| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| void DecodeALaw(int16_t *out, const uint8_t *in, size_t inSize) { |
| if (out != nullptr && in != nullptr) { |
| while (inSize > 0) { |
| inSize--; |
| int32_t x = *in++; |
| |
| int32_t ix = x ^ 0x55; |
| ix &= 0x7f; |
| |
| int32_t iexp = ix >> 4; |
| int32_t mant = ix & 0x0f; |
| |
| if (iexp > 0) { |
| mant += 16; |
| } |
| |
| mant = (mant << 4) + 8; |
| |
| if (iexp > 1) { |
| mant = mant << (iexp - 1); |
| } |
| |
| *out++ = (x > 127) ? mant : -mant; |
| } |
| } |
| } |