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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <audio_utils/primitives.h>
     18 
     19 void ditherAndClamp(int32_t* out, const int32_t *sums, size_t c)
     20 {
     21     size_t i;
     22     for (i=0 ; i<c ; i++) {
     23         int32_t l = *sums++;
     24         int32_t r = *sums++;
     25         int32_t nl = l >> 12;
     26         int32_t nr = r >> 12;
     27         l = clamp16(nl);
     28         r = clamp16(nr);
     29         *out++ = (r<<16) | (l & 0xFFFF);
     30     }
     31 }
     32 
     33 void memcpy_to_i16_from_u8(int16_t *dst, const uint8_t *src, size_t count)
     34 {
     35     dst += count;
     36     src += count;
     37     while (count--) {
     38         *--dst = (int16_t)(*--src - 0x80) << 8;
     39     }
     40 }
     41 
     42 void memcpy_to_u8_from_i16(uint8_t *dst, const int16_t *src, size_t count)
     43 {
     44     while (count--) {
     45         *dst++ = (*src++ >> 8) + 0x80;
     46     }
     47 }
     48 
     49 void memcpy_to_i16_from_i32(int16_t *dst, const int32_t *src, size_t count)
     50 {
     51     while (count--) {
     52         *dst++ = *src++ >> 16;
     53     }
     54 }
     55 
     56 void memcpy_to_i16_from_float(int16_t *dst, const float *src, size_t count)
     57 {
     58     while (count--) {
     59         float f = *src++;
     60         int16_t i;
     61         if (f > 1.0) {
     62             i = 32767;
     63         } else if (f < -1.0) {
     64             i = -32768;
     65         } else {
     66             // does not specifically handle NaN
     67             i = f * 32767.0;
     68         }
     69         *dst++ = i;
     70     }
     71 }
     72 
     73 void downmix_to_mono_i16_from_stereo_i16(int16_t *dst, const int16_t *src, size_t count)
     74 {
     75     while (count--) {
     76         *dst++ = (int16_t)(((int32_t)src[0] + (int32_t)src[1]) >> 1);
     77         src += 2;
     78     }
     79 }
     80 
     81 void upmix_to_stereo_i16_from_mono_i16(int16_t *dst, const int16_t *src, size_t count)
     82 {
     83     while (count--) {
     84         int32_t temp = *src++;
     85         dst[0] = temp;
     86         dst[1] = temp;
     87         dst += 2;
     88     }
     89 }
     90