Learn how easy it is to sync an existing GitHub or Google Code repo to a SourceForge project! See Demo

Close

LZHAM

m^2
2010-09-07
2013-05-23
  • m^2
    m^2
    2010-09-07

    LZHAM is a new codec based on LZMA, slightly weaker yet much faster at decompression.
    https://code.google.com/p/lzham/
    Any chance to see it in UPX?

     
  • Well, we already have NRV for slightly weaker yet much faster at decompression. :-)
    Adding a new compressor is not too easy, so there should be some big benefits for justificating the extra work. Of course patches are always welcome :-)

     
  • m^2
    m^2
    2010-09-08

    Slightly?
    Well, the 25% that I see on my test corpus is far from slight IMO. LZHAM is 1.7% behind with more than twice decompression speed.

     
  • Sure, NRV is not a compression ratio champion, but its decompression speed is excellent.

    Anyway, I  do not see a good use case for LZHAM, because I think on fast hardware users want better compression ratio and do not really care  about decompression speed. On the other hand on slow hardware decompression speed should be as fast as possible.

    Another problem is that the source code if LZHAM seems to be too windows dependent.

     
  • m^2
    m^2
    2010-09-08

    Indeed, LZHAM is Windows-only ATM, but the author stated it's just a temporary issue, the codec is in early development stage.
    Well, actually I think once LZHAM matures, there is no good use case for LZMA in UPX - demo scene is the only place I know where a few kilobytes matter and UPX doesn't excel here anyway.
    And actually I think there is very little space for LZMA now - even on fast machines, if you decompress a big file, it's dog-slow. LZHAM doubles the size threshold at which something stronger then nrv makes sense.