[Zlib-devel] DEF_MEM_LEVEL vs. MAX_MEM_LEVEL

[Mark Adler]

On Apr 11, 2005, at 8:03 AM, Jan Ringoš wrote:
> I compress 65471 bytes long buffers of general data and the output 
> buffer is always few bytes longer with MAX_MEM_LEVEL than with 
> DEF_MEM_LEVEL.

That's why it's the default.  The problem with MAX_MEM_LEVEL is that 
the deflate blocks are larger, and therefore not as adaptive to 
changing data resulting in lower compression.

> How significant is performance gain when MAX_MEM_LEVEL is used?

zlib.h does imply that, but I don't know if there really is a speed 
gain, or by how much if there is one.  You'd have to measure it with 
your compiler and platform anyway to really know.

mark