> > > "Hardware mixing" in ALSA terminology refers to the mixing of multiple > > > sound sources from the PC by the hardware. For example, mplayer > > > output and system notification sounds. > > > > Yeah. I suspect (and Mark apparently did, too) that the original > > poster meant to ask about hardware monitoring, which is completely > > different :-) > > > > Explanation here: > > http://ardour.org/manual/recording/monitoring well, i asked about hardware _mixing_, since it is pretty obscure thing, unlike hardware _monitoring_ :) > Is there a commonly understood meaning? I guess I'm uncommonly (or > commonly for me) in the dark about that. that's troo :) > > I stand corrected. Mark was right - these devices do have hardware > > mixing, they just implement it in an odd way, probably to keep the > > interface similar to other OS. > > its not true to say that with ALSA, they support what is commonly > understood as h/w mixing. you cannot do independent open's of several > subdevices and get the output of each subdevice mixed down to the > outputs. > > yes, they do have a very powerful h/w matrix mixer, but it is not > accessible via a series of independent subdevices. it also is not > supported by the ALSA mixer API at this time. > > > you cannot do independent open's of several > > > subdevices and get the output of each subdevice mixed down to the > > > outputs. > > > > This seems a Linux Software Developer centric statement. What does it mean? > > it means that you can have up to N apps all using the same card without > any s/w mixing going on. each one calls snd_pcm_open() which internally > calls snd_pcm_open_subdevice() and assuming the subdevices are not all > busy, it will work. a subdevice is a "stream" that always sends its > signal to the outputs associated with the PCM device, but can be opened > and closed independently. ok. this clarifies things enough. so, if i use only one app (csound), seems like there's no need to care about this hardware mixing thing. thanx again. -- sex, pot, open source!!
