Re: using deflateSetDictionary DEFLATE ZLIB

On Jul 12, 9:14 pm, Mark Adler <mad...@xxxxxxxxxxxxxxxxxx> wrote:
On Jul 12, 5:38 am, George Wilson <george_wilson_...@xxxxxxxxx> wrote:

1. What happens to dictionary used if it is beyond 32K ?

If more than 32K is provided, only the last 32K is used.

2. Will the data encoded in the look ahead buffer enter the search
buffer at any point of time ? when using deflateSetDirectory ?

The question is not clear (and it's deflateSetDictionary). The
provided dictionary will be processed into the search hash table to
enable finding strings in the dictionary when the data to compress is
provided.

3. Is this deflateSetDictionary available with others like DEFLATE
users like GZIP?

The use of a preset dictionary is not supported by gzip.

4. What kind of variation can be expected with in DEFLATE ZLIB with
deflateSetDirectory ?

Again the question is not clear. If you'd like to know how
compression might be improved, you'll just have to try it yourself.
Your mileage will vary considerably with how similar the dictionary is
to the data to be compressed, and how long the data to be compressed
is.

Mark

Thankyou very much Mark

I have one more question is the zlib lib build for windows is thread
safe.

.

Relevant Pages

  • Re: using deflateSetDictionary DEFLATE ZLIB
    ... buffer at any point of time? ... when using deflateSetDirectory? ... enable finding strings in the dictionary when the data to compress is ... The use of a preset dictionary is not supported by gzip. ...
    (comp.compression)
  • [Question] using deflateSetDictionary DEFLATE ZLIB
    ... the most commonly used strings occur at the end of the dictionary. ... Will the data encoded in the look ahead buffer enter the search ... when using deflateSetDirectory? ... George Wilson ...
    (comp.compression)