[FFmpeg-devel] New asf demuxer

Michael Niedermayer michaelni at gmx.at
Sun Jun 28 18:21:15 CEST 2015

On Sun, Jun 28, 2015 at 04:54:02PM +0200, Nicolas George wrote:
> Le decadi 10 messidor, an CCXXIII, Carl Eugen Hoyos a écrit :
> > From a very quick look, the new code seems mostly 
> > unreviewed
> What makes you say that? Where did you give your "very quick look" exactly?
> > Do you disagree?

> I do disagree, on several counts. First, the old muxer was based on
> reverse-engineering, the new one is based on the spec;

this may be true for the original demuxer 15 years ago, (iam not
its author so iam not the right one to ask about it)

but work was done on it since then
not sure when the specs where first released, there are btw multiple
versions of the specs

> in principle, i.e.
> except when the spec is actually crap, this is better.

from my bugfixing work i did on asf i would not call the spec that
was available "high quality and well matching real files"
that may have changed, i do not know

> Second, someone
> actually took efforts to do so, I take it as a sign that it was considered
> useful by someone knowing the issue better than me.

> Third, a quick glance
> seems to indicate that the new code is cleaner than the old one, I could
> spot an unchecked av_dict_set() immediately for example.

i posted a patch that would simplify such av_dict_set() checks

to return to the topic of this thread
i am happy with either demuxer being default
i would strongly prefer that to be the demuxer which works better
though and it must at least pass fate. (the rewritten demuxer does not
pass fate unless one changes the ref files, the needed changes did look
odd IIRC)

Can someone explain how the rewritten demuxer is better?
That is feature and bugfix wise ?
I do understand that being written later it could use
specs that where not available originally.
What has been added/changed in the specs that lead to differences
in the demuxer implementations ?

also is a maintainer available for the rewritten demuxer ?
that is someone who reviews patches that are posted here and fixes
bugs posted on trac ?


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The real ebay dictionary, page 1
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