ietf-822
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Re: gzip/deflate compression/encoding

2005-06-30 12:31:11


In <42C2265E(_dot_)53F(_at_)xyzzy(_dot_)claranet(_dot_)de> Frank Ellermann 
<nobody(_at_)xyzzy(_dot_)claranet(_dot_)de> writes:

Bruce Lilly wrote:

Conclusions:
1. binary-to-8bit encoding w/o gzip compression is fine for audio,
   image, and video media which already has media-specific compression
   (for 8bit transport, avoiding the 37+% expansion of base64)

Yes

Question:

Are the usual audio, image, etc. formats truly 8bit clean (i.e. are they
guaranteed not to contain NUL or naked CR or LF)?

Of course they aren't.

If not, then you are
back to the 37+% expansion of base64.

Doesn't follow. A binary-to-8bit encoding has enough characters available that
the overhead can be limited to at most 1-2%.

For that matter, is a gzipped file 8bit clean?

It isn't and doesn't have to be.

                                Ned