Writing the scaled excitation to a scratch buffer (borrowing the
'audio' array) instead of modifying it in place avoids the need
to save and restore the unscaled values.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Use saturating addition functions instead of 64-bit intermediates
and separate clipping. This is much faster when dedicated
instructions are available.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Firstly, nothing in this function can overflow 32 bits so the use
of a 64-bit type is completely unnecessary. Secondly, the scale
is either a power of two or 0x7fff. Doing separate loops for these
cases avoids using multiplications. Finally, since only the number
of bits, not the actual value, of the maximum value is needed, the
bitwise or of all the values serves the purpose while being faster.
It is worth noting that even if overflow could happen, it was not
handled correctly anyway.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The operands in both cases are 16-bit so cannot overflow a 32-bit
destination. In gain_scale() the inputs are reduced to 14-bit,
so even the shift cannot overflow.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Adding instead of subtracting the products in the loop allows the
compiler to generate more efficient multiply-accumulate instructions
when 16-bit multiply-subtract is not available. ARM has only
multiply-accumulate for 16-bit operands. In general, if only one
variant exists, it is usually accumulate rather than subtract.
In the same spirit, using the dedicated saturation function enables
use of any special optimised versions of this.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Fixed-point audio codecs often use saturating arithmetic, and
special instructions for these operations are common.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This adds a function to retrieve the number of entries in a
dictionary and updates the places directly accessing what should
be an opaque struct to use this new function instead.
Signed-off-by: Mans Rullgard <mans@mansr.com>
In 16-bit arithmetic, x * 0xffffc is simply x * -4 with extra overflows,
(and the constant was probably meant to be 0xfffc). Combined with the
shift, this simplifies to -x >> 1. Finally, clearing the low two bits
with a 32-bit mask and switching to a 32-bit type allows more efficient
code on 32-bit machines.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The condition is trivially true, but keeping the assert() is
sensible to avoid FFM_HEADER_SIZE ever getting out of sync with
the actual code.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The only compiler I have that does not define the standard
offsetof() macro is "Bruce's C Compiler", a simple compiler
for producing 8/16-bit 8086 code, usually for use in early
stages of PC booting.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This list is incomplete (we also use UINT16_MAX), so there does
not appear to be any system we care about that needs these.
Signed-off-by: Mans Rullgard <mans@mansr.com>
At both places this function is called, mb_[xy] == s->mb_[xy]
making the call together with following code equivalent to
simply assigning zeros.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The main benefit of inlining this function is from constant
propagation for the 'field_based' argument. Instead of inlining
all calls, create two versions of the function for field_based
values of 0 and 1.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This file defines a single, huge function, MPV_motion(), which
although being declared inline is not actually inlined by the
compiler (for good reason). There is thus no sense in defining
this function in a header file, resulting in multiple copies of
it in the final library.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This adds a hidden config variable for the mpegvideo.o dependency
and selects from the codecs which require it.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This macro is only used in two places, both in libavcodec, so this
is a more sensible place for it.
Two small tweaks to the macro are made:
- removing the trailing semicolon
- dropping unnecessary 'volatile' from the x86 asm
Signed-off-by: Mans Rullgard <mans@mansr.com>
Many compilers need special flags to compile *.h files as regular
source code, if they will do so at all. Rather than hoping all
compilers will have such a flag and adding mappings for it, create
wrapper .c files for test building single headers.
This allows using the regular rule for compiling C files without the
need for special flags, and it also provides proper dependency tracking
for these objects.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Some compilers do not support the Q/R modifiers used to access
the low/high parts of a 64-bit register pair. Check for this
and disable all uses of it when not supported.
Fixes bug #337.
Signed-off-by: Mans Rullgard <mans@mansr.com>
It appears that something goes wrong in old nasm versions when the
%+ operator is used in the last argument of a macro invocation and
this argument is tested with %ifdef within the macro. This patch
rearranges the macro arguments such that the %+ operator is never
used in the last argument.
nasm does not support 'CPU foonop' directives. This adds a configure
test for the directive and uses it only if supported.
Signed-off-by: Mans Rullgard <mans@mansr.com>
yasm tolerates mismatch between movd/movq and source register size,
adjusting the instruction according to the register. nasm is more
strict.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This simplifies adding extra flags for individual programs
and also allows more than one object file per program.
Signed-off-by: Mans Rullgard <mans@mansr.com>
In the GNU assembler, a relational expression, bizarrely, has the
value -1 if true, whereas in Apple's it is +1. This patch makes
sure the correct expression is used in both cases.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The clang integrated assembler does not support pre-UAL syntax,
while gcc requires pre-UAL syntax for ARM code. A patch[1] for
clang to support the old syntax as well has been ignored since
January.
This patch chooses the syntax appropriate for each compiler,
allowing both to build the code. Notably, this change allows
building for iphone with the latest Apple Xcode update.
[1] http://llvm.org/bugs/show_bug.cgi?id=11855
Signed-off-by: Mans Rullgard <mans@mansr.com>
This allows building dct-test even if aandcttab.o is not pulled in
by any enabled codec. The DCT with which these tables are used does
not use them directly, so building it without the tables is possible.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Reordering the members in this struct reduces the holes required
to maintain alignment. With this order, the only remaining, and
unavoidable, hole is 3 bytes following left_nnz.
Signed-off-by: Mans Rullgard <mans@mansr.com>
These functions are not faster than other mmx implementations on
any hardware I have been able to test on, and they are horribly
inaccurate. There is thus no reason to ever use them.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The standard syntax requires two destination registers for
LDRD/STRD instructions. Some versions of the GNU assembler
allow using only one with the second implicit, others are
more strict.
Signed-off-by: Mans Rullgard <mans@mansr.com>
These decoders use a special non-MPEG2 IDCT. Call it directly
instead of going through dsputil. There is never any reason
to use a regular IDCT with these decoders or to use the EA IDCT
with other codecs.
This also fixes the bizarre situation of eamad and eatqi decoding
incorrectly if eatgq is disabled.
Signed-off-by: Mans Rullgard <mans@mansr.com>
There is no sense in pulling in this monster struct just for
a handful of fields. The code does not call any functions
expecting an MpegEncContext.
Signed-off-by: Mans Rullgard <mans@mansr.com>
MMX-enabled systems by default use some dsputil functions differing
from the C versions. Adding these flags ensures accurate ones are
used everywhere.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This allows non-standard replacements for the -c compiler flag.
Some compilers use other flags or no flag at all in place of
the usual one.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This allows using non-standard flags for running the C preprocessor.
The -o flag must be included in this setting due to strange syntax
required by some compilers.
Set the correct flags for tms470.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This adds a full identification probe of CC, AS, LD and HOSTCC,
and sets up correct flags and dependency tracking for each.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Use compiler-specific replacements for the -o flag in check_cc.
This makes tests work properly with compilers using non-standard
flags.
The tms470 flags are updated to work with this scheme.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This allows filtering of linker flags the same was as already
supported for CFLAGS. The filter must be initialised to 'echo'
early since it is invoked by --extra-ldflags.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This is not used and the current design would not work properly
if mixing tools needing different filters.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This moves all VP3-specific function pointers from dsputil to a
new vp3dsp context. There is no reason to ever use the VP3 IDCT
where an MPEG2 IDCT is expected or vice versa.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This simplifies testing arbitrary code fragments within a function
body.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Instead of inlining everything into ff_h264_hl_decode_mb(), use
explicit templating to create versions of the called functions
with constant parameters filled in. This greatly speeds up
compilation of h264.c and reduces the code size without any
measurable impact on performance.
Compilation time for h264.c on an i7 goes from 30s to 5.5s.
Code size is reduced by 430kB.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This tool uses lavfi internal symbols not accessible in shared
libraries. TESTPROGS are linked statically to allow them use of
library internals not normally exported.
Signed-off-by: Mans Rullgard <mans@mansr.com>
The buffers are only allocated once, although it can happen from
any of a few different places, so there is no need to use realloc.
Using av_malloc() ensures they are aligned suitably for SIMD
optimisations.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Currently, --enable-small turns av_always_inline into plain inline,
which is more or less ignored by the compiler. While the intent of
this is probably to reduce code size by avoiding some inlining, it
has more far-reaching effects.
We use av_always_inline in two situations:
1. The body of a function is smaller than the call overhead.
Instances of these are abundant in libavutil, the bswap.h
functions being good examples.
2. The function is a template relying on constant propagation
through inlined calls for sane code generation. These are
often found in motion compensation code.
Both of these types of functions should be inlined even if targeting
small code size.
Although GCC has heuristics for detecting the first of these types,
it is not always reliable, especially when the function uses inline
assembler, which is often the reason for having those functions in
the first place, so making it explicit is generally a good idea.
The size increase from inlining template-type functions is usually
much smaller than it seems due to different branches being mutually
exclusive between the different invocations. The dead branches can,
however, only be removed after inlining and constant propagation have
been performed, which means the initial cost estimate for inlining
these is much higher than is actually the case, resulting in GCC
often making bad choices if left to its own devices.
Furthermore, the GCC inliner limits how much it allows a function to
grow due to automatic inlining of calls, and this appears to not take
call overhead into account. When nested inlining is used, the limit
may be hit before the innermost level is reached. In some cases, this
has prevented inlining of type 1 functions as defined above, resulting
in significant performance loss.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Mans Rullgard
