BSD video capture emulation question

John-Mark Gurney gurney_j at
Thu Jul 10 13:40:50 PDT 2003

Steve O'Hara-Smith wrote this message on Thu, Jul 10, 2003 at 22:29 +0200:
> On Thu, 10 Jul 2003 12:13:29 -0700
> John-Mark Gurney <gurney_j at> wrote:
> JMG> Yes, video capture in FreeBSD is sorely lacking.  I recently did a
> JMG> Zoran driver and found that the bktr interface is horrid.
> 	Did you make it fit the bktr interface then ? Is there any chance
> of it working in RELENG_4 ? If so can I play with it ?

Yes, I followed the bktr interface, but the bktr interface needs to
disappear ASAP!  The bktr interface is very bad as we make FreeBSD
multiplatform.  It lets the user supply the physical address when doing
video overlay to the video card.  This should be handled by the driver,
not the userland app.

It is only for -current.  There was some issues w/ -stable that other
people had, but I'm not sure what it was.  I don't have any -stable boxes
right now (nor any i386 boxes for that matter), so work is kind of frozen.

I would prefer to design a new extensive interface for multimedia before
putting more work into the driver.

> 	AFAICS what's needed is someone with some insight into what makes
> a good video API if FreeBSD is ever going to get one. The innards of
> things like ffmpeg and transcode are probably worth looking at as models.

Hmmm.  I'll have to look at that.

But there is more than just codec handling.  One of the features that
the Zoran card supports is the ability to have two sources (since as
external video and MJPEG playback) one in a window of the other.  But
you need to only have one video clock running the output.  This should
be handled by the video api so the drivers just write the raw interface
and the api does the manipulation of the driver.

It's quite a complex situation.

  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."

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