1 /*
2 * Copyright (c) 2022, Alliance for Open Media. All rights reserved
3 *
4 * This source code is subject to the terms of the BSD 3-Clause Clear License
5 * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
6 * License was not distributed with this source code in the LICENSE file, you
7 * can obtain it at www.aomedia.org/license/software-license/bsd-3-c-c. If the
8 * Alliance for Open Media Patent License 1.0 was not distributed with this
9 * source code in the PATENTS file, you can obtain it at
10 * www.aomedia.org/license/patent.
11 */
12 #include "iamf/common/utils/sample_processing_utils.h"
13
14 #include <cstddef>
15 #include <cstdint>
16
17 #include "absl/log/check.h"
18 #include "absl/log/log.h"
19 #include "absl/status/status.h"
20 #include "absl/strings/str_cat.h"
21
22 namespace iamf_tools {
23
WritePcmSample(uint32_t sample,uint8_t sample_size,bool big_endian,uint8_t * const buffer,size_t & write_position)24 absl::Status WritePcmSample(uint32_t sample, uint8_t sample_size,
25 bool big_endian, uint8_t* const buffer,
26 size_t& write_position) {
27 // Validate assumptions of the logic in the `for` loop below.
28 if (sample_size % 8 != 0 || sample_size > 32) [[unlikely]] {
29 return absl::InvalidArgumentError(
30 absl::StrCat("Invalid sample size: ", sample_size));
31 }
32
33 for (int shift = 32 - sample_size; shift < 32; shift += 8) {
34 uint8_t byte = 0;
35 if (big_endian) [[unlikely]] {
36 byte = (sample >> ((32 - sample_size) + (32 - (shift + 8)))) & 0xff;
37 } else {
38 byte = (sample >> shift) & 0xff;
39 }
40 buffer[write_position++] = byte;
41 }
42
43 return absl::OkStatus();
44 }
45
46 } // namespace iamf_tools
47