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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c')
-rw-r--r-- | third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c b/third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c new file mode 100644 index 0000000000..1c82cff50f --- /dev/null +++ b/third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c @@ -0,0 +1,108 @@ +/* + * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include "common_audio/signal_processing/include/signal_processing_library.h" + +/* Tables for data buffer indexes that are bit reversed and thus need to be + * swapped. Note that, index_7[{0, 2, 4, ...}] are for the left side of the swap + * operations, while index_7[{1, 3, 5, ...}] are for the right side of the + * operation. Same for index_8. + */ + +/* Indexes for the case of stages == 7. */ +static const int16_t index_7[112] = { + 1, 64, 2, 32, 3, 96, 4, 16, 5, 80, 6, 48, 7, 112, 9, 72, 10, 40, 11, 104, + 12, 24, 13, 88, 14, 56, 15, 120, 17, 68, 18, 36, 19, 100, 21, 84, 22, 52, + 23, 116, 25, 76, 26, 44, 27, 108, 29, 92, 30, 60, 31, 124, 33, 66, 35, 98, + 37, 82, 38, 50, 39, 114, 41, 74, 43, 106, 45, 90, 46, 58, 47, 122, 49, 70, + 51, 102, 53, 86, 55, 118, 57, 78, 59, 110, 61, 94, 63, 126, 67, 97, 69, + 81, 71, 113, 75, 105, 77, 89, 79, 121, 83, 101, 87, 117, 91, 109, 95, 125, + 103, 115, 111, 123 +}; + +/* Indexes for the case of stages == 8. */ +static const int16_t index_8[240] = { + 1, 128, 2, 64, 3, 192, 4, 32, 5, 160, 6, 96, 7, 224, 8, 16, 9, 144, 10, 80, + 11, 208, 12, 48, 13, 176, 14, 112, 15, 240, 17, 136, 18, 72, 19, 200, 20, + 40, 21, 168, 22, 104, 23, 232, 25, 152, 26, 88, 27, 216, 28, 56, 29, 184, + 30, 120, 31, 248, 33, 132, 34, 68, 35, 196, 37, 164, 38, 100, 39, 228, 41, + 148, 42, 84, 43, 212, 44, 52, 45, 180, 46, 116, 47, 244, 49, 140, 50, 76, + 51, 204, 53, 172, 54, 108, 55, 236, 57, 156, 58, 92, 59, 220, 61, 188, 62, + 124, 63, 252, 65, 130, 67, 194, 69, 162, 70, 98, 71, 226, 73, 146, 74, 82, + 75, 210, 77, 178, 78, 114, 79, 242, 81, 138, 83, 202, 85, 170, 86, 106, 87, + 234, 89, 154, 91, 218, 93, 186, 94, 122, 95, 250, 97, 134, 99, 198, 101, + 166, 103, 230, 105, 150, 107, 214, 109, 182, 110, 118, 111, 246, 113, 142, + 115, 206, 117, 174, 119, 238, 121, 158, 123, 222, 125, 190, 127, 254, 131, + 193, 133, 161, 135, 225, 137, 145, 139, 209, 141, 177, 143, 241, 147, 201, + 149, 169, 151, 233, 155, 217, 157, 185, 159, 249, 163, 197, 167, 229, 171, + 213, 173, 181, 175, 245, 179, 205, 183, 237, 187, 221, 191, 253, 199, 227, + 203, 211, 207, 243, 215, 235, 223, 251, 239, 247 +}; + +void WebRtcSpl_ComplexBitReverse(int16_t* __restrict complex_data, int stages) { + /* For any specific value of stages, we know exactly the indexes that are + * bit reversed. Currently (Feb. 2012) in WebRTC the only possible values of + * stages are 7 and 8, so we use tables to save unnecessary iterations and + * calculations for these two cases. + */ + if (stages == 7 || stages == 8) { + int m = 0; + int length = 112; + const int16_t* index = index_7; + + if (stages == 8) { + length = 240; + index = index_8; + } + + /* Decimation in time. Swap the elements with bit-reversed indexes. */ + for (m = 0; m < length; m += 2) { + /* We declare a int32_t* type pointer, to load both the 16-bit real + * and imaginary elements from complex_data in one instruction, reducing + * complexity. + */ + int32_t* complex_data_ptr = (int32_t*)complex_data; + int32_t temp = 0; + + temp = complex_data_ptr[index[m]]; /* Real and imaginary */ + complex_data_ptr[index[m]] = complex_data_ptr[index[m + 1]]; + complex_data_ptr[index[m + 1]] = temp; + } + } + else { + int m = 0, mr = 0, l = 0; + int n = 1 << stages; + int nn = n - 1; + + /* Decimation in time - re-order data */ + for (m = 1; m <= nn; ++m) { + int32_t* complex_data_ptr = (int32_t*)complex_data; + int32_t temp = 0; + + /* Find out indexes that are bit-reversed. */ + l = n; + do { + l >>= 1; + } while (l > nn - mr); + mr = (mr & (l - 1)) + l; + + if (mr <= m) { + continue; + } + + /* Swap the elements with bit-reversed indexes. + * This is similar to the loop in the stages == 7 or 8 cases. + */ + temp = complex_data_ptr[m]; /* Real and imaginary */ + complex_data_ptr[m] = complex_data_ptr[mr]; + complex_data_ptr[mr] = temp; + } + } +} |