so is VST support pretty buggy?

I’ve been using Ardour with a real client in my meager piecemeal studio with pretty good success. I’m excited for this project’s future.

However, ever since I compiled 2.10 with VST support, Ardour has misbehaved pretty badly. Nothing mission critical like corrupting sessions, but nonetheless annoying. Chances are some of these things are the results of misconfiguations on my system or are known bugs (or ar not Ardour-related), but I figured I’d throw them out to see if anyone has any advice – even if that advice is “shut up and wait until the next release”:

-Random crashing (together with Jack); usually when adding tracks or opening a plugin for editing, but I think at other times too. (actually this happened occasionally pre-2.1/pre-vst also)

-Tracks randomly shuffling their order, when reloading a session or (this is the weird one) when checking/unchecking any track’s visibility. One session got so bad I had a tough time finding the tracks I was looking for (it was a 30+ track session).

-Muting/Soloing logic behaving very strangely; Tracks being silent except when soloed (or being silent when soloed), no audio output at all when certain plugins are enabled (sometimes only for certain sections on the timeline), track and bus soloing/muting just generally not doing what you’d expect.

So anyway, a couple of negatives, but overall my experience has been overwhelmingly positive. Keep up the great work… someday I’ll dust off my programming hat and join development. A FOSS DAW is a project that needs to succeed.

Oh and my setup is: dual-AMD MP2800, 1.2GB ram, UbuntuStudio Gutsy (realtime kernel), Layla3G audio interface.

((As a tiny tiny side note, being that I am using this software in a semi-real studio with paying clients, I thought it appropriate to subscribe; but it doesn’t show that I’m subscribed in my profile. Is there any way I can fix that? Should I just unsubscribe and resubscribe? I suppose it’s not really a big deal.))

Aah, I’m just now reading the page on generating backtraces, I’ll try my best to produce some. I should have explored this site more thoroughly before posing.

Here’s another one: Anyone have any idea why the audio for the whole session would cut out when one particular track has no audio? As soon as the region on that track begins playback, the whole session plays back, but not otherwise. When I move or stretch the region forward or backward in time, the audio for the whole session follows; it’s as if that region boundaries are controlling the muting on the whole session. When there is no audio, certain tracks when soloed will produce sound, others will not; still others become muted when soloed. Should I just ditch VST support? Anyone know if that’s what might be causing this oddness?

I would think it unlikely that VST support is the root cause of your problems. Have you carefully checked the routing ? That’s the first thing that comes in mind.

I use ardour 2.0-ongoing with VST support. The only odd thing I came across when it comes to muting or soloing is with busses. When I mute a bus, as expected the whole bunch of tracks connected to that bus are silenced during playback. But when I solo the bus, I hear the whole session as if there was no soloing at all. Apart from that, no, I cannot say I experienced your issues.

wait a sec! the shuffling … yeah, I noticed that. If I enable / disable a group in the mixer window, tracks will be reshuffled. Pretty annoying when you have zillions of tracks …

  1. you cannot properly debug ardour if it is built with VST support

  2. VST support will always be buggy. Think about what we are trying to do: load and run shared code objects written for another operating system within an application written for Linux. There is no way (sort of waiting 10 more years) for this to ever be considered reliable.

  3. the “random reshuffle” of track order is a bug we’re aware of but don’t fully understand the cause. it is related to code that was added a month or two ago that allows you to sync the order of tracks in the editor and mixer window (or not).

  4. the “cut out” problem is almost certainly caused by VST issues.

Thanks guys.

Ultimately I will probably ditch VST support either way. I’m working on a studio that will feature (mostly) outboard mixing and effects, a sort of hybrid between the new free audio world and vintage gear. Plus as I get more comfortable with the ladspa stuff that’s out there, I’ll need vst less and less. I do wish there were two things though: a good ladspa multi-band comp, and a good convolution reverb.

I think I narrowed down the soloing thing a bit… I think you’re right Paul, because it seems to be related to plugins, though not necessarily VST ones. On the tracks whose solo logic is misbehaving, I found I can often bypass the effects on the track or else re-load the plugin (delete/re-instantiate) and things go back to normal. I have noticed what you mentioned also, Thorgal, that when soloing a bus, all it does is mute the other busses; rather than also muting all the channels that might be connected directly to the master bus or another downstream bus. I work around it by routing all the audio tracks into busses, and the busses into the master mix. For example, I’ll have a drum bus, a vox bus, a reverb bus, and an instruments bus, even if I could have fed the instruments straight into the master.

aha, that’s the catch : soloing bus only affect other busses. So somehow the code makes a distinction between tracks and busses when it comes to the solo function. Is it on purpose ?

thorgal, yes it is on purpose.

it may change in the future, but not until several other deep architectural changes.

Ever since I “upgraded” to ardourvst I have experienced similar problems to the ones posted above. And on top of that, I even have problems in projects that haven’t even seen a vst plugin (but running in ardourvst anyway).

The most annoying one, apart from a few crashes, is that sometimes a ladspa plugin will start to act strangely, as in suddenly popping loudly and muting its track completely without actually having the mute button engaged. Bear in mind the pop is reflected on the max level as something like 30 or even hundreds of dbs if remember I well, and I even saw the “nan” symbol in there. The plugins that I have seen misbehaving this way are multiband eq and SC4, although the compressor will not pop, but cut the signal as if the threshold level was never reached. Bypassing them will unmute the track. Sometimes deleting and adding them again several times restores everything to normal. But a simple modification of a parameter in a plugin in a completely different track can trigger this again in the original misbehaving track.

It certanly looks VST related, as least on my system, and it seems the routing between plugins is screwed.

Any ideas on what can be done about it?

Samus, that’s interesting because I’ve been seeing similar behaviour on mine. I uninstalled my LADSPA plugin rpms and built them from source and the problem seemed to go away,although I’ve not tested it very thoroughly.