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From: S. C. C. <s_c...@ho...> - 2016-05-04 16:46:50
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I had a student send me a project where LinuxSampler was not rendering audio when mixing the project down to MP3. I decided to investigate and discovered that I can reproduce the issue. It seems to be related to LinuxSampler re-loading its instruments when project mix down begins. I made a video demonstrating this bug here: https://youtu.be/ZdEY9G21FPo Anybody know what might be going on here? -~Chris |
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From: Christian S. <sch...@li...> - 2016-05-09 15:48:32
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On Wednesday, May 04, 2016 11:46:41 S. Christian Collins wrote: > I had a student send me a project where LinuxSampler was not rendering > audio when mixing the project down to MP3. I decided to investigate and > discovered that I can reproduce the issue. It seems to be related to > LinuxSampler re-loading its instruments when project mix down begins. I > made a video demonstrating this bug here: https://youtu.be/ZdEY9G21FPo > > Anybody know what might be going on here? Not sure whether that's really a bug of the sampler. I am frequently using the VST plugin version of the sampler with Cubase and I never encountered that it would reload anything if I start to bounce a song to an audio file. Usually the respective sound is loaded by the sampler (plugin) when you open a song in your DAW, but not when you export the song to an audio file. Are you using a MIDI map with LinuxSampler and changing the sound with MIDI program change or are you rather loading the sound explicitly from a specific file? Have you tried another DAW application? CU Christian |
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From: S. C. C. <s_c...@ho...> - 2016-05-09 20:41:04
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On 05/09/2016 10:50 AM, Christian Schoenebeck wrote: > On Wednesday, May 04, 2016 11:46:41 S. Christian Collins wrote: >> I had a student send me a project where LinuxSampler was not rendering >> audio when mixing the project down to MP3. I decided to investigate and >> discovered that I can reproduce the issue. It seems to be related to >> LinuxSampler re-loading its instruments when project mix down begins. I >> made a video demonstrating this bug here: https://youtu.be/ZdEY9G21FPo >> >> Anybody know what might be going on here? > Not sure whether that's really a bug of the sampler. I am frequently using the > VST plugin version of the sampler with Cubase and I never encountered that it > would reload anything if I start to bounce a song to an audio file. Usually > the respective sound is loaded by the sampler (plugin) when you open a song in > your DAW, but not when you export the song to an audio file. > > Are you using a MIDI map with LinuxSampler and changing the sound with MIDI > program change or are you rather loading the sound explicitly from a specific > file? No MIDI program changes are involved. I'm simply loading the Maestro Concert Grand <http://sonimusicae.free.fr/matshelgesson-maestro-en.html> using the Fantasia interface that comes up when opening the VST GUI. > Have you tried another DAW application? Yes. Here are the results: First, a couple notes: * My ASIO driver is only available at 48 KHz, so that is the rate all my DAWs are running at. * Here is the MIDI file <https://dl.dropboxusercontent.com/u/8126161/Blue%20Storm.mid> that I have been using for this test (student composition, please do not share). Set the DAW to 70 BPM for correct tempo. Test results: * *Acoustica Mixcraft 7 x64/x86 + LinuxSampler x64/x86:* mixing down to 44.1 or 48 KHz audio = LinuxSampler reloads its samples at beginning of mixdown, audio renders as silence. * *SONAR x64 + LinuxSampler x64:* mixing down to 44.1 or 48 KHz audio = samples are not re-loaded, audio renders normally * *Reaper x64 + LinuxSampler x64:* mixing down to 48 KHz audio works as expected, but mixing down to 44.1 causes LinuxSampler to reload its samples, and the audio renders as silence. So that makes two out of my three DAWs that run into this problem. I actually work for Acoustica, so if you have any specific questions about what messages Mixcraft is sending to the plugin when mixing down, let me know and I can pass them on to the developer. -~Chris |
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From: Christian S. <sch...@li...> - 2016-05-10 10:49:32
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On Monday, May 09, 2016 14:39:13 S. Christian Collins wrote: > > Have you tried another DAW application? > > Yes. Here are the results: > > First, a couple notes: > > * My ASIO driver is only available at 48 KHz, so that is the rate all > my DAWs are running at. > * Here is the MIDI file > <https://dl.dropboxusercontent.com/u/8126161/Blue%20Storm.mid> that > I have been using for this test (student composition, please do not > share). Set the DAW to 70 BPM for correct tempo. > > Test results: > > * *Acoustica Mixcraft 7 x64/x86 + LinuxSampler x64/x86:* mixing down > to 44.1 or 48 KHz audio = LinuxSampler reloads its samples at > beginning of mixdown, audio renders as silence. > * *SONAR x64 + LinuxSampler x64:* mixing down to 44.1 or 48 KHz audio > = samples are not re-loaded, audio renders normally > * *Reaper x64 + LinuxSampler x64:* mixing down to 48 KHz audio works > as expected, but mixing down to 44.1 causes LinuxSampler to reload > its samples, and the audio renders as silence. The sample rate used is probably not the actual problem. It is noteworthy that the sampler must cache additional sample points of certain samples in case the DAW increases the audio period size. That is unavoidable and takes a moment. And during offline (non real-time) audio rendering DAWs usually switch to a much bigger period size than the DAW is using during regular real-time operation while you are editing the song etc. A DAW usually does so by default (on offline renders) to decrease the CPU load while rendering and thus to decrease the time it takes to finish rendering the entire song. Because the lower the audio period size, the higher the CPU load will be and thus a higher period size means a lower CPU load. However LinuxSampler only caches additional sample points when the period size is increased, not when being decreased, nor when being increased back to a period size it had before. That means the second time you start the audio mixdown it should work as expected. Correct? CU Christian |
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From: S. C. C. <s_c...@ho...> - 2016-05-11 18:11:53
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On 05/10/2016 05:51 AM, Christian Schoenebeck wrote: > <snip> > The sample rate used is probably not the actual problem. It is noteworthy that > the sampler must cache additional sample points of certain samples in case the > DAW increases the audio period size. That is unavoidable and takes a moment. > And during offline (non real-time) audio rendering DAWs usually switch to a > much bigger period size than the DAW is using during regular real-time > operation while you are editing the song etc. A DAW usually does so by default > (on offline renders) to decrease the CPU load while rendering and thus to > decrease the time it takes to finish rendering the entire song. Because the > lower the audio period size, the higher the CPU load will be and thus a higher > period size means a lower CPU load. > > However LinuxSampler only caches additional sample points when the period size > is increased, not when being decreased, nor when being increased back to a > period size it had before. That means the second time you start the audio > mixdown it should work as expected. Correct? Repeated mixdowns all fail in the same way (in both Mixcraft and Reaper). It is interesting that the samples get reloaded both at the beginning of the mixdown and also at the end. So each mixdown causes LinuxSampler to reload the samples twice. -~Chris |
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