[FFmpeg-devel] [RFC] Moving ffprobe's writers to lavu

[Paul B Mahol]

On 4/10/20, Nicolas George <george at nsup.org> wrote:
> Hi.
>
> In the comments on a recent patch to implement statistics outputs for a
> specific filter, I noted that this is something that many filters need
> to do, and therefore in need of unification. I also observed some JSON
> code in a filter, which does not belong there.
>
> https://ffmpeg.org/pipermail/ffmpeg-devel/2020-April/260178.html
>
> It reminded me of a project I have had for some time: moving the writers
> written for ffprobe (XML, JSON, INI, etc.) into libavutil.
>
> I am pretty sure it is doable, but I am also sure there will be
> pitfalls, cases where the writer are very specific to ffprobe's need and
> some careful design is needed to make them generic while keeping
> compatibility.
>
> And in any case, it will be quite some work, I do not want to do it if
> it will be bikeshedded to death, so I first put the principle on
> discussion here.
>
> Do you think it is a good idea to add functions to produce formatted
> output for structured data in libavutil?
>
>
> There is another, smaller pitfall: where do these functions output to?
> ffprobe outputs to stdout; the patch quoted above outputs through AVIO
> to any supported format; some filters put data as string metadata. The
> obvious answer to that is to "write" to a callback, and have the
> callback decide to write the data to stdout, AVIO or a memory buffer.
>
> A few months ago, I proposed the draft of an elegant (IMNSHO) API for
> "write to a callback", but it immediately gave signs to be bikeshedded
> to death. If I start working on this project, I intend to finish and use
> it, because it's exactly the kind of use I had in mind for it.
>
> https://ffmpeg.org/pipermail/ffmpeg-devel/2019-December/254042.html
>
> Please share your thoughts, including if only to say you think it is a
> good idea.

I'm very glad you got it.

Your constant bikesheeding against my patches give bikesheeds to your own work.