[FFmpeg-devel] Fwd: GSoC: APNG

[Michael Niedermayer]

On Tue, Mar 24, 2015 at 09:54:07PM +0000, Donny Yang wrote:
> On 25 March 2015 at 04:18, Michael Niedermayer <michaelni at gmx.at> wrote:
> 
> > the generated png files seem to differ
> >
> > ./ffmpeg -i lena.pnm ref.png
> >
> > -rw-r----- 1 michael michael 180438 Mar 24 18:11 after-patches.png
> > -rw-r----- 1 michael michael 180987 Mar 24 18:14 before-patches.png
> >
> 
> It's because the non-APNG version breaks the data into lots of small IDAT
> chunks whereas mine puts it in one big chunk - but are functionally the
> same.

is there any advantage for multiple small IDATs ?
if not i suggest to make the IDAT change to png as well in a seperate
patch so that a single frame APNG and PNG produce identical data
and especially so that the introduction of APNG does not change PNG
files


> Also, my version doesn't output any ancillary chunks (yet - it's planned)
> either, since this is just a "basic" version.
> 
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-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
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