AV_CODEC_CAP_AUTO_THREADS was originally added in b4d44a45f9 to mark
codecs that spawn threads internally and are able to select an optimal
threads count by themselves (all such codecs are wrappers around
external libraries). It is used by lavc generic code to check whether it
should handle thread_count=0 itself or pass the zero directly to the
codec implementation. Within this meaning, it is clearly supposed to be
an internal cap rather than a public one, since from the viewpoint of a
libavcodec user, lavc ALWAYS handles thread_count=0. Whether it happens
in the generic code or within the codec internals is not a meaningful
difference for the caller.
External aspects of this flag will be dealt with in the following
commit.
pthread_wait_cond can wake up unexpectedly (Wikipedia: Spurious_wakeup).
The FF_THREAD_SLICE thread mechanism could spontaneously execute
jobs or allow the caller of avctx->execute to return before all
jobs were complete.
Test both cases to ensure the wakeup is real.
Signed-off-by: Ben Jackson <ben@ben.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Sometimes, if pthread_create() failed, then pthread_cond_wait() could
accidentally be called in the worker threads after the uninit function
had already called pthread_cond_broadcast(), leading to a deadlock.
Don't call pthread_cond_wait() if c->done is set.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Those were useful when avcodec_thread_init() was a public functions. It
was deprecated and removed some time ago, so those checks are not needed
anymore.
Intra codecs do not need an update_thread_context() function and never
call ff_thread_finish_setup(). They rely on ff_thread_get_buffer()
calling it. So call it even if the get_buffer2 function pointer is
avcodec_default_get_buffer2 and it has not been called before.
Just like get_buffer, get_format should not be called from a different
thread if thread_safe_callbacks is not set.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Allows use of AVHWAccel based decoders with frame based multithreading.
The decoders will be forced into an non-concurrent mode by delaying
ff_thread_finish_setup() calls after decoding of the current frame
is finished.
This wastes memory by unnecessarily using multiple threads and thus
copies of the decoder context but allows seamless switching between
hardware accelerated and frame threaded software decoding when the
hardware decoder does not support the stream.
This fixes the following warning with GCC:
libavcodec/pthread.c:35:0: warning: _GNU_SOURCE redefined [enabled by default]
<command-line>::0: note: this is the location of the previous definition
The reason of the presence of this flag is:
% pkg-config --cflags sdl
-D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL
pthread_wait_cond can wake up for no reason (Wikipedia: Spurious_wakeup).
The FF_THREAD_SLICE thread mechanism could spontaneously execute jobs or
allow the caller of avctx->execute to return before all jobs were complete.
This adds tests to both cases to ensure the wakeup is real.
Signed-off-by: Ben Jackson <ben@ben.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This removes all references to AVCodecContext.dsp_mask and marks
it for eviction at the next version bump. It has been superseded
by av_set_cpu_flag_mask() which, unlike this field, works everywhere.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Anton Khirnov
Vittorio Giovara
Mickaël Raulet
Ben Jackson
Derek Buitenhuis
Diego Biurrun
Sean McGovern
Carl Eugen Hoyos
Paul B Mahol
Dave Yeo
Michael Niedermayer
Janne Grunau
Reimar Döffinger
Hendrik Leppkes
Clément Bœsch
Mans Rullgard
Martin Storsjö
Dale Curtis