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fft-internal.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVCODEC_FFT_INTERNAL_H
20 #define AVCODEC_FFT_INTERNAL_H
21 
22 #if FFT_FLOAT
23 
24 #define FIX15(v) (v)
25 #define sqrthalf (float)M_SQRT1_2
26 
27 #define BF(x, y, a, b) do { \
28  x = a - b; \
29  y = a + b; \
30  } while (0)
31 
32 #define CMUL(dre, dim, are, aim, bre, bim) do { \
33  (dre) = (are) * (bre) - (aim) * (bim); \
34  (dim) = (are) * (bim) + (aim) * (bre); \
35  } while (0)
36 
37 #else
38 
39 #define SCALE_FLOAT(a, bits) lrint((a) * (double)(1 << (bits)))
40 
41 #if FFT_FIXED_32
42 
43 #define CMUL(dre, dim, are, aim, bre, bim) do { \
44  int64_t accu; \
45  (accu) = (int64_t)(bre) * (are); \
46  (accu) -= (int64_t)(bim) * (aim); \
47  (dre) = (int)(((accu) + 0x40000000) >> 31); \
48  (accu) = (int64_t)(bre) * (aim); \
49  (accu) += (int64_t)(bim) * (are); \
50  (dim) = (int)(((accu) + 0x40000000) >> 31); \
51  } while (0)
52 
53 #define FIX15(a) av_clip(SCALE_FLOAT(a, 31), -2147483647, 2147483647)
54 
55 #else /* FFT_FIXED_32 */
56 
57 #include "fft.h"
58 #include "mathops.h"
59 
60 void ff_mdct_calcw_c(FFTContext *s, FFTDouble *output, const FFTSample *input);
61 
62 #define FIX15(a) av_clip(SCALE_FLOAT(a, 15), -32767, 32767)
63 
64 #define sqrthalf ((int16_t)((1<<15)*M_SQRT1_2))
65 
66 #define BF(x, y, a, b) do { \
67  x = (a - b) >> 1; \
68  y = (a + b) >> 1; \
69  } while (0)
70 
71 #define CMULS(dre, dim, are, aim, bre, bim, sh) do { \
72  (dre) = (MUL16(are, bre) - MUL16(aim, bim)) >> sh; \
73  (dim) = (MUL16(are, bim) + MUL16(aim, bre)) >> sh; \
74  } while (0)
75 
76 #define CMUL(dre, dim, are, aim, bre, bim) \
77  CMULS(dre, dim, are, aim, bre, bim, 15)
78 
79 #define CMULL(dre, dim, are, aim, bre, bim) \
80  CMULS(dre, dim, are, aim, bre, bim, 0)
81 
82 #endif /* FFT_FIXED_32 */
83 
84 #endif /* FFT_FLOAT */
85 
86 #define ff_imdct_calc_c FFT_NAME(ff_imdct_calc_c)
87 #define ff_imdct_half_c FFT_NAME(ff_imdct_half_c)
88 #define ff_mdct_calc_c FFT_NAME(ff_mdct_calc_c)
89 
90 void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
91 void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
92 void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
93 
94 #endif /* AVCODEC_FFT_INTERNAL_H */