Change #239982

Comments

avfilter/x86/scene_sad: add high bit depth AVX2/AVX512 version
Since psadbw only exists for 8-bits, we have to emulate it for 16-bit
inputs. The simplest sequence is to use a normal subtraction, which is safe
as long as the inputs do not exceed 32767 - so limit this implementation
to 15-bit inputs and below.

For 16-bit inputs, we could in theory instead use a pminw / pmaxw to ensure
the resulting difference does not overflow, but this is slower, and also
breaks the subsequent use of pmaddwd, so I opted to skip 16-bit SIMD for
now.

scene_sad10_c:                                      114175.6 ( 1.00x)
scene_sad10_avx2:                                     9617.7 (11.87x)
scene_sad10_avx512:                                   5208.8 (21.92x)
scene_sad12_c:                                      114537.8 ( 1.00x)
scene_sad12_avx2:                                     9614.0 (11.91x)
scene_sad12_avx512:                                   5186.3 (22.08x)
scene_sad14_c:                                      114113.9 ( 1.00x)
scene_sad14_avx2:                                     9612.9 (11.87x)
scene_sad14_avx512:                                   5186.0 (22.00x)
scene_sad15_c:                                      114108.9 ( 1.00x)
scene_sad15_avx2:                                     9612.3 (11.87x)
scene_sad15_avx512:                                   5186.4 (22.00x)
scene_sad16_c:                                      114136.0 ( 1.00x)

Changed files

• libavfilter/x86/scene_sad.asm
• libavfilter/x86/scene_sad_init.c