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 */
41static 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
119av_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