[Speex-dev] NOP pattern - how to make SPEEX packets bigger?

[Jean-Marc Valin]

You need to pad with 01111 (15 encoded in 5 bits). speex_bits_insert_terminator
does that, but it assumes nobody will add anything after.

    Jean-Marc


Selon Ralph Giles <giles at xiph.org>:

> On Fri, Dec 17, 2004 at 09:29:13AM +0100, Tomasz Pyra wrote:
>
> > How can I add some size to SPEEX encoded packets without affecting
> > decoding results?
> >
> > I need it to fit smaller (due to VAD) packets in CBR acm-wav file.
>
> I'm not entirely familiar with how speex handles packet lengths, but
> have you tried just padding the packet out and seeing if the decoder
> still handles them properly? It looks like most of the reads are
> contingent, so it may find the natural end of the data on its own.
>
> If you do try that, I'd suggest testing with a number of different
> padding values, in particular 0xFF, 0xF0, 0x0F and 0x00 to make sure
> you're not getting through by accident. 0xFF seems especially likely
> to either terminate the packet or cause an error.
>
> And if that scheme doesn't work, you can always embed a private packet
> length before each packet so your wav-demux layer can throw away the
> padding before handing the data off to the decoder.
>
> Hope that is of some help, anyway,
>  -r
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