[mythtv] Switching to cmake: how to add extra ffmpeg params at configure?

[David Hampton]

On Fri, 2025-03-28 at 09:29 +0100, Piotr Oniszczuk wrote:
> David,
> 
> 
> 
> > Wiadomość napisana przez David Hampton via mythtv-dev
> > <mythtv-dev at mythtv.org> w dniu 27 mar 2025, o godz. 22:14:
> > 
> > On Thu, 2025-03-27 at 18:05 +0100, Piotr Oniszczuk wrote:
> > > Guys,
> > > 
> > > I’m switching to cmake
> > > what is best way to specify additional ffmpeg params at cmake
> > > configure ?
> > 
> > What kind of arguments?  Do they include spaces in the values?
> 
> Starting point is set like:
> https://github.com/warpme/minimyth2/blob/b4b03a77401edc65221784c79a87ef01a97934ac/script/myth-master/mythtv/Makefile#L238
>  till L265 or so
> In target cmake I’ll optimise list of options so list will be
> probably shorter nevertheless there will be multiple options i want
> to pass to ffmpeg (some of them are extra as i’m adding extra code to
> ffmpeg) 
> 
> > 
> > If I don't have to parse spaces, I should be able to add an extra
> > variable you can set on the command line that gets passed to FFmpeg
> > configure.  If I have to parse spaces, its much more of a pain.
> 
> Indeed - in my experiments i already discovered spaces are problem…

Let me rephrase my statement.  Multiple options shouldn't be a problem,
so I can get something like -DFF_USER_OPTS="--enable-xxx --disable-yyy"
working fairly easily.  Options contain a space in their value are what
I'm concerned about, like --foo-path="/path/name/containing a space". 
Trying to parse something like this:

  -DFF_USER_OPTS='--enable-xxx --foo-path="/path name"'
  -DFF_USER_OPTS="--enable-xxx --foo-path=\"/path name\""

is where I think it will get tricky.

There are a couple of path based arguments in your list, but most look
like simple enable/disable arguments without values.
 
David