This adds av_warn_unused_result to functions whose return codes need to
be checked.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
It's been argued that the benefits of the current implementation far outweight
those of making the structs opaque.
This deprecation is not present in any release, so it can be safely removed.
Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
The return code here should be checked.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
The open syscall can obviously fail, and its return code needs to be
checked.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
It has already been demonstrated that the de Bruijn method has benefits
over the current implementation: commit 971d12b7f9.
That commit implemented it for long long, this extends it to the int version.
Tested with FATE.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
changing the context state and restoring it is not safe if another
thread writes data into the fifo
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This reduces the memory & cache need from 256 to 64 bytes
the code also seems faster with this change
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This uses Stein's binary GCD algorithm:
https://en.wikipedia.org/wiki/Binary_GCD_algorithm
to get a roughly 4x speedup over Euclidean GCD on standard architectures
with a compiler intrinsic for ctzll, and a roughly 2x speedup otherwise.
At the moment, the compiler intrinsic is used on GCC and Clang due to
its easy availability.
Quick note regarding overflow: yes, subtractions on int64_t can, but the
llabs takes care of that. The llabs is also guaranteed to be safe, with
no annoying INT64_MIN business since INT64_MIN being a power of 2, is
shifted down before being sent to llabs.
The binary GCD needs ff_ctzll, an extension of ff_ctz for long long (int64_t). On
GCC, this is provided by a built-in. On Microsoft, there is a
BitScanForward64 analog of BitScanForward that should work; but I can't confirm.
Apparently it is not available on 32 bit builds; so this may or may not
work correctly. On Intel, per the documentation there is only an
intrinsic for _bit_scan_forward and people have posted on forums
regarding _bit_scan_forward64, but often their documentation is
woeful. Again, I don't have it, so I can't test.
As such, to be safe, for now only the GCC/Clang intrinsic is added, the rest
use a compiled version based on the De-Bruijn method of Leiserson et al:
http://supertech.csail.mit.edu/papers/debruijn.pdf.
Tested with FATE, sample benchmark (x86-64, GCC 5.2.0, Haswell)
with a START_TIMER and STOP_TIMER in libavutil/rationsl.c, followed by a
make fate.
aac-am00_88.err:
builtin:
714 decicycles in av_gcd, 4095 runs, 1 skips
de-bruijn:
1440 decicycles in av_gcd, 4096 runs, 0 skips
previous:
2889 decicycles in av_gcd, 4096 runs, 0 skips
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
GCC 3.4 introduced an attribute warn_unused_result to warn when a programmer
discards the return value. Applying this judiciously across the codebase can help
in fixing a lot of problems. At a high level, functions which return error codes
should always be checked. More concretely, consider the functions ff_add_format
and the like in avfilter/formats.h. A quick examination shows that a large portion
of libavfilter fails to handle the associated errors, usually AVERROR(ENOMEM).
The above example was where I observed the utility of this, but it should be
useful in many places across the code base.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
They're short enough that inlining them actually reduces code size due to
all the overhead associated with making a function call.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
These field are difficult to interpret, and are provided by a single
encoder (mpegvideoenc). In general they do not belong to a structure
containing raw data only, so remove them from AVFrame.
Mpegvideoenc now uses a private field in Picture for its internal
computations.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
MIPS R6 supports unaligned memory access and does not have
the load/store-left/right family of instructions.
Signed-off-by: Vicente Olivert Riera <Vincent.Riera at imgtec.com>
Signed-off-by: Luca Barbato <lu_zero at gentoo.org>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Most functions are valid over a domain and range of [0.0-1.0] but
some are defined over greater. This patch does not deal with
AVColorRange and assumes AVCOL_RANGE_JPEG for the returned values.
Signed-off-by: Kevin Wheatley <kevin.j.wheatley@gmail.com>
Signed-off-by: Kevin Wheatley <kevin.j.wheatley@gmail.com>
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Ensure that the components are ordered consistently, ie. always
RGB(A) and YUV(A). This allows to identify a specific plane on a given
pixel format without hard-coding knowledge of the plane order.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
There is no practical benefit in having this structure elements
bit packed given the size of the structure and its usage.
Change types from uint16_t (packed) to plain int in order to simplify
modifying the structure and accessing its fields.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
FATE refs changed to accomodate for the new default behavior of the function.
Numbers are now interpreted as a channel layout, instead of a number of channels.
Timothy Gu
Ganesh Ajjanagadde
James Almer
Michael Niedermayer
wang-bin
Zhang Rui
Luca Barbato
Vittorio Giovara
Ronald S. Bultje
Rodger Combs
Henrik Gramner
Vicente Olivert Riera
Timo Rothenpieler
Kevin Wheatley
Hendrik Leppkes
Clément Bœsch
wm4