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