pixels from the top appear at bottom of the image x264 895

[simonhowson]

I have noticed a very strange problem with an encode I just made using x264 895 (Jarod's patched build).

I made the encode from an NTSC DVD source that is non-anamorphic (not 16:9 enhanced). The film is 2.35:1 widescreen, set inside the 720 x 480 NTSC image.

I cropped and resized this to 640 x 272, and encoded it using the iPhone profile in MeGUI.

The resulting file has pixels that should be at the very top of the image, but appear at the bottom. Obviously this is a very annoying artifact that I would like to avoid. However, I am unsure if this is an x264 issue, or a cropping or resizing issue.

All my files are the latest stable versions recommended by MeGUI.

I aplogise if this thread should be in the MeGUI forum, but I don't know if this is a problem with the script, or with x264 itself.

I have checked the source VOB which does not have this problem, and I played script in Nero Showtime which didn't show the error.

Here is the script I used:

DGDecode_mpeg2source("E:\DVDRIPS2\VTS_02_1.d2v",info=3)
ColorMatrix(hints=true)
#deinterlace
crop( 0, 106, -2, -102)

BicubicResize(640,272,0.333,0.333) # Bicubic (Soft)
mergechroma(blur(1.3)) # Little Noise

[lexor]

well, rule out the filters first. open the avs file in some player and see if the line is at the bottom. if it is, it's the filters, remove them and start adding them one by one to see which one it is.

[simonhowson]

I played the script in both Nero ShowTime 4 and the latest version of Media Player Classic Home Cinema, and neither show the artifact which suggests to me it is the encoding process itself. But I guess it is possible that they are both cropping the image slightly at the bottom which means I don't see it. it is a very thin line at the bottom maybe only 1 or 2 pixels tall. But it is very annoying. I don't see it when I am playing it on my iPod Classic, but that's possibly just because the screen is tiny.

[Guest]

Change to:

crop( 0, 104, -2, -104)

For YV12 crop vertically by multiples of 4.

[simonhowson]

Change to:

crop( 0, 104, -2, -104)

For YV12 crop vertically by multiples of 4.

Ah OK. I just did whatever autocrop come up with.

Is it possible to encode this film to a 640 anamorphic file? Or is that pointless because - since the film is 2.35:1, and DVD itself isn't anamorphic - it has to increase the vertical size which just reduces quality that isn't made up for by the anamorphic enhancement?

I tried some settings but it wanted to encode the vertical height smaller with anamorphic turned on than with it off which didn't make any sense.

[Selur]

For YV12 crop vertically by multiples of 4.
@neuron2: Just for clarification_ Isn't that just an avisynth problem/restriciton? iirc Yv12 itself would be fine with mod2 for width and height if the material is progressive.

[foxyshadis]

It's only a restriction on output, internally there's no problem as long as it's progressive.

You might also remove crop and change it to BicubicResize(640,272,0.333,0.333, 0, 106, -2, -102) to allow any crop you want, even subpixel, and faster as well.