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ac3dsp.h
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1 /*
2  * AC-3 DSP functions
3  * Copyright (c) 2011 Justin Ruggles
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVCODEC_AC3DSP_H
23 #define AVCODEC_AC3DSP_H
24 
25 #include <stdint.h>
26 
27 /**
28  * Number of mantissa bits written for each bap value.
29  * bap values with fractional bits are set to 0 and are calculated separately.
30  */
31 extern const uint16_t ff_ac3_bap_bits[16];
32 
33 typedef struct AC3DSPContext {
34  /**
35  * Set each encoded exponent in a block to the minimum of itself and the
36  * exponents in the same frequency bin of up to 5 following blocks.
37  * @param exp pointer to the start of the current block of exponents.
38  * constraints: align 16
39  * @param num_reuse_blocks number of blocks that will reuse exponents from the current block.
40  * constraints: range 0 to 5
41  * @param nb_coefs number of frequency coefficients.
42  */
43  void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs);
44 
45  /**
46  * Calculate the maximum MSB of the absolute value of each element in an
47  * array of int16_t.
48  * @param src input array
49  * constraints: align 16. values must be in range [-32767,32767]
50  * @param len number of values in the array
51  * constraints: multiple of 16 greater than 0
52  * @return a value with the same MSB as max(abs(src[]))
53  */
54  int (*ac3_max_msb_abs_int16)(const int16_t *src, int len);
55 
56  /**
57  * Left-shift each value in an array of int16_t by a specified amount.
58  * @param src input array
59  * constraints: align 16
60  * @param len number of values in the array
61  * constraints: multiple of 32 greater than 0
62  * @param shift left shift amount
63  * constraints: range [0,15]
64  */
65  void (*ac3_lshift_int16)(int16_t *src, unsigned int len, unsigned int shift);
66 
67  /**
68  * Right-shift each value in an array of int32_t by a specified amount.
69  * @param src input array
70  * constraints: align 16
71  * @param len number of values in the array
72  * constraints: multiple of 16 greater than 0
73  * @param shift right shift amount
74  * constraints: range [0,31]
75  */
76  void (*ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift);
77 
78  /**
79  * Convert an array of float in range [-1.0,1.0] to int32_t with range
80  * [-(1<<24),(1<<24)]
81  *
82  * @param dst destination array of int32_t.
83  * constraints: 16-byte aligned
84  * @param src source array of float.
85  * constraints: 16-byte aligned
86  * @param len number of elements to convert.
87  * constraints: multiple of 32 greater than zero
88  */
89  void (*float_to_fixed24)(int32_t *dst, const float *src, unsigned int len);
90 
91  /**
92  * Calculate bit allocation pointers.
93  * The SNR is the difference between the masking curve and the signal. AC-3
94  * uses this value for each frequency bin to allocate bits. The snroffset
95  * parameter is a global adjustment to the SNR for all bins.
96  *
97  * @param[in] mask masking curve
98  * @param[in] psd signal power for each frequency bin
99  * @param[in] start starting bin location
100  * @param[in] end ending bin location
101  * @param[in] snr_offset SNR adjustment
102  * @param[in] floor noise floor
103  * @param[in] bap_tab look-up table for bit allocation pointers
104  * @param[out] bap bit allocation pointers
105  */
106  void (*bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end,
107  int snr_offset, int floor,
108  const uint8_t *bap_tab, uint8_t *bap);
109 
110  /**
111  * Update bap counts using the supplied array of bap.
112  *
113  * @param[out] mant_cnt bap counts for 1 block
114  * @param[in] bap array of bap, pointing to start coef bin
115  * @param[in] len number of elements to process
116  */
117  void (*update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len);
118 
119  /**
120  * Calculate the number of bits needed to encode a set of mantissas.
121  *
122  * @param[in] mant_cnt bap counts for all blocks
123  * @return mantissa bit count
124  */
125  int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]);
126 
127  void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs);
128 
129  void (*sum_square_butterfly_int32)(int64_t sum[4], const int32_t *coef0,
130  const int32_t *coef1, int len);
131 
132  void (*sum_square_butterfly_float)(float sum[4], const float *coef0,
133  const float *coef1, int len);
134 
135  void (*downmix)(float **samples, float (*matrix)[2], int out_ch,
136  int in_ch, int len);
137 
138  void (*downmix_fixed)(int32_t **samples, int16_t (*matrix)[2], int out_ch,
139  int in_ch, int len);
140 
141  /**
142  * Apply symmetric window in 16-bit fixed-point.
143  * @param output destination array
144  * constraints: 16-byte aligned
145  * @param input source array
146  * constraints: 16-byte aligned
147  * @param window window array
148  * constraints: 16-byte aligned, at least len/2 elements
149  * @param len full window length
150  * constraints: multiple of ? greater than zero
151  */
152  void (*apply_window_int16)(int16_t *output, const int16_t *input,
153  const int16_t *window, unsigned int len);
154 } AC3DSPContext;
155 
156 void ff_ac3dsp_init (AC3DSPContext *c, int bit_exact);
157 void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact);
158 void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact);
159 void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact);
160 
161 #endif /* AVCODEC_AC3DSP_H */
void(* ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift)
Right-shift each value in an array of int32_t by a specified amount.
Definition: ac3dsp.h:76
void(* float_to_fixed24)(int32_t *dst, const float *src, unsigned int len)
Convert an array of float in range [-1.0,1.0] to int32_t with range [-(1<<24),(1<<24)].
Definition: ac3dsp.h:89
static int shift(int a, int b)
Definition: sonic.c:82
void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp_mips.c:403
void(* sum_square_butterfly_float)(float sum[4], const float *coef0, const float *coef1, int len)
Definition: ac3dsp.h:132
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int(* ac3_max_msb_abs_int16)(const int16_t *src, int len)
Calculate the maximum MSB of the absolute value of each element in an array of int16_t.
Definition: ac3dsp.h:54
void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp_init.c:198
void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact)
static const uint16_t mask[17]
Definition: lzw.c:38
int8_t exp
Definition: eval.c:64
static SDL_Window * window
Definition: ffplay.c:364
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int32_t
#define src
Definition: vp9dsp.c:530
void(* extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs)
Definition: ac3dsp.h:127
const uint16_t ff_ac3_bap_bits[16]
Number of mantissa bits written for each bap value.
Definition: ac3dsp.c:140
void(* bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end, int snr_offset, int floor, const uint8_t *bap_tab, uint8_t *bap)
Calculate bit allocation pointers.
Definition: ac3dsp.h:106
void(* apply_window_int16)(int16_t *output, const int16_t *input, const int16_t *window, unsigned int len)
Apply symmetric window in 16-bit fixed-point.
Definition: ac3dsp.h:152
void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp.c:279
int(* compute_mantissa_size)(uint16_t mant_cnt[6][16])
Calculate the number of bits needed to encode a set of mantissas.
Definition: ac3dsp.h:125
void(* update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len)
Update bap counts using the supplied array of bap.
Definition: ac3dsp.h:117
static double c[64]
void(* ac3_lshift_int16)(int16_t *src, unsigned int len, unsigned int shift)
Left-shift each value in an array of int16_t by a specified amount.
Definition: ac3dsp.h:65
void(* ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
Set each encoded exponent in a block to the minimum of itself and the exponents in the same frequency...
Definition: ac3dsp.h:43
int len
void(* downmix_fixed)(int32_t **samples, int16_t(*matrix)[2], int out_ch, int in_ch, int len)
Definition: ac3dsp.h:138
void(* downmix)(float **samples, float(*matrix)[2], int out_ch, int in_ch, int len)
Definition: ac3dsp.h:135
void(* sum_square_butterfly_int32)(int64_t sum[4], const int32_t *coef0, const int32_t *coef1, int len)
Definition: ac3dsp.h:129
void INT64 start
Definition: avisynth_c.h:690