On Jul 24 11:52, Gerd Spalink wrote: > After reading the discussion, I agree to give archetypes a try to fix dup. > I'll keep a copy of the linked list solution as a reference. > > Regarding the sharing/dup stuff, there are three different things to > consider: > > 1. Independent processes > > They should be able to open as many /dev/dsp devices as the hardware > supplies. On my hardware (AC97 on-board sound), > I have an arbitrary number of playback devices. > All output is converted to a common sampling rate and added somewhere > inside the win32 mmsystem. It ends up on the same set of speakers. > I only have a single recording device. > All these devices should have different memory areas for their state. > This case also applies to one process calling open several times. > > 2. Different processes related as parent/child > > If the parent has opened the device before the fork, child and parent > should share the same device. Unfortunately, Win32 seems not to allow > DuplicateHandle for wave devices, so as a work around the current > implementation does not open the handle in the open call but later > in read/write. This solution works for the players/recorders I tried. > But it has the following faults: > 1. The open does not really reserve the device. The device reservation > only works for devices that have already started to read/write. > 2. Currently, state changes in the child are not affecting > the device state in the parent, neither the other way around. > Some shared memory between these processes would improve things. > But a child process could not stop a ongoing recording if the parent has > started it and vice versa because the win32 device is still not shared. > IMHO the only way to really share a wave device in this case > is to have a common process that calls all the Win32 wave functions. > > Does anyone know how to duplicate a win32 wave device handle between > processes?
I'm probably an computer audio device ignorant (I love my "real" HiFi devices, though) but... what's different with the win32 wave device that the usual DuplicateHandle shouldn't work? Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Co-Project Leader mailto:[EMAIL PROTECTED] Red Hat, Inc.
