--- a/misc/libphysfs/lzma/7zFormat.txt Wed May 16 18:22:28 2018 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,471 +0,0 @@
-7z Format description (2.30 Beta 25)
------------------------------------
-
-This file contains description of 7z archive format.
-7z archive can contain files compressed with any method.
-See "Methods.txt" for description for defined compressing methods.
-
-
-Format structure Overview
--------------------------
-
-Some fields can be optional.
-
-Archive structure
-~~~~~~~~~~~~~~~~~
-SignatureHeader
-[PackedStreams]
-[PackedStreamsForHeaders]
-[
- Header
- or
- {
- Packed Header
- HeaderInfo
- }
-]
-
-
-
-Header structure
-~~~~~~~~~~~~~~~~
-{
- ArchiveProperties
- AdditionalStreams
- {
- PackInfo
- {
- PackPos
- NumPackStreams
- Sizes[NumPackStreams]
- CRCs[NumPackStreams]
- }
- CodersInfo
- {
- NumFolders
- Folders[NumFolders]
- {
- NumCoders
- CodersInfo[NumCoders]
- {
- ID
- NumInStreams;
- NumOutStreams;
- PropertiesSize
- Properties[PropertiesSize]
- }
- NumBindPairs
- BindPairsInfo[NumBindPairs]
- {
- InIndex;
- OutIndex;
- }
- PackedIndices
- }
- UnPackSize[Folders][Folders.NumOutstreams]
- CRCs[NumFolders]
- }
- SubStreamsInfo
- {
- NumUnPackStreamsInFolders[NumFolders];
- UnPackSizes[]
- CRCs[]
- }
- }
- MainStreamsInfo
- {
- (Same as in AdditionalStreams)
- }
- FilesInfo
- {
- NumFiles
- Properties[]
- {
- ID
- Size
- Data
- }
- }
-}
-
-HeaderInfo structure
-~~~~~~~~~~~~~~~~~~~~
-{
- (Same as in AdditionalStreams)
-}
-
-
-
-Notes about Notation and encoding
----------------------------------
-
-7z uses little endian encoding.
-
-7z archive format has optional headers that are marked as
-[]
-Header
-[]
-
-REAL_UINT64 means real UINT64.
-
-UINT64 means real UINT64 encoded with the following scheme:
-
- Size of encoding sequence depends from first byte:
- First_Byte Extra_Bytes Value
- (binary)
- 0xxxxxxx : ( xxxxxxx )
- 10xxxxxx BYTE y[1] : ( xxxxxx << (8 * 1)) + y
- 110xxxxx BYTE y[2] : ( xxxxx << (8 * 2)) + y
- ...
- 1111110x BYTE y[6] : ( x << (8 * 6)) + y
- 11111110 BYTE y[7] : y
- 11111111 BYTE y[8] : y
-
-
-
-Property IDs
-------------
-
-0x00 = kEnd,
-
-0x01 = kHeader,
-
-0x02 = kArchiveProperties,
-
-0x03 = kAdditionalStreamsInfo,
-0x04 = kMainStreamsInfo,
-0x05 = kFilesInfo,
-
-0x06 = kPackInfo,
-0x07 = kUnPackInfo,
-0x08 = kSubStreamsInfo,
-
-0x09 = kSize,
-0x0A = kCRC,
-
-0x0B = kFolder,
-
-0x0C = kCodersUnPackSize,
-0x0D = kNumUnPackStream,
-
-0x0E = kEmptyStream,
-0x0F = kEmptyFile,
-0x10 = kAnti,
-
-0x11 = kName,
-0x12 = kCreationTime,
-0x13 = kLastAccessTime,
-0x14 = kLastWriteTime,
-0x15 = kWinAttributes,
-0x16 = kComment,
-
-0x17 = kEncodedHeader,
-
-
-7z format headers
------------------
-
-SignatureHeader
-~~~~~~~~~~~~~~~
- BYTE kSignature[6] = {'7', 'z', 0xBC, 0xAF, 0x27, 0x1C};
-
- ArchiveVersion
- {
- BYTE Major; // now = 0
- BYTE Minor; // now = 2
- };
-
- UINT32 StartHeaderCRC;
-
- StartHeader
- {
- REAL_UINT64 NextHeaderOffset
- REAL_UINT64 NextHeaderSize
- UINT32 NextHeaderCRC
- }
-
-
-...........................
-
-
-ArchiveProperties
-~~~~~~~~~~~~~~~~~
-BYTE NID::kArchiveProperties (0x02)
-for (;;)
-{
- BYTE PropertyType;
- if (aType == 0)
- break;
- UINT64 PropertySize;
- BYTE PropertyData[PropertySize];
-}
-
-
-Digests (NumStreams)
-~~~~~~~~~~~~~~~~~~~~~
- BYTE AllAreDefined
- if (AllAreDefined == 0)
- {
- for(NumStreams)
- BIT Defined
- }
- UINT32 CRCs[NumDefined]
-
-
-PackInfo
-~~~~~~~~~~~~
- BYTE NID::kPackInfo (0x06)
- UINT64 PackPos
- UINT64 NumPackStreams
-
- []
- BYTE NID::kSize (0x09)
- UINT64 PackSizes[NumPackStreams]
- []
-
- []
- BYTE NID::kCRC (0x0A)
- PackStreamDigests[NumPackStreams]
- []
-
- BYTE NID::kEnd
-
-
-Folder
-~~~~~~
- UINT64 NumCoders;
- for (NumCoders)
- {
- BYTE
- {
- 0:3 DecompressionMethod.IDSize
- 4:
- 0 - IsSimple
- 1 - Is not simple
- 5:
- 0 - No Attributes
- 1 - There Are Attributes
- 7:
- 0 - Last Method in Alternative_Method_List
- 1 - There are more alternative methods
- }
- BYTE DecompressionMethod.ID[DecompressionMethod.IDSize]
- if (!IsSimple)
- {
- UINT64 NumInStreams;
- UINT64 NumOutStreams;
- }
- if (DecompressionMethod[0] != 0)
- {
- UINT64 PropertiesSize
- BYTE Properties[PropertiesSize]
- }
- }
-
- NumBindPairs = NumOutStreamsTotal - 1;
-
- for (NumBindPairs)
- {
- UINT64 InIndex;
- UINT64 OutIndex;
- }
-
- NumPackedStreams = NumInStreamsTotal - NumBindPairs;
- if (NumPackedStreams > 1)
- for(NumPackedStreams)
- {
- UINT64 Index;
- };
-
-
-
-
-Coders Info
-~~~~~~~~~~~
-
- BYTE NID::kUnPackInfo (0x07)
-
-
- BYTE NID::kFolder (0x0B)
- UINT64 NumFolders
- BYTE External
- switch(External)
- {
- case 0:
- Folders[NumFolders]
- case 1:
- UINT64 DataStreamIndex
- }
-
-
- BYTE ID::kCodersUnPackSize (0x0C)
- for(Folders)
- for(Folder.NumOutStreams)
- UINT64 UnPackSize;
-
-
- []
- BYTE NID::kCRC (0x0A)
- UnPackDigests[NumFolders]
- []
-
-
-
- BYTE NID::kEnd
-
-
-
-SubStreams Info
-~~~~~~~~~~~~~~
- BYTE NID::kSubStreamsInfo; (0x08)
-
- []
- BYTE NID::kNumUnPackStream; (0x0D)
- UINT64 NumUnPackStreamsInFolders[NumFolders];
- []
-
-
- []
- BYTE NID::kSize (0x09)
- UINT64 UnPackSizes[]
- []
-
-
- []
- BYTE NID::kCRC (0x0A)
- Digests[Number of streams with unknown CRC]
- []
-
-
- BYTE NID::kEnd
-
-
-Streams Info
-~~~~~~~~~~~~
-
- []
- PackInfo
- []
-
-
- []
- CodersInfo
- []
-
-
- []
- SubStreamsInfo
- []
-
- BYTE NID::kEnd
-
-
-FilesInfo
-~~~~~~~~~
- BYTE NID::kFilesInfo; (0x05)
- UINT64 NumFiles
-
- for (;;)
- {
- BYTE PropertyType;
- if (aType == 0)
- break;
-
- UINT64 Size;
-
- switch(PropertyType)
- {
- kEmptyStream: (0x0E)
- for(NumFiles)
- BIT IsEmptyStream
-
- kEmptyFile: (0x0F)
- for(EmptyStreams)
- BIT IsEmptyFile
-
- kAnti: (0x10)
- for(EmptyStreams)
- BIT IsAntiFile
-
- case kCreationTime: (0x12)
- case kLastAccessTime: (0x13)
- case kLastWriteTime: (0x14)
- BYTE AllAreDefined
- if (AllAreDefined == 0)
- {
- for(NumFiles)
- BIT TimeDefined
- }
- BYTE External;
- if(External != 0)
- UINT64 DataIndex
- []
- for(Definded Items)
- UINT32 Time
- []
-
- kNames: (0x11)
- BYTE External;
- if(External != 0)
- UINT64 DataIndex
- []
- for(Files)
- {
- wchar_t Names[NameSize];
- wchar_t 0;
- }
- []
-
- kAttributes: (0x15)
- BYTE AllAreDefined
- if (AllAreDefined == 0)
- {
- for(NumFiles)
- BIT AttributesAreDefined
- }
- BYTE External;
- if(External != 0)
- UINT64 DataIndex
- []
- for(Definded Attributes)
- UINT32 Attributes
- []
- }
- }
-
-
-Header
-~~~~~~
- BYTE NID::kHeader (0x01)
-
- []
- ArchiveProperties
- []
-
- []
- BYTE NID::kAdditionalStreamsInfo; (0x03)
- StreamsInfo
- []
-
- []
- BYTE NID::kMainStreamsInfo; (0x04)
- StreamsInfo
- []
-
- []
- FilesInfo
- []
-
- BYTE NID::kEnd
-
-
-HeaderInfo
-~~~~~~~~~~
- []
- BYTE NID::kEncodedHeader; (0x17)
- StreamsInfo for Encoded Header
- []
-
-
----
-End of document