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

[Dennis]

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?

Thank you all.