1 /*
2 * Copyright (c) 2019 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 #include "modules/audio_coding/codecs/opus/audio_coder_opus_common.h"
12
13 namespace webrtc {
14
GetFormatParameter(const SdpAudioFormat & format,const std::string & param)15 absl::optional<std::string> GetFormatParameter(const SdpAudioFormat& format,
16 const std::string& param) {
17 auto it = format.parameters.find(param);
18 if (it == format.parameters.end())
19 return absl::nullopt;
20
21 return it->second;
22 }
23
24 // Parses a comma-separated string "1,2,0,6" into a std::vector<unsigned char>.
25 template <>
GetFormatParameter(const SdpAudioFormat & format,const std::string & param)26 absl::optional<std::vector<unsigned char>> GetFormatParameter(
27 const SdpAudioFormat& format,
28 const std::string& param) {
29 std::vector<unsigned char> result;
30 const std::string comma_separated_list =
31 GetFormatParameter(format, param).value_or("");
32 size_t pos = 0;
33 while (pos < comma_separated_list.size()) {
34 const size_t next_comma = comma_separated_list.find(',', pos);
35 const size_t distance_to_next_comma = next_comma == std::string::npos
36 ? std::string::npos
37 : (next_comma - pos);
38 auto substring_with_number =
39 comma_separated_list.substr(pos, distance_to_next_comma);
40 auto conv = rtc::StringToNumber<int>(substring_with_number);
41 if (!conv.has_value()) {
42 return absl::nullopt;
43 }
44 result.push_back(*conv);
45 pos += substring_with_number.size() + 1;
46 }
47 return result;
48 }
49
50 } // namespace webrtc
51