Es geschah am Wednesday 29 October 2008 als Chris Cherrett schrieb: > When you say 3 engine instances being 3 audio output devices, I get a > bit confused. Are you saying that if you create 3 audio output devices > Fantasia, that would create 3 sampler engine instances each with it's > own settings?
Exactly. It works like this: when you select an audio output device for a sampler channel, the sampler internally connects the respective audio output device with the respective sampler channel and in this situation it will check in a map, if there was already an engine instance for this audio device created. If yes, it will use the same engine instance. If there's no engine instance stored in the map for the given audio output device, then a new engine instance will be created and stored in the map, so next time the audio device is connected to another sampler channel, it will use the same engine instance. Why do we create a separate engine instance for each device? Because usually each audio device is a separate independent thread. And most parts of the engine instance actually run by that thread of the respective audio device. This might sound like a suboptimal implementation. But everything has its pros and contras. Of course you could also implement it in a way that every audio device uses one and the same engine instance. But in this case we would have to make use of synchronization techniques which would decrease performance and / or even harm RT stability. Downside of current solution is that we waste more memory, because each engine instances needs a certain amount of memory on its own. And keep in mind, that every engine instance also has its own disk thread responsible for streaming large samples from disk. The big advantage however is that people can currently already make use of multiple CPUs / CPU cores by creating one audio device (e.g. multiple jack audio output devices, using jackdmp) for each CPU / core. CU Christian ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Linuxsampler-devel mailing list Linuxsampler-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxsampler-devel
