Jim Lux skrev 2011-09-19 18:48:
On 9/17/2011 12:18 PM, Ben / SM0KBW wrote:
Jim Lux skrev 2011-09-13 17:39:
On 9/12/2011 9:38 PM, Sal wrote:
wrote in message
...



Wait a minute. What this guy is selling is a streaming audio app,
not a
"shortwave radio" program.

Correct. The screen display is a "fake" radio. Tsk, tsk!



Oddly, I have been looking for a simple streaming audio app (to bring
back audio from remote receivers via 802.11 for a antenna measurement
project)... This one is clearly not it, but what else is out there.

I have used IHU, http://ihu.sourceforge.net/ for voip streaming. It's
for Linux and that maybe disqualfies that program?

being Linux doesn't disqualify it, but having no support for other OSes
sort of does..

At least it has a command line interface (useful for the remote end,
which is a small Linux box) (bearing in mind the author's warning:

Those options are useful for quick launch (at least for me ,
but I don't think it's a good idea to use them (they might be buggy),
in the future I may use standard GNU getopt, but for the moment
please use the graphic interface instead.


And it has a variety of flavors. And it might be possible to compile it
to run under OS-X or windows (not in emulation or VM, but using a useful
library)

The real gripe I have is that the data format isn't described anywhere
(at least not that google can find). reading through the source code
finds stuff about headers, stream sync, etc. but there's no obvious
description of what the UDP/TCP packets look like. In fact, there's no
comments in the source code, for the most part.

So if you DID want to write your own endpoint, it would be mighty tough.

I'm not sure what you mean with data format, but I assume you are
talking about the audio stream. IHU is just a simple interface to
Speex, http://www.speex.org/, and that is a free audio compressing
codec, at least free in the sense of BSD License.

The documentation for Speex is rather comprehensive, and it covers the
RTP format and the API.

73
Ben / SM0KBW

I'm not sure what you mean with data format, but I assume you are
talking about the audio stream. IHU is just a simple interface to
Speex, http://www.speex.org/, and that is a free audio compressing
codec, at least free in the sense of BSD License.


The documentation for Speex is rather comprehensive, and it covers the
RTP format and the API.

Hmm.. Appendix C of the Speex doc does provide a RTP example. However,
IHU doesn't say anywhere that this is what it does (it does say it uses
speex for compression). It's also not clear that IHU is actually using
RTP frames. It seems that IHU has its own homegrown packet format:
(in packet.cpp)

ARCHITECTURE OF THE PACKET
*
* A IHU packet consists of 2 parts:
* 1) Header
* 2) Data
*
* THE HEADER
*
* THe header is made up of 3 parts:
*
* a) SYNC Pattern (3 bytes)
* The pattern consists of the fixed ASCII string: "IHU"
*
* b) Packet SIZE (1 byte): unsigned char that contains
* the size of the packet (min size 5, max size 256)
*
* c) INFO data (1 byte)
* It contains those informations (in order):
* - OBSOLETE: still used for bakward compatibility (versions 0.6.x)
* Speex mode (3 bits). It can be:
* IHU_INFO_MODE_ULTRAWIDE
* IHU_INFO_MODE_WIDE
* IHU_INFO_MODE_NARROW
* - Packet type (5 bits). It can be:
* IHU_INFO_RESET 0x0
* IHU_INFO_INIT 0x1
* IHU_INFO_AUDIO 0x2
* IHU_INFO_CRYPTED_AUDIO 0x3
* IHU_INFO_KEY_REQUEST 0x4
* IHU_INFO_NEW_KEY 0x5
* IHU_INFO_ANSWER 0x6
* IHU_INFO_CLOSE 0x7
* IHU_INFO_REFUSE 0x8
* IHU_INFO_RING 0x3f
* IHU_INFO_RING_REPLY 0x3e
*
* d) Data LENGTH (1 byte): unsigned char that contains
* the size of the following DATA part (min 0, max 250)
*
* THE DATA
*
* This part of the packet is of variable size (min 0, max 250 bytes)
* and it contains the data to be trasmitted.
* It can be absent (if the packet doesn't need to transmit any data)
* or, can be audio data or keys for encpryption.
* The type of data transmitted is specified in the INFO header
*
*/


anyway.. the point is that while IHU probably works just fine, it's like
a lot of other undocumented utilities out the it works for what it's
original author intended, and if you want to use it as a basis for
software that you'd write, it's great.


However, my whole question was really to see if some simple
off-the-shelf multiplatform already existed. (i.e. I'd rather spend my
time doing things OTHER than writing audio transport code)

Jim Lux skrev 2011-09-19 23:00:

I'm not sure what you mean with data format, but I assume you are
talking about the audio stream. IHU is just a simple interface to
Speex, http://www.speex.org/, and that is a free audio compressing
codec, at least free in the sense of BSD License.


The documentation for Speex is rather comprehensive, and it covers the
RTP format and the API.

Hmm.. Appendix C of the Speex doc does provide a RTP example. However,
IHU doesn't say anywhere that this is what it does (it does say it uses
speex for compression). It's also not clear that IHU is actually using
RTP frames. It seems that IHU has its own homegrown packet format:
(in packet.cpp)

ARCHITECTURE OF THE PACKET
*
* A IHU packet consists of 2 parts:
* 1) Header
* 2) Data
*
* THE HEADER
*
* THe header is made up of 3 parts:
*
* a) SYNC Pattern (3 bytes)
* The pattern consists of the fixed ASCII string: "IHU"
*
* b) Packet SIZE (1 byte): unsigned char that contains
* the size of the packet (min size 5, max size 256)
*
* c) INFO data (1 byte)
* It contains those informations (in order):
* - OBSOLETE: still used for bakward compatibility (versions 0.6.x)
* Speex mode (3 bits). It can be:
* IHU_INFO_MODE_ULTRAWIDE
* IHU_INFO_MODE_WIDE
* IHU_INFO_MODE_NARROW
* - Packet type (5 bits). It can be:
* IHU_INFO_RESET 0x0
* IHU_INFO_INIT 0x1
* IHU_INFO_AUDIO 0x2
* IHU_INFO_CRYPTED_AUDIO 0x3
* IHU_INFO_KEY_REQUEST 0x4
* IHU_INFO_NEW_KEY 0x5
* IHU_INFO_ANSWER 0x6
* IHU_INFO_CLOSE 0x7
* IHU_INFO_REFUSE 0x8
* IHU_INFO_RING 0x3f
* IHU_INFO_RING_REPLY 0x3e
*
* d) Data LENGTH (1 byte): unsigned char that contains
* the size of the following DATA part (min 0, max 250)
*
* THE DATA
*
* This part of the packet is of variable size (min 0, max 250 bytes)
* and it contains the data to be trasmitted.
* It can be absent (if the packet doesn't need to transmit any data)
* or, can be audio data or keys for encpryption.
* The type of data transmitted is specified in the INFO header
*
*/


anyway.. the point is that while IHU probably works just fine, it's like
a lot of other undocumented utilities out the it works for what it's
original author intended, and if you want to use it as a basis for
software that you'd write, it's great.


However, my whole question was really to see if some simple
off-the-shelf multiplatform already existed. (i.e. I'd rather spend my
time doing things OTHER than writing audio transport code)


You are probably right. I've used IHU to see if Speex was good enough to
use as an audiolink. I didn't scrutinize the source code. I am planning
to establish a link between my noisy home (Stockholm) and my
summerhouse. Anyhow that good suitable audiolink software has yet to be
written


73
Bengt / SM0KBW

Ben / SM0KBW wrote:
You are probably right. I've used IHU to see if Speex was good enough to
use as an audiolink. I didn't scrutinize the source code. I am planning
to establish a link between my noisy home (Stockholm) and my
summerhouse. Anyhow that good suitable audiolink software has yet to be
written

Sure it has. Look up SVXLINK. It was intended to link a repeater with remote
sites, but you don't actually need to have a radio on either end. It has full
rig control with a serial interface, although one ham here built a USB one
and I believe it interfaces to commercial ones.

It has remote receiver support with voting if there is more than one,
remote transmitter support and a multiuser Echolink client.

It even has the capability to be controlled via DTMF tones built in.

Geoff.


--
Geoffrey S. Mendelson N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.

Geoffrey S. Mendelson skrev 2011-09-20 11:04:
Ben / SM0KBW wrote:
You are probably right. I've used IHU to see if Speex was good enough to
use as an audiolink. I didn't scrutinize the source code. I am planning
to establish a link between my noisy home (Stockholm) and my
summerhouse. Anyhow that good suitable audiolink software has yet to be
written

Sure it has. Look up SVXLINK. It was intended to link a repeater with remote
sites, but you don't actually need to have a radio on either end. It has full
rig control with a serial interface, although one ham here built a USB one
and I believe it interfaces to commercial ones.

It has remote receiver support with voting if there is more than one,
remote transmitter support and a multiuser Echolink client.

It even has the capability to be controlled via DTMF tones built in.

Geoff.


The SVXLINK project is an intresting one if I want to do FM and or
ECHOLINK - repeater stuff. If I just want an an audiostream then
it's i.m.h.o just to bloated with these DTMF, CTCSS .....


73
Ben / SM0KBW

Ben / SM0KBW wrote:

The SVXLINK project is an intresting one if I want to do FM and or
ECHOLINK - repeater stuff. If I just want an an audiostream then
it's i.m.h.o just to bloated with these DTMF, CTCSS .....

Bloat is relative. It's a reasonably small program that runs under Linux,
you probably could wedge it with the extras turned off onto an old router.

Gone are the days that speak freely was available, and you could run
remote audio pickups via piping the audio via ssh.

(sendprogram) | ssh computer (receiveprogam)

Worked well for me to pipe a receiver in Jerusalem via frame relay to a
remote speaker in Tel Aviv. This used 8k bits per second (plus overhead)
of a 64k bits per second line.

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.