Maker Pro
Maker Pro

Compressing Voice Sound.

J

Jamie

Jan 1, 1970
0
Pooh said:
Boki wrote:




12 bit is good for voice. Better than 8 bit. 16 bit isn't needed for voice
though.




mp3 is the obvious choice of codec. There are others of course but I expect you
want one that is licence free ?

Graham
i've seen 4..6 bits used in Phone/Voice fax type interfaces , its find
for voice links.
 
P

PeteS

Jan 1, 1970
0
Boki said:
Hi All,
I am newbie.
I have a image sensor, and I am sending continuosly jpg picture to client
via Bluetooth.
Now, I want to add voice sound.


Q1: Should I add new chip ? or just mic component only ? ( not high quality
use, just record voice )

Q2: What the bandwidth do I need? ( it seems a straming protocol ... my
god.. huge work... could you please advice a simple way ? )


Best regards,
Boki.

If you need to synchronise the sound, you may have issues.

Bluetooth has a data channel (SCO) designed specifically for voice, and
it's simply a matter of interfacing to it properly.

The channel is PCM, with (usually) the following options on voice:

A-Law
u-Law
2s complement.

Of course, you have to provide the codec and perhaps the PCM clock and
framing.

Cheers

PeteS
 
W

Walter Harley

Jan 1, 1970
0
Pooh Bear said:
I'd say
" it's been done / finished ". It's = 'it has' in this case
" it's done " is equally good. Where it's = 'it is' - lol - that's
english
for you !

I think "it's been done" might be a Britishism? To my American ears that
phrase would suggest that the work was done by someone else. That is, if
you asked me "how'd your project go" and I answered "it's been done" I would
be suggesting that I hired someone else to do it for me :)

But "it's finished" or "it's done" both sound correct to my ears.

I could also say "I'm done", or "I'm finished". ("I'm" rather than "It's".)
But those suggest that I am done working on the project but the project
itself is perhaps not quite done - perhaps I got tired of it and quit
prematurely, or perhaps it's a team effort and only my part is complete.
There is also a slight echo of "I'm done for", meaning perhaps that the
project concluded so poorly that I expect a failing grade.

-walter
 
K

Ken Taylor

Jan 1, 1970
0
Boki said:
Of course not new chip. :)

No, no idea yet.... the one is my 12bit 1-V sigma-delta modulator ......
many problems there :p

Good, 4KHz.
Telephone quality is enough, when I speed up my Bluetooth transmission and
then I will select in advance.

Any suggestion codec? Just have a look/reference : )

I hope the data rate is as small as possible...


Best regards,
Boki.
Take a look at Winbond's voice codecs:
http://www.winbond.com/e-winbondhtm/partner/b_2_m_1.htm
or even Zarlink (http"//www.zarlink.com) though they're more telecom's
and not necessarily useful to you.

Cheers.

Ken
 
R

Rich Grise, but drunk

Jan 1, 1970
0
I think "it's been done" might be a Britishism? To my American ears that
phrase would suggest that the work was done by someone else. That is, if
you asked me "how'd your project go" and I answered "it's been done" I would
be suggesting that I hired someone else to do it for me :)

"I don't need to do this, it's been done before." :)

Boy, do we now get to expand our curricula vitae to include not only
tutornig newbies in electronics, but tutoring ESL folks in English?

Sounds like too much work for me. ;-P

But somehow, I suddenly find myself impelled to decline "is", from
memory:

I am
You are
He/she/it is
We are
You are
They are
I was
You were
He/she/it was
we were
you were
they were
I have been
you have been
he/she/it has been
we have been
you have been
they have been
I had been
you had been

And so on, with tenses and declensions that don't even have _names_ in
English! Some of those forms are _adverbs_! So, it's excusable that
English is a little confusing, but I'm one of the lucky ones - a year
or so of HS Latin really helps with that sort of thing, if you're of a
mind to learn. :)

Cheers!
Rich
 
B

Boki

Jan 1, 1970
0
Sure, it is a long time we did that... ( manufacturing jobs move to
mainland )
RD job market ... I guess is OK, but of course, not as high salary (but low
tax) as oversea unless some people are really good in the world.

I can feel the presure from mainland/india especially is their software
engineer...

Best regards,
Boki.
 
P

PeteS

Jan 1, 1970
0
Further to my previous post, I am using a *single* bluetooth module
that simultaneously passes both voice and data. Data is passed on the
ACL channel using the Serial port profile and audio is passed on the
SCO channel. Note that for most devices, the two endpoints must be the
same.

The serial port data is passed on the TxD/RxD pair (with appropriate
flow control) and the audio is passed on the PCM highway. In my case, I
have different implementations using companded audio in one case and
linear (2s complement) 13 bit data in another.

Cheers

PeteS
 
F

Fred Abse

Jan 1, 1970
0
But somehow, I suddenly find myself impelled to decline "is", from
memory:

If we're into semantics, I think it's "compelled to conjugate"

:))
 
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