Log in

View Full Version : Deblocking in MPEG4 ASP???

Irakli
7th November 2007, 16:07
Hello, everybody.

I just came across this (http://www.compression.ru/video/codec_comparison/subjective_codecs_comparison_en.html) document which compares x264, DivX, XviD and WMV. Interesting thing is that the document mentions that:

Probably, XviD results could be improved by switching on deblocking algorithm (this algorithm isn't used by default).

But if I am not mistaken, deblocking is part of the standard for h264/MPEG4 AVC but not MPEG4 ASP. So I am a bit confused here. Is it mistake in the document? If not, could you please help me by explaining what kind of deblocking do they mean?

Thanks in advance.
Regards,
Irakli.
Dark Shikari
7th November 2007, 16:25
That test is pretty much BS because it compares Xvid without deblocking with DivX with deblocking, and wonders why Xvid mysteriously looks worse.

What do you mean there is no "deblocking part of the standard" for H.264/AVC? Of course there is, its called the inloop deblocker.
Irakli
7th November 2007, 16:36
What do you mean there is no "deblocking part of the standard" for H.264/AVC? Of course there is, its called the inloop deblocker.

Sorry, I made spelling mistake. Of course, I know about inloop deblocking in h264/MPEG4 AVC. I will correct my post.

So my question was whether there is such thing as deblocking in MPEG4 ASP?

Regards,
Irakli
Sergey A. Sablin
7th November 2007, 17:56
Sorry, I made spelling mistake. Of course, I know about inloop deblocking in h264/MPEG4 AVC. I will correct my post.

So my question was whether there is such thing as deblocking in MPEG4 ASP?

Regards,
Irakli

no, it's just postprocessing
Irakli
7th November 2007, 18:14
no, it's just postprocessing

Thanks for reply!
...But this actually means that the comparison between DivX and XviD becomes a bit unfair here, because in real life most people just use the same decoder with unchanging settings for both XviD and DivX (postprocessing is either turned off for both or enabled for both, e.g. ffdshow, standalones, etc.).

Regards,
Irakli
Sharktooth
7th November 2007, 18:55
exactly. that's why
That test is pretty much BS because it compares Xvid without deblocking with DivX with deblocking, and wonders why Xvid mysteriously looks worse.