[Fedora-packaging] Packaging Gnac (An audio converter for GNOME)

[Michael Schwendt]

On Mon, 18 Jan 2010 23:27:12 +0200, Manuel wrote:

> Actually as an ordinary user you would see an application that claims to 
> support a file type, but it does not. Most users have no idea what a 
> plugin is. And they do not care. They just want the application to 
> simply work (trust me on this one, I am doing user support since '87 and 
> I've had my share of WTFs).

Though, for those who do research about 3rd party add-on packages, installing
additional GStreamer plugin packages will make this particular app work.
Plus, the app's default .desktop file will not need a modification.
That's the only benefit. The users will not need to install a gnac-freeworld
packages to extend the application. Nobody will need to create and
maintain that extra package.

However, in the same way the 3rd party add-on packages provide additional
codecs to GStreamer, they may also

 - supply support for even further file types _not_ covered by
   the .desktop file,
 - remove support for file types regardless of what the .desktop file says.

It boils down to deciding how Fedora would like it to be handled in
general. There are no guidelines about that yet. Fedora _without_ added
3rd party repositories does not provide MP3 support. Do we want software
to advertise MP3 support nevertheless?  If so, what conditions must be
met? Clear error messages about failures to handle files, even if
"secret"/undocumented 3rd party codecs pkgs are missing?
How much weight do we give 3rd party add-on repositories in Fedora's
packages even if we cannot create RPM dependencies for any add-ons?

In another review, an audio utility examines files with "sox". Fedora's
"sox" does not handle .mp3, .mpc, .wma and many other file formats either.
It cannot easily be extended. One way to extend it is to _replace_ it
with an ugly shell-wrapper-script that handles some file types with
external tools, albeit in a very basic way only. Such a replacement
packages is not available yet, afaik. So, if the app pretended that
it would handle MP3, it would be wrong and also confusing. On the contrary,
if it only advertised support for the file types that Fedora's software
collection can handle, I would find that okay.

> I might be persuaded to accept an error 
> message saying "It seems you want to play a file of type XYZ but 
> unfortunately you miss some bits. For a full blown experience, please 
> visit http://<useful hint goes here>  install the support for XYZ and 
> retry". But I would remove without hesitation an application which pops 
> in just to say "Hey, Johny! Remember what you have just tried ? Guess 
> what ! It does not work ! (No, Johny, I will not tell you why, go figure 
> that yourself.)".

That's close to what Gnac does currently, unfortunately. It doesn't
complain at all about adding a file it doesn't understand. Later, upon
starting the conversion, it only says

  Conversion complete with errors

in its status bar. Which isn't true. Actually the conversion had failed
entirely. On the console it's not much more specific:

  Gnac failed to convert file file:///home/qa/Desktop/audio/test/1.wma
  Error message: An error occured during conversion