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This work is sponsored by, and copyright, Google. These are ported from the ARM version; thanks to the larger amount of registers available, we can do the loop filters with 16 pixels at a time. The implementation is fully templated, with a single macro which can generate versions for both 8 and 16 pixels wide, for both 4, 8 and 16 pixels loop filters (and the 4/8 mixed versions as well). For the 8 pixel wide versions, it is pretty close in speed (the v_4_8 and v_8_8 filters are the best examples of this; the h_4_8 and h_8_8 filters seem to get some gain in the load/transpose/store part). For the 16 pixels wide ones, we get a speedup of around 1.2-1.4x compared to the 32 bit version. Examples of runtimes vs the 32 bit version, on a Cortex A53: ARM AArch64 vp9_loop_filter_h_4_8_neon: 144.0 127.2 vp9_loop_filter_h_8_8_neon: 207.0 182.5 vp9_loop_filter_h_16_8_neon: 415.0 328.7 vp9_loop_filter_h_16_16_neon: 672.0 558.6 vp9_loop_filter_mix2_h_44_16_neon: 302.0 203.5 vp9_loop_filter_mix2_h_48_16_neon: 365.0 305.2 vp9_loop_filter_mix2_h_84_16_neon: 365.0 305.2 vp9_loop_filter_mix2_h_88_16_neon: 376.0 305.2 vp9_loop_filter_mix2_v_44_16_neon: 193.2 128.2 vp9_loop_filter_mix2_v_48_16_neon: 246.7 218.4 vp9_loop_filter_mix2_v_84_16_neon: 248.0 218.5 vp9_loop_filter_mix2_v_88_16_neon: 302.0 218.2 vp9_loop_filter_v_4_8_neon: 89.0 88.7 vp9_loop_filter_v_8_8_neon: 141.0 137.7 vp9_loop_filter_v_16_8_neon: 295.0 272.7 vp9_loop_filter_v_16_16_neon: 546.0 453.7 The speedup vs C code in checkasm tests is around 2-7x, which is pretty much the same as for the 32 bit version. Even if these functions are faster than their 32 bit equivalent, the C version that we compare to also became around 1.3-1.7x faster than the C version in 32 bit. Based on START_TIMER/STOP_TIMER wrapping around a few individual functions, the speedup vs C code is around 4-5x. Examples of runtimes vs C on a Cortex A57 (for a slightly older version of the patch): A57 gcc-5.3 neon loop_filter_h_4_8_neon: 256.6 93.4 loop_filter_h_8_8_neon: 307.3 139.1 loop_filter_h_16_8_neon: 340.1 254.1 loop_filter_h_16_16_neon: 827.0 407.9 loop_filter_mix2_h_44_16_neon: 524.5 155.4 loop_filter_mix2_h_48_16_neon: 644.5 173.3 loop_filter_mix2_h_84_16_neon: 630.5 222.0 loop_filter_mix2_h_88_16_neon: 697.3 222.0 loop_filter_mix2_v_44_16_neon: 598.5 100.6 loop_filter_mix2_v_48_16_neon: 651.5 127.0 loop_filter_mix2_v_84_16_neon: 591.5 167.1 loop_filter_mix2_v_88_16_neon: 855.1 166.7 loop_filter_v_4_8_neon: 271.7 65.3 loop_filter_v_8_8_neon: 312.5 106.9 loop_filter_v_16_8_neon: 473.3 206.5 loop_filter_v_16_16_neon: 976.1 327.8 The speed-up compared to the C functions is 2.5 to 6 and the cortex-a57 is again 30-50% faster than the cortex-a53. Signed-off-by: Martin Storsjö <martin@martin.st> |
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compat | ||
doc | ||
libavcodec | ||
libavdevice | ||
libavfilter | ||
libavformat | ||
libavresample | ||
libavutil | ||
libswscale | ||
presets | ||
tests | ||
tools | ||
.gitattributes | ||
.gitignore | ||
.travis.yml | ||
arch.mak | ||
avconv_dxva2.c | ||
avconv_filter.c | ||
avconv_opt.c | ||
avconv_qsv.c | ||
avconv_vaapi.c | ||
avconv_vda.c | ||
avconv_vdpau.c | ||
avconv.c | ||
avconv.h | ||
avplay.c | ||
avprobe.c | ||
Changelog | ||
cmdutils_common_opts.h | ||
cmdutils.c | ||
cmdutils.h | ||
common.mak | ||
configure | ||
COPYING.GPLv2 | ||
COPYING.GPLv3 | ||
COPYING.LGPLv2.1 | ||
COPYING.LGPLv3 | ||
CREDITS | ||
INSTALL | ||
library.mak | ||
LICENSE | ||
Makefile | ||
README | ||
README.md | ||
RELEASE | ||
version.sh |
Libav
Libav is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodec
provides implementation of a wider range of codecs.libavformat
implements streaming protocols, container formats and basic I/O access.libavutil
includes hashers, decompressors and miscellaneous utility functions.libavfilter
provides a mean to alter decoded Audio and Video through chain of filters.libavdevice
provides an abstraction to access capture and playback devices.libavresample
implements audio mixing and resampling routines.libswscale
implements color conversion and scaling routines.
Tools
- avconv is a command line toolbox to manipulate, convert and stream multimedia content.
- avplay is a minimalistic multimedia player.
- avprobe is a simple analisys tool to inspect multimedia content.
- Additional small tools such as
aviocat
,ismindex
andqt-faststart
.
Documentation
The offline documentation is available in the doc/ directory.
The online documentation is available in the main website and in the wiki.
Examples
Conding examples are available in the doc/example directory.
License
Libav codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.