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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /third_party/libwebrtc/api/audio_codecs/audio_decoder_factory_template.h | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | third_party/libwebrtc/api/audio_codecs/audio_decoder_factory_template.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/audio_codecs/audio_decoder_factory_template.h b/third_party/libwebrtc/api/audio_codecs/audio_decoder_factory_template.h new file mode 100644 index 0000000000..7ea0c91372 --- /dev/null +++ b/third_party/libwebrtc/api/audio_codecs/audio_decoder_factory_template.h @@ -0,0 +1,145 @@ +/* + * 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. + */ + +#ifndef API_AUDIO_CODECS_AUDIO_DECODER_FACTORY_TEMPLATE_H_ +#define API_AUDIO_CODECS_AUDIO_DECODER_FACTORY_TEMPLATE_H_ + +#include <memory> +#include <vector> + +#include "api/audio_codecs/audio_decoder_factory.h" +#include "api/field_trials_view.h" +#include "api/make_ref_counted.h" +#include "api/scoped_refptr.h" + +namespace webrtc { + +namespace audio_decoder_factory_template_impl { + +template <typename... Ts> +struct Helper; + +// Base case: 0 template parameters. +template <> +struct Helper<> { + static void AppendSupportedDecoders(std::vector<AudioCodecSpec>* specs) {} + static bool IsSupportedDecoder(const SdpAudioFormat& format) { return false; } + static std::unique_ptr<AudioDecoder> MakeAudioDecoder( + const SdpAudioFormat& format, + absl::optional<AudioCodecPairId> codec_pair_id, + const FieldTrialsView* field_trials) { + return nullptr; + } +}; + +// Inductive case: Called with n + 1 template parameters; calls subroutines +// with n template parameters. +template <typename T, typename... Ts> +struct Helper<T, Ts...> { + static void AppendSupportedDecoders(std::vector<AudioCodecSpec>* specs) { + T::AppendSupportedDecoders(specs); + Helper<Ts...>::AppendSupportedDecoders(specs); + } + static bool IsSupportedDecoder(const SdpAudioFormat& format) { + auto opt_config = T::SdpToConfig(format); + static_assert(std::is_same<decltype(opt_config), + absl::optional<typename T::Config>>::value, + "T::SdpToConfig() must return a value of type " + "absl::optional<T::Config>"); + return opt_config ? true : Helper<Ts...>::IsSupportedDecoder(format); + } + static std::unique_ptr<AudioDecoder> MakeAudioDecoder( + const SdpAudioFormat& format, + absl::optional<AudioCodecPairId> codec_pair_id, + const FieldTrialsView* field_trials) { + auto opt_config = T::SdpToConfig(format); + return opt_config ? T::MakeAudioDecoder(*opt_config, codec_pair_id) + : Helper<Ts...>::MakeAudioDecoder(format, codec_pair_id, + field_trials); + } +}; + +template <typename... Ts> +class AudioDecoderFactoryT : public AudioDecoderFactory { + public: + explicit AudioDecoderFactoryT(const FieldTrialsView* field_trials) { + field_trials_ = field_trials; + } + + std::vector<AudioCodecSpec> GetSupportedDecoders() override { + std::vector<AudioCodecSpec> specs; + Helper<Ts...>::AppendSupportedDecoders(&specs); + return specs; + } + + bool IsSupportedDecoder(const SdpAudioFormat& format) override { + return Helper<Ts...>::IsSupportedDecoder(format); + } + + std::unique_ptr<AudioDecoder> MakeAudioDecoder( + const SdpAudioFormat& format, + absl::optional<AudioCodecPairId> codec_pair_id) override { + return Helper<Ts...>::MakeAudioDecoder(format, codec_pair_id, + field_trials_); + } + + const FieldTrialsView* field_trials_; +}; + +} // namespace audio_decoder_factory_template_impl + +// Make an AudioDecoderFactory that can create instances of the given decoders. +// +// Each decoder type is given as a template argument to the function; it should +// be a struct with the following static member functions: +// +// // Converts `audio_format` to a ConfigType instance. Returns an empty +// // optional if `audio_format` doesn't correctly specify a decoder of our +// // type. +// absl::optional<ConfigType> SdpToConfig(const SdpAudioFormat& audio_format); +// +// // Appends zero or more AudioCodecSpecs to the list that will be returned +// // by AudioDecoderFactory::GetSupportedDecoders(). +// void AppendSupportedDecoders(std::vector<AudioCodecSpec>* specs); +// +// // Creates an AudioDecoder for the specified format. Used to implement +// // AudioDecoderFactory::MakeAudioDecoder(). +// std::unique_ptr<AudioDecoder> MakeAudioDecoder( +// const ConfigType& config, +// absl::optional<AudioCodecPairId> codec_pair_id); +// +// ConfigType should be a type that encapsulates all the settings needed to +// create an AudioDecoder. T::Config (where T is the decoder struct) should +// either be the config type, or an alias for it. +// +// Whenever it tries to do something, the new factory will try each of the +// decoder types in the order they were specified in the template argument +// list, stopping at the first one that claims to be able to do the job. +// +// TODO(kwiberg): Point at CreateBuiltinAudioDecoderFactory() for an example of +// how it is used. +template <typename... Ts> +rtc::scoped_refptr<AudioDecoderFactory> CreateAudioDecoderFactory( + const FieldTrialsView* field_trials = nullptr) { + // There's no technical reason we couldn't allow zero template parameters, + // but such a factory couldn't create any decoders, and callers can do this + // by mistake by simply forgetting the <> altogether. So we forbid it in + // order to prevent caller foot-shooting. + static_assert(sizeof...(Ts) >= 1, + "Caller must give at least one template parameter"); + + return rtc::make_ref_counted< + audio_decoder_factory_template_impl::AudioDecoderFactoryT<Ts...>>( + field_trials); +} + +} // namespace webrtc + +#endif // API_AUDIO_CODECS_AUDIO_DECODER_FACTORY_TEMPLATE_H_ |