From: Jonathan W. <jw...@ph...> - 2010-12-04 12:45:25
|
Clemens Ladisch wrote: > Jonathan Woithe wrote: > > Arnold wrote: > > > [FFADO] > > > the code-base is versatile enough to use different devices of different > > > vendors together as one soundcard (try that with alsa on pci or usb). > > This works just fine with devices that have a word clock input ... > : > The ALSA framework is orientated towards sound devices; hotpluggable > devices are among them, and do work. Thanks for the clarifications. As I mentioned I am only vaguely familiar with the intracacies of ALSA. > > and - importantly - always offer the same number of I/Os to userspace. > > ALSA can change the number of channels and the number of PCM devices at > any time; the only thing that is not possible is changing this while > a stream is running. Ok. Certainly changing the channel configuration at runtime is not required. The issue with many firewire devices is that the number of I/Os and in some cases their configuration will change depending on device settings (sample rate, optical port mode and so on). > IIRC this feature was desired for aggregating devices and changing their > configuration on the fly. Again, I think this belongs into Jack. Aggregating devices does seem to be something which lies outside the scope of the kernel. Managing device configuration - especially when it changes the streaming format - probably does have to be in the kernel (or at the very least the kernel has to be aware when the device configuration is changed so it can account for the streaming changes). Regards jonathan |