FFmpeg/libavcodec/aarch64/opusdsp_neon.S
Lynne 4d2f62150d aarch64/opusdsp: implement NEON accelerated postfilter and deemphasis
153372 UNITS in postfilter_c,   65536 runs,      0 skips
73164 UNITS in postfilter_neon,   65536 runs,      0 skips -> 2.1x speedup

80591 UNITS in deemphasis_c,  131072 runs,      0 skips
43969 UNITS in deemphasis_neon,  131072 runs,      0 skips -> 1.83x speedup

Total decoder speedup: ~15% on a Raspberry Pi 3 (from 28.1x to 33.5x realtime)

Deemphasis SIMD based on the following unrolling:
const float c1 = CELT_EMPH_COEFF, c2 = c1*c1, c3 = c2*c1, c4 = c3*c1;
float state = coeff;

for (int i = 0; i < len; i += 4) {
    y[0] = x[0] + c1*state;
    y[1] = x[1] + c2*state + c1*x[0];
    y[2] = x[2] + c3*state + c1*x[1] + c2*x[0];
    y[3] = x[3] + c4*state + c1*x[2] + c2*x[1] + c3*x[0];

    state = y[3];
    y += 4;
    x += 4;
}

Unlike the x86 version, duplication is used instead of pslldq so
the structure and tables are different.
2019-04-10 01:08:54 +02:00

114 lines
2.8 KiB
ArmAsm

/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/aarch64/asm.S"
// 0.85..^1 0.85..^2 0.85..^3 0.85..^4
const tab_st, align=4
.word 0x3f599a00, 0x3f38f671, 0x3f1d382a, 0x3f05a32f
endconst
const tab_x0, align=4
.word 0x0, 0x3f599a00, 0x3f38f671, 0x3f1d382a
endconst
const tab_x1, align=4
.word 0x0, 0x0, 0x3f599a00, 0x3f38f671
endconst
const tab_x2, align=4
.word 0x0, 0x0, 0x0, 0x3f599a00
endconst
function ff_opus_deemphasis_neon, export=1
movrel x4, tab_st
ld1 {v4.4s}, [x4]
movrel x4, tab_x0
ld1 {v5.4s}, [x4]
movrel x4, tab_x1
ld1 {v6.4s}, [x4]
movrel x4, tab_x2
ld1 {v7.4s}, [x4]
fmul v0.4s, v4.4s, v0.s[0]
1: ld1 {v1.4s, v2.4s}, [x1], #32
fmla v0.4s, v5.4s, v1.s[0]
fmul v3.4s, v7.4s, v2.s[2]
fmla v0.4s, v6.4s, v1.s[1]
fmla v3.4s, v6.4s, v2.s[1]
fmla v0.4s, v7.4s, v1.s[2]
fmla v3.4s, v5.4s, v2.s[0]
fadd v1.4s, v1.4s, v0.4s
fadd v2.4s, v2.4s, v3.4s
fmla v2.4s, v4.4s, v1.s[3]
st1 {v1.4s, v2.4s}, [x0], #32
fmul v0.4s, v4.4s, v2.s[3]
subs w2, w2, #8
b.gt 1b
mov s0, v2.s[3]
ret
endfunc
function ff_opus_postfilter_neon, export=1
ld1 {v0.4s}, [x2]
dup v1.4s, v0.s[1]
dup v2.4s, v0.s[2]
dup v0.4s, v0.s[0]
add w1, w1, #2
sub x1, x0, x1, lsl #2
ld1 {v3.4s}, [x1]
fmul v3.4s, v3.4s, v2.4s
1: add x1, x1, #4
ld1 {v4.4s}, [x1]
add x1, x1, #4
ld1 {v5.4s}, [x1]
add x1, x1, #4
ld1 {v6.4s}, [x1]
add x1, x1, #4
ld1 {v7.4s}, [x1]
fmla v3.4s, v7.4s, v2.4s
fadd v6.4s, v6.4s, v4.4s
ld1 {v8.4s}, [x0]
fmla v8.4s, v5.4s, v0.4s
fmul v6.4s, v6.4s, v1.4s
fadd v6.4s, v6.4s, v3.4s
fadd v8.4s, v8.4s, v6.4s
fmul v3.4s, v7.4s, v2.4s
st1 {v8.4s}, [x0], #16
subs w3, w3, #4
b.gt 1b
ret
endfunc