[FFmpeg-devel] [PATCH] lavf: add ffprobe demuxer

[Stefano Sabatini]

On date Friday 2016-09-23 09:34:19 +0200, wm4 encoded:
> On Thu, 22 Sep 2016 18:50:27 +0200
> Stefano Sabatini <stefasab at gmail.com> wrote:
[...]
> > Ping. I'd like to commit this if there are no objections. Also,
> > possibly add a muxer to generate output directly readable by the
> > demuxer (this way we don't need ffprobe for generating the output, and
> > we avoid the ordering issue).
> 
> I'm sorry to jump in as a nay-sayer, but it looks like a quite fishy
> concept and I still don't get why it's supposed to be needed. The
> documentation also doesn't say what this is supposed to be useful for.

I'll extend the documentation to add some possibly useful use cases.

My use case: I need to build a data stream with scripting/manual
editing. Since I don't want to have to rely on a binary format (which
is not ideal for that use case) I needed a format simple enough to be
written and analysed without special tools, but with a simple text
editor.

Also, if coupled with a muxer it allows to create an output, tweak it
(e.g. to change the timestamps) and feed it to FFmpeg, which might be
useful from time to time to test/debug specific features.

The alternative might be to build a tool for converting to
custom-format to a "binary" format accepted by FFmpeg, but I want
to avoid the need for an additional tool.

This format is my second attempt after the fftextdata format, which
was regarded too limited. This one is based on the ffprobe default
output (although it's simplified).

> It's also potentially a security issue (lots of text parsing, and can
> construct inputs which might be tricky for API users).
> 
> I probably can't stop you from pushing this, but at least it shouldn't
> be enabled by default.

I understand the security concerns, and I have no objections against
disabling this by default if developers prefer this way.
-- 
FFmpeg = Freak Frightening Merciless Pacific Erroneous Glue