[FFmpeg-devel] [PATCH 3/3] apng: Add a basic APNG muxer

[Donny Yang]

On 1 April 2015 at 22:57, Paul B Mahol <onemda at gmail.com> wrote:

> On 4/1/15, Donny Yang <work at kota.moe> wrote:
> > On 1 April 2015 at 17:03, Paul B Mahol <onemda at gmail.com> wrote:
> >
> >> Dana 31. 3. 2015. 22:59 osoba "Donny Yang" <work at kota.moe> napisala je:
> >> > +#include <zlib.h>
> >>
> >> This is missing dependency on zlib in configure.
> >>
> > Fixed
> >
> >
>
> But this is more appropriate for APNG encoder. APNG muxer seems to not
> use zlib at all.
>
It's used for it's crc32 functions for editing/creating chunks.


> Also mime type seems wrong, and extension should be commented out as
> to not clash with png image creation. One would need to use "-f apng"
> parameters.

mime type of APNG being "image/png" is a feature to ensure full
interoperability between normal PNG and APNG files.
That is, if an APNG image is served, and the client doesn't understand
APNG, it will just read it as a normal PNG file due to its identical mime
type.
https://www.google.com.au/search?q=apng+mime+type

As for conflicting with PNG image creation, this was discussed a bit back:
http://ffmpeg.org/pipermail/ffmpeg-devel/2015-March/170667.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2015-March/170692.html