avdevice/decklink: remove pthread dependency
authorAaron Levinson <alevinsn@aracnet.com>
Sat, 15 Apr 2017 06:41:46 +0000 (08:41 +0200)
committerMarton Balint <cus@passwd.hu>
Sat, 15 Apr 2017 10:26:21 +0000 (12:26 +0200)
commit9e86a61870c1652cdcc6a34646aee40d973ba23b
tree219d266c41b2f2a1f13d99742cea1618ff5c0a16
parente8547647292ee827db593a4d5b60f041a6af9769
avdevice/decklink: remove pthread dependency

Purpose: avdevice/decklink: Removed pthread dependency by replacing
semaphore used in code appropriately.  Doing so makes it easier to
build ffmpeg using Visual C++ on Windows.  This is a contination of
Kyle Schwarz's "avdevice/decklink: Remove pthread dependency" patch
that is available at https://patchwork.ffmpeg.org/patch/2654/ .  This
patch wasn't accepted, and as far as I can tell, there was no
follow-up after it was rejected.

Notes: Used Visual Studio 2015 (with update 3) for this.

Comments:

-- configure: Eliminated pthreads dependency for decklink_indev_deps
   and decklink_outdev_deps and replaced with threads dependency

-- libavdevice/decklink_common.cpp / .h:
a) Eliminated semaphore and replaced with a combination of a mutex,
   condition variable, and a counter (frames_buffer_available_spots).
b) Removed include of pthread.h and semaphore.h and now using
   libavutil/thread.h instead.

-- libavdevice/decklink_dec.cpp: Eliminated include of pthread.h and
   semaphore.h.

-- libavdevice/decklink_enc.cpp:
a) Eliminated include of pthread.h and semaphore.h.
b) Replaced use of semaphore with the equivalent using a combination
   of a mutex, condition variable, and a counter
   (frames_buffer_available_spots).  In theory, libavutil/thread.h and
   the associated code could have been modified instead to add
   cross-platform implementations of the sem_ functions, but an
   inspection of the ffmpeg source base indicates that there are only
   two cases in which semaphores are used (including this one that was
   replaced), so it was deemed to not be worth the effort.

Signed-off-by: Marton Balint <cus@passwd.hu>
configure
libavdevice/decklink_common.cpp
libavdevice/decklink_common.h
libavdevice/decklink_dec.cpp
libavdevice/decklink_enc.cpp