2 * GMC (Global Motion Compensation)
4 * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavutil/mem.h"
24 #include "libavutil/ppc/types_altivec.h"
25 #include "libavutil/ppc/util_altivec.h"
26 #include "libavcodec/dsputil.h"
27 #include "dsputil_altivec.h"
30 altivec-enhanced gmc1. ATM this code assume stride is a multiple of 8,
31 to preserve proper dst alignment.
33 void ff_gmc1_altivec(uint8_t *dst /* align 8 */, uint8_t *src /* align1 */, int stride, int h, int x16, int y16, int rounder)
35 const DECLARE_ALIGNED(16, unsigned short, rounder_a) = rounder;
36 const DECLARE_ALIGNED(16, unsigned short, ABCD)[8] =
38 (16-x16)*(16-y16), /* A */
39 ( x16)*(16-y16), /* B */
40 (16-x16)*( y16), /* C */
41 ( x16)*( y16), /* D */
42 0, 0, 0, 0 /* padding */
44 register const vector unsigned char vczero = (const vector unsigned char)vec_splat_u8(0);
45 register const vector unsigned short vcsr8 = (const vector unsigned short)vec_splat_u16(8);
46 register vector unsigned char dstv, dstv2, src_0, src_1, srcvA, srcvB, srcvC, srcvD;
47 register vector unsigned short Av, Bv, Cv, Dv, rounderV, tempA, tempB, tempC, tempD;
49 unsigned long dst_odd = (unsigned long)dst & 0x0000000F;
50 unsigned long src_really_odd = (unsigned long)src & 0x0000000F;
52 tempA = vec_ld(0, (const unsigned short*)ABCD);
53 Av = vec_splat(tempA, 0);
54 Bv = vec_splat(tempA, 1);
55 Cv = vec_splat(tempA, 2);
56 Dv = vec_splat(tempA, 3);
58 rounderV = vec_splat((vec_u16)vec_lde(0, &rounder_a), 0);
60 // we'll be able to pick-up our 9 char elements
61 // at src from those 32 bytes
62 // we load the first batch here, as inside the loop
63 // we can re-use 'src+stride' from one iteration
64 // as the 'src' of the next.
65 src_0 = vec_ld(0, src);
66 src_1 = vec_ld(16, src);
67 srcvA = vec_perm(src_0, src_1, vec_lvsl(0, src));
69 if (src_really_odd != 0x0000000F) {
70 // if src & 0xF == 0xF, then (src+1) is properly aligned
71 // on the second vector.
72 srcvB = vec_perm(src_0, src_1, vec_lvsl(1, src));
76 srcvA = vec_mergeh(vczero, srcvA);
77 srcvB = vec_mergeh(vczero, srcvB);
80 dst_odd = (unsigned long)dst & 0x0000000F;
81 src_really_odd = (((unsigned long)src) + stride) & 0x0000000F;
83 dstv = vec_ld(0, dst);
85 // we we'll be able to pick-up our 9 char elements
86 // at src + stride from those 32 bytes
87 // then reuse the resulting 2 vectors srvcC and srcvD
88 // as the next srcvA and srcvB
89 src_0 = vec_ld(stride + 0, src);
90 src_1 = vec_ld(stride + 16, src);
91 srcvC = vec_perm(src_0, src_1, vec_lvsl(stride + 0, src));
93 if (src_really_odd != 0x0000000F) {
94 // if src & 0xF == 0xF, then (src+1) is properly aligned
95 // on the second vector.
96 srcvD = vec_perm(src_0, src_1, vec_lvsl(stride + 1, src));
101 srcvC = vec_mergeh(vczero, srcvC);
102 srcvD = vec_mergeh(vczero, srcvD);
105 // OK, now we (finally) do the math :-)
106 // those four instructions replaces 32 int muls & 32 int adds.
107 // isn't AltiVec nice ?
108 tempA = vec_mladd((vector unsigned short)srcvA, Av, rounderV);
109 tempB = vec_mladd((vector unsigned short)srcvB, Bv, tempA);
110 tempC = vec_mladd((vector unsigned short)srcvC, Cv, tempB);
111 tempD = vec_mladd((vector unsigned short)srcvD, Dv, tempC);
116 tempD = vec_sr(tempD, vcsr8);
118 dstv2 = vec_pack(tempD, (vector unsigned short)vczero);
121 dstv2 = vec_perm(dstv, dstv2, vcprm(0,1,s0,s1));
123 dstv2 = vec_perm(dstv, dstv2, vcprm(s0,s1,2,3));
126 vec_st(dstv2, 0, dst);