[Speex-dev] In-band user data

[Thorvald Natvig]

Hi,

I'm moving my "metadata" which accompanies some of the speech packets 
into the speex bits. However, as usual, I'm a bit confused.

The manual (PDF from current SVN), section 5.10 (bottom of page 21) 
states that:

"Finally, applications may define custom in-band messages using mode 13. 
The size of the message in bytes is encoded with
5 bits, so that the decoder can skip it if it doesn’t know how to 
interpret it."

Ok, so I prepend my data as such:

speex_bits_pack(&sbBits, 13, 5);
speex_bits_pack(&sbBits, length, 5);
// bla bla insert my stuff then encode the packet.

And this works :) My custom handler, set with SPEEX_SET_USER_HANDLER is 
called and everything is good.

However, I kinda wondered what would happen if that handler WASN'T 
installed... And things aren't so good then.

Looking at the code in speex_callbacks.c, it seems the 
speex_default_user_handler first unpacks 4 bits as size, then advances 
8*size + 5 bits.
First of all, shouldn't that be 5 bits for size (to match manual)? And 
where did that '+ 5 bits' come from?


Next, and slightly unrelated question:
Why does
int jitter_buffer_update_delay(JitterBuffer *jitter, JitterBufferPacket 
*packet, spx_int32_t *start_offset);
include the packet parameter? It's not used in the code, and it also 
makes the API slightly confusing as it's very unclear what that 
parameter should be :)