[MPlayer-users] Re: 1080i to 1080p mpeg2 or x264?

[Loren Merritt]

On Tue, 28 Feb 2006, Steven Adeff wrote:
> On 2/28/06, Loren Merritt <lorenm at u.washington.edu> wrote:
>>
>> At least in x264, it's more efficient to leave it at 1080 and let x264
>> decide what to stuff in the bar, rather than force blackness. Any
>> compliant h264 decoder will crop it off on playback.
>> (of course, scaling/cropping to 1088 or 1072 also work)
>
> does x264 automatically make it 1088 then?

yes.

>>> Though I don't know if the processing time is worth the space trade
>>> off to go to mpeg2 so right now this is more academic for me...
>>
>> Then try mpeg4.
>
> oops I mean to go to mpeg4, mpeg4 takes 5x the time to encode over
> mpeg2 from my tests but only nets about 20% file size savings.

Are you sure?
In a quick test with no mpeg4-specific options, I got mpeg4 vs mpeg2 is 
18% slower and 16% lower bitrate per psnr.
mbd=2:trell:vmax_b_frames=1:subcmp=2:last_pred=2:vcodec=(mpeg4|mpeg2video)
Of course you can make it really slow if you turn on everything, so 
just don't do that.

--Loren Merritt