[FFmpeg-devel] [PATCH] speex extradata in flv demuxer

Justin Ruggles justin.ruggles
Mon Jun 22 23:55:35 CEST 2009


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.

-Justin



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