[x265] Next steps on my road map

[Steve Borho]

On 04/08, Xinyue Lu wrote:
> Hi,
> 
> Here are some patches that are applied in my personal mod, and I'd like to know which of them do you have interests so
> that I can clean up and submit to official repo.
> 
> 1. Logging to file with --log-file <file.log> --log-file-level <LEVEL>.

dunno, we have --csv already for logging per-frame stats.  Is there a
really good use case for this?

you could probably talk me into a logging callback funcdef in
x265_param, so we call a user function instead of writing directly to
stderr.

> 2. LAVF Input, can take common media files as input directly, e.g. MKV or MP4 files.
> Potentially add --demuxer <demuxer> option to manually pick a demuxer.
> Potentially replace --y4m, remove bForceY4m.
> 
> The original authors of this patch is Mike Gurlitz <mike.gurlitz at gmail.com> and Steven Walters <kemuri9 at gmail.com>.
> 
> LAVF Library is LGPL/GPL/nonfree.
> 
> 3. Matroska Muxer
> 
> The original author is Mike Matsnev <mike at haali.su>.
> 
> 4. L-Smash MP4 Muxer
> 
> The original authors are:
> Laurent Aimar <fenrir at via.ecp.fr>
> Loren Merritt <lorenm at u.washington.edu>
> Yusuke Nakamura <muken.the.vfrmaniac at gmail.com>
> Takashi Hirata <silverfilain at gmail.com>
> golgol7777 <golgol7777 at gmail.com>
> 
> And liblsmash is GPL.
> 
> - - -
> 
> Apart from your interests, the license problem is also what I'm concerning about.
> 
> x265 can be licensed under commercial license. Can we still port the patch / function from x264? Do you have an
> agreement that you can use x264 code base / patches without licensing problem?

we are allowed to use or adapt source code from x264.

> When linking against lsmash (or maybe libav) should I place an option like ENABLE_GPL inside CMakeList?

yes, it would be necessary

> Should these demuxers / muxers be enabled by default during compiling?

>From my point of view, it would make some sense to have matroska support
in the repository since it is an open format and reasonably simple and
it would allow us to open output streams in more media viewers; it would
serve as a debugging feature.

The rest has a much higher burden - we would have to add and maintain
different build options for GPL vs commercial customers, and have to
maintain interface code to external libraries.  My first impulse would
be to keep them as external patches, but I'm willing to listen to other
opinions on this.

At least after your recent refactors it should be clean to keep
additional muxers in external patches. I think they would only need to
touch files in source/output.

-- 
Steve Borho