Re: Changes to emacs/src/ChangeLog

Re: Changes to emacs/src/ChangeLog

[Kim F. Storm]

YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp> writes:

> +2006-05-06  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
> +
> +	* image.c (Qduration) [MAC_OS]: New variable.
> +	(syms_of_image) [MAC_OS]: Intern and staticpro it.
> +	[MAC_OS] (gif_load): Save image extension data in img->data.lisp_val.

The format you have chosen for the GIF extension data on MAC_OS is
completely different from the "raw" extension data which is returned for
other systems.  This makes it harder to use the data at the Lisp level.

Since it is trivial to emulate the "raw" format for the duration extension,
I would prefer if you do this, instead of using a different format.  E.g.:

unsigned char tem[4] = { 0, (duration)&0xff, ((duration)>>8)&0xff, 0 };

result = list4 (Qcount,
       		make_number (images),
       		make_number (0xF9),
       		make_unibyte_string (tem, 4));
        

-- 
Kim F. Storm  http://www.cua.dk

Re: Changes to emacs/src/ChangeLog

[YAMAMOTO Mitsuharu]

>>>>> On Mon, 08 May 2006 00:06:43 +0200, storm@cua.dk (Kim F. Storm) said:

> The format you have chosen for the GIF extension data on MAC_OS is
> completely different from the "raw" extension data which is returned
> for other systems.  This makes it harder to use the data at the Lisp
> level.

> Since it is trivial to emulate the "raw" format for the duration
> extension, I would prefer if you do this, instead of using a
> different format.

Actually I thought about that, but didn't do so because the Graphic
Control Extension block labeled with 0xf9 has other kinds of
information and they cannot be emulated directly.  Do you think it is
OK to drop them?

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp

Re: Changes to emacs/src/ChangeLog

[Kim F. Storm]

YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp> writes:

> Actually I thought about that, but didn't do so because the Graphic
> Control Extension block labeled with 0xf9 has other kinds of
> information and they cannot be emulated directly.  Do you think it is
> OK to drop them?

Yes.

IMO, it is better to simulate what you can, rather than using a
completely different format.

I don't know what to put there, but in a GIF I have here,
the first byte is 9 and the fourth byte is 63.

Perhaps it is better to just put 0 there, to indicate that
the value is unknown.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk