IStreamedCompressedInfo Class Reference

#include <AudioDecompress.h>

Inheritance diagram for IStreamedCompressedInfo:

Public Member Functions
ENGINE_API	IStreamedCompressedInfo ()
virtual ENGINE_API	~IStreamedCompressedInfo ()
virtual ENGINE_API bool	ReadCompressedInfo (const uint8 *InSrcBufferData, uint32 InSrcBufferDataSize, FSoundQualityInfo *QualityInfo) override
virtual ENGINE_API bool	ReadCompressedData (uint8 *Destination, bool bLooping, uint32 BufferSize) override
virtual ENGINE_API void	SeekToTime (const float SeekTime) override
virtual ENGINE_API void	SeekToFrame (const uint32 SeekFrame) override
virtual ENGINE_API void	ExpandFile (uint8 *DstBuffer, struct FSoundQualityInfo *QualityInfo) override
virtual void	EnableHalfRate (bool HalfRate) override
virtual uint32	GetSourceBufferSize () const override
virtual bool	UsesVorbisChannelOrdering () const override
virtual int	GetStreamBufferSize () const override
virtual bool	SupportsStreaming () const override
virtual ENGINE_API bool	StreamCompressedInfoInternal (const FSoundWaveProxyPtr &InWaveProxy, FSoundQualityInfo *QualityInfo) override
virtual ENGINE_API bool	StreamCompressedData (uint8 *Destination, bool bLooping, uint32 BufferSize, int32 &OutNumBytesStreamed) override
virtual int32	GetCurrentChunkIndex () const override
virtual int32	GetCurrentChunkOffset () const override
virtual bool	IsStreamedCompressedInfo () const override
virtual bool	ParseHeader (const uint8 *InSrcBufferData, uint32 InSrcBufferDataSize, FSoundQualityInfo *QualityInfo)=0
virtual bool	CreateDecoder ()=0
virtual FDecodeResult	Decode (const uint8 *CompressedData, const int32 CompressedDataSize, uint8 *OutPCMData, const int32 OutputPCMDataSize)=0
virtual void	PrepareToLoop ()
virtual int32	GetFrameSize ()=0
virtual uint32	GetMaxFrameSizeSamples () const =0
int32	GetStreamSeekBlockIndex () const
int32	GetStreamSeekBlockOffset () const
Public Member Functions inherited from ICompressedAudioInfo
ENGINE_API	ICompressedAudioInfo ()
virtual ENGINE_API	~ICompressedAudioInfo ()
virtual bool	ReleaseStreamChunk (bool bBlockUntilReleased)
ENGINE_API bool	StreamCompressedInfo (USoundWave *Wave, struct FSoundQualityInfo *QualityInfo)
ENGINE_API bool	StreamCompressedInfo (const FSoundWaveProxyPtr &Wave, struct FSoundQualityInfo *QualityInfo)
virtual ENGINE_API bool	HasError () const
virtual const FSoundWaveProxyPtr &	GetStreamingSoundWave () const

Protected Member Functions
ENGINE_API uint32	Read (void *Outbuffer, uint32 DataSize)
int32	DecompressToPCMBuffer (uint16 FrameSize)
uint32	IncrementCurrentSampleCount (uint32 NewSamples)
uint32	WriteFromDecodedPCM (uint8 *Destination, uint32 BufferSize)
uint32	ZeroBuffer (uint8 *Destination, uint32 BufferSize)
ENGINE_API const uint8 *	GetLoadedChunk (const FSoundWaveProxyPtr &InSoundWave, uint32 ChunkIndex, uint32 &OutChunkSize)
void	RetainNextChunkInSequence (const FSoundWaveProxyPtr &InSoundWave, const uint32 InChunkIndex)
const FStreamedAudioChunkSeekTable &	GetCurrentSeekTable () const
FStreamedAudioChunkSeekTable &	GetCurrentSeekTable ()
Protected Member Functions inherited from ICompressedAudioInfo
bool	WantsFilteredLogging () const

Protected Attributes
bool	bIsStreaming
const uint8 *	SrcBufferData
uint32	SrcBufferDataSize
uint32	SrcBufferOffset
uint32	AudioDataOffset
uint32	AudioDataChunkIndex
uint32	TrueSampleCount
uint32	CurrentSampleCount
uint8	NumChannels
uint32	MaxFrameSizeSamples
uint32	SampleStride
TArray< uint8 >	LastDecodedPCM
uint32	LastPCMByteSize
uint32	LastPCMOffset
bool	bStoringEndOfFile
int32	CurrentChunkIndex
uint32	SrcBufferPadding
FAudioChunkHandle	CurCompressedChunkHandle
FAudioChunkHandle	NextPlayingChunkHandle
TPimplPtr< FStreamedAudioChunkSeekTable >	CurrentChunkSeekTable
std::atomic< int32 >	StreamSeekBlockIndex
int32	StreamSeekBlockOffset
uint32	StreamSeekToAudioFrames = INDEX_NONE
Protected Attributes inherited from ICompressedAudioInfo
bool	bHasError = false
bool	bWantsFilteredLogging = false
FSoundWaveProxyPtr	StreamingSoundWave

Detailed Description

Default implementation of a streamed compressed audio format. Can be subclassed to support streaming of a specific asset format. Handles all the platform independent aspects of file format streaming for you (dealing with UE streamed assets)

Constructor & Destructor Documentation

IStreamedCompressedInfo()

IStreamedCompressedInfo::IStreamedCompressedInfo

(

)

~IStreamedCompressedInfo()

IStreamedCompressedInfo::~IStreamedCompressedInfo ( )

virtualdefault

Member Function Documentation

CreateDecoder()

virtual bool IStreamedCompressedInfo::CreateDecoder ( )

pure virtual

Create the compression format dependent decoder object.

Implemented in FPcmAudioInfoHybrid, FBinkAudioInfo, FOpusAudioInfo, and FRadAudioInfo.

Decode()

virtual FDecodeResult IStreamedCompressedInfo::Decode ( const uint8 *  CompressedData, const int32  CompressedDataSize, uint8 *  OutPCMData, const int32  OutputPCMDataSize  )

pure virtual

Decode the input compressed frame data into output PCMData buffer.

Implemented in FPcmAudioInfoHybrid, FBinkAudioInfo, FOpusAudioInfo, and FRadAudioInfo.

DecompressToPCMBuffer()

int32 IStreamedCompressedInfo::DecompressToPCMBuffer ( uint16  FrameSize )

protected

Decompresses a frame of data to PCM buffer

Parameters

FrameSize

Size of the frame in bytes

Returns

The number of audio frames that were decompressed (< 0 indicates error)

EnableHalfRate()

virtual void IStreamedCompressedInfo::EnableHalfRate ( bool  HalfRate )

inlineoverridevirtual

Sets decode to half-rate

Parameters

HalfRate

Whether Half rate is enabled

Implements ICompressedAudioInfo.

ExpandFile()

void IStreamedCompressedInfo::ExpandFile ( uint8 *  DstBuffer, struct FSoundQualityInfo *  QualityInfo  )

overridevirtual

Decompress an entire data file to a TArray

Implements ICompressedAudioInfo.

GetCurrentChunkIndex()

virtual int32 IStreamedCompressedInfo::GetCurrentChunkIndex ( ) const

inlineoverridevirtual

Gets the chunk index that was last read from (for Streaming Manager requests)

Reimplemented from ICompressedAudioInfo.

GetCurrentChunkOffset()

virtual int32 IStreamedCompressedInfo::GetCurrentChunkOffset ( ) const

inlineoverridevirtual

Gets the offset into the chunk that was last read to (for Streaming Manager priority)

Reimplemented from ICompressedAudioInfo.

GetCurrentSeekTable() [1/2]

FStreamedAudioChunkSeekTable & IStreamedCompressedInfo::GetCurrentSeekTable ( )

protected

GetCurrentSeekTable() [2/2]

const FStreamedAudioChunkSeekTable & IStreamedCompressedInfo::GetCurrentSeekTable ( ) const

protected

Gets the current chunks seektable instance (or creates one)

Returns

the currently loaded chunk seektable

GetFrameSize()

virtual int32 IStreamedCompressedInfo::GetFrameSize ( )

pure virtual

Return the size of the current compression frame

Implemented in FPcmAudioInfoHybrid, FBinkAudioInfo, FOpusAudioInfo, and FRadAudioInfo.

GetLoadedChunk()

const uint8 * IStreamedCompressedInfo::GetLoadedChunk ( const FSoundWaveProxyPtr &  InSoundWave, uint32  ChunkIndex, uint32 &  OutChunkSize  )

protected

Helper function for getting a chunk of compressed audio.

Parameters

	InSoundWave	Pointer to the soundwave to get compressed audio from.
	ChunkIndex	the index of the chunk to get from InSoundWave.
[out]	OutChunkSize	the size of the chunk.

Returns

a pointer to the chunk if it's loaded, nullptr otherwise.

GetMaxFrameSizeSamples()

virtual uint32 IStreamedCompressedInfo::GetMaxFrameSizeSamples ( ) const

pure virtual

The size of the decode PCM buffer size.

Implemented in FPcmAudioInfoHybrid, FBinkAudioInfo, FOpusAudioInfo, and FRadAudioInfo.

GetSourceBufferSize()

virtual uint32 IStreamedCompressedInfo::GetSourceBufferSize ( ) const

inlineoverridevirtual

Gets the size of the source buffer originally passed to the info class (bytes)

Implements ICompressedAudioInfo.

GetStreamBufferSize()

virtual int IStreamedCompressedInfo::GetStreamBufferSize ( ) const

inlineoverridevirtual

Gets the preferred size for a streaming buffer for this decompression scheme

Implements ICompressedAudioInfo.

GetStreamSeekBlockIndex()

int32 IStreamedCompressedInfo::GetStreamSeekBlockIndex ( ) const

inline

GetStreamSeekBlockOffset()

int32 IStreamedCompressedInfo::GetStreamSeekBlockOffset ( ) const

inline

IncrementCurrentSampleCount()

uint32 IStreamedCompressedInfo::IncrementCurrentSampleCount ( uint32  NewSamples )

protected

Adds to the count of samples that have currently been decoded

Parameters

NewSamples

How many samples have been decoded

Returns

How many samples were actually part of the true sample count

IsStreamedCompressedInfo()

virtual bool IStreamedCompressedInfo::IsStreamedCompressedInfo ( ) const

inlineoverridevirtual

Returns whether this instance can be cast to a IStreamedCompressedInfo. Surprisingly SupportsStreaming doesn't work for this.

Reimplemented from ICompressedAudioInfo.

ParseHeader()

virtual bool IStreamedCompressedInfo::ParseHeader ( const uint8 *  InSrcBufferData, uint32  InSrcBufferDataSize, FSoundQualityInfo *  QualityInfo  )

pure virtual

Parse the header information from the input source buffer data. This is dependent on compression format.

Implemented in FPcmAudioInfoHybrid, FBinkAudioInfo, FOpusAudioInfo, and FRadAudioInfo.

PrepareToLoop()

virtual void IStreamedCompressedInfo::PrepareToLoop ( )

inlinevirtual

Optional method to allow decoder to prepare to loop.

Reimplemented in FPcmAudioInfoHybrid, FOpusAudioInfo, and FRadAudioInfo.

Read()

uint32 IStreamedCompressedInfo::Read ( void *  Outbuffer, uint32  DataSize  )

protected

Reads from the internal source audio buffer stream of the given data size.

ReadCompressedData()

bool IStreamedCompressedInfo::ReadCompressedData ( uint8 *  Destination, bool  bLooping, uint32  BufferSize  )

overridevirtual

Decompresses data to raw PCM data.

Parameters

Destination	where to place the decompressed sound
bLooping	whether to loop the sound by seeking to the start, or pad the buffer with zeroes
BufferSize	number of bytes of PCM data to create

Returns

bool true if the end of the data was reached (for both single shot and looping sounds)

Implements ICompressedAudioInfo.

ReadCompressedInfo()

bool IStreamedCompressedInfo::ReadCompressedInfo ( const uint8 *  InSrcBufferData, uint32  InSrcBufferDataSize, FSoundQualityInfo *  QualityInfo  )

overridevirtual

Reads the header information of a compressed format

Parameters

InSrcBufferData	Source compressed data
InSrcBufferDataSize	Size of compressed data
QualityInfo	Quality Info (to be filled out). This can be null in the case of most implementations of FSoundBuffer::ReadCompressedInfo

Implements ICompressedAudioInfo.

RetainNextChunkInSequence()

void IStreamedCompressedInfo::RetainNextChunkInSequence ( const FSoundWaveProxyPtr &  InSoundWave, const uint32  InChunkIndex  )

protected

SeekToFrame()

void IStreamedCompressedInfo::SeekToFrame ( const uint32  Frame )

overridevirtual

Seeks to specific frame in the audio (Some formats might not be seekable)

Implements ICompressedAudioInfo.

Reimplemented in FPcmAudioInfoHybrid, FOpusAudioInfo, FBinkAudioInfo, and FRadAudioInfo.

SeekToTime()

void IStreamedCompressedInfo::SeekToTime ( const float  SeekTime )

overridevirtual

Seeks to time (Some formats might not be seekable)

Implements ICompressedAudioInfo.

Reimplemented in FPcmAudioInfoHybrid, FOpusAudioInfo, FBinkAudioInfo, and FRadAudioInfo.

StreamCompressedData()

bool IStreamedCompressedInfo::StreamCompressedData ( uint8 *  Destination, bool  bLooping, uint32  BufferSize, int32 &  OutNumBytesStreamed  )

overridevirtual

Decompresses streamed data to raw PCM data.

Parameters

Destination	where to place the decompressed sound
bLooping	whether to loop the sound by seeking to the start, or pad the buffer with zeros
BufferSize	number of bytes of PCM data to create

Returns

bool true if the end of the data was reached (for both single shot and looping sounds)

Reimplemented from ICompressedAudioInfo.

StreamCompressedInfoInternal()

bool IStreamedCompressedInfo::StreamCompressedInfoInternal ( const FSoundWaveProxyPtr &  InWaveProxy, FSoundQualityInfo *  QualityInfo  )

overridevirtual

Internal override implemented by subclasses.

Implements ICompressedAudioInfo.

SupportsStreaming()

virtual bool IStreamedCompressedInfo::SupportsStreaming ( ) const

inlineoverridevirtual

Whether this decompression class supports streaming decompression

Reimplemented from ICompressedAudioInfo.

UsesVorbisChannelOrdering()

virtual bool IStreamedCompressedInfo::UsesVorbisChannelOrdering ( ) const

inlineoverridevirtual

Whether the decompressed audio will be arranged using Vorbis' channel ordering See http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-800004.3.9 for details

Implements ICompressedAudioInfo.

WriteFromDecodedPCM()

uint32 IStreamedCompressedInfo::WriteFromDecodedPCM ( uint8 *  Destination, uint32  BufferSize  )

protected

Writes data from decoded PCM buffer, taking into account whether some PCM has been written before

Parameters

Destination	Where to place the decoded sound
BufferSize	Size of the destination buffer in bytes

Returns

How many bytes were written

ZeroBuffer()

uint32 IStreamedCompressedInfo::ZeroBuffer ( uint8 *  Destination, uint32  BufferSize  )

protected

Zeroes the contents of a buffer

Parameters

Destination	Buffer to zero
BufferSize	Size of the destination buffer in bytes

Returns

How many bytes were zeroed

Member Data Documentation

AudioDataChunkIndex

uint32 IStreamedCompressedInfo::AudioDataChunkIndex

protected

The chunk index where the actual audio data starts.

AudioDataOffset

uint32 IStreamedCompressedInfo::AudioDataOffset

protected

Where the actual audio data starts in the current streamed chunk. Accounts for header offset.

bIsStreaming

bool IStreamedCompressedInfo::bIsStreaming

protected

bool set before ParseHeader. Whether we are streaming a file or not.

bStoringEndOfFile

bool IStreamedCompressedInfo::bStoringEndOfFile

protected

If we're currently reading the final buffer.

CurCompressedChunkHandle

FAudioChunkHandle IStreamedCompressedInfo::CurCompressedChunkHandle

protected

Chunk Handle to ensure that this chunk of streamed audio is not deleted while we are using it.

CurrentChunkIndex

int32 IStreamedCompressedInfo::CurrentChunkIndex

protected

The current chunk index in the streamed chunks.

CurrentChunkSeekTable

TPimplPtr<FStreamedAudioChunkSeekTable> IStreamedCompressedInfo::CurrentChunkSeekTable

protected

If there's a chunked seek-table present, this contains the current chunks portion.

CurrentSampleCount

uint32 IStreamedCompressedInfo::CurrentSampleCount

protected

How many samples we've currently read in the source file.

LastDecodedPCM

TArray<uint8> IStreamedCompressedInfo::LastDecodedPCM

protected

The decoded PCM byte array from the last decoded frame.

LastPCMByteSize

uint32 IStreamedCompressedInfo::LastPCMByteSize

protected

The amount of PCM data in bytes was decoded last.

LastPCMOffset

uint32 IStreamedCompressedInfo::LastPCMOffset

protected

The current offset in the last decoded PCM buffer.

MaxFrameSizeSamples

uint32 IStreamedCompressedInfo::MaxFrameSizeSamples

protected

The maximum number of samples per decode frame.

NextPlayingChunkHandle

FAudioChunkHandle IStreamedCompressedInfo::NextPlayingChunkHandle

protected

Handle to the next chunk in sequence. Added once we're playing, to prevent it being dropped before it's played.

NumChannels

uint8 IStreamedCompressedInfo::NumChannels

protected

Number of channels (left/right) in the source file.

SampleStride

uint32 IStreamedCompressedInfo::SampleStride

protected

The number of bytes per interleaved sample (NumChannels * sizeof(int16)).

SrcBufferData

const uint8* IStreamedCompressedInfo::SrcBufferData

protected

Ptr to the current streamed chunk.

SrcBufferDataSize

uint32 IStreamedCompressedInfo::SrcBufferDataSize

protected

Size of the current streamed chunk.

SrcBufferOffset

uint32 IStreamedCompressedInfo::SrcBufferOffset

protected

What byte we're currently reading in the streamed chunk.

SrcBufferPadding

uint32 IStreamedCompressedInfo::SrcBufferPadding

protected

Number of bytes of padding used, overridden in some implementations. Defaults to 0.

StreamSeekBlockIndex

std::atomic<int32> IStreamedCompressedInfo::StreamSeekBlockIndex

protected

When a streaming seek request comes down, this is the block we are going to. INDEX_NONE means no seek pending. When using the legacy streaming system this is read on a thread other than the decompression thread to prime the correct chunk, so it needs an atomic. It's only ever set on one thread, and the read has no timing restrictions, so no lock is necessary. Also the legacy streamer isn't used anymore anyway.

This and StreamSeekBlockOffset are expected to be set by the codec's SeekToTime() function.

StreamSeekBlockOffset

int32 IStreamedCompressedInfo::StreamSeekBlockOffset

protected

When a streaming seek request comes down, this is the offset in to the block we want to start decoding from.

StreamSeekToAudioFrames

uint32 IStreamedCompressedInfo::StreamSeekToAudioFrames = INDEX_NONE

protected

If using the Chunked seek-tables, we request the seek in samples so we can resolve after the chunk table loads.

TrueSampleCount

uint32 IStreamedCompressedInfo::TrueSampleCount

protected

The total sample count of the source file.

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The documentation for this class was generated from the following files:

• Engine/Source/Runtime/Engine/Public/AudioDecompress.h
• Engine/Source/Runtime/Engine/Private/AudioDecompress.cpp