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/*
* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "api/audio_codecs/opus/audio_decoder_opus.h"
#include <memory>
#include <utility>
#include <vector>
#include "absl/strings/match.h"
#include "modules/audio_coding/codecs/opus/audio_decoder_opus.h"
namespace webrtc {
bool AudioDecoderOpus::Config::IsOk() const {
if (sample_rate_hz != 16000 && sample_rate_hz != 48000) {
// Unsupported sample rate. (libopus supports a few other rates as
// well; we can add support for them when needed.)
return false;
}
if (num_channels != 1 && num_channels != 2) {
return false;
}
return true;
}
absl::optional<AudioDecoderOpus::Config> AudioDecoderOpus::SdpToConfig(
const SdpAudioFormat& format) {
const auto num_channels = [&]() -> absl::optional<int> {
auto stereo = format.parameters.find("stereo");
if (stereo != format.parameters.end()) {
if (stereo->second == "0") {
return 1;
} else if (stereo->second == "1") {
return 2;
} else {
return absl::nullopt; // Bad stereo parameter.
}
}
return 1; // Default to mono.
}();
if (absl::EqualsIgnoreCase(format.name, "opus") &&
format.clockrate_hz == 48000 && format.num_channels == 2 &&
num_channels) {
Config config;
config.num_channels = *num_channels;
if (!config.IsOk()) {
RTC_DCHECK_NOTREACHED();
return absl::nullopt;
}
return config;
} else {
return absl::nullopt;
}
}
void AudioDecoderOpus::AppendSupportedDecoders(
std::vector<AudioCodecSpec>* specs) {
AudioCodecInfo opus_info{48000, 1, 64000, 6000, 510000};
opus_info.allow_comfort_noise = false;
opus_info.supports_network_adaption = true;
SdpAudioFormat opus_format(
{"opus", 48000, 2, {{"minptime", "10"}, {"useinbandfec", "1"}}});
specs->push_back({std::move(opus_format), opus_info});
}
std::unique_ptr<AudioDecoder> AudioDecoderOpus::MakeAudioDecoder(
Config config,
absl::optional<AudioCodecPairId> /*codec_pair_id*/,
const FieldTrialsView* field_trials) {
if (!config.IsOk()) {
RTC_DCHECK_NOTREACHED();
return nullptr;
}
return std::make_unique<AudioDecoderOpusImpl>(config.num_channels,
config.sample_rate_hz);
}
} // namespace webrtc
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