Hi all,
I want help a friend to set a budget cards based (dvb-t and dvb-s) vdr box in a standard computer (not micro-atx) I don't have the hardware info (only cpu athlon 1800) but the connector to be used is s-video to scart-tv. We have planned to set softdevice and use the tv-out of a vga card to connect it to the tv. Do you recommend any vga card or any kind work with softdevice?. I need directfb or only softdevice?
I have no experience with softdevice. I actually have an epia system but with a ff nexus card.
Thanks.
On Mon, 14 Nov 2005 15:48:04 +0100 Leo Márquez leo@calidae.net wrote:
Hi all,
I want help a friend to set a budget cards based (dvb-t and dvb-s) vdr box in a standard computer (not micro-atx) I don't have the hardware info (only cpu athlon 1800) but the connector to be used is s-video to scart-tv. We have planned to set softdevice and use the tv-out of a vga card to connect it to the tv. Do you recommend any vga card or any kind work with softdevice?. I need directfb or only softdevice?
I have no experience with softdevice. I actually have an epia system but with a ff nexus card.
Thanks.
Hi,
I would not recommend using the tv-out of a graphics card. It will break interlacing, so you'll get a lot worse motion quality than with a FF-card or Dxr3/Hollywood+. It won't matter if you only watch movies, but for sports, news and other live video it will be bad.
If you still wish to go for softdevice or vdr-xine (I'd recommend the latter for its deinterlacing modes), setting things up will be easiest eith a cheap nVidia card and X.org instead of DirectFB. Anything newer than GeForce 4 MX440 is easy to setup for TwinView, so don't waste money on a new board if you have one of these lying around. You may not even need a window manager for X, or only a very light one (twm, fvwm) so the startup time is almost the same with that combination as with DirectFB.
Dualhead Matrox cards (G400-G550) would be better for tv-output, but they are harder to setup. With them it is better to use DirectFB and it would even be possible to preserve interlacing, but I'm not sure if softdevice supports that.
-- Niko Mikkilä
Leo Márquez wrote:
I don't have the hardware info (only cpu athlon 1800) but the connector to be used is s-video to scart-tv. We have planned to set softdevice and use the tv-out of a vga card to connect it to the tv.
Personally I use a DXR3 card as is mentioned elsewhere. Another card that I've tried briefly is the PVR350, see http://ivtvdriver.org/ Both cards have a good quality S-Video TV-Out but the DXR3 plugin seemed to work a little better then the PVR350 plugin.
My personal experience seems to be that most TV-Out on VGA cards are designed to run best at 60Hz output for the US market. When configured to run in 50Hz PAL, for a UK TV, it seems like the VGA modelines are still clocked at 60Hz with some (poor) down-conversion to 50Hz being done in the TV-Out circuitry. This looks fine on static content but any movement results in juddering or blurring. This is especially noticeable on the scrolling text trackers often present on news programmes.
This doesn't appear to be just a pure interlacing problem. I've tried tweaking the 50Hz TV-out of EPIA, NVidia & ATI VGA systems and none of them match the quality of hardware designed for dedicated TV usage, e.g. DXR3, PVR350 (and presumably the FF cards although I've not tried one myself.).
Jon
On Mon, 14 Nov 2005 23:49:07 +0000 Jon Burgess jburgess@uklinux.net wrote:
This doesn't appear to be just a pure interlacing problem. I've tried tweaking the 50Hz TV-out of EPIA, NVidia & ATI VGA systems and none of them match the quality of hardware designed for dedicated TV usage, e.g. DXR3, PVR350 (and presumably the FF cards although I've not tried one myself.).
NVidia and ATI cards filter the display by default to reduce flickering. Of course, this destroys interlacing as well. Some more advanced tv-out configuration programs allow one to turn the filter off on some chips, but that won't be enough. The video decoder or player still needs to synchronize its display to the output fields so that they are always displayed in the right order. AFAIK only the Matrox cards have an interrupt that makes this possible in the software side.
For a very detailed discussion on these issues, see VDR mailing list archives in October, 2004. The thread starts here, but you'll need to read it through to see the situation (which hasn't changed as of now) completely: http://www.linvdr.net/mailinglists/vdr/2004/10/msg00922.html
Luckily the interlaced CRT televisions are being phased out and soon we'll only have nice progressive panels and projectors. Just waiting for the 1080p @ 50Hz broadcasts ;)
-- Niko Mikkilä
Niko Mikkila wrote:
On Mon, 14 Nov 2005 23:49:07 +0000 Jon Burgess jburgess@uklinux.net wrote: For a very detailed discussion on these issues, see VDR mailing list archives in October, 2004. The thread starts here, but you'll need to read it through to see the situation (which hasn't changed as of now) completely: http://www.linvdr.net/mailinglists/vdr/2004/10/msg00922.html
Thanks for the pointer, i'll take a good look at it.
Luckily the interlaced CRT televisions are being phased out and soon we'll only have nice progressive panels and projectors. Just waiting for the 1080p @ 50Hz broadcasts ;)
... to be replaced with a different set of issues around HDMI, MPEG4, WMV9, DRM etc.
I'm thinking about making a jump to the new generation but when I look closely at the specs for LCDs and Plasmas I've yet to find a model that says that it really does a native 50Hz display for VGA or DVI. The detailed spec sheets for every model that i've looked at all quote a 60Hz vertical refresh rate for the digital inputs. I'd love to be proved wrong, but for now i'll be sticking to my SD CRT.
Jon
On Dienstag, 15. November 2005 01:44, Niko Mikkila wrote:
On Mon, 14 Nov 2005 23:49:07 +0000
Luckily the interlaced CRT televisions are being phased out and soon we'll only have nice progressive panels and projectors. Just waiting for the 1080p @ 50Hz broadcasts ;)
Damm, that mode will be 1080i. Interlaced. 25fps with 2 fields. So interlacing vs. deinterlacing starts again :-( .
On Tue, 15 Nov 2005 07:23:44 +0100 Stefan Lucke stefan@lucke.in-berlin.de wrote:
On Dienstag, 15. November 2005 01:44, Niko Mikkila wrote:
On Mon, 14 Nov 2005 23:49:07 +0000
Luckily the interlaced CRT televisions are being phased out and soon we'll only have nice progressive panels and projectors. Just waiting for the 1080p @ 50Hz broadcasts ;)
Damm, that mode will be 1080i. Interlaced. 25fps with 2 fields. So interlacing vs. deinterlacing starts again :-( .
Indeed, that's why I used the smiley. Considering the advances in lossy video compression techniques, it is really mindboggling that they are still pushing such an ancient motion compressing technique that does more harm than good when used together with the modern compression techniques, not to even mention that the displays are progressive. I know H.264 supports interlacing, but I'm pretty sure it is there only to please the broadcasters and people processing interlaced video, not for actual efficiency reasons.
Well, with digital television standards things change more rapidly than in the analogue age. Once they get HDTV rolling, it may not take too long until 1080p@50fps is technically feasible. Perhaps within 10 years we'll get it through internet -- no DVB cards required. DRM is a bitch though.
-- Niko Mikkilä
On Mon, 2005-11-14 at 23:49 +0000, Jon Burgess wrote:
Leo Márquez wrote:
I don't have the hardware info (only cpu athlon 1800) but the connector to be used is s-video to scart-tv. We have planned to set softdevice and use the tv-out of a vga card to connect it to the tv.
Personally I use a DXR3 card as is mentioned elsewhere. Another card that I've tried briefly is the PVR350, see http://ivtvdriver.org/ Both cards have a good quality S-Video TV-Out but the DXR3 plugin seemed to work a little better then the PVR350 plugin.
My personal experience seems to be that most TV-Out on VGA cards are designed to run best at 60Hz output for the US market. When configured to run in 50Hz PAL, for a UK TV, it seems like the VGA modelines are still clocked at 60Hz with some (poor) down-conversion to 50Hz being done in the TV-Out circuitry. This looks fine on static content but any movement results in juddering or blurring. This is especially noticeable on the scrolling text trackers often present on news programmes.
This doesn't appear to be just a pure interlacing problem. I've tried tweaking the 50Hz TV-out of EPIA, NVidia & ATI VGA systems and none of them match the quality of hardware designed for dedicated TV usage, e.g. DXR3, PVR350 (and presumably the FF cards although I've not tried one myself.).
I used a dxr3 for a long time. I am now using a g450.
I must say that with directfb & softdevice the g450 does produce a good picture via TV out.
The setup is a bit of a pain - I think the documentation should be updated.
The one outstanding issue I have is that I cannot view 16:9 material croped/latterboxed onto my 4:3 display without distortions. (This is a known problem, but there is now solution yet)
Outside this, I certainly would recommend a matrox over a dxr3 for vdr.
Jon
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