Mihai Moldovan kirjoitti: > Hi Hannu, > > got another little question on vmixctl... :) > > Due to the yet fixed preventing me from recording anything with the > audigyls card, I tried to attach VMIX to both my PCI *and* onboard card. > > However, ... > > deff oss # vmixctl attach /dev/oss/oss_audigyls0/pcm0 > /dev/oss/oss_via970/pcm0 > VMIXCTL_ATTACH: Input/output error > > It seems like it doesn't work too well... maybe because > /dev/oss/oss_audigyls0/pcm0 already IS a full duplex device? > > Both audigyls and via97 will attach vmix by default. It is not necessary to use vmixctl attach and it will always fail.
> Legacy device /dev/dsp0 > Caps: DUPLEX TRIGGER MMAP > Modes: IN/OUT > > Well... I just want to use the output feature there and the input > feature from my onboard soundcard, is that possible? > It is not possible. There are two reasons: 1) Both sound cards have attached vmix during boot. It's not possible to attach vmix again before "vmixctl detach" is implemented. 2) Even after that the two sound card scheme will not work. Two sound cards never have exactly the same sampling rate. Even the nominal rate is (say) 48000 Hz it's likely that card 1 has "real" frequency of 48001 Hz and the second card has 47999 Hz (measured against the master clock provided by the gods). This drift in sample rates means that after a while the devices will get seriously out of sync. There will be dropouts in recording or playback depending on which sound card has the slowest sampling rate. It will be possible to do duplex with two sound cards only if they are both slaved to the same clock signal. Only "high end" sound cards have capability to use external sync. Normal consumer devices like audigyls and via97 will never work properly. Best regards, Hannu _______________________________________________ oss-devel mailing list oss-devel@mailman.opensound.com http://mailman.opensound.com/mailman/listinfo/oss-devel
