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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/libwebrtc/modules/audio_coding/codecs/ilbc/get_lsp_poly.c | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | third_party/libwebrtc/modules/audio_coding/codecs/ilbc/get_lsp_poly.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/get_lsp_poly.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/get_lsp_poly.c new file mode 100644 index 0000000000..e0fb21caf0 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/get_lsp_poly.c @@ -0,0 +1,84 @@ +/* + * Copyright (c) 2011 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. + */ + +/****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + WebRtcIlbcfix_GetLspPoly.c + +******************************************************************/ + +#include "modules/audio_coding/codecs/ilbc/get_lsp_poly.h" + +#include "modules/audio_coding/codecs/ilbc/defines.h" + +/*----------------------------------------------------------------* + * Construct the polynomials F1(z) and F2(z) from the LSP + * (Computations are done in Q24) + * + * The expansion is performed using the following recursion: + * + * f[0] = 1; + * tmp = -2.0 * lsp[0]; + * f[1] = tmp; + * for (i=2; i<=5; i++) { + * b = -2.0 * lsp[2*i-2]; + * f[i] = tmp*f[i-1] + 2.0*f[i-2]; + * for (j=i; j>=2; j--) { + * f[j] = f[j] + tmp*f[j-1] + f[j-2]; + * } + * f[i] = f[i] + tmp; + * } + *---------------------------------------------------------------*/ + +void WebRtcIlbcfix_GetLspPoly( + int16_t *lsp, /* (i) LSP in Q15 */ + int32_t *f) /* (o) polonymial in Q24 */ +{ + int32_t tmpW32; + int i, j; + int16_t high, low; + int16_t *lspPtr; + int32_t *fPtr; + + lspPtr = lsp; + fPtr = f; + /* f[0] = 1.0 (Q24) */ + (*fPtr) = (int32_t)16777216; + fPtr++; + + (*fPtr) = WEBRTC_SPL_MUL((*lspPtr), -1024); + fPtr++; + lspPtr+=2; + + for(i=2; i<=5; i++) + { + (*fPtr) = fPtr[-2]; + + for(j=i; j>1; j--) + { + /* Compute f[j] = f[j] + tmp*f[j-1] + f[j-2]; */ + high = (int16_t)(fPtr[-1] >> 16); + low = (int16_t)((fPtr[-1] & 0xffff) >> 1); + + tmpW32 = 4 * high * *lspPtr + 4 * ((low * *lspPtr) >> 15); + + (*fPtr) += fPtr[-2]; + (*fPtr) -= tmpW32; + fPtr--; + } + *fPtr -= *lspPtr * (1 << 10); + + fPtr+=i; + lspPtr+=2; + } + return; +} |