xref: /third_party/ffmpeg/libavcodec/rv34dsp.c (revision cabdff1a)
1/*
2 * RV30/40 decoder common dsp functions
3 * Copyright (c) 2007 Mike Melanson, Konstantin Shishkov
4 * Copyright (c) 2011 Janne Grunau
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/**
24 * @file
25 * RV30/40 decoder common dsp functions
26 */
27
28#include "rv34dsp.h"
29#include "libavutil/common.h"
30
31/**
32 * @name RV30/40 inverse transform functions
33 * @{
34 */
35
36static av_always_inline void rv34_row_transform(int temp[16], int16_t *block)
37{
38    int i;
39
40    for(i = 0; i < 4; i++){
41        const int z0 = 13*(block[i+4*0] +    block[i+4*2]);
42        const int z1 = 13*(block[i+4*0] -    block[i+4*2]);
43        const int z2 =  7* block[i+4*1] - 17*block[i+4*3];
44        const int z3 = 17* block[i+4*1] +  7*block[i+4*3];
45
46        temp[4*i+0] = z0 + z3;
47        temp[4*i+1] = z1 + z2;
48        temp[4*i+2] = z1 - z2;
49        temp[4*i+3] = z0 - z3;
50    }
51}
52
53/**
54 * Real Video 3.0/4.0 inverse transform + sample reconstruction
55 * Code is almost the same as in SVQ3, only scaling is different.
56 */
57static void rv34_idct_add_c(uint8_t *dst, ptrdiff_t stride, int16_t *block){
58    int      temp[16];
59    int      i;
60
61    rv34_row_transform(temp, block);
62    memset(block, 0, 16*sizeof(int16_t));
63
64    for(i = 0; i < 4; i++){
65        const int z0 = 13*(temp[4*0+i] +    temp[4*2+i]) + 0x200;
66        const int z1 = 13*(temp[4*0+i] -    temp[4*2+i]) + 0x200;
67        const int z2 =  7* temp[4*1+i] - 17*temp[4*3+i];
68        const int z3 = 17* temp[4*1+i] +  7*temp[4*3+i];
69
70        dst[0] = av_clip_uint8( dst[0] + ( (z0 + z3) >> 10 ) );
71        dst[1] = av_clip_uint8( dst[1] + ( (z1 + z2) >> 10 ) );
72        dst[2] = av_clip_uint8( dst[2] + ( (z1 - z2) >> 10 ) );
73        dst[3] = av_clip_uint8( dst[3] + ( (z0 - z3) >> 10 ) );
74
75        dst  += stride;
76    }
77}
78
79/**
80 * RealVideo 3.0/4.0 inverse transform for DC block
81 *
82 * Code is almost the same as rv34_inv_transform()
83 * but final coefficients are multiplied by 1.5 and have no rounding.
84 */
85static void rv34_inv_transform_noround_c(int16_t *block){
86    int temp[16];
87    int i;
88
89    rv34_row_transform(temp, block);
90
91    for(i = 0; i < 4; i++){
92        const int z0 = 39*(temp[4*0+i] +    temp[4*2+i]);
93        const int z1 = 39*(temp[4*0+i] -    temp[4*2+i]);
94        const int z2 = 21* temp[4*1+i] - 51*temp[4*3+i];
95        const int z3 = 51* temp[4*1+i] + 21*temp[4*3+i];
96
97        block[i*4+0] = (z0 + z3) >> 11;
98        block[i*4+1] = (z1 + z2) >> 11;
99        block[i*4+2] = (z1 - z2) >> 11;
100        block[i*4+3] = (z0 - z3) >> 11;
101    }
102}
103
104static void rv34_idct_dc_add_c(uint8_t *dst, ptrdiff_t stride, int dc)
105{
106    int i, j;
107
108    dc = (13*13*dc + 0x200) >> 10;
109    for (i = 0; i < 4; i++)
110    {
111        for (j = 0; j < 4; j++)
112            dst[j] = av_clip_uint8( dst[j] + dc );
113
114        dst += stride;
115    }
116}
117
118static void rv34_inv_transform_dc_noround_c(int16_t *block)
119{
120    int16_t dc = (13 * 13 * 3 * block[0]) >> 11;
121    int i, j;
122
123    for (i = 0; i < 4; i++, block += 4)
124        for (j = 0; j < 4; j++)
125            block[j] = dc;
126}
127
128/** @} */ // transform
129
130
131av_cold void ff_rv34dsp_init(RV34DSPContext *c)
132{
133    c->rv34_inv_transform    = rv34_inv_transform_noround_c;
134    c->rv34_inv_transform_dc = rv34_inv_transform_dc_noround_c;
135
136    c->rv34_idct_add    = rv34_idct_add_c;
137    c->rv34_idct_dc_add = rv34_idct_dc_add_c;
138
139#if ARCH_ARM
140    ff_rv34dsp_init_arm(c);
141#elif ARCH_X86
142    ff_rv34dsp_init_x86(c);
143#endif
144}
145