DVDShrink : Slight Halo

[Mephiston]

Backed up 2 movies.

Used Max. Sharp on one, and Sharp on the other. Compression was 80% on both of them.

If you look closely, both movies have a slight halo around objexts, especially where there are good colour changes (Yellow on Black or something).

Is this a side effect of the sharpening filter ?

I doubt it would be very noticeable on a reg Tv at a distance, my LCD tends to bring out the worst of a movie so i can see it quite distinctly (Even though it's faint). Funny thing is i don't see it on the extras encoded at a much higher ratio.

[wingnut]

Hi there,

is it possible the disc in question had a lot of edge enhancement to start with? if you play the original on your LCD can you see any ringing on that (allbeit a lot subtler ringing that you're seeing on the backup)

Ed

[nwg]

It aslo sounds like the disc already had edge enhancement to me.

I have seen Transcoders make it worse or never caused it, unless too much compression is used.

[writersblock29]

@Mephiston

There isn't actually a "filter" in DVD Shrink. The settings allow Shrink to decide how to remove certain information (and from what areas). There's really no re-encoding at all going on with what Shrink does to a movie's stream... it's just selective removing of information until a desired filesize is achieved.

If by "haloing," you mean that the artifacts are worse around moving objects -- "outlining" them, if you will -- what you're most likely seeing can be explained by the motion compensation of the original encoder. Since the original had the advantage of a higher bitrate, the motion vectors used were adequate. But without the same bitrate (ala, DVD Shrink's output, which now has a lower bitrate) and the same motion compensation that the original encoder used (Shrink does no re-encoding, so no adjustment would have been either done or possible), the artifacts show up. This is a nutshell explaination... hopefully it gives you an idea of what's happening, however.

You may see less artifacts by selecting "Smooth" on these projects. It'll be at the expense of sharpness to detail, but the overall image might be more agreeable to you. The problem with any transcoder is that sharpening the detail will also sharpen the artifacts. Like Mr. Shrink states, it's a compromise.