[Ffmpeg-devel] [PATCH] fast h264 decoding

Zoltan Hidvegi mplayer
Wed Jul 13 20:21:58 CEST 2005


Reimar D?ffinger wrote:
[ Charset ISO-8859-1 unsupported, converting... ]
> Hi,
> On Wed, Jul 13, 2005 at 12:25:06PM -0500, Zoltan Hidvegi wrote:
> > Reimar D?ffinger wrote:
> > > It disables the deblocking step when fast is set, for the samples I have
> > > it doesn't make a visual difference, but decoding time goes down from
> > 
> > I thought that in h264 the deblocked image is used for motion
> > prediction of future frames, which means that this would significantly
> > degrade quality.  But I'm really not a h264 expert, so maybe I'm wrong.
> 
> Yes, probably. But for the case of high bitrate HDTV that doesn't really
> matter *g*, whereas nearly twice the speed certainly does.
> I think it would be really a good idea to have such an option, though I
> am not sure if it should "re-use" the fast option or not (and e.g. create
> a new one instead).

Would it be hard to have several levels of this option, e.g. level1
disables deblocking only on frames which are not used for prediction,
level2 disables deblocking on all b-frames, and level3 disables all
deblocking (which could cause artifacts to propagate and accumulate).

Zoli





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