GStreamer regression analysis [was: GNOME and GStreamer]

["Ronald S. Bultje" <rbultje ronald bitfreak net>]

Hi,

I ran a quick regression analysis on the few GStreamer modules that I
could quickly get to build (totem plus all subparts, gnome-media).
Summary of results: totem does some good things and also does not do
some things, it has quite many regressions (as Christian already
mentioned). The mozilla plugin and nautilus properties pages are
completely broken. The thumbnailer sometimes works and sometimes not.
GNOME-media: most apps (gnome-cd, gst-mixer) work fine (no regressions),
g-s-r only works for some formats (surprisingly, vorbis didn't work) and
playback is completely broken. Conclusion: I leave that open.

Part 1, totem.

First, general:
- appears unstable; I've reported several crashes, hangs, 100% cpu
cases, etc. in bugzilla. In some cases where the file doesn't play but
also doesn't crash, I get multiple or no error dialogs, which gives the
impression of bad integration of GStreamer backend in Totem frontend.
- the video screen does not update when a menu is expanded and then
clicked away. The video screen becomes cyan (?!), instead of the nice
Totem logo from Jakub.
- first start takes hellishly long (>10s on my laptop), apparently
because of a registry rebuild. You'll need to provide some user feedback
here (e.g. a splash screen), the user will think the app is broken and
Linux (or GNOME, for that matter) sucks.

Video playback:
- mpeg, vob: basic playback works, slider is wrong after seek, hangs on
eos. No metadata provided
- avi: appears to work. seeking is very slow.
- matroska, mkv: appears to work, hangs on eos.
- quicktime, mp4: some movies work, some movies don't. Seeking is
broken. Hangs on eos.
- ogg, theora: appears to work, no video metadata provided.
- asf, wmv: doesn't work.
- gaming formats (quake, final fantasy etc.): doesn't work.
- vcd, dvd: doesn't work.
- multi-language/language-selection (audio in mkv, ogm): the files I
tested didn't work, but that may be related to other problems... I
haven't been able to actually get the language selection menu item
sensitive for any multi-language file I tried... Unsure if this works or
not. Probably doesn't [1].
- subtitles (subtitles embedded in mkv, ogm, or separate text files):
doesn't work [1] [2].

Audio playback:
- wma (Windows Audio): doesn't work.
- mp3: appears to work. Unsure about non-utf8 tags.
- ogg, vorbis: works, except for minor metadata twitch.
- m4a: wish I could say, can't find sample files. :-( I apparently
removed all of them from my HD...

Nautilus properties page:
- blank for all file types above. Doesn't work.

Firefox plugin:
- doesn't work for the few file types I could find in websites (wmv,
mov).

Thumbnailing:
- works for some (quicktime/mp4, ogg), not for others (mkv, mpg/vob).

Part 2, gnome-media

didn't build for me, requires some more patches to be 0.10 aware. I'll
commit those monday if I decide to roll the 0.10 version for a tarball
(which is yet undecided). Makes an overall better impression than Totem.

gstreamer-properties:
- should be moved back to some behind screen, since gst now contains
autodetection elements and most, if not all, users will no longer need
gstreamer-properties.

gnome-cd:
- works.

gst-mixer:
- works

gnome-sound-recorder:
- vorbis audio recording does not work. MPEG-4/AAC audio recording is no
longer available. FLAC/WAV works fine, and MP3 (once added in
media-profiles) appears to work also.
- playback is broken for all formats.
- Totem hangs on EOS for all files created by g-s-r, unsure if that's
related to the earlier hang-bugs or a file creation bug.

Conclusions

For all bugs above, I've filed bugs on http://bugzilla.gnome.org/ so
that relevant people can have a look at the bugs. There's quite a few of
them. I'd like to suggest that relevant maintainers & co give ideas on
how those will be fixed and which regressions will be left open for
2.14, from there on we can decide if it's worth it for GNOME to jump
ship and ship 0.10 rather than 0.8.
0.8 is not unmaintained, btw, I intend to do a new release containing
all fixes I provided to make the totem firefox plugin work fine. There's
also a crasher fix in there, IIRC. If anything else pops up, I'll
consider including that, also. If there's serious bugs, I may even have
a look at them.

Let's start the real discussion now!

Cheers,
Ronald

[1] Possibly blocker bugs for localization purposes.
[2] Thomas mentioned that subtitles depend on filler events (some
GStreamer API peculiarity) and that it's OK for them to not work since
they're undiscoverable. Those two are mutually exclusive. There's two
types of subtitles, those embedded in the actual media file (ogm, mkv)
and those in separate files (.sub for .avi, etc.). The former depends on
fillers and is very discoverable, since it's automagic: the file
contains subtitles and thus they play, similar to audio files making
sounds or video files giving funny colors on your screen in a particular
composition (AKA image). The latter may not be very discoverable,
depending on whether people read docs or not, but does not require
fillers.