel mailing list > LMM...@li... > https://lists.sourceforge.net/lists/listinfo/lmms-devel > > |
From: Stefan F. <st...@sf...> - 2010-05-29 10:02:53
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Hello Paul (and all the others)! > I wonder how most DAWs handle this. LMMS only performs automation > once, before each buffer is processed. > uhh,... ... depending on how this is done, it may be OK (but not good, however) or it may be absolutly unaccaptably bad... > for pre-recorded automation (and automation track) it is theoretically > possible to do it sample-exact, since the values are known in advance. > For live tweaking, I dont know what to do.. > Well, I'm not sure what you try to distinguish with this. But performing sample-exact calculations of the audio-automation (and the envelopes) is possible in realtime (at least on the sample-rates used for realtime-preview and -playback), too, nowadays... So I maybe don't get the point... Of course you may not want to save the automation-data for every single sample (this would be lots of data...), so usually the audomation-data would be saved only with 100Hz to 500Hz and interpolated sample-exactly inbetween. Without having done further test-renderings of the output of lmms and without having looked deeply at the source-code of these... Yes, any block-wise calculations of volumes can be the source of a multitude of different click-sounds. Knowledge of this fact goes back to the days of simple audio-trackers (like soundtracker or future-composer and such sorts of programs). These had a time-base of 50Hz or 60Hz for historic reasons, so any sort of audio-automation (increasing the volume on every "tick") was prone to clicks with a frequency of either 50Hz or 60Hz. To come arround this, at least sample-exact linear volume-ramping was used inbetween the automation-steps... This arises some questions: 1. Is lmms doing these block-wise calculations only(!) for audio-automation or is it utilizing this sort of calculation even for audio-envelopes? I ask because I have these click-sounds not only when using audio-automation but also when using just envelopes... and sometimes even without using any of these. 2. May it be the case that for some reason uninitialized variable-values leak into this process? I noticed some rather strange clicks in the audio-output of at least the current master I can't explain otherwise. They seem to be completely random and completely unrelated to the actual audio. But they seem to happen before the sinc-downsampler (oversampling). 3. Is there some sort of ramping used? Linear approximation or anything better to soften the edges of the blocks? Just to clarify this: I have these strange click-sounds not only when using envelopes and or audio-automation. It's just that they appear to be a lot stronger and a lot more frequent when using envelopes and or audio-automation. These do happen so often for me, that currently I can't use lmms for any serious production. Not even for short ones (radio-jingles or so...). :-( cu Stefan PS: I may (or may not -- depends on my other workload), set up some simpe test-files and render these with different settings. This might or might not give someone a clue where to look for these clicks... If so, may I post these files (and their output, as highly compressed OGG-files) to this list or may I use some ftp-space for it? Just asking what would be the preferred variant? > -Paul > > 2010/5/17 Louigi Verona <lou...@gm...>: > >> I have reported clicking on low values as well. Would be good if it is >> fixed. >> >> I also tried doing rapid volume changes, like with an LFO, and it would also >> generate crackling. >> I dunno if its the same issue. >> >> Louigi. >> >> ------------------------------------------------------------------------------ >> >> >> _______________________________________________ >> LMMS-devel mailing list >> LMM...@li... >> https://lists.sourceforge.net/lists/listinfo/lmms-devel >> >> >> > |
From: Tobias D. <tob...@gm...> - 2010-05-29 10:14:49
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Hi, Am Samstag, 29. Mai 2010, um 12:02:18 schrieb Stefan Fendt: > Well, I'm not sure what you try to distinguish with this. But performing > sample-exact calculations of the audio-automation (and the envelopes) is > possible in realtime (at least on the sample-rates used for > realtime-preview and -playback), too, nowadays... So I maybe don't get > the point... Doing that for all controls still is not feasible. Changing some parameters sometimes causes a complete recalculation of a model and thus is not realtime safe. I however agree with that it should be possible with simple controls like volume, panning etc. > Without having done further test-renderings of the output of lmms and > without having looked deeply at the source-code of these... Yes, any > block-wise calculations of volumes can be the source of a multitude of > different click-sounds. In this case it is. Furthermore this depends on the resolution of the according control. At least in older versions we used integers [0:100] for volume which is far too coarse. > 1. Is lmms doing these block-wise calculations only(!) for > audio-automation or is it utilizing this sort of calculation even > for audio-envelopes? No, all envelopes and LFOs are sample-exact. > I ask because I have these click-sounds not > only when using audio-automation but also when using just > envelopes... You rather mean, when disabling them? Because then the signal is taken as generated by the generator without any further processing. A simple phase shift could cause discontinuous jumps . > 2. May it be the case that for some reason uninitialized > variable-values leak into this process? I noticed some rather > strange clicks in the audio-output of at least the current master Me too. Not sure whether it has to do with the new FX mixer. As far as I know the 0.4.x series is not affected by this. Maybe someone should run Valgrind on the master branch version. > 3. Is there some sort of ramping used? Linear approximation or > anything better to soften the edges of the blocks? Currently not - and sometimes unsteady jumps might be desired. I'm not sure what way to go here.. > Just to clarify this: I have these strange click-sounds not only when > using envelopes and or audio-automation. It's just that they appear to > be a lot stronger and a lot more frequent when using envelopes and or > audio-automation. I'm really interested in the proposed test files :-) Toby |
From: Paul G. <dr...@gm...> - 2010-05-29 19:56:44
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Just another thought. Even the plugin technologies (LADSPA and LV2 at least) only support controller values being interpreted once, before the processing of each buffer. So, it would seem that the problem would still exist even if LMMS supported sample exact (or any multiple-values-per-buffer-period granularity). The solution instead lies in the implementation of the plugin. The plugin must internally ramp the controls as needed during the processing. I imagine most properly written plugins already do this. Most LMMS plugins probably do not. Things like the FX-mixer sliders and instrument volume knobs are directly backed by their model and contain no state IIRC. So, LMMS could add a library for interpolation of control values, and we would need to utilize it in the various processing stages. The resolution of the automation events can stay at period boundaries. Another thought: 48000Hz / 1024 samples ~= 50Hz, so, that seems like a reasonable rate to me... Paul On Sat, May 29, 2010 at 6:14 AM, Tobias Doerffel <tob...@gm...> wrote: > Hi, > > Am Samstag, 29. Mai 2010, um 12:02:18 schrieb Stefan Fendt: >> Well, I'm not sure what you try to distinguish with this. But performing >> sample-exact calculations of the audio-automation (and the envelopes) is >> possible in realtime (at least on the sample-rates used for >> realtime-preview and -playback), too, nowadays... So I maybe don't get >> the point... > Doing that for all controls still is not feasible. Changing some parameters > sometimes causes a complete recalculation of a model and thus is not realtime > safe. I however agree with that it should be possible with simple controls > like volume, panning etc. > >> Without having done further test-renderings of the output of lmms and >> without having looked deeply at the source-code of these... Yes, any >> block-wise calculations of volumes can be the source of a multitude of >> different click-sounds. > In this case it is. Furthermore this depends on the resolution of the > according control. At least in older versions we used integers [0:100] for > volume which is far too coarse. > >> 1. Is lmms doing these block-wise calculations only(!) for >> audio-automation or is it utilizing this sort of calculation even >> for audio-envelopes? > No, all envelopes and LFOs are sample-exact. > >> I ask because I have these click-sounds not >> only when using audio-automation but also when using just >> envelopes... > You rather mean, when disabling them? Because then the signal is taken as > generated by the generator without any further processing. A simple phase shift > could cause discontinuous jumps . > >> 2. May it be the case that for some reason uninitialized >> variable-values leak into this process? I noticed some rather >> strange clicks in the audio-output of at least the current master > Me too. Not sure whether it has to do with the new FX mixer. As far as I know > the 0.4.x series is not affected by this. Maybe someone should run Valgrind on > the master branch version. > >> 3. Is there some sort of ramping used? Linear approximation or >> anything better to soften the edges of the blocks? > Currently not - and sometimes unsteady jumps might be desired. I'm not sure > what way to go here.. > >> Just to clarify this: I have these strange click-sounds not only when >> using envelopes and or audio-automation. It's just that they appear to >> be a lot stronger and a lot more frequent when using envelopes and or >> audio-automation. > I'm really interested in the proposed test files :-) > > Toby > > ------------------------------------------------------------------------------ > > > _______________________________________________ > LMMS-devel mailing list > LMM...@li... > https://lists.sourceforge.net/lists/listinfo/lmms-devel > > |
From: Stefan F. <st...@sf...> - 2010-05-30 13:48:30
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Am 29.05.2010 12:14, schrieb Tobias Doerffel: > I'm really interested in the proposed test files :-) > OK, so here we go... ;-) I have done 4 testfiles. Test1 and test2 are identic but test2 uses mixer-channels while test1 just outputs on the master-channel. Same is with test3 and test4. Because we all agree that the blockwise processing of the automation-data is one of the sources of clicks I have intentionally left that out and focussed on the mixer (as Toby suggested)... So, I just tried to verify that the new mixer is the source of the "other" click-sounds. BTW: if you know that the automation is processed blockwise you can circumvent nearly all of the clicks coming out of it,... so I (for the time being) regard this as a feature... not a real bug. On the long term run (at least for volume/pitch/pan-automation) something like the linear-graph-automations blender uses would be a solution, as you can have smooth transitions with them where you want it smooth and you can have discontinuities were you want them either... (Maybe I'll do some Mocup-Graphics to further explain the concept but... not now...). Back to the spurious clicks in the master... At first there are gazillions of compiler-warnings about unused parameters. I'm not sure if they all are harmless... Then I attached two valgrind-runs which show a probable problem of uninitialized data for the WavefileRenderer. But I am pretty sure that this only is the source of the garbage-samples at the beginning of the file. Despite that, valgrind doesn't find uninitialized variables... Most prominent fact: despite that there doesn't seem to be uninited values, the clicks do only occur if the sound is routed to FX-Mixer-Channels instead of the Master-Out. At least I was not able to produce the clicks when just routing everything to the Master-Channel... I hope the attached files are of use for someone... ;-) cu and have a nice (rest of the) weekend! Stefan |
From: Stefan F. <st...@sf...> - 2010-05-17 05:49:40
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Am 16.05.2010 12:55, schrieb Tobiasz Karoń: > Hi, I'am a LMMS 0.4.6 user under Ubuntu Studio 9.10 AMD-64 > > There is a problem with volume automation - at very low sounds it > causes some clicks. Here is my track, you should hear it at the > beginning when the bass is fading-in (it is a really low sound - > better use headphones): http://www.mediafire.com/?jn2zdmnzign. Here is > the source file if you want to see it: > http://www.mediafire.com/?hjn4mjm31d4. Hope that helps improving LMMS > :) You guys are doing great job! hmm,... very, very low bass... you know that it's only a very few Herz above human listening-limits? That would be 20 Hz and your bass is roughly at 30Hz... I bet there's plenty of people arround whom cannot hear that sound neither on a good loudspeaker/amp combo nor with headphones... Despite that, the "clicks" do sound like what I try to fight out of the git-version (where it is much worse)-- but... to date without any success,... cu Stefan |
From: Louigi V. <lou...@gm...> - 2010-05-17 07:19:58
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I have reported clicking on low values as well. Would be good if it is fixed. I also tried doing rapid volume changes, like with an LFO, and it would also generate crackling. I dunno if its the same issue. Louigi. |