[CELT-dev] adding celt support to netjack some questions.

torbenh at gmx.de torbenh at gmx.de
Mon Nov 24 12:33:24 PST 2008


i am currently adding celt support to netjack.
very nice to see a free low-latency codec :)

i currently dont require robustness against packet loss,
because the sync code of netjack does not handle packet loss very
gracefully. how much bandwidth is wasted for this feature ?

is it sensible, to have the data downsampled berfore encoding , in 
order to reduce bandwidth ? i suspect that just using celt to do this
is more sensible, and leaves me with higher quality of the signal.

the signal data is obtained from individual jack ports.
i would need one additional step to make the frames interleaved.
how much bandwidth would i save if i was using one encoder, for
all channels, instead of n encoders for n channels ?
considering the signals are not really correlated.

there might be transmission of several stereo or otherwise
correlated signals though. But i would be happier with an API
that supported individual buffers for each channel.

can i hook up the decoder to an already running stream ?
netjacks protocol is stateless. and i was using downsampling and
bit rate reduction to do compression only. which are stateless
things to do.

at first glance i did not see a function which tells me the
latency of the encoding/decoding (its the overlap i guess)
i need this to make the latency compensation code work.

how RT-safe is the code ?
does it use malloc during encoding/decoding ?

well... i will make the code use several encoders for now, and await
some responses.

torben Hohn

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