smearing effect with qpel enabled

[sysKin]

Hi folks,
I was wondering if you could help me with the ugly smearing effect that is sometimes visible in xvid qpel encodings (bframes or not).

Could you confirm that it's only visible when motion is from the upper edge of the screen, down? That could really help me.

Also, can you check (or rather: confirm) in which decoders the artifact is seen? XviD, DivX (use motion precision 4 to allow DivX decode the clip), ffdshow, _more_ ?

Thanks a lot,

Radek

PS. can you imagine this is the first thread I've started?

[kastro68]

I can confirm blockiness when DX50 fourcc is used. Works fine with XVID fourcc though... however, every now and then you would see some slight glitches in the video, not that obvious though.

[Didée]

Confirmation on smearing from top - when it's there, it is very visible most times.
Also: sometimes a little smearing from left - but very subtile, I guess I already missed it quite some times.

AND - alas:
On a couple of occasions, I had the following:
A solid-colored 16x16 macroblock appearing in the very right-bottom corner, slowly destroying the picture up to the next I-frame.

All these show up through ffdshow, and in Vdub[Mod], too. Didn't try xvid.ax yet, sorry.

[unplugged]

First, with last compiles, especially with CVS 25/11 the smearing has been drastically reduced, I still see a bit of this effect when using EnvivioTV MPEG4 decoder (after conversion to .MP4 with MPEG4IP 0.9.7) and with ffdshow-20021113 (internal code).
Using latest Nic xvid decoder (25/11) or the other bundled with Koepi's 20021125 the AVIs coded with Koepi's xvid-20021125 looks virtually perfect, no smearing.
My test settings were motion precision 6 + Chroma motion + QPel + BF 3/150%/100% + BVOP compat. + temporary DX50 fourcc (further changed to XVID) at fixed quantizer 2 (just for testing).
I m using Avisynth 2.5a 20021125, MPEG2DEC3 0.93, VirtualDubMod 20021124.

Excellent video quality with xvid ordinary decoder and despite little-little smearing MP4-ISO viewing quality with EnvivioTV is excellent too!

Congrat. sysKin and all team, keep up fixing ;)

[serbersan]

Using latest Nic xvid decoder (25/11) or the other bundled with Koepi's 20021125 the AVIs coded with Koepi's xvid-20021125 looks virtually perfect, no smearing.

I totally agree with unplugged. Only I've noticed smearing with ffdshow.

Could you confirm that it's only visible when motion is from the upper edge of the screen, down? That could really help me.

Well I've only seen in static backgrounds, walls, for example. In a scene an actor is talking I've seen this smearing in the little detailed background around him. My results where with qpel only, no bframes, no chroma estimation, no lumi masking....


I hope it could help. Cheer up sysKin¡¡¡

[Sgt_Strider]

Originally posted by unplugged
First, with last compiles, especially with CVS 25/11 the smearing has been drastically reduced, I still see a bit of this effect when using EnvivioTV MPEG4 decoder (after conversion to .MP4 with MPEG4IP 0.9.7) and with ffdshow-20021113 (internal code).
Using latest Nic xvid decoder (25/11) or the other bundled with Koepi's 20021125 the AVIs coded with Koepi's xvid-20021125 looks virtually perfect, no smearing.
My test settings were motion precision 6 + Chroma motion + QPel + BF 3/150%/100% + BVOP compat. + temporary DX50 fourcc (further changed to XVID) at fixed quantizer 2 (just for testing).
I m using Avisynth 2.5a 20021125, MPEG2DEC3 0.93, VirtualDubMod 20021124.

Excellent video quality with xvid ordinary decoder and despite little-little smearing MP4-ISO viewing quality with EnvivioTV is excellent too!

Congrat. sysKin and all team, keep up fixing ;)

What mp4 player are you using to view mpeg 4 advance profiles? In order to get mp4 container, don't you need to use AAC audio? :confused:

[Didée]

Originally posted by unplugged
First, with last compiles, especially with CVS 25/11 the smearing has been drastically reduced...
Confirmed - but I'd say noticeably, not drastically.

Using latest Nic xvid decoder (25/11) or the other bundled with Koepi's 20021125 the AVIs coded with Koepi's xvid-20021125 looks virtually perfect.
For me, smearing still appears - with latest xvid.ax, too.

My test settings were motion precision 6 + Chroma motion + QPel + BF 3/150%/100% + BVOP compat. + temporary DX50 fourcc (further changed to XVID) at fixed quantizer 2 (just for testing).
Uh-ha! Unplugged, please try again with higher quants, q4, q5, or so.
At (fixed) quantizer 2, the smearing indeed is almost invisible - but q2 is not 'real life'.

---------

Syskin,

I also saw one defect, where a big, grey-colored object moves partially out of the frame (to the left) and returns. There, the part being beyond the frame's boudary was kind of 'mirrored' into the visible frame.
Shall I upload a short sample?

[unplugged]

Originally posted by Sgt_Strider
What mp4 player are you using to view mpeg 4 advance profiles? In order to get mp4 container, don't you need to use AAC audio? :confused:
I don't need sound for that, I use mp4 only for temporary testing, mainly to know how current xvid builds are conform to MPEG4 ISO standard, it's an important point for me (since in the past there were some bugged builds that compensated encoder defects by symmetrical decoder defects :scared:, nice heh? :-x).

you can download EnvivioTV player from www.envivio.com and can create .mp4 files form AVIs with MPEG4IP tool mp4creator

grab MPEG4IP 0.9.7 binaries (various nice tools + player) at DEXT page http://peque.metropoliglobal.com/dext/index.html
I have saved a simple batch file like this to further use drag'n'drop the AVI file
c:\App\Media\MPEG4IP\Tools\mp4creator60 -create=%1 -rate=25 %1.mp4

@didée & sysKin: sorry to have not tried more...