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mpegvideo_altivec.c
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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 #include "libavutil/attributes.h"
29 #include "libavutil/cpu.h"
30 #include "libavutil/ppc/cpu.h"
33 #include "libavcodec/mpegvideo.h"
34 
35 #if HAVE_ALTIVEC
36 
37 /* AltiVec version of dct_unquantize_h263
38  this code assumes `block' is 16 bytes-aligned */
39 static void dct_unquantize_h263_altivec(MpegEncContext *s,
40  int16_t *block, int n, int qscale)
41 {
42  int i, level, qmul, qadd;
43  int nCoeffs;
44 
45  qadd = (qscale - 1) | 1;
46  qmul = qscale << 1;
47 
48  if (s->mb_intra) {
49  if (!s->h263_aic) {
50  if (n < 4)
51  block[0] = block[0] * s->y_dc_scale;
52  else
53  block[0] = block[0] * s->c_dc_scale;
54  }else
55  qadd = 0;
56  i = 1;
57  nCoeffs= 63; //does not always use zigzag table
58  } else {
59  i = 0;
60  av_assert2(s->block_last_index[n]>=0);
61  nCoeffs= s->intra_scantable.raster_end[ s->block_last_index[n] ];
62  }
63 
64  {
65  register const vector signed short vczero = (const vector signed short)vec_splat_s16(0);
66  DECLARE_ALIGNED(16, short, qmul8) = qmul;
67  DECLARE_ALIGNED(16, short, qadd8) = qadd;
68  register vector signed short blockv, qmulv, qaddv, nqaddv, temp1;
69  register vector bool short blockv_null, blockv_neg;
70  register short backup_0 = block[0];
71  register int j = 0;
72 
73  qmulv = vec_splat((vec_s16)vec_lde(0, &qmul8), 0);
74  qaddv = vec_splat((vec_s16)vec_lde(0, &qadd8), 0);
75  nqaddv = vec_sub(vczero, qaddv);
76 
77  // vectorize all the 16 bytes-aligned blocks
78  // of 8 elements
79  for(; (j + 7) <= nCoeffs ; j+=8) {
80  blockv = vec_ld(j << 1, block);
81  blockv_neg = vec_cmplt(blockv, vczero);
82  blockv_null = vec_cmpeq(blockv, vczero);
83  // choose between +qadd or -qadd as the third operand
84  temp1 = vec_sel(qaddv, nqaddv, blockv_neg);
85  // multiply & add (block{i,i+7} * qmul [+-] qadd)
86  temp1 = vec_mladd(blockv, qmulv, temp1);
87  // put 0 where block[{i,i+7} used to have 0
88  blockv = vec_sel(temp1, blockv, blockv_null);
89  vec_st(blockv, j << 1, block);
90  }
91 
92  // if nCoeffs isn't a multiple of 8, finish the job
93  // using good old scalar units.
94  // (we could do it using a truncated vector,
95  // but I'm not sure it's worth the hassle)
96  for(; j <= nCoeffs ; j++) {
97  level = block[j];
98  if (level) {
99  if (level < 0) {
100  level = level * qmul - qadd;
101  } else {
102  level = level * qmul + qadd;
103  }
104  block[j] = level;
105  }
106  }
107 
108  if (i == 1) {
109  // cheat. this avoid special-casing the first iteration
110  block[0] = backup_0;
111  }
112  }
113 }
114 
115 #endif /* HAVE_ALTIVEC */
116 
118 {
119 #if HAVE_ALTIVEC
121  return;
122 
123  if ((s->avctx->dct_algo == FF_DCT_AUTO) ||
124  (s->avctx->dct_algo == FF_DCT_ALTIVEC)) {
125  s->dct_unquantize_h263_intra = dct_unquantize_h263_altivec;
126  s->dct_unquantize_h263_inter = dct_unquantize_h263_altivec;
127  }
128 #endif /* HAVE_ALTIVEC */
129 }
const char * s
Definition: avisynth_c.h:631
int dct_algo
DCT algorithm, see FF_DCT_* below.
Definition: avcodec.h:2947
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:53
uint8_t raster_end[64]
Definition: idctdsp.h:32
mpegvideo header.
int h263_aic
Advanded INTRA Coding (AIC)
Definition: mpegvideo.h:94
void(* dct_unquantize_h263_intra)(struct MpegEncContext *s, int16_t *block, int n, int qscale)
Definition: mpegvideo.h:516
Macro definitions for various function/variable attributes.
void(* dct_unquantize_h263_inter)(struct MpegEncContext *s, int16_t *block, int n, int qscale)
Definition: mpegvideo.h:518
#define av_cold
Definition: attributes.h:74
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition: avassert.h:63
av_cold void ff_mpv_common_init_ppc(MpegEncContext *s)
#define vec_s16
Definition: types_altivec.h:30
#define FF_DCT_ALTIVEC
Definition: avcodec.h:2954
#define PPC_ALTIVEC(flags)
Definition: cpu.h:26
#define FF_DCT_AUTO
Definition: avcodec.h:2948
int block_last_index[12]
last non zero coefficient in block
Definition: mpegvideo.h:93
int n
Definition: avisynth_c.h:547
ScanTable intra_scantable
Definition: mpegvideo.h:98
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:76
Contains misc utility macros and inline functions.
uint8_t level
Definition: svq3.c:150
MpegEncContext.
Definition: mpegvideo.h:88
struct AVCodecContext * avctx
Definition: mpegvideo.h:105
static int16_t block[64]
Definition: dct-test.c:110