src/third_party/webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.c

   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 #include "pcm16b.h"
  13
  14 #include <stdlib.h>
  15 #ifdef WEBRTC_ARCH_BIG_ENDIAN
  16 #include <string.h>
  17 #endif
  18
  19 #include "webrtc/typedefs.h"
  20
  21 #define HIGHEND 0xFF00
  22 #define LOWEND    0xFF
  23
  24
  25
  26 /* Encoder with int16_t Output */
  27 int16_t WebRtcPcm16b_EncodeW16(const int16_t* speechIn16b,
  28                                int16_t length_samples,
  29                                int16_t* speechOut16b)
  30 {
  31 #ifdef WEBRTC_ARCH_BIG_ENDIAN
  32     memcpy(speechOut16b, speechIn16b, length_samples * sizeof(int16_t));
  33 #else
  34     int i;
  35     for (i = 0; i < length_samples; i++) {
  36         speechOut16b[i]=(((uint16_t)speechIn16b[i])>>8)|((((uint16_t)speechIn16b[i])<<8)&0xFF00);
  37     }
  38 #endif
  39     return length_samples << 1;
  40 }
  41
  42
  43 /* Encoder with char Output (old version) */
  44 int16_t WebRtcPcm16b_Encode(int16_t *speech16b,
  45                             int16_t len,
  46                             unsigned char *speech8b)
  47 {
  48     int16_t samples=len*2;
  49     int16_t pos;
  50     int16_t short1;
  51     int16_t short2;
  52     for (pos=0;pos<len;pos++) {
  53         short1=HIGHEND & speech16b[pos];
  54         short2=LOWEND & speech16b[pos];
  55         short1=short1>>8;
  56         speech8b[pos*2]=(unsigned char) short1;
  57         speech8b[pos*2+1]=(unsigned char) short2;
  58     }
  59     return(samples);
  60 }
  61
  62
  63 /* Decoder with int16_t Input instead of char when the int16_t Encoder is used */
  64 int16_t WebRtcPcm16b_DecodeW16(int16_t *speechIn16b,
  65                                int16_t length_bytes,
  66                                int16_t *speechOut16b,
  67                                int16_t* speechType)
  68 {
  69 #ifdef WEBRTC_ARCH_BIG_ENDIAN
  70     memcpy(speechOut16b, speechIn16b, length_bytes);
  71 #else
  72     int i;
  73     int samples = length_bytes >> 1;
  74
  75     for (i=0;i<samples;i++) {
  76         speechOut16b[i]=(((uint16_t)speechIn16b[i])>>8)|(((uint16_t)(speechIn16b[i]&0xFF))<<8);
  77     }
  78 #endif
  79
  80     *speechType=1;
  81
  82     return length_bytes >> 1;
  83 }
  84
  85 /* "old" version of the decoder that uses char as input (not used in NetEq any more) */
  86 int16_t WebRtcPcm16b_Decode(unsigned char *speech8b,
  87                             int16_t len,
  88                             int16_t *speech16b)
  89 {
  90     int16_t samples=len>>1;
  91     int16_t pos;
  92     int16_t shortval;
  93     for (pos=0;pos<samples;pos++) {
  94         shortval=((unsigned short) speech8b[pos*2]);
  95         shortval=(shortval<<8)&HIGHEND;
  96         shortval=shortval|(((unsigned short) speech8b[pos*2+1])&LOWEND);
  97         speech16b[pos]=shortval;
  98     }
  99     return(samples);
 100 }