[MEncoder-users] about filmdint/pullup

[vdmsss]

Thanks Peter. See below.

On 29 Jul 2007, at 22:44, Peter Cordes wrote:
> vdmsss wrote:
>> Hello. I have been playing with filmdint. My main source are films
>> broadcast on DVB at 50i, and since most tutorials and discussions
>> around are based on NTSC, and I am left with some doubts:
>
>>       Can filmdint (or pullup) be used to convert from 50i to 24p?
>
>  The only reason you want to convert FPS is so it matches  
> tutorials?  Don't
> do that.  PAL is usually much easier, because it's almost never  
> telecined,
> just sped up, so you can just skip the parts of tutorials that deal  
> with
> maybe needing to inverse telecine.

The reasons I want to this is to encode movies with the original  
frames (as much as possible), and secondarily to learn to use  
filmdint/pullup and other advanced features of mencoder. Following  
previous advice on this list, I have toyed with slowing the movie  
down (-speed 23.976/25, even though I am not yet really confident on  
why -ofps would be wrong). Seems to work quite well, including the  
audio.

>  There are filters to make sure the field order is right in PAL video.
> -vf phase  can swap fields if your film looks combed.  That reminds  
> me, I
> added some hysteresis to -vf phase a while ago in an attempt to get  
> a Star
> Trek PAL DVD to look reasonable, but it's an NTSC->PAL conversion  
> from the
> hard-telecined source for special-effects scenes, so it's all crappy.
> I should post the patch somewhere, since it did seem to help.
>
>  Anyway, if you really really want to convert frame rate, none of  
> the video
> frames have to change, you just need to stretch the audio to match the
> framerate.

The point is that, as I said, most of my sources are from DVB-T, and  
sometimes it can be tricky to understand what needs to be  
deinterlaced and what can be left unchanged. Do you know of any tools  
on MacOSX (or indeed mencoder demuxer option) that would allow me to  
inspect fields and their flags? (I often use Project X to demux, but  
it doesn't give much info on the streams, and what it gives is not  
always documented...)

> There are ways to filter audio to change the length without
> changing pitch.  Maybe look for a LADSPA filter to do that.  Or  
> avidemux can
> do it, I think.  Probably audio editors like audacity can, too, but  
> then
> you'd have to dump the audio to .wav and manually edit it.

Thanks.