[linux-dvb] How to access /dev/videoK from /dev/dvb/adapterN?
Klaus.Schmidinger at cadsoft.de
Sat Jun 17 10:59:59 CEST 2006
Manu Abraham wrote:
> Ralph Metzler wrote:
>> Klaus Schmidinger writes:
>> > An application that uses the LinuxDVB driver can access the
>> > DVB devices via /dev/dvb/adapterN/* (N = 0, 1, ...). However,
>> > when it wants to, for instance, capture the current image on
>> > a device (like VDR with its GRAB command), it needs to access
>> > /dev/videoK, where 'K' is a number that is not directly related
>> > to the 'N' mentioned above for the DVB device.
>> > > So VDR has to do some guessing on which /dev/videoK device might
>> > belong to the /dev/dvb/adapterN device. This is getting particularly
>> > problematic if there are also other /dev/video devices that have
>> > nothing to do with any DVB devices.
>> > > Is there a defined way in which an application can query a DVB
>> > device for its related /dev/video device?
>> Currently not.
>> Since upcoming cards with decoder and V4L interface for those will
>> need it too, should we add a call for this? In the DVB video device?
>> We might also need something like this for audio.
> Like what we discussed earlier, what about making the nodes children to
> the adapter device, this will shoot at least 2 or 3 birds in one shot.
> ie a /dev/dvb/adapterX device, all are just child nodes of the adapter
> This would solve
> (1) solve the issue with the demux for multistandard devices
> (2) This current situation
> (3) Calls that might belong to more than one device/belonging to the
> card etc
I wouldn't mind _where_ the video device is that I need to use
for grabbing the image, so that would be fine with me.
However, the name /dev/dvb/adapterN/videoM is already taken - or
could that same node be used for image grabbing?
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