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}
This commit is contained in:
committed by
Commit Bot
parent
6674846b4a
commit
bb547203bf
61
modules/audio_coding/codecs/ilbc/lsf_to_lsp.c
Normal file
61
modules/audio_coding/codecs/ilbc/lsf_to_lsp.c
Normal file
@ -0,0 +1,61 @@
|
||||
/*
|
||||
* 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_Lsf2Lsp.c
|
||||
|
||||
******************************************************************/
|
||||
|
||||
#include "defines.h"
|
||||
#include "constants.h"
|
||||
|
||||
/*----------------------------------------------------------------*
|
||||
* conversion from lsf to lsp coefficients
|
||||
*---------------------------------------------------------------*/
|
||||
|
||||
void WebRtcIlbcfix_Lsf2Lsp(
|
||||
int16_t *lsf, /* (i) lsf in Q13 values between 0 and pi */
|
||||
int16_t *lsp, /* (o) lsp in Q15 values between -1 and 1 */
|
||||
int16_t m /* (i) number of coefficients */
|
||||
) {
|
||||
int16_t i, k;
|
||||
int16_t diff; /* difference, which is used for the
|
||||
linear approximation (Q8) */
|
||||
int16_t freq; /* normalized frequency in Q15 (0..1) */
|
||||
int32_t tmpW32;
|
||||
|
||||
for(i=0; i<m; i++)
|
||||
{
|
||||
freq = (int16_t)((lsf[i] * 20861) >> 15);
|
||||
/* 20861: 1.0/(2.0*PI) in Q17 */
|
||||
/*
|
||||
Upper 8 bits give the index k and
|
||||
Lower 8 bits give the difference, which needs
|
||||
to be approximated linearly
|
||||
*/
|
||||
k = freq >> 8;
|
||||
diff = (freq&0x00ff);
|
||||
|
||||
/* Guard against getting outside table */
|
||||
|
||||
if (k>63) {
|
||||
k = 63;
|
||||
}
|
||||
|
||||
/* Calculate linear approximation */
|
||||
tmpW32 = WebRtcIlbcfix_kCosDerivative[k] * diff;
|
||||
lsp[i] = WebRtcIlbcfix_kCos[k] + (int16_t)(tmpW32 >> 12);
|
||||
}
|
||||
|
||||
return;
|
||||
}
|
||||
Reference in New Issue
Block a user