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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:28:17 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:28:17 +0000 |
commit | 7a46c07230b8d8108c0e8e80df4522d0ac116538 (patch) | |
tree | d483300dab478b994fe199a5d19d18d74153718a /spa/plugins/audioconvert/hilbert.h | |
parent | Initial commit. (diff) | |
download | pipewire-7a46c07230b8d8108c0e8e80df4522d0ac116538.tar.xz pipewire-7a46c07230b8d8108c0e8e80df4522d0ac116538.zip |
Adding upstream version 0.3.65.upstream/0.3.65upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'spa/plugins/audioconvert/hilbert.h')
-rw-r--r-- | spa/plugins/audioconvert/hilbert.h | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/spa/plugins/audioconvert/hilbert.h b/spa/plugins/audioconvert/hilbert.h new file mode 100644 index 0000000..103e6e9 --- /dev/null +++ b/spa/plugins/audioconvert/hilbert.h @@ -0,0 +1,69 @@ +/* Hilbert function + * + * Copyright © 2021 Wim Taymans + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#ifndef HILBERT_H +#define HILBERT_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include <errno.h> +#include <stddef.h> +#include <math.h> + +static inline void blackman_window(float *taps, int n_taps) +{ + int n; + for (n = 0; n < n_taps; n++) { + float w = 2 * M_PI * n / (n_taps-1); + taps[n] = 0.3635819 - 0.4891775 * cos(w) + + 0.1365995 * cos(2 * w) - 0.0106411 * cos(3 * w); + } +} + +static inline int hilbert_generate(float *taps, int n_taps) +{ + int i; + + if ((n_taps & 1) == 0) + return -EINVAL; + + for (i = 0; i < n_taps; i++) { + int k = -(n_taps / 2) + i; + if (k & 1) { + float pk = M_PI * k; + taps[i] *= (1.0f - cosf(pk)) / pk; + } else { + taps[i] = 0.0f; + } + } + return 0; +} + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* HILBERT_H */ |