diff options
Diffstat (limited to 'codec2_fft.c')
-rw-r--r-- | codec2_fft.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/codec2_fft.c b/codec2_fft.c new file mode 100644 index 0000000..14b8670 --- /dev/null +++ b/codec2_fft.c | |||
@@ -0,0 +1,158 @@ | |||
1 | /* | ||
2 | * codec2_fft.c | ||
3 | * | ||
4 | * Created on: 24.09.2016 | ||
5 | * Author: danilo | ||
6 | */ | ||
7 | |||
8 | #include "codec2_fft.h" | ||
9 | |||
10 | #include "debug_alloc.h" | ||
11 | |||
12 | #ifdef USE_KISS_FFT | ||
13 | #include "_kiss_fft_guts.h" | ||
14 | |||
15 | #else | ||
16 | #if 0 | ||
17 | // caching constants in RAM did not seem to have an effect on performance | ||
18 | // TODO: Decide what to with this code | ||
19 | #define FFT_INIT_CACHE_SIZE 4 | ||
20 | const arm_cfft_instance_f32* fft_init_cache[FFT_INIT_CACHE_SIZE]; | ||
21 | |||
22 | static const arm_cfft_instance_f32* arm_fft_instance2ram(const arm_cfft_instance_f32* in) | ||
23 | { | ||
24 | |||
25 | arm_cfft_instance_f32* out = malloc(sizeof(arm_cfft_instance_f32)); | ||
26 | |||
27 | if (out) { | ||
28 | memcpy(out,in,sizeof(arm_cfft_instance_f32)); | ||
29 | out->pBitRevTable = malloc(out->bitRevLength * sizeof(uint16_t)); | ||
30 | out->pTwiddle = malloc(out->fftLen * sizeof(float32_t)); | ||
31 | memcpy((void*)out->pBitRevTable,in->pBitRevTable,out->bitRevLength * sizeof(uint16_t)); | ||
32 | memcpy((void*)out->pTwiddle,in->pTwiddle,out->fftLen * sizeof(float32_t)); | ||
33 | } | ||
34 | return out; | ||
35 | } | ||
36 | |||
37 | |||
38 | static const arm_cfft_instance_f32* arm_fft_cache_get(const arm_cfft_instance_f32* romfft) | ||
39 | { | ||
40 | const arm_cfft_instance_f32* retval = NULL; | ||
41 | static int used = 0; | ||
42 | for (int i = 0; fft_init_cache[i] != NULL && i < used; i++) | ||
43 | { | ||
44 | if (romfft->fftLen == fft_init_cache[i]->fftLen) | ||
45 | { | ||
46 | retval = fft_init_cache[i]; | ||
47 | break; | ||
48 | } | ||
49 | } | ||
50 | if (retval == NULL && used < FFT_INIT_CACHE_SIZE) | ||
51 | { | ||
52 | retval = arm_fft_instance2ram(romfft); | ||
53 | fft_init_cache[used++] = retval; | ||
54 | } | ||
55 | if (retval == NULL) | ||
56 | { | ||
57 | retval = romfft; | ||
58 | } | ||
59 | return retval; | ||
60 | } | ||
61 | #endif | ||
62 | #endif | ||
63 | |||
64 | void codec2_fft_free(codec2_fft_cfg cfg) | ||
65 | { | ||
66 | #ifdef USE_KISS_FFT | ||
67 | KISS_FFT_FREE(cfg); | ||
68 | #else | ||
69 | FREE(cfg); | ||
70 | #endif | ||
71 | } | ||
72 | |||
73 | codec2_fft_cfg codec2_fft_alloc(int nfft, int inverse_fft, void* mem, size_t* lenmem) | ||
74 | { | ||
75 | codec2_fft_cfg retval; | ||
76 | #ifdef USE_KISS_FFT | ||
77 | retval = kiss_fft_alloc(nfft, inverse_fft, mem, lenmem); | ||
78 | #else | ||
79 | retval = MALLOC(sizeof(codec2_fft_struct)); | ||
80 | retval->inverse = inverse_fft; | ||
81 | switch(nfft) | ||
82 | { | ||
83 | case 128: | ||
84 | retval->instance = &arm_cfft_sR_f32_len128; | ||
85 | break; | ||
86 | case 256: | ||
87 | retval->instance = &arm_cfft_sR_f32_len256; | ||
88 | break; | ||
89 | case 512: | ||
90 | retval->instance = &arm_cfft_sR_f32_len512; | ||
91 | break; | ||
92 | // case 1024: | ||
93 | // retval->instance = &arm_cfft_sR_f32_len1024; | ||
94 | // break; | ||
95 | default: | ||
96 | abort(); | ||
97 | } | ||
98 | // retval->instance = arm_fft_cache_get(retval->instance); | ||
99 | #endif | ||
100 | return retval; | ||
101 | } | ||
102 | |||
103 | codec2_fftr_cfg codec2_fftr_alloc(int nfft, int inverse_fft, void* mem, size_t* lenmem) | ||
104 | { | ||
105 | codec2_fftr_cfg retval; | ||
106 | #ifdef USE_KISS_FFT | ||
107 | retval = kiss_fftr_alloc(nfft, inverse_fft, mem, lenmem); | ||
108 | #else | ||
109 | retval = MALLOC(sizeof(codec2_fftr_struct)); | ||
110 | retval->inverse = inverse_fft; | ||
111 | retval->instance = MALLOC(sizeof(arm_rfft_fast_instance_f32)); | ||
112 | arm_rfft_fast_init_f32(retval->instance,nfft); | ||
113 | // memcpy(&retval->instance->Sint,arm_fft_cache_get(&retval->instance->Sint),sizeof(arm_cfft_instance_f32)); | ||
114 | #endif | ||
115 | return retval; | ||
116 | } | ||
117 | void codec2_fftr_free(codec2_fftr_cfg cfg) | ||
118 | { | ||
119 | #ifdef USE_KISS_FFT | ||
120 | KISS_FFT_FREE(cfg); | ||
121 | #else | ||
122 | FREE(cfg->instance); | ||
123 | FREE(cfg); | ||
124 | #endif | ||
125 | } | ||
126 | |||
127 | // there is a little overhead for inplace kiss_fft but this is | ||
128 | // on the powerful platforms like the Raspberry or even x86 PC based ones | ||
129 | // not noticeable | ||
130 | // the reduced usage of RAM and increased performance on STM32 platforms | ||
131 | // should be worth it. | ||
132 | void codec2_fft_inplace(codec2_fft_cfg cfg, codec2_fft_cpx* inout) | ||
133 | { | ||
134 | |||
135 | #ifdef USE_KISS_FFT | ||
136 | kiss_fft_cpx in[512]; | ||
137 | // decide whether to use the local stack based buffer for in | ||
138 | // or to allow kiss_fft to allocate RAM | ||
139 | // second part is just to play safe since first method | ||
140 | // is much faster and uses less RAM | ||
141 | if (cfg->nfft <= 512) | ||
142 | { | ||
143 | memcpy(in,inout,cfg->nfft*sizeof(kiss_fft_cpx)); | ||
144 | kiss_fft(cfg, in, (kiss_fft_cpx*)inout); | ||
145 | } | ||
146 | else | ||
147 | { | ||
148 | kiss_fft(cfg, (kiss_fft_cpx*)inout, (kiss_fft_cpx*)inout); | ||
149 | } | ||
150 | #else | ||
151 | arm_cfft_f32(cfg->instance,(float*)inout,cfg->inverse,1); | ||
152 | if (cfg->inverse) | ||
153 | { | ||
154 | arm_scale_f32((float*)inout,cfg->instance->fftLen,(float*)inout,cfg->instance->fftLen*2); | ||
155 | } | ||
156 | |||
157 | #endif | ||
158 | } | ||