[Mplayer-dvb] Patch for dvbscale of mplayer

[Martin Hoffmann]

Am Samstag, 25. Mai 2002 14:42 schrieben Sie:
> Hi,
>
> > from VDR which are 480x576 (and are meant 4:3 ;-)
>
> the dvbscale was made for avi files.
> for mpegs (like vdr files) it has no sense to re-encoding them, why don't
> you play them using the card's decoder ?
Naa, you got me wrong !
I have converted VDR recordings (mpeg) to divx4 Avis using mencoder - and 
since my primary output target is TV via DVBs, i haven't rescaled them ! 
That's why they are 480x576 !
I do know, that they are not really avi compliant - since i should have 
scaled them to 768x576 or to 480x360 - since AVI has always square pixels !

> anyway the problem is only that dvbscale plugin uses the original
> resolution instead of teh prescaled (to correct aspect) resolution.
Okay, but this way it's more flexible !? I guess prescaling wouldnt know how 
to scale my 480x576 avi (how could it know ?)
But in dvbscale context, the 480x576 resolution makes sense and can be 
treated specially !

time for another format like avi, that support aspect ratio values for mpeg4 
!!! Maybe MCF or something ! Then we would get rid of this nasty aspect ratio 
problem !

> > Also using videos that are 5:4 or something (discussed here earlier)
> > playback in fullscreen (no black bars left or right)
> > So actually it's done the following way: Everything with an aspect ratio
> > smaller than 4:3 is pushed to 4:3, since i guess that's what was meant !
>
> is TV screen 5:4 or 4:3 ?
> maybe changing aspect constant from 768 to 720 (or 704) woudl be better
> solution.
No, TV IS 4:3 - but i simply scale everything beingt smaller in width than 
4:3 up to 4:3. For example this is something like 352x288 - which is in fact 
often used for 4:3 !
Really 5:4 wouldnt fill the complete 4:3 screen - there would be black bars 
at the left and right - and so i squeeze it a little to fill the 4:3 screen 
(yess, ignoring aspect, a little :-) But i don't know a serious video format 
that is meant to produce black bars at the left and right ! So i thought this 
is a good idea !

> > @Arpi: what have i done wrong in this patch ? mplayer sometimes reports
> > craz y
> > values like VO: 480x576 -> XXXx921 (i do not understand why this is
> > printed -
> > obviously it does not rescale to Y=921 - anyway that would not work....!)
>
> as you use only the X value from the dvbscale (expand=0:576) it ignores
> others.
Okay, it is only meant to expand to y=576 and leave X as it is !
But how is mplayer calculating the 480x921 it reports ??? I do not get that !

Martin