

There are some possible cases when archive is corrupted: Possible values for first byte in End Header:ġ7 - End Header contains the link to Metadata Block.Ġ1 - Metadata block is stored in End Header. Note: if the file was compressed with LZMA method, the first byte Real offset of End Header in example archive = 0x20 + 0x0E59 = 0x0E79Ģ0: 00 21 16 89. Relative offset of End Header is relative from the end of Start Header, Note: If 7z archive contains only one file without encryption,ħ-Zip stores Metadata for that file in End Header in uncompressed form,Īnd there are only 3 main blocks in that case.Īrchive example: a.7z (3740 bytes) that contains 5 files compressed with LZMA method.Ġ000000000: 37 7A BC AF 27 1C 00 04 5B 38 BE F9 59 0E 00 00Ġ000000010: 00 00 00 00 23 00 00 00 00 00 00 00 7A 63 68 FDĠ000000020: 00 21 16 89 6C 71 3D AB 7D 89 E6 3C 2E BE 60 24Ġ0: 6 bytes: 37 7A BC AF 27 1C - SignatureĠ8: 4 bytes: 5B 38 BE F9 - CRC of the following 20 bytesĠC: 8 bytes: 59 0E 00 00 00 00 00 00 - relative offset of End Headerġ4: 8 bytes: 23 00 00 00 00 00 00 00 - the length of End HeaderġC: 4 bytes: 7A 63 68 FD - CRC of the End Header End Header: it contains link to Compressed Metadata Block.Compressed Metadata Block for files: it contains links to Compressed Data, information about compression methods, CRC, file names, sizes, timestamps and so on.Start Header (32 bytes): it contains signature and link to End Header.


How to recover corrupted 7z archive How to recover corrupted 7z archive Try latest version of 7-Zip
