[MPlayer-users] Re: best encoder ?

[Karsten Mueller]

Martin Hoffmann wrote:

[...]

>>OIC, but since I *do* intend to do playback on TV, what side effects are
>>there, if any ?
> 
> Deinterlacing gives blurry picture on some motion scenes !
> Judge yourself: Record ntv (scrolling text at bottom) 

I can't record ntv :( I have only cable not satellite ;) But I got the
point :)

> (1) play it as original VDR file 
> (2) encode it with lavc WITHOUT -vop pp -npp lb 
> (3) encode it with deinterlacing -vop pp -npp lb
> (4) Then try Deinterlacing by dropping one field -vop pp -npp li (if i 
> remember right)
> Now judge yourself !
> I guess you'll find (1) and (2) looking best ! (3) is blurry and (4) is less 
> resolution !
> Now, why not using (2) with lavc / divx ?? Because the encoder does not treat 
> interlaced fields (lines) correctly - he will just encode "dumb" - so he 
> wastes a lot of bits on the interlaced lines thinking these are high-details 
> - this way we waste too much bits !

Shouldn't I be able to recognize interlaced material on a PC screen on
playback ? I'm not...

> On the other hand, xvid with interlacing turned on decides on a per Macroblock 
> basis (if i remember right) if it's interlaced or not ! So he will encode the 
> whole picture (as it's not, or less moving on ntv) non-interlaced (as lavc) 
> and the bottom part as interlaced ! (Basically encoding every odd and even 
> lines seperately ...)

... which costs lots of bits...

> 
> Regarding Wasted bitrate you should try (2) on any fast moving scenes that are 
> full screen interlaced (e.g. TV Shows with camera movement!)
> 
> Try it !

I'm doing that (2) all the time since I never used deinterlacing and I'm
quite satisfied with the result. Nevertheless, if it could be better,
I'll surely give it a try :)

[...]
>>Hopefully this will be a configurable option ? Since I crop my
>>"cinemascoped" movies an aspect ratio would be no good idea ;)
> 
> Don't get me wrong, AVI alway has sqare pixels per definition - I'm not going 
> to break this for 16:9 material (for 4:3 i do, but that's another story) - I 
> had just some mistake when scaling 16:9 material !
> Now it does scale to the correct Y values: 720x405  or 480x270 and so on !
> Old versions did scale to 480x432 which in fact is NOT 16:9 assuming sqare 
> pixels !
> 
> Does this break anything you use ?
> If so, tell me how it should be ? Leave it 480x576 (original resolution) - or 
> what ?

I just encoded an old James Bond movie with cropping (*all* black 
surroundings have been cropped, horizontally and vertically) resulting 
in a totally unusual aspect ratio of 2:1 (672 x 336 pixel). MPlayer
automagically centers this on playback which gives me back the
"original" but without the TV station's logo (WDR in this case).

[...]

> Is the size gain really that much by cropping the bars ? I always thought this 
> would not be much gain ...

Even a few saved Megs could decide over fitting on a 650, 700 or an 
(expensive) 800 MB CD-R :). Cropping *definitely* speeds up encoding
(I had up to 70 fps (!) with lavc on that particlar movie ) since
without cropping the black borders still *have to* be processed even if
they are resulting in only a few bits I guess...


> 
> Martin
> 
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-- 
with best regards
---
Karsten Mueller
Softwaredevelopment / Keyaccount Manager
RATIO Entwicklungen GmbH
Admiralitaetstr. 59
20459 Hamburg
Email: mailto:kmu at ratio.de