On Thu, 11 Aug 2005, CPM wrote:

>   In Kino, they use yuvdenoise like this:
> 
> ...|yuvdenoise -F -f | yuvscaler -v 0 -O VCD -n p | mpeg2enc -v 0 -f 1 
> -I 0 -n p -a 2  -o 'cliptestc'.mpv'
> 
> or like this:
> 
> ...|yuvdenoise -F | yuvscaler -v 0 -O VCD -n p | mpeg2enc -v 0 -f 1 -I 0 
> -n p -a 2  -o 'cliptestc'.mpv'
> 
>   As mjpeg has changed, which is the good new version?

        None of the above :)

> 1) yuvdenoise -F => ... | yuvdeinterlace | yuvdenoise | ...
> 2) yuvdenoise -F -f => ... | yuvdeinterlace | ...
> 3) yuvdenoise -F => ... | yuvdeinterlace | yuvdenoise | ...
> 4) yuvdenoise -F -f => ... | yuvdeinterlace | ...

        yuvdenoise does not support -F so the correct usage is simply
        "yuvdenoise" (slightly old versions may support "-f" but the cvs
        version has neither -F or -f).

>   The goal is to transform DV file in a mpeg file (VCD, SVCD, DVD).

        Oh, ok - so you will be doing the encoding multiple times (once for
        each format).

        VCDs (mpeg2enc -f 1) is progressive MPEG-1.  'yuvscaler' will
        automatically deinterlace when "-O VCD" is used - thus 'yuvdeinterlace'
        is not needed.  I think, from a very quick look at the yuvscaler code,
        that the two fields are blended together during the downscaling.  It
        may be preferable to use 'y4mscaler -O preset=VCD '-I ilace=BOTTOM_ONLY'
        (y4mscaler can be found at http://www.mir.com/DMG/Software/)

        SVCDs use MPEG-2 and one of the big avantages of MPEG-2 over MPEG-1
        is the support for interlaced video!  So in this case also you probably
        do not want to use 'yuvdeinterlace'.  For SVCDs:

           ... | yuvdenoise | mpeg2enc -f 4 -q 5 ... |  ...

        Similarily for DVD it is probably better to not deinterlace (that
        can be done at playback time in most MPEG playing software).  Simply
        denoise and go into the encoder:

                ... | yuvdenoise | mpeg2enc -f 8 -q 4 ... | ...

        Another denoising program that is part of mjpegtools is 'y4mdenoise',
        you may want to experiment with that and see how it works for you.

        DVD (and to a slightly lesser extent) encoding parameters have been
        the subject of MUCH discussion on this list.  I think if you browse
        the mailinglist archives you will find some useful information about
        setting the bitrate, selecting the quality (-q) and other options.

        My personal preference is to never deinterlace at encoding time
        (NOTE: this is not the same thing as removing the NTSC 2:3 pulldown
        for material which originated on film).  Deinterlacing can be done
        at playback time (MPlayer for example has numerous filters to do this).

        Good Luck!

        Cheers,
        Steven Schultz



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