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Martin Storsjö dd299a2d6d arm: vp9: Add NEON loop filters 
This work is sponsored by, and copyright, Google.

The implementation tries to have smart handling of cases
where no pixels need the full filtering for the 8/16 width
filters, skipping both calculation and writeback of the
unmodified pixels in those cases. The actual effect of this
is hard to test with checkasm though, since it tests the
full filtering, and the benefit depends on how many filtered
blocks use the shortcut.

Examples of relative speedup compared to the C version, from checkasm:
                          Cortex       A7     A8     A9    A53
vp9_loop_filter_h_4_8_neon:          2.72   2.68   1.78   3.15
vp9_loop_filter_h_8_8_neon:          2.36   2.38   1.70   2.91
vp9_loop_filter_h_16_8_neon:         1.80   1.89   1.45   2.01
vp9_loop_filter_h_16_16_neon:        2.81   2.78   2.18   3.16
vp9_loop_filter_mix2_h_44_16_neon:   2.65   2.67   1.93   3.05
vp9_loop_filter_mix2_h_48_16_neon:   2.46   2.38   1.81   2.85
vp9_loop_filter_mix2_h_84_16_neon:   2.50   2.41   1.73   2.85
vp9_loop_filter_mix2_h_88_16_neon:   2.77   2.66   1.96   3.23
vp9_loop_filter_mix2_v_44_16_neon:   4.28   4.46   3.22   5.70
vp9_loop_filter_mix2_v_48_16_neon:   3.92   4.00   3.03   5.19
vp9_loop_filter_mix2_v_84_16_neon:   3.97   4.31   2.98   5.33
vp9_loop_filter_mix2_v_88_16_neon:   3.91   4.19   3.06   5.18
vp9_loop_filter_v_4_8_neon:          4.53   4.47   3.31   6.05
vp9_loop_filter_v_8_8_neon:          3.58   3.99   2.92   5.17
vp9_loop_filter_v_16_8_neon:         3.40   3.50   2.81   4.68
vp9_loop_filter_v_16_16_neon:        4.66   4.41   3.74   6.02

The speedup vs C code is around 2-6x. The numbers are quite
inconclusive though, since the checkasm test runs multiple filterings
on top of each other, so later rounds might end up with different
codepaths (different decisions on which filter to apply, based
on input pixel differences). Disabling the early-exit in the asm
doesn't give a fair comparison either though, since the C code
only does the necessary calcuations for each row.

Based on START_TIMER/STOP_TIMER wrapping around a few individual
functions, the speedup vs C code is around 4-9x.

This is pretty similar in runtime to the corresponding routines
in libvpx. (This is comparing vpx_lpf_vertical_16_neon,
vpx_lpf_horizontal_edge_8_neon and vpx_lpf_horizontal_edge_16_neon
to vp9_loop_filter_h_16_8_neon, vp9_loop_filter_v_16_8_neon
and vp9_loop_filter_v_16_16_neon - note that the naming of horizonal
and vertical is flipped between the libraries.)

In order to have stable, comparable numbers, the early exits in both
asm versions were disabled, forcing the full filtering codepath.

                           Cortex           A7      A8      A9     A53
vp9_loop_filter_h_16_8_neon:             597.2   472.0   482.4   415.0
libvpx vpx_lpf_vertical_16_neon:         626.0   464.5   470.7   445.0
vp9_loop_filter_v_16_8_neon:             500.2   422.5   429.7   295.0
libvpx vpx_lpf_horizontal_edge_8_neon:   586.5   414.5   415.6   383.2
vp9_loop_filter_v_16_16_neon:            905.0   784.7   791.5   546.0
libvpx vpx_lpf_horizontal_edge_16_neon: 1060.2   751.7   743.5   685.2

Our version is consistently faster on on A7 and A53, marginally slower on
A8, and sometimes faster, sometimes slower on A9 (marginally slower in all
three tests in this particular test run).

Signed-off-by: Martin Storsjö <martin@martin.st>
2016-11-11 14:16:42 +02:00
compat Add a compat dummy stdatomic.h used when threading is disabled 2016-10-02 18:57:56 +02:00
doc examples/decode_audio: Add missing header for av_free() 2016-11-10 10:33:19 +01:00
libavcodec arm: vp9: Add NEON loop filters 2016-11-11 14:16:42 +02:00
libavdevice Use avpriv_report_missing_feature() where appropriate 2016-11-08 17:54:34 +01:00
libavfilter lavfi: Hardware map filter 2016-11-03 23:49:05 +00:00
libavformat matroskaenc: write updated STREAMINFO metadata for FLAC streams if available 2016-11-10 09:15:24 +01:00
libavresample build: Change structure of the linker version script templates 2016-05-29 16:43:11 +02:00
libavutil arm: Clear the gp register alias at the end of functions 2016-11-10 14:01:04 +02:00
libswscale swscale: Add GRAY12 2016-11-07 22:42:00 +01:00
presets presets: spelling error in libvpx 1080p50_60 2011-10-22 00:28:56 +02:00
tests checkasm: add vp9dsp.itxfm_add tests. 2016-11-11 11:09:05 +02:00
tools aviocat: Support avio options 2016-10-25 15:43:56 +02:00
.gitattributes Treat all '*.pnm' files as non-text file 2014-11-28 17:52:43 -05:00
.gitignore build: Ignore generated mapfile and remove it on distclean 2016-05-27 11:27:24 +02:00
.travis.yml travis: Enable OSX integration 2015-11-17 16:51:00 +01:00
arch.mak ppc: vsx: Implement float_dsp 2015-05-31 12:07:11 +02:00
avconv_dxva2.c avconv_dxva2: add a profile check for hevc 2016-07-20 16:33:09 +02:00
avconv_filter.c avconv: make sure the filtergraph is freed on init failure 2016-10-02 11:41:45 +02:00
avconv_opt.c avconv: Correct function pointer assignments in options array 2016-11-08 16:48:41 +01:00
avconv_qsv.c avconv_qsv: use the actual pixel format provided by lavc 2016-07-22 19:08:12 +02:00
avconv_vaapi.c avconv_vaapi: Convert to use hw_frames_ctx only 2016-08-30 22:16:01 +01:00
avconv_vda.c avconv: vda: Unlock the pixel buffer once it is accessed 2015-07-09 00:10:13 +02:00
avconv_vdpau.c avconv_vdpau: use the hwcontext device creation API 2016-05-26 15:40:34 +02:00
avconv.c avconv: Drop stray leftover debug output 2016-11-09 20:51:55 +01:00
avconv.h avconv: support parsing bitstream filter options 2016-11-02 10:08:28 +01:00
avplay.c avplay: Correct function pointer assignments in options array 2016-11-08 17:20:30 +01:00
avprobe.c avprobe: Add -show_stream_entry to get a single stream property 2016-11-01 11:27:52 -04:00
Changelog Changelog: mark the release 12 branch 2016-08-31 08:08:32 +02:00
cmdutils_common_opts.h avplay: Accept cpuflags option 2013-10-22 10:49:31 +02:00
cmdutils.c avconv: switch to the new BSF API 2016-03-20 08:15:01 +01:00
cmdutils.h avconv: use read_file() for reading the 2pass stats 2015-07-19 09:37:11 +02:00
common.mak build: Simplify postprocessing of linker version script files 2016-05-29 16:49:16 +02:00
configure libxvid: Require availability of mkstemp() 2016-11-11 10:17:07 +01:00
COPYING.GPLv2
COPYING.GPLv3 Add configure option to upgrade (L)GPL to version 3. 2009-06-05 11:04:03 +00:00
COPYING.LGPLv2.1 cosmetics: Delete empty lines at end of file. 2012-02-09 12:26:45 +01:00
COPYING.LGPLv3 Add configure option to upgrade (L)GPL to version 3. 2009-06-05 11:04:03 +00:00
CREDITS partially rename FFmpeg to Libav 2011-03-16 21:54:39 +01:00
INSTALL doc: clarify configure features 2011-04-07 02:54:12 +02:00
library.mak build: Drop duplicate asm recipe 2016-10-17 16:25:35 +02:00
LICENSE Remove the legacy X11 screen grabber 2016-07-29 19:03:10 +02:00
Makefile build: Hardcode avversion.h dependency 2016-10-27 11:54:06 +02:00
README doc: Add more information in the README 2014-08-16 00:49:22 +02:00
README.md doc: Add travis badge 2015-09-14 00:19:08 +02:00
RELEASE Make the RELEASE file match with the most recent tag 2016-10-14 13:52:51 -04:00
version.sh build: remove hardcoded name of version header 2016-09-15 21:59:15 +02:00

README.md

Libav

Build Status

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 and qt-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.