[FFmpeg-devel] [PATCH] QCELP decoder

Reynaldo H. Verdejo Pinochet reynaldo
Wed Nov 26 01:54:05 CET 2008


Kenan Gillet wrote:
> Currently, the only demuxer that handles QCELP is the MOV
> demuxer.
> All the samples we have, are in different flavors of MOV files (mov,  
> 3g2, k3g)
> In all those files, 1 MOV frame corresponds to 1 QCELP frame:
> there is no bundling.

Kenan, The way I see its simple, use the decoder to decode. To
parse a frame beyond what the spec mandates, account for transport
oddities or whatnot, either correctly patch the demuxer or use
a parser. Its not OK to put such code in the decoder, even if
it makes everything 'just work', its not the correct solution
not to mention the need for a parser was long ago understood and
accounted for.

>>> a parser. But right now, I think the focus is on making the QCELP
>>> decoder works on the different flavor of MOV files, and it does not
>>> need any parser.

It does need a parser, thats not under discussion. You're putting
parsing code in the decoder, that's the issue here.

>> Having custom packet parsing code (not talking about codec frame
>> parsing) in the decoder is not a clean solution, this should be
>> handled with a parser. Even more if this is just to handle a subset
>> of files. There is an skeleton parser on the SoC repo. Maybe you
>> could add to it?
> Ok, let me rephrase it:
> Making QCELP decoding available in every possible/existing format
> is definitely a long term goal

So was making IFQ work or handle ERASURES but we both bitted
that bullet long ago. I'm just asking you to put the code
where it belongs, there is a parser in the SoC repo, put
the parsing code there.

> But my CURRENT focus is to merge the QCELP decoder, so that it
> can correctly decode all the samples we have and be as specs
> compliant as possible.

You are going out-spec with the parsing, and please don't get me
wrong -- I like that, I'm just telling you to put the code where
it belongs. At least for starters, we both know that parser will
have to be extended latter.

> Furthermore, I am not comfortable to add code that has not been
> tested on real world samples; it is just my philosophy...

Again --

You are already adding the code. I'm not asking you to add anything
more, Or to take care about debundling tied-up RTSP transported codec
frames -- no. Just move YOUR parsing code to the correct place.

> Concerning the "custom packet parsing code", I would like to know
> what it refers to, because I am not sure to understand your comment.

I meant what I wrote, If the data you're getting its out-spec then
its customly packed, that is.-

Keep up the good work.


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