github-mirrors/FFmpeg
1
0
Fork 0
mirror of https://mirror.skon.top/https://github.com/FFmpeg/FFmpeg synced 2026-04-20 21:00:41 +08:00
Code Issues Packages Projects Releases Wiki Activity

swscale/aarch64: add NEON sws_ops backend

Browse Source 
This commit pieces together the previous few commits to implement the
NEON backend for sws_ops.

In essence, a tool which runs on the target (sws_ops_aarch64) is used
to enumerate all the functions that the backend needs to implement. The
list it generates is stored in the repository (ops_entries.c).

The list from above is used at build time by a code generator tool
(ops_asmgen) to implement all the sws_ops functions the NEON backend
supports, and generate a lookup function in C to retrieve the assembly
function pointers.

At runtime, the NEON backend fetches the function pointers to the
assembly functions and chains them together in a continuation-passing
style design, similar to the x86 backend.

The following speedup is observed from legacy swscale to NEON:
A520: Overall speedup=3.780x faster, min=0.137x max=91.928x
A720: Overall speedup=4.129x faster, min=0.234x max=92.424x

And the following from the C sws_ops implementation to NEON:
A520: Overall speedup=5.513x faster, min=0.927x max=14.169x
A720: Overall speedup=4.786x faster, min=0.585x max=20.157x

The slowdowns from legacy to NEON are the same for C/x86. Mostly low
bit-depth conversions that did not perform dithering in legacy.

The 0.585x outlier from C to NEON is gbrpf32le -> gbrapf32le, which is
mostly memcpy with the C implementation. All other conversions are
better.

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Ramiro Polla <ramiro.polla@gmail.com>
This commit is contained in:
Ramiro Polla
2026-03-10 15:40:37 +01:00
parent 534757926f
commit 2517c328fc
7 changed files with 318 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
ffbuild/common.mak
View File

@@ -197,7 +197,7 @@ endif
clean::
$(RM) $(BIN2CEXE) $(CLEANSUFFIXES:%=ffbuild/%)
%.c %.h %.pc %.ver %.version: TAG = GEN
%.c %.h %.S %.pc %.ver %.version: TAG = GEN
# Dummy rule to stop make trying to rebuild removed or renamed headers
%.h %_template.c:
@@ -266,7 +266,7 @@ $(TOOLOBJS): | tools
OUTDIRS := $(OUTDIRS) $(dir $(OBJS) $(HOBJS) $(HOSTOBJS) $(SHLIBOBJS) $(STLIBOBJS) $(TESTOBJS))
CLEANSUFFIXES = *.d *.gcda *.gcno *.h.c *.ho *.map *.o *.objs *.pc *.ptx *.ptx.gz *.ptx.c *.spv *.spv.gz *.spv.c *.ver *.version *.html.gz *.html.c *.css.min.gz *.css.min *.css.c *$(DEFAULT_X86ASMD).asm *~ *.ilk *.pdb
CLEANSUFFIXES = *.d *.gcda *.gcno *.h.c *.ho *.map *.o *.objs *.pc *.ptx *.ptx.gz *.ptx.c *.spv *.spv.gz *.spv.c *.gen.c *.gen.S *.ver *.version *.html.gz *.html.c *.css.min.gz *.css.min *.css.c *$(DEFAULT_X86ASMD).asm *~ *.ilk *.pdb
LIBSUFFIXES = *.a *.lib *.so *.so.* *.dylib *.dll *.def *.dll.a
define RULES