[mythtv-users] Resolutions for PAL

Jon Dye jon at pecorous.co.uk
Fri Dec 19 05:59:32 EST 2003


Christian Hack wrote:

>>I'm tweaking my profile settings and am trying to decide the best 
>>resolutions to use for the 4 standard profiles.  I am in a 
>>PAL area and 
>>the examples given in the docs are for NTSC and although it does give 
>>some info on PAL.  I was wondering what other people were 
>>using or is it 
>>just a case of trial and error to see what looks/performs best?
> 
> Yes trial and error. But the docs are fairly clear. The differences
> between PAL and NTSC are essentially the number of lines (excluding the
> colour bandwidth). So in the examples replace 480 with 576 and 240 with
> 288 for PAL land. Horizontal resolution is for all intents and purposes
> the same between NTSC and PAL. Personally I use 640x576 or 480x576.

Do I need to make the ratio 4:3 when choosing resolutions?

>>Also, I am using RTjpeg because I understand that this uses less CPU 
>>than MPEG4 but what is the tradeoff when using MPEG4/RTjpeg 
>>for transcoding?
> 
> MPEG4 files require more CPU but take less disk space (mine are of the
> order of 1 GB/hour)
> RTJPEG files require less CPU but more disk space. I can't give examples
> since I never used RTJPEG but from memory I recorded a few things in
> RTJPEG by accident and saw files of the order 4-5GB/hour on a fairly
> noisy signal (interference in the PC)

Thanks, I'll have a play with MPEG4 then and see if my CPU can keep up, 
I want to save some more disk space until I get a larger disk!

JD



More information about the mythtv-users mailing list