[Ffmpeg-devel] Native zlib decoder

Måns Rullgård mans
Mon Mar 19 17:41:06 CET 2007

As you may have gathered, I started working on a native zlib decoder for lavc.

I have the basics working, i.e. I can decode a single deflate block coded with
any of the coding methods (uncompressed, fixed Huffman tables, dynamic Huffman

Before I go further, I'd like some opinions on what kind of API would be most
useful within lavc.  If I hear nothing, I'll examine the existing usage of
zlib and try to make something suitable for all the cases.

My main concern is output buffer management.  The decoder needs access to the
last 32k of output, and I'd prefer not to copy data when it can be avoided.

The PNG decoder, for instance, is easy to handle.  The output data size is
known in advance, and the entire compressed input is available at once.  I'd
like to also cope with arbitrarily long inputs and outputs without adversely
affecting the simple cases.

M?ns Rullg?rd
mans at mansr.com

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