We now test that the selected fourcc actually works by calling vaGetImage.
Initial patch from Gwenole Beauchesne.

No functional changes.

No functional changes.

Two new functions added:

 * val = libvlc_audio_get_delay( p_mi )
 * libvlc_audio_set_delay( p_mi, i_delay )

The delay is measured in microseconds.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

As suggested by Jan Janak <jan@ryngle.com>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Entity encoding was missing (for options) in generation of an xspf playlist.
On the reading side the entity decoding is all fine.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

This reverts commit f5b8b43a.

This reverts commit 8c1d2b3e.

 - add an optional display callback,
 - make unlock callback optional (planes could be static),
 - pass an opaque picture identifier from lock to unlock and display
   callbacks (this would enable multiple pictures later),
 - pass pixel planes back to the unlock callback for convenience,
 - use pointer VLC variables instead of configuration strings,
 - fix an unlikely memory leak.

avcodec native decoder has priority over libvpx one, and I don't know
howto change that easily. Fix #3820

Fixes eg youtube viewing.

The signal handler currently does nothing anyway, so this was a waste.

Returns NULL if the variable cannot be inherited - pointers can never
be found in the configuration.

typo and double free

Also accept filter-name without +/- as enabled one, so user can see
messages by just typing module-name without any other syntax.