7696954335449ed9e9628a3056d3f0467adf174b
[deb_ffmpeg.git] / mpegvideodsp.c
1 /*
2 * GMC (Global Motion Compensation), AltiVec-enabled
3 *
4 * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23 #include "libavutil/mem.h"
24 #include "libavutil/ppc/types_altivec.h"
25 #include "libavutil/ppc/util_altivec.h"
26 #include "libavcodec/mpegvideodsp.h"
27
28 #if HAVE_ALTIVEC
29 /* AltiVec-enhanced gmc1. ATM this code assumes stride is a multiple of 8
30 * to preserve proper dst alignment. */
31 static void gmc1_altivec(uint8_t *dst /* align 8 */, uint8_t *src /* align1 */,
32 int stride, int h, int x16, int y16, int rounder)
33 {
34 int i;
35 const DECLARE_ALIGNED(16, unsigned short, rounder_a) = rounder;
36 const DECLARE_ALIGNED(16, unsigned short, ABCD)[8] = {
37 (16 - x16) * (16 - y16), /* A */
38 (x16) * (16 - y16), /* B */
39 (16 - x16) * (y16), /* C */
40 (x16) * (y16), /* D */
41 0, 0, 0, 0 /* padding */
42 };
43 register const vector unsigned char vczero =
44 (const vector unsigned char) vec_splat_u8(0);
45 register const vector unsigned short vcsr8 =
46 (const vector unsigned short) vec_splat_u16(8);
47 register vector unsigned char dstv, dstv2, srcvB, srcvC, srcvD;
48 register vector unsigned short tempB, tempC, tempD;
49 unsigned long dst_odd = (unsigned long) dst & 0x0000000F;
50 unsigned long src_really_odd = (unsigned long) src & 0x0000000F;
51 register vector unsigned short tempA =
52 vec_ld(0, (const unsigned short *) ABCD);
53 register vector unsigned short Av = vec_splat(tempA, 0);
54 register vector unsigned short Bv = vec_splat(tempA, 1);
55 register vector unsigned short Cv = vec_splat(tempA, 2);
56 register vector unsigned short Dv = vec_splat(tempA, 3);
57 register vector unsigned short rounderV =
58 vec_splat((vec_u16) vec_lde(0, &rounder_a), 0);
59
60 /* we'll be able to pick-up our 9 char elements at src from those
61 * 32 bytes we load the first batch here, as inside the loop we can
62 * reuse 'src + stride' from one iteration as the 'src' of the next. */
63 register vector unsigned char src_0 = vec_ld(0, src);
64 register vector unsigned char src_1 = vec_ld(16, src);
65 register vector unsigned char srcvA = vec_perm(src_0, src_1,
66 vec_lvsl(0, src));
67
68 if (src_really_odd != 0x0000000F)
69 /* If (src & 0xF) == 0xF, then (src + 1) is properly aligned
70 * on the second vector. */
71 srcvB = vec_perm(src_0, src_1, vec_lvsl(1, src));
72 else
73 srcvB = src_1;
74 srcvA = vec_mergeh(vczero, srcvA);
75 srcvB = vec_mergeh(vczero, srcvB);
76
77 for (i = 0; i < h; i++) {
78 dst_odd = (unsigned long) dst & 0x0000000F;
79 src_really_odd = (((unsigned long) src) + stride) & 0x0000000F;
80
81 dstv = vec_ld(0, dst);
82
83 /* We'll be able to pick-up our 9 char elements at src + stride from
84 * those 32 bytes then reuse the resulting 2 vectors srvcC and srcvD
85 * as the next srcvA and srcvB. */
86 src_0 = vec_ld(stride + 0, src);
87 src_1 = vec_ld(stride + 16, src);
88 srcvC = vec_perm(src_0, src_1, vec_lvsl(stride + 0, src));
89
90 if (src_really_odd != 0x0000000F)
91 /* If (src & 0xF) == 0xF, then (src + 1) is properly aligned
92 * on the second vector. */
93 srcvD = vec_perm(src_0, src_1, vec_lvsl(stride + 1, src));
94 else
95 srcvD = src_1;
96
97 srcvC = vec_mergeh(vczero, srcvC);
98 srcvD = vec_mergeh(vczero, srcvD);
99
100 /* OK, now we (finally) do the math :-)
101 * Those four instructions replace 32 int muls & 32 int adds.
102 * Isn't AltiVec nice? */
103 tempA = vec_mladd((vector unsigned short) srcvA, Av, rounderV);
104 tempB = vec_mladd((vector unsigned short) srcvB, Bv, tempA);
105 tempC = vec_mladd((vector unsigned short) srcvC, Cv, tempB);
106 tempD = vec_mladd((vector unsigned short) srcvD, Dv, tempC);
107
108 srcvA = srcvC;
109 srcvB = srcvD;
110
111 tempD = vec_sr(tempD, vcsr8);
112
113 dstv2 = vec_pack(tempD, (vector unsigned short) vczero);
114
115 if (dst_odd)
116 dstv2 = vec_perm(dstv, dstv2, vcprm(0, 1, s0, s1));
117 else
118 dstv2 = vec_perm(dstv, dstv2, vcprm(s0, s1, 2, 3));
119
120 vec_st(dstv2, 0, dst);
121
122 dst += stride;
123 src += stride;
124 }
125 }
126 #endif /* HAVE_ALTIVEC */
127
128 av_cold void ff_mpegvideodsp_init_ppc(MpegVideoDSPContext *c)
129 {
130 #if HAVE_ALTIVEC
131 c->gmc1 = gmc1_altivec;
132 #endif /* HAVE_ALTIVEC */
133 }