Re: Default info methods

[Fran Burstall (Gmail)]

I propose to the following default config scheme instead:
- If emms-print-metadata, tinytag or exiftool is found, use only one of
  them.  The assumption here is that any of these suffices to supply all
  metadata for all tracks.
- Otherwise use emms-info-native.  This can be augmented by mp3info (for
  id3v1 tags).  Ogginfo, metaflac and opusinfo are superseded by
  emms-info-native, so they can be ignored.
What do you think?

I think this is a good idea.

---Fran

On Sat, 6 Mar 2021 at 18:47, Petteri Hintsanen <petterih@iki.fi> wrote:

Hi all,

While working on Chapter 13 "Track Information" of Emms manual, I
realized that Emms actually populates emms-info-functions on startup via
emms-all.  I think this is the right thing to do, as it provides
functional metadata support out of the box.

But the way emms-all does this could be improved.  Now it snoops if any
of the following programs is installed and if yes, it adds the
corresponding info method to emms-info-functions:

 - emms-info-mp3info-program
 - emms-info-ogginfo-program-name
 - emms-info-opusinfo-program-name

Finally it unconditionally adds emms-info-cueinfo.  For completeness we
could add exiftool, emms-print-metadata, metaflac and emms-info-native
into emms-all too.  Tinytag is a tad bit difficult because it is a
Python library, not a separate executable.  But I think we should try to
detect its presence as well, and add emms-info-tinytag if it is
available.

There is a caveat in this strategy though.  If there are multiple info
methods configured at the same time, all of them will be called, and
metadata from latter methods will override the metadata from earlier
ones.  This is desirable if the methods are functionally orthogonal,
like emms-info-mp3info and emms-info-ogginfo, but problematic when the
methods are feature-par with each other, like emms-info-tinytag and
emms-info-exiftool.  In the latter case Emms invokes two processes to
get almost the same information, where only one would usually suffice.

I propose to the following default config scheme instead:

- If emms-print-metadata, tinytag or exiftool is found, use only one of
  them.  The assumption here is that any of these suffices to supply all
  metadata for all tracks.

- Otherwise use emms-info-native.  This can be augmented by mp3info (for
  id3v1 tags).  Ogginfo, metaflac and opusinfo are superseded by
  emms-info-native, so they can be ignored.

What do you think?

--
Petteri