1 /*
2 * Copyright (c) 2002 Dieter Shirley
3 *
4 * dct_unquantize_h263_altivec:
5 * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 #include <stdlib.h>
25 #include <stdio.h>
26
27 #include "config.h"
28
29 #include "libavutil/attributes.h"
30 #include "libavutil/cpu.h"
31 #include "libavutil/mem_internal.h"
32 #include "libavutil/ppc/cpu.h"
33 #include "libavutil/ppc/util_altivec.h"
34
35 #include "libavcodec/mpegvideo.h"
36
37 #if HAVE_ALTIVEC
38
39 /* AltiVec version of dct_unquantize_h263
40 this code assumes `block' is 16 bytes-aligned */
dct_unquantize_h263_altivec(MpegEncContext * s,int16_t * block,int n,int qscale)41 static void dct_unquantize_h263_altivec(MpegEncContext *s,
42 int16_t *block, int n, int qscale)
43 {
44 int i, level, qmul, qadd;
45 int nCoeffs;
46
47 qadd = (qscale - 1) | 1;
48 qmul = qscale << 1;
49
50 if (s->mb_intra) {
51 if (!s->h263_aic) {
52 if (n < 4)
53 block[0] = block[0] * s->y_dc_scale;
54 else
55 block[0] = block[0] * s->c_dc_scale;
56 }else
57 qadd = 0;
58 i = 1;
59 nCoeffs= 63; //does not always use zigzag table
60 } else {
61 i = 0;
62 av_assert2(s->block_last_index[n]>=0);
63 nCoeffs= s->intra_scantable.raster_end[ s->block_last_index[n] ];
64 }
65
66 {
67 register const vector signed short vczero = (const vector signed short)vec_splat_s16(0);
68 DECLARE_ALIGNED(16, short, qmul8) = qmul;
69 DECLARE_ALIGNED(16, short, qadd8) = qadd;
70 register vector signed short blockv, qmulv, qaddv, nqaddv, temp1;
71 register vector bool short blockv_null, blockv_neg;
72 register short backup_0 = block[0];
73 register int j = 0;
74
75 qmulv = vec_splat((vec_s16)vec_lde(0, &qmul8), 0);
76 qaddv = vec_splat((vec_s16)vec_lde(0, &qadd8), 0);
77 nqaddv = vec_sub(vczero, qaddv);
78
79 // vectorize all the 16 bytes-aligned blocks
80 // of 8 elements
81 for(; (j + 7) <= nCoeffs ; j+=8) {
82 blockv = vec_ld(j << 1, block);
83 blockv_neg = vec_cmplt(blockv, vczero);
84 blockv_null = vec_cmpeq(blockv, vczero);
85 // choose between +qadd or -qadd as the third operand
86 temp1 = vec_sel(qaddv, nqaddv, blockv_neg);
87 // multiply & add (block{i,i+7} * qmul [+-] qadd)
88 temp1 = vec_mladd(blockv, qmulv, temp1);
89 // put 0 where block[{i,i+7} used to have 0
90 blockv = vec_sel(temp1, blockv, blockv_null);
91 vec_st(blockv, j << 1, block);
92 }
93
94 // if nCoeffs isn't a multiple of 8, finish the job
95 // using good old scalar units.
96 // (we could do it using a truncated vector,
97 // but I'm not sure it's worth the hassle)
98 for(; j <= nCoeffs ; j++) {
99 level = block[j];
100 if (level) {
101 if (level < 0) {
102 level = level * qmul - qadd;
103 } else {
104 level = level * qmul + qadd;
105 }
106 block[j] = level;
107 }
108 }
109
110 if (i == 1) {
111 // cheat. this avoid special-casing the first iteration
112 block[0] = backup_0;
113 }
114 }
115 }
116
117 #endif /* HAVE_ALTIVEC */
118
ff_mpv_common_init_ppc(MpegEncContext * s)119 av_cold void ff_mpv_common_init_ppc(MpegEncContext *s)
120 {
121 #if HAVE_ALTIVEC
122 if (!PPC_ALTIVEC(av_get_cpu_flags()))
123 return;
124
125 if ((s->avctx->dct_algo == FF_DCT_AUTO) ||
126 (s->avctx->dct_algo == FF_DCT_ALTIVEC)) {
127 s->dct_unquantize_h263_intra = dct_unquantize_h263_altivec;
128 s->dct_unquantize_h263_inter = dct_unquantize_h263_altivec;
129 }
130 #endif /* HAVE_ALTIVEC */
131 }
132