36e1ad9b5d
According to project structure discussed with Andrew. We want to flatten out the hierarchy and minimize the number of GYP files. No changes at all are being made in the source files; they are just moved. The only modified files are the GYP file and Android.mk Kevin: I updated relative paths in Android.mk so please verify it is correct, since I don't know how to build that. Review URL: http://webrtc-codereview.appspot.com/256006 git-svn-id: http://webrtc.googlecode.com/svn/trunk@894 4adac7df-926f-26a2-2b94-8c16560cd09d
89 lines
3.1 KiB
C
89 lines
3.1 KiB
C
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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/******************************************************************
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iLBC Speech Coder ANSI-C Source Code
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WebRtcIlbcfix_HpInput.c
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******************************************************************/
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#include "defines.h"
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/*----------------------------------------------------------------*
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* high-pass filter of input with *0.5 and saturation
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*---------------------------------------------------------------*/
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void WebRtcIlbcfix_HpInput(
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WebRtc_Word16 *signal, /* (i/o) signal vector */
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WebRtc_Word16 *ba, /* (i) B- and A-coefficients (2:nd order)
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{b[0] b[1] b[2] -a[1] -a[2]} a[0]
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is assumed to be 1.0 */
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WebRtc_Word16 *y, /* (i/o) Filter state yhi[n-1] ylow[n-1]
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yhi[n-2] ylow[n-2] */
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WebRtc_Word16 *x, /* (i/o) Filter state x[n-1] x[n-2] */
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WebRtc_Word16 len) /* (i) Number of samples to filter */
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{
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int i;
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WebRtc_Word32 tmpW32;
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WebRtc_Word32 tmpW32b;
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for (i=0; i<len; i++) {
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/*
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y[i] = b[0]*x[i] + b[1]*x[i-1] + b[2]*x[i-2]
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+ (-a[1])*y[i-1] + (-a[2])*y[i-2];
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*/
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tmpW32 = WEBRTC_SPL_MUL_16_16(y[1], ba[3]); /* (-a[1])*y[i-1] (low part) */
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tmpW32 += WEBRTC_SPL_MUL_16_16(y[3], ba[4]); /* (-a[2])*y[i-2] (low part) */
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tmpW32 = (tmpW32>>15);
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tmpW32 += WEBRTC_SPL_MUL_16_16(y[0], ba[3]); /* (-a[1])*y[i-1] (high part) */
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tmpW32 += WEBRTC_SPL_MUL_16_16(y[2], ba[4]); /* (-a[2])*y[i-2] (high part) */
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tmpW32 = (tmpW32<<1);
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tmpW32 += WEBRTC_SPL_MUL_16_16(signal[i], ba[0]); /* b[0]*x[0] */
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tmpW32 += WEBRTC_SPL_MUL_16_16(x[0], ba[1]); /* b[1]*x[i-1] */
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tmpW32 += WEBRTC_SPL_MUL_16_16(x[1], ba[2]); /* b[2]*x[i-2] */
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/* Update state (input part) */
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x[1] = x[0];
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x[0] = signal[i];
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/* Rounding in Q(12+1), i.e. add 2^12 */
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tmpW32b = tmpW32 + 4096;
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/* Saturate (to 2^28) so that the HP filtered signal does not overflow */
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tmpW32b = WEBRTC_SPL_SAT((WebRtc_Word32)268435455, tmpW32b, (WebRtc_Word32)-268435456);
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/* Convert back to Q0 and multiply with 0.5 */
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signal[i] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmpW32b, 13);
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/* Update state (filtered part) */
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y[2] = y[0];
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y[3] = y[1];
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/* upshift tmpW32 by 3 with saturation */
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if (tmpW32>268435455) {
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tmpW32 = WEBRTC_SPL_WORD32_MAX;
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} else if (tmpW32<-268435456) {
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tmpW32 = WEBRTC_SPL_WORD32_MIN;
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} else {
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tmpW32 = WEBRTC_SPL_LSHIFT_W32(tmpW32, 3);
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}
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y[0] = (WebRtc_Word16)(tmpW32 >> 16);
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y[1] = (WebRtc_Word16)((tmpW32 - WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)y[0], 16))>>1);
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}
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return;
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}
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