[FFmpeg-devel] [PATCH] speex extradata in flv demuxer
Tue Jun 23 19:06:45 CEST 2009
On Tue, Jun 23, 2009 at 02:32:27PM +0200, Aurelien Jacobs wrote:
> On Tue, Jun 23, 2009 at 12:46:21PM +0200, Michael Niedermayer wrote:
> > On Mon, Jun 22, 2009 at 05:55:35PM -0400, Justin Ruggles wrote:
> > > Michael Niedermayer wrote:
> > > > On Sun, Jun 21, 2009 at 02:32:33PM -0400, Justin Ruggles wrote:
> > > >> Hi,
> > > >>
> > > >> This patch for the FLV demuxer builds a Speex header and puts it in
> > > >> extradata. Our libspeex wrapper decoder works without it, but some
> > > >> other decoders might not. It is also needed for stream copy.
> > > >
> > > > is this header flv specific?
> > > > if its not flv speific id say it does not belong in the flv muxer
> > > > but maybe iam missing some details that make this the best solution ...
> > >
> > > FLV does not contain the header at all, which is the reason for the
> > > patch. Instead FLV defines some of the values to be fixed and, from
> > > what I can tell so far, either ignores the rest or assumes they will be
> > > the libspeex default. There is no Speex specification per-se (except
> > > for RTFS), and the FLV/SWF spec does not say how this is handled.
> > >
> > > An alternative to building a Speex header with FLV-specific values would
> > > be a generic struct and functions to build/write/read a Speex header.
> > > That would basically be a reimplementation of speex_header.[ch] from
> > > libspeex.
> > let me ask differently
> > normally, an encoder build extradata that ALL muxers store,
> > nothing you said explain why its not done like that. What you do is
> > you have added code that appears to belong in the speex encoder into the
> > muxer
> > What am i missing?
> You are missing the fact that the patch don't touch the muxer at all...
> It add code to the demuxer. FLV files in the wild contain speex data with
> no explicit extradata. Generating some extradata (matching the FLV default
> speex parameters) is required for remuxing or decoding of those speex-in-FLV
oops, in that case the patch is ok
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
I am the wisest man alive, for I know one thing, and that is that I know
nothing. -- Socrates
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