1. Epic GamesDeveloper
  3. FCompression

FCompression

API > API/Runtime > API/Runtime/Core > API/Runtime/Core/Misc

References

   
Module Core
Header /Engine/Source/Runtime/Core/Public/Misc/Compression.h
Include #include "Misc/Compression.h"

Syntax

struct FCompression

Functions

  Type Name Description
Public function Static bool

CompressMemory ( FName FormatName,
void* CompressedBuffer,
int64& CompressedSize,
const void* UncompressedBuffer,
int64 UncompressedSize,
ECompressionFlags Flags,
uintptr_t CompressionData
)

 Thread-safe abstract compression routine.
Public function Static bool

CompressMemory ( FName FormatName,
void* CompressedBuffer,
int32& CompressedSize,
const void* UncompressedBuffer,
int32 UncompressedSize,
ECompressionFlags Flags,
int32 CompressionData
)

 Thunks to 64 bit CompressMemory, favor that.
Public function Static bool

CompressMemoryBound ( FName InFormatName,
int64& OutBufferSizeRequired,
int64 InUncompressedSizeBytes,
uintptr_t InCompressionData
)

 Thread-safe abstract compression routine to query buffer requirements for a compression operation.
Public function Static int32

CompressMemoryBound ( FName FormatName,
int32 UncompressedSize,
ECompressionFlags Flags,
int32 CompressionData
)

 Thunks to the 64 bit, prefer that as this can only Fatal on error!
Public function Static bool

CompressMemoryIfWorthDecompressing ( FName FormatName,
int32 MinBytesSaved,
int32 MinPercentSaved,
void* CompressedBuffer,
int32& CompressedSize,
const void* UncompressedBuffer,
int32 UncompressedSize,
ECompressionFlags Flags,
int32 CompressionData
)

 32 bit thunk. This legacy function doens't separate bOutWasCompressed vs general compress failure and will return false in both cases.
Public function Static bool

CompressMemoryIfWorthDecompressing ( FName FormatName,
bool& bOutWasCompressed,
int64 MinBytesSaved,
int32 MinPercentSaved,
void* CompressedBuffer,
int64& CompressedSize,
const void* UncompressedBuffer,
int64 UncompressedSize,
ECompressionFlags Flags,
uintptr_t CompressionData
)

 Same as CompressMemory but evaluates if the compression gain is worth the runtime decode time.
Public function Static FName Deprecating this because we "should", but all internal references to these flags were deprecated in 4.21 so hopefully no one is using them anymore!
Public function Static FString

GetCompressorDDCSuffix ( FName FormatName
)

 Returns a string which can be used to identify if a format has become out of date
Public function Static uint32

GetCompressorVersion ( FName FormatName
)

 Returns a version number for a specified format
Public function Static bool

GetMaximumCompressedSize ( FName InFormatName,
int64& OutMaxCompressedSize,
int64 InUncompressedSizeBytes,
uintptr_t InCompressionData
)

 Thread-safe abstract compression routine to query maximum compressed size that could be made.
Public function Static int32

GetMaximumCompressedSize ( FName FormatName,
int32 UncompressedSize,
ECompressionFlags Flags,
int32 CompressionData
)

 Thunks to the 64 bit version, prefer that as this can only Fatal on error!
Public function Static bool

IsFormatValid ( FName FormatName
)

 Checks to see if a format will be usable, so that a fallback can be used
Public function Static bool

UncompressMemory ( FName FormatName,
void* UncompressedBuffer,
int64 UncompressedSize,
const void* CompressedBuffer,
int64 CompressedSize,
ECompressionFlags Flags,
uintptr_t CompressionData
)

 Thread-safe abstract decompression routine.
Public function Static bool

UncompressMemoryStream ( FName FormatName,
void* UncompressedBuffer,
int64 UncompressedSize,
IMemoryReadStream* Stream,
int64 StreamOffset,
int64 CompressedSize,
ECompressionFlags Flags,
uintptr_t CompressionData
)

 Wraps UncompressMemory to provide access with a IMemoryReadStream interface, attempting to avoid copying in to a contiguous buffer doe decompression if the format supports it.
Public function Static bool

VerifyCompressionFlagsValid ( int32 InCompressionFlags
)

 Verifies if the passed in value represents valid compression flags

Constants

Name Description
CompressionFormats Mapping of Compression FNames to their compressor objects
CompressionFormatsCriticalSection  
CompressorDstBytes Number of bytes after compression. Nubmer of bytes after compression.
CompressorSrcBytes Number of bytes before compression.
CompressorTimeCycles CompressionData is per-compressor data passed through this API and is interpreted by the codecs.

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page