2 * Floating point AAN DCT
3 * this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)
5 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
6 * Copyright (c) 2003 Roman Shaposhnik
8 * Permission to use, copy, modify, and/or distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
24 * Floating point AAN DCT
25 * @author Michael Niedermayer <michaelni@gmx.at>
29 #include "libavutil/internal.h"
30 #include "libavutil/libm.h"
34 /* numbers generated by arbitrary precision arithmetic followed by truncation
35 to 36 fractional digits (enough for a 128-bit IEEE quad, see /usr/include/math.h
36 for this approach). This guarantees a "best effort precision".
38 #define B0 1.000000000000000000000000000000000000L
39 #define B1 0.720959822006947913789091890943021267L // (cos(pi*1/16)sqrt(2))^-1
40 #define B2 0.765366864730179543456919968060797734L // (cos(pi*2/16)sqrt(2))^-1
41 #define B3 0.850430094767256448766702844371412325L // (cos(pi*3/16)sqrt(2))^-1
42 #define B4 1.000000000000000000000000000000000000L // (cos(pi*4/16)sqrt(2))^-1
43 #define B5 1.272758580572833938461007018281767032L // (cos(pi*5/16)sqrt(2))^-1
44 #define B6 1.847759065022573512256366378793576574L // (cos(pi*6/16)sqrt(2))^-1
45 #define B7 3.624509785411551372409941227504289587L // (cos(pi*7/16)sqrt(2))^-1
47 #define A1 M_SQRT1_2 // cos(pi*4/16)
48 #define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2)
49 #define A5 0.38268343236508977170 // cos(pi*6/16)
50 #define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2)
52 static const FLOAT postscale[64]={
53 B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7,
54 B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7,
55 B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7,
56 B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7,
57 B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7,
58 B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7,
59 B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7,
60 B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7,
63 static av_always_inline void row_fdct(FLOAT temp[64], int16_t *data)
65 FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
66 FLOAT tmp10, tmp11, tmp12, tmp13;
67 FLOAT z2, z4, z11, z13;
70 for (i=0; i<8*8; i+=8) {
71 tmp0= data[0 + i] + data[7 + i];
72 tmp7= data[0 + i] - data[7 + i];
73 tmp1= data[1 + i] + data[6 + i];
74 tmp6= data[1 + i] - data[6 + i];
75 tmp2= data[2 + i] + data[5 + i];
76 tmp5= data[2 + i] - data[5 + i];
77 tmp3= data[3 + i] + data[4 + i];
78 tmp4= data[3 + i] - data[4 + i];
85 temp[0 + i]= tmp10 + tmp11;
86 temp[4 + i]= tmp10 - tmp11;
90 temp[2 + i]= tmp13 + tmp12;
91 temp[6 + i]= tmp13 - tmp12;
100 z5 = (tmp4 - tmp6) * A5;
105 z2= tmp4*(A2+A5) - tmp6*A5;
106 z4= tmp6*(A4-A5) + tmp4*A5;
113 temp[5 + i]= z13 + z2;
114 temp[3 + i]= z13 - z2;
115 temp[1 + i]= z11 + z4;
116 temp[7 + i]= z11 - z4;
120 void ff_faandct(int16_t *data)
122 FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
123 FLOAT tmp10, tmp11, tmp12, tmp13;
124 FLOAT z2, z4, z11, z13;
130 row_fdct(temp, data);
132 for (i=0; i<8; i++) {
133 tmp0= temp[8*0 + i] + temp[8*7 + i];
134 tmp7= temp[8*0 + i] - temp[8*7 + i];
135 tmp1= temp[8*1 + i] + temp[8*6 + i];
136 tmp6= temp[8*1 + i] - temp[8*6 + i];
137 tmp2= temp[8*2 + i] + temp[8*5 + i];
138 tmp5= temp[8*2 + i] - temp[8*5 + i];
139 tmp3= temp[8*3 + i] + temp[8*4 + i];
140 tmp4= temp[8*3 + i] - temp[8*4 + i];
147 data[8*0 + i]= lrintf(postscale[8*0 + i] * (tmp10 + tmp11));
148 data[8*4 + i]= lrintf(postscale[8*4 + i] * (tmp10 - tmp11));
152 data[8*2 + i]= lrintf(postscale[8*2 + i] * (tmp13 + tmp12));
153 data[8*6 + i]= lrintf(postscale[8*6 + i] * (tmp13 - tmp12));
162 z5 = (tmp4 - tmp6) * A5;
167 z2= tmp4*(A2+A5) - tmp6*A5;
168 z4= tmp6*(A4-A5) + tmp4*A5;
175 data[8*5 + i]= lrintf(postscale[8*5 + i] * (z13 + z2));
176 data[8*3 + i]= lrintf(postscale[8*3 + i] * (z13 - z2));
177 data[8*1 + i]= lrintf(postscale[8*1 + i] * (z11 + z4));
178 data[8*7 + i]= lrintf(postscale[8*7 + i] * (z11 - z4));
182 void ff_faandct248(int16_t *data)
184 FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
185 FLOAT tmp10, tmp11, tmp12, tmp13;
191 row_fdct(temp, data);
193 for (i=0; i<8; i++) {
194 tmp0 = temp[8*0 + i] + temp[8*1 + i];
195 tmp1 = temp[8*2 + i] + temp[8*3 + i];
196 tmp2 = temp[8*4 + i] + temp[8*5 + i];
197 tmp3 = temp[8*6 + i] + temp[8*7 + i];
198 tmp4 = temp[8*0 + i] - temp[8*1 + i];
199 tmp5 = temp[8*2 + i] - temp[8*3 + i];
200 tmp6 = temp[8*4 + i] - temp[8*5 + i];
201 tmp7 = temp[8*6 + i] - temp[8*7 + i];
208 data[8*0 + i] = lrintf(postscale[8*0 + i] * (tmp10 + tmp11));
209 data[8*4 + i] = lrintf(postscale[8*4 + i] * (tmp10 - tmp11));
213 data[8*2 + i] = lrintf(postscale[8*2 + i] * (tmp13 + tmp12));
214 data[8*6 + i] = lrintf(postscale[8*6 + i] * (tmp13 - tmp12));
221 data[8*1 + i] = lrintf(postscale[8*0 + i] * (tmp10 + tmp11));
222 data[8*5 + i] = lrintf(postscale[8*4 + i] * (tmp10 - tmp11));
226 data[8*3 + i] = lrintf(postscale[8*2 + i] * (tmp13 + tmp12));
227 data[8*7 + i] = lrintf(postscale[8*6 + i] * (tmp13 - tmp12));