Blackfin dct_quantize_bfin routine
[libav.git] / libavcodec / bfin / mpegvideo_bfin.c
1 /*
2 * BlackFin MPEGVIDEO OPTIMIZATIONS
3 *
4 * Copyright (C) 2007 Marc Hoffman <mmh@pleasantst.com>
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 "dsputil.h"
24 #include "mpegvideo.h"
25 #include "avcodec.h"
26 #include "dsputil_bfin.h"
27
28
29 extern void ff_bfin_fdct (DCTELEM *block) attribute_l1_text;
30
31
32 static int dct_quantize_bfin (MpegEncContext *s,
33 DCTELEM *block, int n,
34 int qscale, int *overflow)
35 {
36 int last_non_zero, q, start_i;
37 const short *qmat;
38 short *bias;
39 const uint8_t *scantable= s->intra_scantable.scantable;
40 short dc;
41 int max=0;
42
43 PROF("fdct",0);
44 ff_bfin_fdct (block);
45 EPROF();
46
47 PROF("denoise",1);
48 if(s->dct_error_sum)
49 s->denoise_dct(s, block);
50 EPROF();
51
52 PROF("quant-init",2);
53 if (s->mb_intra) {
54 if (!s->h263_aic) {
55 if (n < 4)
56 q = s->y_dc_scale;
57 else
58 q = s->c_dc_scale;
59 q = q << 3;
60 } else
61 /* For AIC we skip quant/dequant of INTRADC */
62 q = 1 << 3;
63
64 /* note: block[0] is assumed to be positive */
65 dc = block[0] = (block[0] + (q >> 1)) / q;
66 start_i = 1;
67 last_non_zero = 0;
68 bias = s->q_intra_matrix16[qscale][1];
69 qmat = s->q_intra_matrix16[qscale][0];
70
71 } else {
72 start_i = 0;
73 last_non_zero = -1;
74 bias = s->q_inter_matrix16[qscale][1];
75 qmat = s->q_inter_matrix16[qscale][0];
76
77 }
78 EPROF();
79
80 PROF("quantize",4);
81
82 /* for(i=start_i; i<64; i++) { */
83 /* sign = (block[i]>>15)|1; */
84 /* level = ((abs(block[i])+bias[0])*qmat[i])>>16; */
85 /* if (level < 0) level = 0; */
86 /* max |= level; */
87 /* level = level * sign; */
88 /* block[i] = level; */
89 /* } */
90
91 asm volatile
92 ("i2=%1;\n\t"
93 "r1=[%1++]; \n\t"
94 "r0=r1>>>15 (v); \n\t"
95 "lsetup (0f,1f) lc0=%3; \n\t"
96 "0: r0=r0|%4; \n\t"
97 " r1=abs r1 (v) || r2=[%2++];\n\t"
98 " r1=r1+|+%5; \n\t"
99 " r1=max(r1,%6) (v); \n\t"
100 " r1.h=(a1 =r1.h*r2.h), r1.l=(a0 =r1.l*r2.l) (tfu); \n\t"
101 " %0=%0|r1; \n\t"
102 " r0.h=(a1 =r1.h*r0.h), r0.l=(a0 =r1.l*r0.l) (is) || r1=[%1++];\n\t"
103 "1: r0=r1>>>15 (v) || [i2++]=r0;\n\t"
104 "r1=%0>>16; \n\t"
105 "%0=%0|r1; \n\t"
106 "%0.h=0; \n\t"
107 : "=&d" (max)
108 : "b" (block), "b" (qmat), "a" (32), "d" (0x00010001), "d" (bias[0]*0x10001), "d" (0)
109 : "R0","R1","R2", "I2");
110 if (start_i == 1) block[0] = dc;
111
112 EPROF();
113
114
115 PROF("zzscan",5);
116
117 asm volatile
118 ("r0=b[%1--] (x); \n\t"
119 "lsetup (0f,1f) lc0=%3; \n\t" /* for(i=63; i>=start_i; i--) { */
120 "0: p0=r0; \n\t" /* j = scantable[i]; */
121 " p0=%2+(p0<<1); \n\t" /* if (block[j]) { */
122 " r0=w[p0]; \n\t" /* last_non_zero = i; */
123 " cc=r0==0; \n\t" /* break; */
124 " if !cc jump 2f; \n\t" /* } */
125 "1: r0=b[%1--] (x); \n\t" /* } */
126 " %0=%4; \n\t"
127 " jump 3f; \n\t"
128 "2: %0=lc0; \n\t"
129 "3:\n\t"
130
131 : "=d" (last_non_zero)
132 : "a" (scantable+63), "a" (block), "a" (63), "d" (last_non_zero)
133 : "P0","R0");
134
135 EPROF();
136
137 *overflow= s->max_qcoeff < max; //overflow might have happened
138
139 bfprof();
140
141 /* we need this permutation so that we correct the IDCT, we only permute the !=0 elements */
142 if (s->dsp.idct_permutation_type != FF_NO_IDCT_PERM)
143 ff_block_permute(block, s->dsp.idct_permutation, scantable, last_non_zero);
144
145 return last_non_zero;
146 }
147
148 void MPV_common_init_bfin (MpegEncContext *s)
149 {
150 s->dct_quantize= dct_quantize_bfin;
151 }
152