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

Justin Ruggles justin.ruggles
Thu Jun 25 00:11:35 CEST 2009

Michael Niedermayer wrote:
> 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
>> streams.
> oops, in that case the patch is ok

Thanks. applied.


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