| /* |
| * 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_CbMemEnergyCalc.c |
| |
| ******************************************************************/ |
| |
| #include "defines.h" |
| |
| /* Compute the energy of the rest of the cb memory |
| * by step wise adding and subtracting the next |
| * sample and the last sample respectively */ |
| void WebRtcIlbcfix_CbMemEnergyCalc( |
| WebRtc_Word32 energy, /* (i) input start energy */ |
| WebRtc_Word16 range, /* (i) number of iterations */ |
| WebRtc_Word16 *ppi, /* (i) input pointer 1 */ |
| WebRtc_Word16 *ppo, /* (i) input pointer 2 */ |
| WebRtc_Word16 *energyW16, /* (o) Energy in the CB vectors */ |
| WebRtc_Word16 *energyShifts, /* (o) Shift value of the energy */ |
| WebRtc_Word16 scale, /* (i) The scaling of all energy values */ |
| WebRtc_Word16 base_size /* (i) Index to where the energy values should be stored */ |
| ) |
| { |
| WebRtc_Word16 j,shft; |
| WebRtc_Word32 tmp; |
| WebRtc_Word16 *eSh_ptr; |
| WebRtc_Word16 *eW16_ptr; |
| |
| |
| eSh_ptr = &energyShifts[1+base_size]; |
| eW16_ptr = &energyW16[1+base_size]; |
| |
| for(j=0;j<range-1;j++) { |
| |
| /* Calculate next energy by a +/- |
| operation on the edge samples */ |
| tmp = WEBRTC_SPL_MUL_16_16(*ppi, *ppi); |
| tmp -= WEBRTC_SPL_MUL_16_16(*ppo, *ppo); |
| energy += WEBRTC_SPL_RSHIFT_W32(tmp, scale); |
| energy = WEBRTC_SPL_MAX(energy, 0); |
| |
| ppi--; |
| ppo--; |
| |
| /* Normalize the energy into a WebRtc_Word16 and store |
| the number of shifts */ |
| |
| shft = (WebRtc_Word16)WebRtcSpl_NormW32(energy); |
| *eSh_ptr++ = shft; |
| |
| tmp = WEBRTC_SPL_LSHIFT_W32(energy, shft); |
| *eW16_ptr++ = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmp, 16); |
| } |
| } |