[mythtv] MythTV with Radeon 8500DV?

Matt Zimmerman mythtv-dev@snowman.net
Sun, 13 Oct 2002 12:55:00 -0400

On Thu, Oct 10, 2002 at 11:14:53PM -0400, Isaac Richards wrote:

> I'd say you're on something if you think any Creative made card has decent
> sound-quality, but...  =)  Reports have it that the Radeon drivers
> (hardware?) don't allow simultaneous recording and playback of video.

My understanding and experience is this.  With a Radeon card and the GATOS
drivers (I am using a Radeon all-in-wonder 7500), it is possible to:

1. Overlay video into a window or full-screen (Xv)

2. Capture video (v4l)

3. Scale prerecorded video in hardware (Xv)

With the following restrictions:

- In order to do #2, you must do #1 at the same time (though the window need
  not be displayed on-screen).  This is a hardware restriction; there is no
  separate capture device.  Video capture is done from video memory.

- You may not do #1 and #3 at the same time, and therefore not #2 and #3 at
  the same time due to the previous restriction.  This is also a hardware
  restriction, but there may be a driver workaround in the future.

So, if you have the bogomips to scale playback in software, this would work
fine (assuming MythTV will do the scaling), as long as you leave xawtv or
avview running to provide the input.  I do not know about controlling the
tuner from MythTV; I have never used the tuner except with xawtv and avview.
Of course, this would not take advantage of one of the nice features of the
card, which is the ability to display live TV input directly to a window
without using any significant CPU time or I/O bandwidth.

In my setup, I have a Hauppauge card in addition to the Radeon, and would
eventually like to be able to use both in MythTV.  I haven't played with it
much, though, and since it would interfere with playback, I will probably
wait until that restriction is lifted.

 - mdz