git-svn-id: http://webrtc.googlecode.com/svn/trunk@4 4adac7df-926f-26a2-2b94-8c16560cd09d

2011-05-30 11:22:19 +00:00
parent 01813fe945
commit 77ae29bc81
1153 changed files with 404089 additions and 0 deletions
--- a/modules/audio_coding/codecs/iLBC/main/source/frame_classify.c
+++ b/modules/audio_coding/codecs/iLBC/main/source/frame_classify.c
@@ -0,0 +1,88 @@
+/*
+ *  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_FrameClassify.c
+
+******************************************************************/
+
+#include "defines.h"
+#include "constants.h"
+
+/*----------------------------------------------------------------*
+ *  Classification of subframes to localize start state
+ *---------------------------------------------------------------*/
+
+WebRtc_Word16 WebRtcIlbcfix_FrameClassify(
+    /* (o) Index to the max-energy sub frame */
+    iLBC_Enc_Inst_t *iLBCenc_inst,
+    /* (i/o) the encoder state structure */
+    WebRtc_Word16 *residualFIX /* (i) lpc residual signal */
+                                                ){
+  WebRtc_Word16 max, scale;
+  WebRtc_Word32 ssqEn[NSUB_MAX-1];
+  WebRtc_Word16 *ssqPtr;
+  WebRtc_Word32 *seqEnPtr;
+  WebRtc_Word32 maxW32;
+  WebRtc_Word16 scale1;
+  WebRtc_Word16 pos;
+  int n;
+
+  /*
+    Calculate the energy of each of the 80 sample blocks
+    in the draft the 4 first and last samples are windowed with 1/5...4/5
+    and 4/5...1/5 respectively. To simplify for the fixpoint we have changed
+    this to 0 0 1 1 and 1 1 0 0
+  */
+
+  max = WebRtcSpl_MaxAbsValueW16(residualFIX, iLBCenc_inst->blockl);
+  scale=WebRtcSpl_GetSizeInBits(WEBRTC_SPL_MUL_16_16(max,max));
+
+  /* Scale to maximum 24 bits so that it won't overflow for 76 samples */
+  scale = scale-24;
+  scale1 = WEBRTC_SPL_MAX(0, scale);
+
+  /* Calculate energies */
+  ssqPtr=residualFIX + 2;
+  seqEnPtr=ssqEn;
+  for (n=(iLBCenc_inst->nsub-1); n>0; n--) {
+    (*seqEnPtr) = WebRtcSpl_DotProductWithScale(ssqPtr, ssqPtr, 76, scale1);
+    ssqPtr += 40;
+    seqEnPtr++;
+  }
+
+  /* Scale to maximum 20 bits in order to allow for the 11 bit window */
+  maxW32 = WebRtcSpl_MaxValueW32(ssqEn, (WebRtc_Word16)(iLBCenc_inst->nsub-1));
+  scale = WebRtcSpl_GetSizeInBits(maxW32) - 20;
+  scale1 = WEBRTC_SPL_MAX(0, scale);
+
+  /* Window each 80 block with the ssqEn_winTbl window to give higher probability for
+     the blocks in the middle
+  */
+  seqEnPtr=ssqEn;
+  if (iLBCenc_inst->mode==20) {
+    ssqPtr=(WebRtc_Word16*)WebRtcIlbcfix_kStartSequenceEnrgWin+1;
+  } else {
+    ssqPtr=(WebRtc_Word16*)WebRtcIlbcfix_kStartSequenceEnrgWin;
+  }
+  for (n=(iLBCenc_inst->nsub-1); n>0; n--) {
+    (*seqEnPtr)=WEBRTC_SPL_MUL(((*seqEnPtr)>>scale1), (*ssqPtr));
+    seqEnPtr++;
+    ssqPtr++;
+  }
+
+  /* Extract the best choise of start state */
+  pos = WebRtcSpl_MaxIndexW32(ssqEn, (WebRtc_Word16)(iLBCenc_inst->nsub-1)) + 1;
+
+  return(pos);
+}