[FFmpeg-devel] [PATCH v2 07/13] avfilter/x86/f_ebur128: add x86 AVX implementation

Michael Niedermayer michael at niedermayer.cc
Sat Jun 14 04:12:22 EEST 2025


Hi Niklas

On Fri, Jun 13, 2025 at 06:37:50PM +0200, Niklas Haas wrote:
> From: Niklas Haas <git at haasn.dev>
> 
> Processes two channels in parallel, using 128-bit XMM registers.
> 
> In theory, we could go up to YMM registers to process 4 channels, but this is
> not a gain except for relatively high channel counts (e.g. 7.1), and also
> complicates the sample load/store operations considerably.
> 
> I decided to only add an AVX variant, since the C code is not substantially
> slower enough to justify a separate function just for ancient CPUs.
> ---
>  libavfilter/f_ebur128.c          |  15 ++--
>  libavfilter/f_ebur128.h          |  16 ++++
>  libavfilter/x86/Makefile         |   2 +
>  libavfilter/x86/f_ebur128.asm    | 142 +++++++++++++++++++++++++++++++
>  libavfilter/x86/f_ebur128_init.c |  35 ++++++++
>  5 files changed, 205 insertions(+), 5 deletions(-)
>  create mode 100644 libavfilter/x86/f_ebur128.asm
>  create mode 100644 libavfilter/x86/f_ebur128_init.c

breaks x86-32

src/libavfilter/x86/f_ebur128.asm:116: error: symbol `m8' undefined
src/libavfilter/x86/f_ebur128.asm:118: error: symbol `m9' undefined
src/libavfilter/x86/f_ebur128.asm:119: error: symbol `m10' undefined
src/libavfilter/x86/f_ebur128.asm:120: error: symbol `m11' undefined
src/libavfilter/x86/f_ebur128.asm:121: error: symbol `m12' undefined
src/libavfilter/x86/f_ebur128.asm:122: error: symbol `m13' undefined
src/libavfilter/x86/f_ebur128.asm:124: error: symbol `r7q' undefined
src/libavfilter/x86/f_ebur128.asm:125: error: symbol `r8q' undefined
src/libavfilter/x86/f_ebur128.asm:132: error: symbol `r7q' undefined
src/libavfilter/x86/f_ebur128.asm:91: ... from macro `filter_channels' defined here
src/libavfilter/x86/f_ebur128.asm:57: ... from macro `FILTER' defined here
src//libavutil/x86/x86inc.asm:1654: ... from macro `movsd' defined here
src//libavutil/x86/x86inc.asm:1501: ... from macro `RUN_AVX_INSTR' defined here
src/libavfilter/x86/f_ebur128.asm:132: error: symbol `r7q' undefined
src/libavfilter/x86/f_ebur128.asm:91: ... from macro `filter_channels' defined here
src/libavfilter/x86/f_ebur128.asm:58: ... from macro `FILTER' defined here
src//libavutil/x86/x86inc.asm:1654: ... from macro `movsd' defined here
src//libavutil/x86/x86inc.asm:1501: ... from macro `RUN_AVX_INSTR' defined here
src/libavfilter/x86/f_ebur128.asm:132: error: symbol `r7q' undefined
...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Concerning the gods, I have no means of knowing whether they exist or not
or of what sort they may be, because of the obscurity of the subject, and
the brevity of human life -- Protagoras
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