mORMot Open Source

domek

Member

Registered: 2019-04-09

Posts: 8

SynBzPas.pas and UnCompressBzMem - what is the unpacked size?

I want to use UnCompressBzMem() from SynBZPas.pas to unpack z .bz2 file. But in order to do so I need to know the last parameter:
DestSize: integer
so the size after unpacking. Where do I get this size from an actual .bz2 file?

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,238

Website

Re: SynBzPas.pas and UnCompressBzMem - what is the unpacked size?

I don't think it is allowed by the BZ encoding itself, IIRC.

You should store the uncompressed length somewhere - as we do with our TAlgoCompress wrappers.

domek

Member

Registered: 2019-04-09

Posts: 8

Re: SynBzPas.pas and UnCompressBzMem - what is the unpacked size?

I just have a standard .bz2 file. So I can't unpack it? Somehow programs like 7zip and WinRAR can unpack this file.

jaclas

Member

Registered: 2014-09-12

Posts: 215

Re: SynBzPas.pas and UnCompressBzMem - what is the unpacked size?

Maybe uncompressed size is coded in first bytes of file? Try this.

domek

Member

Registered: 2019-04-09

Posts: 8

Re: SynBzPas.pas and UnCompressBzMem - what is the unpacked size?

@jaclas It's impossible:
https://stackoverflow.com/questions/126 … -file-size

uian2000

Member

Registered: 2014-05-06

Posts: 68

Re: SynBzPas.pas and UnCompressBzMem - what is the unpacked size?

According to the file format defination, we can not get that size before uncompress.