Open Sapi - RAW PCM

[A]

I've no idea about SD also but here are my 2 cents :)

On Tue, Mar 23, 2010 at 2:08 PM, Thomas Lloyd <thomaslloyd at yahoo.com> wrote:
> Hi All,
>
>
> Right I have been a busy bee and now have some questions about Raw Audio
> Streams.
>
> At the moment I am directly reading the RAW PCM data from SAPI. I can do
> what I want with it now. I have a number of questions though.
>
> Do I need to be sending speechd a wav header so it can know what it is
> dealing with or can I just send it the raw data. I think I will need to
> send the wav header but a more in-depth explanation might help having to
> recode later on.

I think that client and server may negotiate the format of the raw
data so sending a wav header should not be necessary. Unfortunately I
can't say exactly if and what is the issue but I'm not sure wav is
good for streaming.

<...>

> The third question is about audio data transfers. I would like to get
> the size of the audio data to be as small as possible so when this gets
> running across the net it will function using less bandwidth. Can I
> supply speech dispatcher with say ogg formatted audio data or Mp3?

I've recently read about www.celt-codec.org which sounds promising but
not yet stable so you know...
speex would be best for low bandwidth concerns but probably not always
at the desired sound quality. Should be good for most uses IMHO.
vorbis and mp3 will probably impose too great delay for many use cases?

Perhaps can be done pluggable?