[MPlayer-users] mpeg2->divx

Arpi arpi at thot.banki.hu
Thu Oct 18 13:16:14 CEST 2001


> > 	That I do not know how to do - I believe it requires some very
> > 	expensive equipment.   
> I believe it doesn't. There must be a software solution, too; since most
> hardware is made of DSPs and microprocessors ;-)

there is a hardware implementation of 24->29.97 fps conversion, using
video camera and film player. it's really very expensive, afaik.

the cheap (software) solution is the 3:2 pulldown.

> > 	Also the audio needs to be converted and
> > 	I am not sure that can be done easily without altering the pitch.
> I've got an idea of how to convert the audio.
> I think it can be done using a conversion from the "time domain" of 
> wave audio (which stores the ampitude each 1/48000 sec) to the 
> "frequency domain" (which stores the amplitudes for the corresponding
> frequencies). 

It won't be perfect. it's ok for big pitch changes (half/fouble freq)
but for few percent changes rounding will kill things.

> For the video though I have no idea how to smoothly convert it....
> Perhaps this can be done by interpolation somehow.
i've heard about software for this. It analyses motion of picture, and
uses motion compensation-like thing for interpolation. so it won't be jerky.

A'rpi / Astral & ESP-team

mailto:arpi at thot.banki.hu

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