FFmpeg
fixed_dsp.h
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47 
48 #ifndef AVUTIL_FIXED_DSP_H
49 #define AVUTIL_FIXED_DSP_H
50 
51 #include <stdint.h>
52 #include "attributes.h"
53 #include "libavcodec/mathops.h"
54 
55 typedef struct AVFixedDSPContext {
56  /* Assume len is a multiple of 16, and arrays are 32-byte aligned */
57  /* Results of multiplications are scaled down by 31 bit (and rounded) if not
58  * stated otherwise */
59 
60  /**
61  * Overlap/add with window function.
62  * Result is scaled down by "bits" bits.
63  * Used primarily by MDCT-based audio codecs.
64  * Source and destination vectors must overlap exactly or not at all.
65  *
66  * @param dst result vector
67  * constraints: 16-byte aligned
68  * @param src0 first source vector
69  * constraints: 16-byte aligned
70  * @param src1 second source vector
71  * constraints: 16-byte aligned
72  * @param win half-window vector
73  * constraints: 16-byte aligned
74  * @param len length of vector
75  * constraints: multiple of 4
76  * @param bits scaling parameter
77  *
78  */
79  void (*vector_fmul_window_scaled)(int16_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len, uint8_t bits);
80 
81  /**
82  * Overlap/add with window function.
83  * Used primarily by MDCT-based audio codecs.
84  * Source and destination vectors must overlap exactly or not at all.
85  *
86  * @param dst result vector
87  * constraints: 32-byte aligned
88  * @param src0 first source vector
89  * constraints: 16-byte aligned
90  * @param src1 second source vector
91  * constraints: 16-byte aligned
92  * @param win half-window vector
93  * constraints: 16-byte aligned
94  * @param len length of vector
95  * constraints: multiple of 4
96  */
97  void (*vector_fmul_window)(int32_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len);
98 
99  /**
100  * Fixed-point multiplication that calculates the entry wise product of two
101  * vectors of integers and stores the result in a vector of integers.
102  *
103  * @param dst output vector
104  * constraints: 32-byte aligned
105  * @param src0 first input vector
106  * constraints: 32-byte aligned
107  * @param src1 second input vector
108  * constraints: 32-byte aligned
109  * @param len number of elements in the input
110  * constraints: multiple of 16
111  */
112  void (*vector_fmul)(int *dst, const int *src0, const int *src1,
113  int len);
114 
115  void (*vector_fmul_reverse)(int *dst, const int *src0, const int *src1, int len);
116  /**
117  * Calculate the entry wise product of two vectors of integers, add a third vector of
118  * integers and store the result in a vector of integers.
119  *
120  * @param dst output vector
121  * constraints: 32-byte aligned
122  * @param src0 first input vector
123  * constraints: 32-byte aligned
124  * @param src1 second input vector
125  * constraints: 32-byte aligned
126  * @param src2 third input vector
127  * constraints: 32-byte aligned
128  * @param len number of elements in the input
129  * constraints: multiple of 16
130  */
131  void (*vector_fmul_add)(int *dst, const int *src0, const int *src1,
132  const int *src2, int len);
133 
134  /**
135  * Calculate the scalar product of two vectors of integers.
136  *
137  * @param v1 first vector, 16-byte aligned
138  * @param v2 second vector, 16-byte aligned
139  * @param len length of vectors, multiple of 4
140  *
141  * @return sum of elementwise products
142  */
143  int (*scalarproduct_fixed)(const int *v1, const int *v2, int len);
144 
145  /**
146  * Calculate the sum and difference of two vectors of integers.
147  *
148  * @param v1 first input vector, sum output, 16-byte aligned
149  * @param v2 second input vector, difference output, 16-byte aligned
150  * @param len length of vectors, multiple of 4
151  */
152  void (*butterflies_fixed)(int *restrict v1, int *restrict v2, int len);
154 
155 /**
156  * Allocate and initialize a fixed DSP context.
157  * note: should be freed with a av_free call when no longer needed.
158  *
159  * @param strict setting to non-zero avoids using functions which may not be IEEE-754 compliant
160  */
162 
165 
166 /**
167  * Calculate the square root
168  *
169  * @param x input fixed point number
170  *
171  * @param bits format of fixed point number (32 - bits).bits
172  *
173  * note: input is normalized to (0, 1) fixed point value
174  */
175 
176 static av_always_inline int fixed_sqrt(int x, int bits)
177 {
178  int retval, bit_mask, guess, square, i;
179  int64_t accu;
180  int shift1 = 30 - bits;
181  int shift2 = bits - 15;
182 
183  if (shift1 > 0) retval = ff_sqrt(x << shift1);
184  else retval = ff_sqrt(x >> -shift1);
185 
186  if (shift2 > 0) {
187  retval = retval << shift2;
188  bit_mask = (1 << (shift2 - 1));
189 
190  for (i=0; i<shift2; i++){
191  guess = retval + bit_mask;
192  accu = (int64_t)guess * guess;
193  square = (int)((accu + bit_mask) >> bits);
194  if (x >= square)
195  retval += bit_mask;
196  bit_mask >>= 1;
197  }
198 
199  }
200  else retval >>= (-shift2);
201 
202  return retval;
203 }
204 
205 #endif /* AVUTIL_FIXED_DSP_H */
AVFixedDSPContext::butterflies_fixed
void(* butterflies_fixed)(int *restrict v1, int *restrict v2, int len)
Calculate the sum and difference of two vectors of integers.
Definition: fixed_dsp.h:152
src1
const pixel * src1
Definition: h264pred_template.c:421
int64_t
long long int64_t
Definition: coverity.c:34
AVFixedDSPContext
Definition: fixed_dsp.h:55
win
static float win(SuperEqualizerContext *s, float n, int N)
Definition: af_superequalizer.c:120
AVFixedDSPContext::vector_fmul_add
void(* vector_fmul_add)(int *dst, const int *src0, const int *src1, const int *src2, int len)
Calculate the entry wise product of two vectors of integers, add a third vector of integers and store...
Definition: fixed_dsp.h:131
ff_fixed_dsp_init_riscv
void ff_fixed_dsp_init_riscv(AVFixedDSPContext *fdsp)
Definition: fixed_dsp_init.c:43
ff_sqrt
#define ff_sqrt
Definition: mathops.h:216
bits
uint8_t bits
Definition: vp3data.h:128
AVFixedDSPContext::scalarproduct_fixed
int(* scalarproduct_fixed)(const int *v1, const int *v2, int len)
Calculate the scalar product of two vectors of integers.
Definition: fixed_dsp.h:143
mathops.h
AVFixedDSPContext::vector_fmul_reverse
void(* vector_fmul_reverse)(int *dst, const int *src0, const int *src1, int len)
Definition: fixed_dsp.h:115
AVFixedDSPContext::vector_fmul
void(* vector_fmul)(int *dst, const int *src0, const int *src1, int len)
Fixed-point multiplication that calculates the entry wise product of two vectors of integers and stor...
Definition: fixed_dsp.h:112
attributes.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
src2
const pixel * src2
Definition: h264pred_template.c:422
av_always_inline
#define av_always_inline
Definition: attributes.h:49
shift2
static const uint8_t shift2[6]
Definition: dxa.c:49
len
int len
Definition: vorbis_enc_data.h:426
square
static int square(int x)
Definition: roqvideoenc.c:196
ff_fixed_dsp_init_x86
void ff_fixed_dsp_init_x86(AVFixedDSPContext *fdsp)
Definition: fixed_dsp_init.c:26
src0
const pixel *const src0
Definition: h264pred_template.c:420
int32_t
int32_t
Definition: audioconvert.c:56
AVFixedDSPContext::vector_fmul_window_scaled
void(* vector_fmul_window_scaled)(int16_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len, uint8_t bits)
Overlap/add with window function.
Definition: fixed_dsp.h:79
fixed_sqrt
static av_always_inline int fixed_sqrt(int x, int bits)
Calculate the square root.
Definition: fixed_dsp.h:176
avpriv_alloc_fixed_dsp
AVFixedDSPContext * avpriv_alloc_fixed_dsp(int strict)
Allocate and initialize a fixed DSP context.
Definition: fixed_dsp.c:151
int
int
Definition: ffmpeg_filter.c:424
shift1
static const uint8_t shift1[6]
Definition: dxa.c:48
AVFixedDSPContext::vector_fmul_window
void(* vector_fmul_window)(int32_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len)
Overlap/add with window function.
Definition: fixed_dsp.h:97