Source/WebCore/platform/graphics/cocoa/SourceBufferParserWebM.h - WebKit - Git at Google

 /*
  * Copyright (C) 2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #pragma once

 #if ENABLE(MEDIA_SOURCE)

 #include "SourceBufferParser.h"
 #include <CoreAudio/CoreAudioTypes.h>
 #include <CoreMedia/CMTime.h>
 #include <pal/spi/cf/CoreMediaSPI.h>
 #include <variant>
 #include <webm/callback.h>
 #include <webm/status.h>
 #include <webm/vp9_header_parser.h>
 #include <wtf/Box.h>
 #include <wtf/Function.h>
 #include <wtf/MediaTime.h>
 #include <wtf/RobinHoodHashSet.h>
 #include <wtf/UniqueRef.h>
 #include <wtf/Vector.h>
 #include <wtf/text/AtomString.h>
 #include <wtf/text/WTFString.h>

 typedef const struct opaqueCMFormatDescription* CMFormatDescriptionRef;
 typedef struct OpaqueCMBlockBuffer *CMBlockBufferRef;

 namespace webm {
 class WebmParser;
 }

 namespace WebCore {

 class MediaSampleAVFObjC;

 class SourceBufferParserWebM : public SourceBufferParser, private webm::Callback {
     WTF_MAKE_FAST_ALLOCATED;
 public:
     class SegmentReader;

     static bool isWebMFormatReaderAvailable();
     static MediaPlayerEnums::SupportsType isContentTypeSupported(const ContentType&);
     static const HashSet<String, ASCIICaseInsensitiveHash>& webmMIMETypes();
     WEBCORE_EXPORT static RefPtr<SourceBufferParserWebM> create(const ContentType&);

     SourceBufferParserWebM();
     ~SourceBufferParserWebM();

     static bool isAvailable();

     const webm::Status& status() const { return m_status; }

     Type type() const { return Type::WebM; }
     WEBCORE_EXPORT void appendData(Segment&&, CompletionHandler<void()>&& = [] { }, AppendFlags = AppendFlags::None) final;
     void flushPendingMediaData() final;
     void setShouldProvideMediaDataForTrackID(bool, uint64_t) final;
     bool shouldProvideMediadataForTrackID(uint64_t) final;
     void resetParserState() final;
     void invalidate() final;

     void flushPendingAudioBuffers();
     void setMinimumAudioSampleDuration(float);

     WEBCORE_EXPORT void setLogger(const WTF::Logger&, const void* identifier) final;

     void provideMediaData(RetainPtr<CMSampleBufferRef>, uint64_t, std::optional<size_t> byteRangeOffset);
     using DidParseTrimmingDataCallback = WTF::Function<void(uint64_t trackID, const MediaTime& discardPadding)>;
     void setDidParseTrimmingDataCallback(DidParseTrimmingDataCallback&& callback)
     {
         m_didParseTrimmingDataCallback = WTFMove(callback);
     }

     enum class ErrorCode : int32_t {
         SourceBufferParserWebMErrorCodeStart = 2000,
         InvalidDocType,
         InvalidInitSegment,
         ReceivedEbmlInsideSegment,
         UnsupportedVideoCodec,
         UnsupportedAudioCodec,
         ContentEncrypted,
         VariableFrameDuration,
     };

     enum class State : uint8_t {
         None,
         ReadingEbml,
         ReadEbml,
         ReadingSegment,
         ReadingInfo,
         ReadInfo,
         ReadingTracks,
         ReadingTrack,
         ReadTrack,
         ReadingCluster,
     };

     enum class CodecType : uint8_t {
         Unsupported,
         VP8,
         VP9,
         Vorbis,
         Opus,
     };

     class TrackData {
         WTF_MAKE_FAST_ALLOCATED;
     public:
         static auto create(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser) -> UniqueRef<TrackData>
         {
             return makeUniqueRef<TrackData>(codecType, trackEntry, Type::Unknown, parser);
         }

         enum class Type {
             Unknown,
             Audio,
             Video,
         };

         TrackData(CodecType codecType, const webm::TrackEntry& trackEntry, Type trackType, SourceBufferParserWebM& parser)
             : m_codec { codecType }
             , m_track { webm::TrackEntry { trackEntry } }
             , m_trackType { trackType }
             , m_parser { parser }
         {
         }
         virtual ~TrackData() = default;

         CodecType codec() const { return m_codec; }
         webm::TrackEntry& track() { return m_track; }
         Type trackType() const { return m_trackType; }

         RetainPtr<CMFormatDescriptionRef> formatDescription() { return m_formatDescription; }
         void setFormatDescription(RetainPtr<CMFormatDescriptionRef>&& description) { m_formatDescription = WTFMove(description); }

         SourceBufferParserWebM& parser() const { return m_parser; }

         virtual webm::Status consumeFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t*, const CMTime&, int)
         {
             ASSERT_NOT_REACHED();
             return webm::Status(webm::Status::kInvalidElementId);
         }

         virtual void resetCompleted()
         {
             m_completeBlockBuffer = nullptr;
         }
         void reset()
         {
             resetCompleted();
             m_completePacketSize = std::nullopt;
             m_partialBytesRead = 0;
             m_currentBlockBuffer = nullptr;
         }

     protected:
         RetainPtr<CMBlockBufferRef> contiguousCompleteBlockBuffer(size_t offset, size_t length) const;
         webm::Status readFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t* bytesRemaining);
         RetainPtr<CMBlockBufferRef> m_completeBlockBuffer;
         std::optional<size_t> m_completePacketSize;
         // Initial allocation size of empty CMBlockBuffer.
         size_t mMaxBlockBufferCapacity { 0 };

     private:
         CodecType m_codec;
         webm::TrackEntry m_track;
         Type m_trackType;
         RetainPtr<CMFormatDescriptionRef> m_formatDescription;
         RetainPtr<CMBlockBufferRef> m_currentBlockBuffer;
         SourceBufferParserWebM& m_parser;
         // Size of the currently incomplete parsed packet.
         size_t m_partialBytesRead { 0 };
     };

     class VideoTrackData : public TrackData {
     public:
         static auto create(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser) -> UniqueRef<VideoTrackData>
         {
             return makeUniqueRef<VideoTrackData>(codecType, trackEntry, parser);
         }

         VideoTrackData(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser)
             : TrackData(codecType, trackEntry, Type::Video, parser)
         {
         }

         webm::Status consumeFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t*, const CMTime&, int) final;

     private:
         void createSampleBuffer(const CMTime&, int, const webm::FrameMetadata&);
         const char* logClassName() const { return "VideoTrackData"; }

 #if ENABLE(VP9)
         vp9_parser::Vp9HeaderParser m_headerParser;
 #endif
     };

     class AudioTrackData : public TrackData {
     public:
         static auto create(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser, float minimumSampleDuration) -> UniqueRef<AudioTrackData>
         {
             return makeUniqueRef<AudioTrackData>(codecType, trackEntry, parser, minimumSampleDuration);
         }

         AudioTrackData(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser, float minimumSampleDuration)
             : TrackData { codecType, trackEntry, Type::Audio, parser }
             , m_minimumSampleDuration { minimumSampleDuration }
         {
         }

         webm::Status consumeFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t*, const CMTime&, int) final;
         void resetCompleted() final;
         void createSampleBuffer(std::optional<size_t> latestByteRangeOffset = std::nullopt);

     private:
         const char* logClassName() const { return "AudioTrackData"; }

         CMTime m_samplePresentationTime;
         CMTime m_packetDuration;
         size_t m_currentPacketByteOffset { 0 };
         uint8_t m_framesPerPacket { 0 };
         Seconds m_frameDuration { 0_s };
         Vector<AudioStreamPacketDescription> m_packetDescriptions;
         size_t mNumFramesInCompleteBlock { 0 };
         // FIXME: 0.5 - 1.0 seconds is a better duration per sample buffer, but use 2 seconds so at least the first
         // sample buffer will play until we fix MediaSampleCursor::createSampleBuffer to deal with `endCursor`.
         float m_minimumSampleDuration { 2 };
     };

     const WTF::Logger* loggerPtr() const { return m_logger.get(); }
     const void* logIdentifier() const { return m_logIdentifier; }

 private:

     TrackData* trackDataForTrackNumber(uint64_t);

     static const MemoryCompactLookupOnlyRobinHoodHashSet<String>& supportedVideoCodecs();
     static const MemoryCompactLookupOnlyRobinHoodHashSet<String>& supportedAudioCodecs();

     // webm::Callback
     webm::Status OnElementBegin(const webm::ElementMetadata&, webm::Action*) final;
     webm::Status OnElementEnd(const webm::ElementMetadata&) final;
     webm::Status OnEbml(const webm::ElementMetadata&, const webm::Ebml&) final;
     webm::Status OnSegmentBegin(const webm::ElementMetadata&, webm::Action*) final;
     webm::Status OnInfo(const webm::ElementMetadata&, const webm::Info&) final;
     webm::Status OnClusterBegin(const webm::ElementMetadata&, const webm::Cluster&, webm::Action*) final;
     webm::Status OnTrackEntry(const webm::ElementMetadata&, const webm::TrackEntry&) final;
     webm::Status OnBlockBegin(const webm::ElementMetadata&, const webm::Block&, webm::Action*) final;
     webm::Status OnBlockEnd(const webm::ElementMetadata&, const webm::Block&) final;
     webm::Status OnSimpleBlockBegin(const webm::ElementMetadata&, const webm::SimpleBlock&, webm::Action*) final;
     webm::Status OnSimpleBlockEnd(const webm::ElementMetadata&, const webm::SimpleBlock&) final;
     webm::Status OnBlockGroupBegin(const webm::ElementMetadata& , webm::Action*);
     webm::Status OnBlockGroupEnd(const webm::ElementMetadata&, const webm::BlockGroup&);
     webm::Status OnFrame(const webm::FrameMetadata&, webm::Reader*, uint64_t* bytesRemaining) final;

     std::unique_ptr<InitializationSegment> m_initializationSegment;
     Vector<std::pair<uint64_t, Ref<Uint8Array>>> m_keyIds;
     webm::Status m_status;
     std::unique_ptr<webm::WebmParser> m_parser;
     bool m_initializationSegmentEncountered { false };
     bool m_initializationSegmentProcessed { false };
     uint32_t m_timescale { 1000 };
     uint64_t m_currentTimecode { 0 };

     State m_state { State::None };

     UniqueRef<SegmentReader> m_reader;

     Vector<UniqueRef<TrackData>> m_tracks;
     using BlockVariant = std::variant<webm::Block, webm::SimpleBlock>;
     std::optional<BlockVariant> m_currentBlock;
     std::optional<uint64_t> m_rewindToPosition;
     float m_minimumAudioSampleDuration { 2 };

     RefPtr<const WTF::Logger> m_logger;
     const void* m_logIdentifier { nullptr };
     uint64_t m_nextChildIdentifier { 0 };
     DidParseTrimmingDataCallback m_didParseTrimmingDataCallback;
 };

 }

 SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::SourceBufferParserWebM)
     static bool isType(const WebCore::SourceBufferParser& parser) { return parser.type() == WebCore::SourceBufferParser::Type::WebM; }
 SPECIALIZE_TYPE_TRAITS_END()

 SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::SourceBufferParserWebM::VideoTrackData)
     static bool isType(const WebCore::SourceBufferParserWebM::TrackData& trackData) { return trackData.trackType() == WebCore::SourceBufferParserWebM::TrackData::Type::Video; }
 SPECIALIZE_TYPE_TRAITS_END()

 SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::SourceBufferParserWebM::AudioTrackData)
     static bool isType(const WebCore::SourceBufferParserWebM::TrackData& trackData) { return trackData.trackType() == WebCore::SourceBufferParserWebM::TrackData::Type::Audio; }
 SPECIALIZE_TYPE_TRAITS_END()

 #endif // ENABLE(MEDIA_SOURCE)
	/*
	* Copyright (C) 2020 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#pragma once

	#if ENABLE(MEDIA_SOURCE)

	#include "SourceBufferParser.h"
	#include <CoreAudio/CoreAudioTypes.h>
	#include <CoreMedia/CMTime.h>
	#include <pal/spi/cf/CoreMediaSPI.h>
	#include <variant>
	#include <webm/callback.h>
	#include <webm/status.h>
	#include <webm/vp9_header_parser.h>
	#include <wtf/Box.h>
	#include <wtf/Function.h>
	#include <wtf/MediaTime.h>
	#include <wtf/RobinHoodHashSet.h>
	#include <wtf/UniqueRef.h>
	#include <wtf/Vector.h>
	#include <wtf/text/AtomString.h>
	#include <wtf/text/WTFString.h>

	typedef const struct opaqueCMFormatDescription* CMFormatDescriptionRef;
	typedef struct OpaqueCMBlockBuffer *CMBlockBufferRef;

	namespace webm {
	class WebmParser;
	}

	namespace WebCore {

	class MediaSampleAVFObjC;

	class SourceBufferParserWebM : public SourceBufferParser, private webm::Callback {
	WTF_MAKE_FAST_ALLOCATED;
	public:
	class SegmentReader;

	static bool isWebMFormatReaderAvailable();
	static MediaPlayerEnums::SupportsType isContentTypeSupported(const ContentType&);
	static const HashSet<String, ASCIICaseInsensitiveHash>& webmMIMETypes();
	WEBCORE_EXPORT static RefPtr<SourceBufferParserWebM> create(const ContentType&);

	SourceBufferParserWebM();
	~SourceBufferParserWebM();

	static bool isAvailable();

	const webm::Status& status() const { return m_status; }

	Type type() const { return Type::WebM; }
	WEBCORE_EXPORT void appendData(Segment&&, CompletionHandler<void()>&& = [] { }, AppendFlags = AppendFlags::None) final;
	void flushPendingMediaData() final;
	void setShouldProvideMediaDataForTrackID(bool, uint64_t) final;
	bool shouldProvideMediadataForTrackID(uint64_t) final;
	void resetParserState() final;
	void invalidate() final;

	void flushPendingAudioBuffers();
	void setMinimumAudioSampleDuration(float);

	WEBCORE_EXPORT void setLogger(const WTF::Logger&, const void* identifier) final;

	void provideMediaData(RetainPtr<CMSampleBufferRef>, uint64_t, std::optional<size_t> byteRangeOffset);
	using DidParseTrimmingDataCallback = WTF::Function<void(uint64_t trackID, const MediaTime& discardPadding)>;
	void setDidParseTrimmingDataCallback(DidParseTrimmingDataCallback&& callback)
	{
	m_didParseTrimmingDataCallback = WTFMove(callback);
	}

	enum class ErrorCode : int32_t {
	SourceBufferParserWebMErrorCodeStart = 2000,
	InvalidDocType,
	InvalidInitSegment,
	ReceivedEbmlInsideSegment,
	UnsupportedVideoCodec,
	UnsupportedAudioCodec,
	ContentEncrypted,
	VariableFrameDuration,
	};

	enum class State : uint8_t {
	None,
	ReadingEbml,
	ReadEbml,
	ReadingSegment,
	ReadingInfo,
	ReadInfo,
	ReadingTracks,
	ReadingTrack,
	ReadTrack,
	ReadingCluster,
	};

	enum class CodecType : uint8_t {
	Unsupported,
	VP8,
	VP9,
	Vorbis,
	Opus,
	};

	class TrackData {
	WTF_MAKE_FAST_ALLOCATED;
	public:
	static auto create(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser) -> UniqueRef<TrackData>
	{
	return makeUniqueRef<TrackData>(codecType, trackEntry, Type::Unknown, parser);
	}

	enum class Type {
	Unknown,
	Audio,
	Video,
	};

	TrackData(CodecType codecType, const webm::TrackEntry& trackEntry, Type trackType, SourceBufferParserWebM& parser)
	: m_codec { codecType }
	, m_track { webm::TrackEntry { trackEntry } }
	, m_trackType { trackType }
	, m_parser { parser }
	{
	}
	virtual ~TrackData() = default;

	CodecType codec() const { return m_codec; }
	webm::TrackEntry& track() { return m_track; }
	Type trackType() const { return m_trackType; }

	RetainPtr<CMFormatDescriptionRef> formatDescription() { return m_formatDescription; }
	void setFormatDescription(RetainPtr<CMFormatDescriptionRef>&& description) { m_formatDescription = WTFMove(description); }

	SourceBufferParserWebM& parser() const { return m_parser; }

	virtual webm::Status consumeFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t*, const CMTime&, int)
	{
	ASSERT_NOT_REACHED();
	return webm::Status(webm::Status::kInvalidElementId);
	}

	virtual void resetCompleted()
	{
	m_completeBlockBuffer = nullptr;
	}
	void reset()
	{
	resetCompleted();
	m_completePacketSize = std::nullopt;
	m_partialBytesRead = 0;
	m_currentBlockBuffer = nullptr;
	}

	protected:
	RetainPtr<CMBlockBufferRef> contiguousCompleteBlockBuffer(size_t offset, size_t length) const;
	webm::Status readFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t* bytesRemaining);
	RetainPtr<CMBlockBufferRef> m_completeBlockBuffer;
	std::optional<size_t> m_completePacketSize;
	// Initial allocation size of empty CMBlockBuffer.
	size_t mMaxBlockBufferCapacity { 0 };

	private:
	CodecType m_codec;
	webm::TrackEntry m_track;
	Type m_trackType;
	RetainPtr<CMFormatDescriptionRef> m_formatDescription;
	RetainPtr<CMBlockBufferRef> m_currentBlockBuffer;
	SourceBufferParserWebM& m_parser;
	// Size of the currently incomplete parsed packet.
	size_t m_partialBytesRead { 0 };
	};

	class VideoTrackData : public TrackData {
	public:
	static auto create(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser) -> UniqueRef<VideoTrackData>
	{
	return makeUniqueRef<VideoTrackData>(codecType, trackEntry, parser);
	}

	VideoTrackData(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser)
	: TrackData(codecType, trackEntry, Type::Video, parser)
	{
	}

	webm::Status consumeFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t*, const CMTime&, int) final;

	private:
	void createSampleBuffer(const CMTime&, int, const webm::FrameMetadata&);
	const char* logClassName() const { return "VideoTrackData"; }

	#if ENABLE(VP9)
	vp9_parser::Vp9HeaderParser m_headerParser;
	#endif
	};

	class AudioTrackData : public TrackData {
	public:
	static auto create(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser, float minimumSampleDuration) -> UniqueRef<AudioTrackData>
	{
	return makeUniqueRef<AudioTrackData>(codecType, trackEntry, parser, minimumSampleDuration);
	}

	AudioTrackData(CodecType codecType, const webm::TrackEntry& trackEntry, SourceBufferParserWebM& parser, float minimumSampleDuration)
	: TrackData { codecType, trackEntry, Type::Audio, parser }
	, m_minimumSampleDuration { minimumSampleDuration }
	{
	}

	webm::Status consumeFrameData(webm::Reader&, const webm::FrameMetadata&, uint64_t*, const CMTime&, int) final;
	void resetCompleted() final;
	void createSampleBuffer(std::optional<size_t> latestByteRangeOffset = std::nullopt);

	private:
	const char* logClassName() const { return "AudioTrackData"; }

	CMTime m_samplePresentationTime;
	CMTime m_packetDuration;
	size_t m_currentPacketByteOffset { 0 };
	uint8_t m_framesPerPacket { 0 };
	Seconds m_frameDuration { 0_s };
	Vector<AudioStreamPacketDescription> m_packetDescriptions;
	size_t mNumFramesInCompleteBlock { 0 };
	// FIXME: 0.5 - 1.0 seconds is a better duration per sample buffer, but use 2 seconds so at least the first
	// sample buffer will play until we fix MediaSampleCursor::createSampleBuffer to deal with `endCursor`.
	float m_minimumSampleDuration { 2 };
	};

	const WTF::Logger* loggerPtr() const { return m_logger.get(); }
	const void* logIdentifier() const { return m_logIdentifier; }

	private:

	TrackData* trackDataForTrackNumber(uint64_t);

	static const MemoryCompactLookupOnlyRobinHoodHashSet<String>& supportedVideoCodecs();
	static const MemoryCompactLookupOnlyRobinHoodHashSet<String>& supportedAudioCodecs();

	// webm::Callback
	webm::Status OnElementBegin(const webm::ElementMetadata&, webm::Action*) final;
	webm::Status OnElementEnd(const webm::ElementMetadata&) final;
	webm::Status OnEbml(const webm::ElementMetadata&, const webm::Ebml&) final;
	webm::Status OnSegmentBegin(const webm::ElementMetadata&, webm::Action*) final;
	webm::Status OnInfo(const webm::ElementMetadata&, const webm::Info&) final;
	webm::Status OnClusterBegin(const webm::ElementMetadata&, const webm::Cluster&, webm::Action*) final;
	webm::Status OnTrackEntry(const webm::ElementMetadata&, const webm::TrackEntry&) final;
	webm::Status OnBlockBegin(const webm::ElementMetadata&, const webm::Block&, webm::Action*) final;
	webm::Status OnBlockEnd(const webm::ElementMetadata&, const webm::Block&) final;
	webm::Status OnSimpleBlockBegin(const webm::ElementMetadata&, const webm::SimpleBlock&, webm::Action*) final;
	webm::Status OnSimpleBlockEnd(const webm::ElementMetadata&, const webm::SimpleBlock&) final;
	webm::Status OnBlockGroupBegin(const webm::ElementMetadata& , webm::Action*);
	webm::Status OnBlockGroupEnd(const webm::ElementMetadata&, const webm::BlockGroup&);
	webm::Status OnFrame(const webm::FrameMetadata&, webm::Reader, uint64_t bytesRemaining) final;

	std::unique_ptr<InitializationSegment> m_initializationSegment;
	Vector<std::pair<uint64_t, Ref<Uint8Array>>> m_keyIds;
	webm::Status m_status;
	std::unique_ptr<webm::WebmParser> m_parser;
	bool m_initializationSegmentEncountered { false };
	bool m_initializationSegmentProcessed { false };
	uint32_t m_timescale { 1000 };
	uint64_t m_currentTimecode { 0 };

	State m_state { State::None };

	UniqueRef<SegmentReader> m_reader;

	Vector<UniqueRef<TrackData>> m_tracks;
	using BlockVariant = std::variant<webm::Block, webm::SimpleBlock>;
	std::optional<BlockVariant> m_currentBlock;
	std::optional<uint64_t> m_rewindToPosition;
	float m_minimumAudioSampleDuration { 2 };

	RefPtr<const WTF::Logger> m_logger;
	const void* m_logIdentifier { nullptr };
	uint64_t m_nextChildIdentifier { 0 };
	DidParseTrimmingDataCallback m_didParseTrimmingDataCallback;
	};

	}

	SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::SourceBufferParserWebM)
	static bool isType(const WebCore::SourceBufferParser& parser) { return parser.type() == WebCore::SourceBufferParser::Type::WebM; }
	SPECIALIZE_TYPE_TRAITS_END()

	SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::SourceBufferParserWebM::VideoTrackData)
	static bool isType(const WebCore::SourceBufferParserWebM::TrackData& trackData) { return trackData.trackType() == WebCore::SourceBufferParserWebM::TrackData::Type::Video; }
	SPECIALIZE_TYPE_TRAITS_END()

	SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::SourceBufferParserWebM::AudioTrackData)
	static bool isType(const WebCore::SourceBufferParserWebM::TrackData& trackData) { return trackData.trackType() == WebCore::SourceBufferParserWebM::TrackData::Type::Audio; }
	SPECIALIZE_TYPE_TRAITS_END()

	#endif // ENABLE(MEDIA_SOURCE)