[vdr] 1:1 pixel mapping - a waste of time?

Seppo Ingalsuo seppo.ingalsuo at iki.fi
Tue Jan 6 11:33:44 CET 2009


Jukka Vaisanen wrote:
> HDMI uses DVI signalling for the video (and audio is hidden in a
> vertical blanking time slot believe it or not) so it may seem like just
> another connector.. however in their finite wisdom the HDMI
> standardization people decided that HDMI will not support arbitrary
> resolutions, but instead only the existing (and back then, planned)
> broadcast resolutions:
>   
HDMI interface does not limit the resolutions (TMDS link max. speed of 
course does but is another matter). It's mostly the "HD Ready" and "Full 
HD" television implementations that support only CEA-861-D modes for 
HDTV. Nothing would prevent HDTVs to introduce other modes in EDID and 
EDID extension blocks similarly as DVI computer monitors do. Though the 
timings would need be defined in such way that there is space for audio.

Fortunately full HD televisions typically support 1:1 pixels over HDMI 
so the limited amount of modes is not that bad. GFX cards will scale 
other resolutions such as 800x600 and 1024x768 VESA modes into the 
native panel resolution.

My 2c: I'm watching also a HD ready television from 2005 and despite of 
2x scaling the difference with DVB PAL content is minimal to my other 
full HD television with only one scaling operation. The quality of the 
SDTV DVB-T/S content is IMHO the bottleneck instead of video scalers. 
Also non 1:1 pixels Gnome desktop is usable. Of course 1 pixel wide too 
small fonts must be avoided.

BR,
Seppo




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