[x264-devel] out-of-range motion vectors

[Robert Swain]

On 31/07/07, CAdevel <cadevel at gmail.com> wrote:
> The standard allows large motion vectors indeed (I recall a quarter window
> as max). However, motion estimation techniques generally limit their search
> range to 16 (or something close to that). Anyway, I encoded the movies with
> x264 using the option "--hex --merange 24" and "--esa --merange 16", where
> 'merange' sets the motion estimation search range. Thus, in principle I
> should not find any motion vector larger than 24 and 16 respectively. But I
> think I did, and that worries me.

The --merange option has different meanings depending on the search
pattern selected. For example, it specifies the size of the region to
be searched for ESA and for the others I think it affects the maximum
iterations or something like that but there would need to be
clarification of this as I'm not certain what it does in each case.

What you're looking for is the --mvrange option.

      --mvrange <integer>     Maximum motion vector length [-1 (auto)]

Pass your desired maximum MV length to this option and it should
produce the results for which you're looking.

Rob
_______________________________________________
x264-devel mailing list
x264-devel at videolan.org
http://mailman.videolan.org/listinfo/x264-devel