[MPlayer-users] postprocessing on avc streams causes blocks?

[Guillaume POIRIER]

Hi,

On 12/8/05, Alexander Wehr <plasmacutter at gmail.com> wrote:
> I've been using a weekly build from the CVS tree to play h.264/avc
> mkv files on my mac and have run into what i think might be a bug.
>
> i was wandering if i could get any confirmation as to weather this is
> a known issue under scrutiny or if i should be reporting it on the
> developer list.
>
> anyway.. if i run any mpeg4 files such as divx or xvid with the
> postprocessing arguments "-vf pp=default/tmpnoise:1:2:3 -autoq 20"  i
> get good post processing.  it'll remove blocks and improve over all
> image quality.
>
> if i apply that same flag to h.264/avc streams it causes intermittant
> macroblocking along the edges of things on the screen.
>
> is there perhaps a separate post processing filter for use on avc
> streams?

In theory, if your H.264 video has been well encoded, you should not
need any post-processing filter during playback. That's because H.264
features an "inloop filter" which purpose is to wisely mask most
encoding artifacts by "piloting" the video decoding decoding chain.

Now, what you have not said is if you're using Linux or MacOSX. I
assume you're using Linux since the known decoding problems with H.264
exists on Linux but not on OSX. That's unfortunately a compiler issue
which is not easy to fix.

You may try to compile Apple's version of GCC to get rid of those
problems: http://developer.apple.com/releasenotes/DeveloperTools/GCC4.html

Good luck

Guillaume
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