mlib_SignalIFFT_1_D64C(3mlib)

1mlib_SignalIFFT_1(3MLIB)  mediaLib Library Functions  mlib_SignalIFFT_1(3MLIB)
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NAME

6       mlib_SignalIFFT_1,         mlib_SignalIFFT_1_S16_S16,         mlib_Sig‐
7       nalIFFT_1_S16C_S16C, mlib_SignalIFFT_1_S16_S16C, mlib_SignalIFFT_1_S16,
8       mlib_SignalIFFT_1_S16C,       mlib_SignalIFFT_1_F32_F32,      mlib_Sig‐
9       nalIFFT_1_F32C_F32C, mlib_SignalIFFT_1_F32_F32C, mlib_SignalIFFT_1_F32,
10       mlib_SignalIFFT_1_F32C,       mlib_SignalIFFT_1_D64_D64,      mlib_Sig‐
11       nalIFFT_1_D64C_D64C, mlib_SignalIFFT_1_D64_D64C, mlib_SignalIFFT_1_D64,
12       mlib_SignalIFFT_1_D64C - signal Inverse Fast Fourier Transform (IFFT)
13

SYNOPSIS

15       cc [ flag... ] file... -lmlib [ library... ]
16       #include <mlib.h>
17
18       mlib_status mlib_SignalIFFT_1_S16_S16(mlib_s16 *dstr, mlib_s16 *dsti,
19            const mlib_s16 *srcr, const mlib_s16 *srci, mlib_s32 order);
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21
22       mlib_status mlib_SignalIFFT_1_S16C_S16C(mlib_s16 *dstc,
23            const mlib_s16 *srcc,
24            mlib_s32 order);
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26
27       mlib_status mlib_SignalIFFT_1_S16_S16C(mlib_s16 *dstr,
28            const mlib_s16 *srcc,
29            mlib_s32 order);
30
31
32       mlib_status mlib_SignalIFFT_1_S16(mlib_s16 *srcdstr,
33            mlib_s16 *srcdsti,
34            mlib_s32 order);
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36
37       mlib_status mlib_SignalIFFT_1_S16C(mlib_s16 *srcdstc,
38            mlib_s32 order);
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40
41       mlib_status mlib_SignalIFFT_1_F32_F32(mlib_f32 *dstr,
42            mlib_f32 *dsti,const mlib_f32 *srcr,
43            const mlib_f32 *srci, mlib_s32 order);
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45
46       mlib_status mlib_SignalIFFT_1_F32C_F32C(mlib_f32 *dstc,
47            const mlib_f32 *srcc,
48            mlib_s32 order);
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50
51       mlib_status mlib_SignalIFFT_1_F32_F32C(mlib_f32 *dstr,
52            const mlib_f32 *srcc,
53            mlib_s32 order);
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55
56       mlib_status mlib_SignalIFFT_1_F32(mlib_f32 *srcdstr,
57            mlib_f32 *srcdsti,
58            mlib_s32 order);
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60
61       mlib_status mlib_SignalIFFT_1_F32C(mlib_f32 *srcdstc,
62            mlib_s32 order);
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65       mlib_status mlib_SignalIFFT_1_D64_D64(mlib_d64 *dstr,
66            mlib_d64 *dsti,
67            const mlib_d64 *srcr, const mlib_d64 *srci, mlib_s32 order);
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69
70       mlib_status mlib_SignalIFFT_1_D64C_D64C(mlib_d64 *dstc,
71            const mlib_d64 *srcc,
72            mlib_s32 order);
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74
75       mlib_status mlib_SignalIFFT_1_D64_D64C(mlib_d64 *dstr,
76            const mlib_d64 *srcc,
77            mlib_s32 order);
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80       mlib_status mlib_SignalIFFT_1_D64(mlib_d64 *srcdstr,
81            mlib_d64 *srcdsti,
82            mlib_s32 order);
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84
85       mlib_status mlib_SignalIFFT_1_D64C(mlib_d64 *srcdstc,
86            mlib_s32 order);
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88

DESCRIPTION

90       Each  of  the  functions  in  this  group performs Inverse Fast Fourier
91       Transform (IFFT).
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93
94       The following equation is used for forward FFT:
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96                   1   N-1
97         dst[k] = ---- SUM {src[n] * exp(-j2*PI*n*k/N)}
98                   C1  n=0
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102       and the following equation is used for inverse FFT (IFFT):
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104                   1   N-1
105         dst[n] = ---- SUM {src[k] * exp(j2*PI*n*k/N)}
106                   C2  k=0
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108
109
110       where
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112         k = 0, 1, ..., (N - 1)
113         n = 0, 1, ..., (N - 1)
114         N = 2**order
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116
117
118       The signal FFT/IFFT functions  can  be  categorized  into  four  groups
119       according to the ScaleMode in the function names in the following form:
120
121         mlib_Signal[FFT|IFFT]_ScaleMode_OutType_InType_OpMode()
122         mlib_Signal[FFT|IFFT]_ScaleMode_DataType_OpMode()
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124
125
126       The scaling factors C1 and C2 used in the equations are defined as fol‐
127       lows:
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129           o      For ScaleMode = 1, C1 = 1 and C2 = 2**order.
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131           o      For ScaleMode = 2, C1 = 2**order and C2 = 1.
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133           o      For ScaleMode = 3, C1 = C2  =  2**(order/2)  when  order  is
134                  even,  or  C1  =  2**((order+1)/2) and C2 = 2**((order-1)/2)
135                  when order is odd.
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137           o      For ScaleMode = 4, C1 = 2**P and C2 = 2**Q, where  P  and  Q
138                  are  adaptive scaling factors and are generated by the func‐
139                  tions.
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141
142       For functions with only real parts for the source signal, the imaginary
143       parts  are  assumed  to be all zero. For functions with only real parts
144       for the destination signal, the  imaginary  parts  are  discarded.  The
145       functions  with only one data type in their names perform the operation
146       in place.
147

PARAMETERS

149       Each function takes some of the following arguments:
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151       dstr       Destination signal array that contains the real parts.
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154       dsti       Destination signal array that contains the imaginary parts.
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157       srcr       Source signal array that contains the real parts.
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160       srci       Source signal array that contains the imaginary parts.
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163       dstc       Complex destination signal  array.  dstc[2*i]  contains  the
164                  real parts, and dstc[2*i+1] contains the imaginary parts.
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167       srcc       Complex  source  signal  array.  srcc[2*i] contains the real
168                  parts, and srcc[2*i+1] contains the imaginary parts.
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171       srcdstr    Source and destination signal array that contains  the  real
172                  parts.
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174
175       srcdsti    Source and destination signal array that contains the imagi‐
176                  nary parts.
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179       srcdstc    Complex source and destination  signal  array.  srcdstc[2*i]
180                  contains  the  real  parts,  and srcdstc[2*i+1] contains the
181                  imaginary parts.
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183
184       order      Order of the transformation. The  base-2  logarithm  of  the
185                  number of data samples.
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187

RETURN VALUES

189       The  function  returns MLIB_SUCCESS if successful. Otherwise it returns
190       MLIB_FAILURE.
191

ATTRIBUTES

193       See attributes(5) for descriptions of the following attributes:
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198       ┌─────────────────────────────┬─────────────────────────────┐
199       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
200       ├─────────────────────────────┼─────────────────────────────┤
201       │Interface Stability          │Committed                    │
202       ├─────────────────────────────┼─────────────────────────────┤
203       │MT-Level                     │MT-Safe                      │
204       └─────────────────────────────┴─────────────────────────────┘
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NAME

SYNOPSIS

DESCRIPTION

PARAMETERS

RETURN VALUES

ATTRIBUTES

SEE ALSO