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 "common.h"
54 #include "libavcodec/mathops.h"
55 
56 typedef struct AVFixedDSPContext {
57  /* Assume len is a multiple of 16, and arrays are 32-byte aligned */
58  /* Results of multiplications are scaled down by 31 bit (and rounded) if not
59  * stated otherwise */
60 
61  /**
62  * Overlap/add with window function.
63  * Result is scaled down by "bits" bits.
64  * Used primarily by MDCT-based audio codecs.
65  * Source and destination vectors must overlap exactly or not at all.
66  *
67  * @param dst result vector
68  * constraints: 16-byte aligned
69  * @param src0 first source vector
70  * constraints: 16-byte aligned
71  * @param src1 second source vector
72  * constraints: 16-byte aligned
73  * @param win half-window vector
74  * constraints: 16-byte aligned
75  * @param len length of vector
76  * constraints: multiple of 4
77  * @param bits scaling parameter
78  *
79  */
80  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);
81 
82  /**
83  * Overlap/add with window function.
84  * Used primarily by MDCT-based audio codecs.
85  * Source and destination vectors must overlap exactly or not at all.
86  *
87  * @param dst result vector
88  * constraints: 32-byte aligned
89  * @param src0 first source vector
90  * constraints: 16-byte aligned
91  * @param src1 second source vector
92  * constraints: 16-byte aligned
93  * @param win half-window vector
94  * constraints: 16-byte aligned
95  * @param len length of vector
96  * constraints: multiple of 4
97  */
98  void (*vector_fmul_window)(int32_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len);
99 
100  /**
101  * Fixed-point multiplication that calculates the entry wise product of two
102  * vectors of integers and stores the result in a vector of integers.
103  *
104  * @param dst output vector
105  * constraints: 32-byte aligned
106  * @param src0 first input vector
107  * constraints: 32-byte aligned
108  * @param src1 second input vector
109  * constraints: 32-byte aligned
110  * @param len number of elements in the input
111  * constraints: multiple of 16
112  */
113  void (*vector_fmul)(int *dst, const int *src0, const int *src1,
114  int len);
115 
116  void (*vector_fmul_reverse)(int *dst, const int *src0, const int *src1, int len);
117  /**
118  * Calculate the entry wise product of two vectors of integers, add a third vector of
119  * integers and store the result in a vector of integers.
120  *
121  * @param dst output vector
122  * constraints: 32-byte aligned
123  * @param src0 first input vector
124  * constraints: 32-byte aligned
125  * @param src1 second input vector
126  * constraints: 32-byte aligned
127  * @param src2 third input vector
128  * constraints: 32-byte aligned
129  * @param len number of elements in the input
130  * constraints: multiple of 16
131  */
132  void (*vector_fmul_add)(int *dst, const int *src0, const int *src1,
133  const int *src2, int len);
134 
135  /**
136  * Calculate the scalar product of two vectors of integers.
137  *
138  * @param v1 first vector, 16-byte aligned
139  * @param v2 second vector, 16-byte aligned
140  * @param len length of vectors, multiple of 4
141  *
142  * @return sum of elementwise products
143  */
144  int (*scalarproduct_fixed)(const int *v1, const int *v2, int len);
145 
146  /**
147  * Calculate the sum and difference of two vectors of integers.
148  *
149  * @param v1 first input vector, sum output, 16-byte aligned
150  * @param v2 second input vector, difference output, 16-byte aligned
151  * @param len length of vectors, multiple of 4
152  */
153  void (*butterflies_fixed)(int *av_restrict v1, int *av_restrict v2, int len);
155 
156 /**
157  * Allocate and initialize a fixed DSP context.
158  * note: should be freed with a av_free call when no longer needed.
159  *
160  * @param strict setting to non-zero avoids using functions which may not be IEEE-754 compliant
161  */
163 
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 */
static float win(SuperEqualizerContext *s, float n, int N)
Macro definitions for various function/variable attributes.
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:132
uint8_t
void(* vector_fmul_reverse)(int *dst, const int *src0, const int *src1, int len)
Definition: fixed_dsp.h:116
static av_always_inline int fixed_sqrt(int x, int bits)
Calculate the square root.
Definition: fixed_dsp.h:176
void ff_fixed_dsp_init_x86(AVFixedDSPContext *fdsp)
#define ff_sqrt
Definition: mathops.h:206
int(* scalarproduct_fixed)(const int *v1, const int *v2, int len)
Calculate the scalar product of two vectors of integers.
Definition: fixed_dsp.h:144
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
static const int shift1[6]
Definition: dxa.c:50
uint8_t bits
Definition: vp3data.h:202
static int square(int x)
Definition: roqvideoenc.c:113
AVFixedDSPContext * avpriv_alloc_fixed_dsp(int strict)
Allocate and initialize a fixed DSP context.
Definition: fixed_dsp.c:148
void(* butterflies_fixed)(int *av_restrict v1, int *av_restrict v2, int len)
Calculate the sum and difference of two vectors of integers.
Definition: fixed_dsp.h:153
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int32_t
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:98
#define src1
Definition: h264pred.c:139
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:113
#define src0
Definition: h264pred.c:138
int
common internal and external API header
static const int shift2[6]
Definition: dxa.c:51
int len
#define av_always_inline
Definition: attributes.h:39
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:80