1/* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11/****************************************************************** 12 13 iLBC Speech Coder ANSI-C Source Code 14 15 WebRtcIlbcfix_GetSyncSeq.c 16 17******************************************************************/ 18 19#include "defines.h" 20#include "constants.h" 21#include "refiner.h" 22#include "nearest_neighbor.h" 23 24/*----------------------------------------------------------------* 25 * get the pitch-synchronous sample sequence 26 *---------------------------------------------------------------*/ 27 28void WebRtcIlbcfix_GetSyncSeq( 29 int16_t *idata, /* (i) original data */ 30 size_t idatal, /* (i) dimension of data */ 31 size_t centerStartPos, /* (i) where current block starts */ 32 size_t *period, /* (i) rough-pitch-period array (Q-2) */ 33 const size_t *plocs, /* (i) where periods of period array are taken (Q-2) */ 34 size_t periodl, /* (i) dimension period array */ 35 size_t hl, /* (i) 2*hl+1 is the number of sequences */ 36 int16_t *surround /* (i/o) The contribution from this sequence 37 summed with earlier contributions */ 38 ){ 39 size_t i, centerEndPos, q; 40 /* Stack based */ 41 size_t lagBlock[2 * ENH_HL + 1]; 42 size_t blockStartPos[2 * ENH_HL + 1]; /* The position to search around (Q2) */ 43 size_t plocs2[ENH_PLOCSL]; 44 45 centerEndPos = centerStartPos + ENH_BLOCKL - 1; 46 47 /* present (find predicted lag from this position) */ 48 49 WebRtcIlbcfix_NearestNeighbor(lagBlock + hl, 50 plocs, 51 2 * (centerStartPos + centerEndPos), 52 periodl); 53 54 blockStartPos[hl] = 4 * centerStartPos; 55 56 /* past (find predicted position and perform a refined 57 search to find the best sequence) */ 58 59 for (q = hl; q > 0; q--) { 60 size_t qq = q - 1; 61 size_t period_q = period[lagBlock[q]]; 62 /* Stop if this sequence would be outside the buffer; that means all 63 further-past sequences would also be outside the buffer. */ 64 if (blockStartPos[q] < period_q + (4 * ENH_OVERHANG)) 65 break; 66 blockStartPos[qq] = blockStartPos[q] - period_q; 67 68 size_t value = blockStartPos[qq] + 4 * ENH_BLOCKL_HALF; 69 value = (value > period_q) ? (value - period_q) : 0; 70 WebRtcIlbcfix_NearestNeighbor(lagBlock + qq, plocs, value, periodl); 71 72 /* Find the best possible sequence in the 4 times upsampled 73 domain around blockStartPos+q */ 74 WebRtcIlbcfix_Refiner(blockStartPos + qq, idata, idatal, centerStartPos, 75 blockStartPos[qq], surround, 76 WebRtcIlbcfix_kEnhWt[qq]); 77 } 78 79 /* future (find predicted position and perform a refined 80 search to find the best sequence) */ 81 82 for (i = 0; i < periodl; i++) { 83 plocs2[i] = plocs[i] - period[i]; 84 } 85 86 for (q = hl + 1; q <= (2 * hl); q++) { 87 88 WebRtcIlbcfix_NearestNeighbor( 89 lagBlock + q, 90 plocs2, 91 blockStartPos[q - 1] + 4 * ENH_BLOCKL_HALF, 92 periodl); 93 94 blockStartPos[q]=blockStartPos[q-1]+period[lagBlock[q]]; 95 96 if (blockStartPos[q] + 4 * (ENH_BLOCKL + ENH_OVERHANG) < 4 * idatal) { 97 98 /* Find the best possible sequence in the 4 times upsampled 99 domain around blockStartPos+q */ 100 WebRtcIlbcfix_Refiner(blockStartPos + q, idata, idatal, centerStartPos, 101 blockStartPos[q], surround, 102 WebRtcIlbcfix_kEnhWt[2 * hl - q]); 103 104 } else { 105 /* Don't add anything since this sequence would 106 be outside the buffer */ 107 } 108 } 109} 110