webrtc/modules/audio_coding/codecs/ilbc/get_lsp_poly.h
Mirko Bonadei bb547203bf Moving src/webrtc into src/.
In order to eliminate the WebRTC Subtree mirror in Chromium, 
WebRTC is moving the content of the src/webrtc directory up
to the src/ directory.

NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
TBR=tommi@webrtc.org

Bug: chromium:611808
Change-Id: Iac59c5b51b950f174119565bac87955a7994bc38
Reviewed-on: https://webrtc-review.googlesource.com/1560
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19845}
2017-09-15 04:25:06 +00:00

47 lines
1.4 KiB
C

/*
* 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.h
******************************************************************/
#ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_ILBC_MAIN_SOURCE_GET_LSP_POLY_H_
#define WEBRTC_MODULES_AUDIO_CODING_CODECS_ILBC_MAIN_SOURCE_GET_LSP_POLY_H_
#include "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 */
#endif