1 /*
2 * Copyright (c) 2024 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "format_converter.h"
17 #include <string>
18
19 namespace OHOS {
20 namespace AudioStandard {
S16MonoToS16Stereo(const BufferDesc & srcDesc,const BufferDesc & dstDesc)21 int32_t FormatConverter::S16MonoToS16Stereo(const BufferDesc &srcDesc, const BufferDesc &dstDesc)
22 {
23 size_t half = 2; // mono(1) -> stereo(2)
24 if (srcDesc.bufLength != dstDesc.bufLength / half || srcDesc.buffer == nullptr || dstDesc.buffer == nullptr) {
25 return -1;
26 }
27 int16_t *stcPtr = reinterpret_cast<int16_t *>(srcDesc.buffer);
28 int16_t *dstPtr = reinterpret_cast<int16_t *>(dstDesc.buffer);
29 size_t count = srcDesc.bufLength / sizeof(int16_t);
30 for (size_t idx = 0; idx < count; idx++) {
31 *(dstPtr++) = *stcPtr;
32 *(dstPtr++) = *stcPtr++;
33 }
34 return 0;
35 }
36
S16StereoToS16Mono(const BufferDesc & srcDesc,const BufferDesc & dstDesc)37 int32_t FormatConverter::S16StereoToS16Mono(const BufferDesc &srcDesc, const BufferDesc &dstDesc)
38 {
39 size_t half = 2; // stereo(2) -> mono(1)
40 if (dstDesc.bufLength != srcDesc.bufLength / half || srcDesc.buffer == nullptr || dstDesc.buffer == nullptr) {
41 return -1;
42 }
43 int16_t *stcPtr = reinterpret_cast<int16_t *>(srcDesc.buffer);
44 int16_t *dstPtr = reinterpret_cast<int16_t *>(dstDesc.buffer);
45 size_t count = srcDesc.bufLength / half / sizeof(int16_t);
46 for (size_t idx = 0; idx < count; idx++) {
47 *(dstPtr++) = (*stcPtr + *(stcPtr + 1)) / 2; // To obtain mono channel, add left to right, then divide by 2
48 stcPtr += 2; // ptr++ on mono is equivalent to ptr+=2 on stereo
49 }
50 return 0;
51 }
52 } // namespace AudioStandard
53 } // namespace OHOS
54