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 #include "absl/strings/string_view.h"
14
15 namespace webrtc {
16
GetFormatParameter(const SdpAudioFormat & format,absl::string_view param)17 absl::optional<std::string> GetFormatParameter(const SdpAudioFormat& format,
18 absl::string_view param) {
19 auto it = format.parameters.find(std::string(param));
20 if (it == format.parameters.end())
21 return absl::nullopt;
22
23 return it->second;
24 }
25
26 // Parses a comma-separated string "1,2,0,6" into a std::vector<unsigned char>.
27 template <>
GetFormatParameter(const SdpAudioFormat & format,absl::string_view param)28 absl::optional<std::vector<unsigned char>> GetFormatParameter(
29 const SdpAudioFormat& format,
30 absl::string_view param) {
31 std::vector<unsigned char> result;
32 const std::string comma_separated_list =
33 GetFormatParameter(format, param).value_or("");
34 size_t pos = 0;
35 while (pos < comma_separated_list.size()) {
36 const size_t next_comma = comma_separated_list.find(',', pos);
37 const size_t distance_to_next_comma = next_comma == std::string::npos
38 ? std::string::npos
39 : (next_comma - pos);
40 auto substring_with_number =
41 comma_separated_list.substr(pos, distance_to_next_comma);
42 auto conv = rtc::StringToNumber<int>(substring_with_number);
43 if (!conv.has_value()) {
44 return absl::nullopt;
45 }
46 result.push_back(*conv);
47 pos += substring_with_number.size() + 1;
48 }
49 return result;
50 }
51
52 } // namespace webrtc
53