Maximum/native/recommended S-Video TVOut resolutions for IGP9100 radeon?

[Mark Knecht]

On Mon, Jul 20, 2009 at 10:21 PM, Alex Deucher<alexdeucher at gmail.com> wrote:
> On Mon, Jul 20, 2009 at 8:15 PM, Mark Knecht<markknecht at gmail.com> wrote:
>> On Mon, Jul 20, 2009 at 5:08 PM, Mark Knecht<markknecht at gmail.com> wrote:
>>> On Mon, Jul 20, 2009 at 4:11 PM, Alex Deucher<alexdeucher at gmail.com> wrote:
>>>> On Mon, Jul 20, 2009 at 7:00 PM, Mark Knecht<markknecht at gmail.com> wrote:
>>>>> Hi,
>>>>>   I'm wondering how I determine what resolutions are supported using
>>>>> xf86-driver-ati with TVOut turned on? My machine is an older Asus
>>>>> Pundit-R with an ATI IGP9100 chipset. I have the Open Source driver
>>>>> running and it's currently set to 800x600 (recommended on the Xorg
>>>>> site) and I'm getting a pretty good picture compared to the older
>>>>> closed-source ATI driver. Big improvement on the noise though. The old
>>>>> ATI driver used a lot of CPU and made the fans run at high speed. So
>>>>> far your Open Source driver doesn't seem to kick the fans up at all so
>>>>> thanks for that.
>>>>>
>>>>>   I've read on the web that S-video was inherently limited to
>>>>> 720x480. Is that true? Does the IGP9100 support that sort of
>>>>> resolution? This machine is hooked only to a TV and only used for
>>>>> MythTV so there are no other considerations other than getting a good
>>>>> picture a few hours a day.
>>>>
>>>> tv-out always outputs native tv timing (NTSC or PAL, etc.).  The
>>>> tv-out block has a scaler the downscales the desktop image to the
>>>> native tv timing.  In theory you can scale any mode with the
>>>> appropriate timing, but at the moment, the driver only supports
>>>> 800x600.
>>>>
>>>> Alex
>>>>
>>>
>>> Alex,
>>>   Thanks for the response. Let me see if I understand it correctly.
>>>
>>> 1) My MythTV backend server is tied to an HD Homerun digitizer and the
>>> program is recorded on the backend at whatever resolution it comes in
>>> on the cable, but let's assume it's 1080i just to make things clear.
>>>
>>> 2) My MythTV frontend requests to play the program and it's sent over
>>> my network, probably still at 1080i.
>>>
>>> 3) The frontend program locally converts the program from 1080i to
>>> either a) the resolution MythTV is set to play at or b) the screen
>>> resolution. Those two may or may not be the same but I assume in my
>>> case they are and it's currently 800x600.
>>>
>>> 4) Whatever the resolution is coming out of MythTV then the radeon
>>> driver & TVOut hardware in the radeon chip then convert to whatever
>>> X-video can actually handle which is something like 720x480?
>>>
>>>   If that's fundamentally correct then at least would I be burning
>>> less power or requiring less of the driver if I set the X11 screen
>>> resolution to the same thing as S-Video?
>>>
>>> Thanks much,
>>> Mark
>>>
>>
>> Or the alternative is that none of that matters because the OS radeon
>> driver must be set at 800x600 or it doesn't work with TVOut. I guess
>> that's what you are saying.
>
> Xv isn't directly related, it's scaled separately based on the size of
> the source and destination surfaces.  In your example the 1920x1080
> image is downscaled to 800x600 if you use Xv to scale it to full
> screen on a 800x600 pixel desktop. The image you are rendering to and
> that's being displayed is currently 800x600 for tv-out; as I said you
> could downscale other modes as well, it's just not implemented yet.
> The actual timing that hits the tv is standard NTSC, PAL, etc.  If
> someone implemented 1024x768 or 1280x1024 support for tv-out the
> timing coming out of the tv port would still be standard tv-timing,
> otherwise your tv wouldn't sync.  However, you desktop would appear on
> the screen  to be the pre-scaled size from the perspective of the size
> of your desktop.
>
> Alex
>

Thanks Alex. That's very helpful.

Cheers,
Mark