[FFmpeg-devel] [PATCH] libavfilter-soc: make scale algorithm configurable

[Stefano Sabatini]

On date Friday 2009-02-13 03:10:26 +0100, Michael Niedermayer encoded:
> On Fri, Feb 13, 2009 at 02:13:38AM +0100, Stefano Sabatini wrote:
> > On date Monday 2009-02-09 19:45:06 +0100, Michael Niedermayer encoded:
> > > On Sun, Feb 08, 2009 at 11:45:34PM +0100, Stefano Sabatini wrote:
> > > > On date Sunday 2009-02-08 03:01:37 +0100, Michael Niedermayer encoded:
> > > > > On Sat, Feb 07, 2009 at 08:30:01PM +0100, Stefano Sabatini wrote:
> > [...]
> > > > > > But I agree on the limitation of the libswscale API, ideally maybe we
> > > > > > should be able to pass in the opaque a pointer to an already allocated
> > > > > > swscale context already containing sws flags + vectors + whatever,
> > > > > > which we could allocate with something like:
> > > > > 
> > > > > am i missing something that make this opaque stuff needed, compared to
> > > > > simply passing char* ?
> > > > 
> > > > I'd like to avoid to convert the sws_flags of the AVFilterGraph to a
> > > > string when creating and inserting the scale filter.
> > > > 
> > > > The scale filter should be able to accept in input the sws context
> > > > parameters from the args string.
> > > > 
> > > > But using the args interface for passing the flags from the
> > > > AVFilterGraph sws_flags to the scale filter is quite awkward, and
> > > > involves doing snprintf in the
> > > > query_formats/avfilter_graph_config_formats() code.
> > > 
> > > i think i prefer if args is used instead of doing funny things with
> > > opaque dummy contexts
> > 
> > New patch, but I still would prefer a solution using somehow a
> > SwsContext in the AVFilterGraph.
> 
> i suspect we see this from a differnt point of view ...
> iam scared of passing 5 filter private contexts around randomly in
> AVFi*
> 
> now its just sws but that might change ...
> and a string is much clearer in that case ...

Fine, and we can change it later if we extend the lsws API, lavfi
major bumps shouldn't be too much an issue at this early stage.

Waiting for review/OK.

A possible issue we have now is that we need to escape the '=' char in
the command, for example:

ffplay ~/samples/asian-commercials-are-weird.flv -vfilters "scale=300:200:sws_flags\=experimental+bitexact+full_chroma_inp"

If we don't want to require such escaping for the '=' char, we could
apply the attached patch, but I'm not sure it's a good idea.

Regards.
-- 
FFmpeg = Faithless and Free Mean Pacific Eccentric Gem
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