[FFmpeg-devel] [PATCH] add md5 muxer

[Reimar Döffinger]

On Sun, Sep 27, 2009 at 10:56:30PM +0200, Michael Niedermayer wrote:
> On Sun, Sep 27, 2009 at 07:53:18PM +0200, Reimar D?ffinger wrote:
> > On Sun, Sep 27, 2009 at 07:31:00PM +0200, Michael Niedermayer wrote:
> > > On Sun, Sep 27, 2009 at 12:04:27PM +0200, Reimar D?ffinger wrote:
> > > > we have -f crc, but IMO 32 bit crc are a bit little for a whole file and
> > > > also we use md5sum in the regression tests, so I'd propose to add a -f
> > > > md5 as in attached patch.
> > > 
> > > why md5 instead of sha1?
> > 
> > Because md5 makes more sense for the simple reasons that
> > 1) we already use it in regression tests
> > 2) a md5/md5sum binary is available anywhere, I do not know
> >    something comparable for sha
> > 3) for security-relevant stuff they are all "useless"
> > 
> 
> > Which leaves me to ask: why sha1? I don't really see anything in
> > its favour 
> 
> well, because someone could use it with source files under outside
> control.
> I would guess that in that case it can likely be used to return
> misleading values ...

For that sha256 may barely be enough, but surely not sha1.
However it's not a big deal to provide both or more, the question is
just how. I'd favour a one muxer per hash format approach (though
possibly in the same file as for the raw formats).