Close #8467

1. fix build error for ios.
2. fix vlc_getProxyUrl always return NULL on osx.
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

close #6217

still needs some testing

close #8375

The new thread avoids blocking the audio pipeline while waiting for a
picture buffer. The Goom plugin already follows the same approach.

This mostly reverts commit fc5156cc.
This also fixes a use-after-free bug.

Signed-off-by: Rafaël Carré <funman@videolan.org>

Signed-off-by: Rafaël Carré <funman@videolan.org>

configure.ac disable/don't load avcapture module and its framework if AVFoundation is not present (OS 10.6)
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

configure.ac: fix linking the OSX UI module if the AVFoundation framework isn't present (read: OSX 10.6)

This module lets you capture video devices with the AVFoundation framework on Mac OS X.
It is an upgrade of the qtcapture module. Currently no GUI integration yet.
Only available via command line

Usage: avcapture://
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

Assuming stereo is fairly safe and still better than not decoding anything.
This is what gstreamer does, and mplayer might do the same thing.

Note that updated meta are still marked with access_t.info.i_update,
which remains undefined in case of threaded stream filter. Luckily,
unlike pf_control() re-entrancy, unprotected access to info.i_update
cannot crash on any practical system.

This was only used for INPUT_UPDATE_SIZE.