[FFmpeg-user] vertical lines noise in scaled raw video.

[Dennis]

On Wed, Nov 9, 2011 at 11:05 AM, Andy Sheen <sheen.andy at googlemail.com>wrote:

> I've downloaded your ffmpeg recode. As far as I can tell I can't see any
> vertical lines on a calibrated monitor (playing with mpc-hc).
>
> Do you have the latest drivers for your graphics card? Tried it on a
> different PC/output device? It may be a rendering problem.
>
> Dennis wrote on Wed 09 Nov at 15:31 UK time
> > A long story, but will try to keep it short.
> >
> > Was converting MPEG2 to H,.264 noticed that video has faint but
> persistent
> > vertical lines top to bottom. It's not extremely noticeable, but gets
> very
> > annoying as lines stay in one place and 'burn in' after a while.
> >
> > Playback: QuickTime, VLC and FFplay media players.
> > Encoding: FFmpeg 0.8.6 release with latest libx264 (Nov 5th tar ball).
> >
> > Source file:http://www.mediafire.com/?khrzaps202b1ksq
> > FFmpeg & libx264: http://www.mediafire.com/?3fkyzo1oh5d6l72
> > X264 encode(y4m to H264): http://www.mediafire.com/?g8x2ww1rcwhm08k
> > y4m file (scaled to 800x448 by ffmpeg):
> > http://www.mediafire.com/?y8cvvk07r1vegna
> >
> > Any advice on removing these lines, perhaps a video filter? Or other ways
> > control the reduction of chroma spread, so that dark grays are encoded as
> > black?
>

Here's the screenshot with "find edges" filter applied by ImageJ :
http://www.mediafire.com/?0hesdf21e6a2ok2
these lines get amplified when encoded by x264, if I can suppress the
amplification it'd be kinda cool.