On Mon, Jul 15, 2002 at 01:29:38PM -0400, Paul Davis wrote: > >as i said above, nice work, and nice that someone does this. > >i tried yesterday your mmap implemantation and at least get it to work > >somehow, but im right that: > > > >outbuffer = (area->addr + (area->first + area->step * (offset)) / 8); > > > >returns only a pointer to the buffer? i have to do: > > > > memset(outbuffer, 0, frames_transmit); > > memcpy(outbuffer, data, frames_transmit); > > > >to really wright data to the buffer. i get also some kind of fragments > >staying in buffer if i guess one 'frames_transmit' is smaller than the > >written before or/and if its not aligned to fragment_size, a funny > >effect, but im currently don't know how to clean it up. > > forget all this and use snd_pcm_mmap_copy_areas.
thanx, i finally managed to get 'clear' sound using memcopy -> outbuffer but the problem is if i try to transfer it in 'big' chunks my app segfaults at outbuffer = (area->addr + (area->first + area->step * (offset)) / 8);. not always, but randomly on some parts while playing soundfiles. if i split it in smaller parts it works but it seems that some samples were skipped or remainig in the buffer, causing this fragmented sound. i dont know, maybe my memory is to slow or i have bad memory, if this is the problem then this mechanism is a good memory-checker ;) anyway. how does snd_pcm_area_copy() work? are there any sample-implementations? by a quick look through jack-alsa-driver-src (ca. 1 week old cvs) it seems to use a similar mechanism as above. > > forget all that and use ... well, you know ;) > yes, i have also a jack-plugin in pipe and already did a kind of 'sounding' prototype but cause the app uses push&write method i thought that i have to establish another buffer in it for safe reading. im now stucking on this buffer thing. i get data also only in plain int's so this will be probably another problem. -- regards ____- joy ________/\---------%%%___________----------- webcast every sunday 2000 cest at pingfm.org pgp key at: x-hkp://wwwkeys.de.pgp.net
