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Test
john@...
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AW: Test
"siegfried jackstien" <siegfried.jackstien@...>
- . ... -
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..--..
-----Ursprüngliche Nachricht-----
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Re: Bridging the digital voice and data gap
"Tony Langdon, VK3JED" <vk3jed@...>
At 01:43 AM 8/2/2012, you wrote:
Maybe your all confused... audio doesn't have to come out a speaker to be analog. To be perfectly clear, the dv-dongle is still converting a digital signal to an analog one... and a second chip is required to go into any another digital code. Even if a lossless digital codec is used in between (like wave or similar), the conversion to a lossy format like AMBE is the troublesome one... not the conversion to analog. Yes, less signal is lost vs going out a speaker and into a microphone, but the principles I stated before are largely the same, and I'm not convinced the resulting stream of bits will be legibleNo, the DV dongle converts a PCM bitstream to an AMBE coded bitstream and vice-versa. There is no analog audio near a DV Dongle (have you ever managed to get an analog signal down a USB bus? ;) ). Conversions between codecs are better when there is no intervening A/D and D/A pair to go through, so running a DV Dongle (or equivalent) back to back with an IMBE equivalent will give the best result possible. You are right in one thing, the result won't be perfect, may not be pretty, but it may be functional. Only one way to find out! :) If the number of transcodes is limited to the bare minimum (i.e. 1), then you may get along with it. Oh, and a case in point, telephony systems (e.g. Asterisk) do convert between codecs when necssary, so that you can attach any phone to the system, regardless of what code the network is running. The phone just needs to be capable of using at least one of the codecs Asterisk supports. Asterisk also decodes and recodes any participants in a conference call. Of course, most of the codecs used in telephony are a lot less "aggressive", but the principle works rather well. 73 de VK3JED / VK3IRL http://vkradio.com
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Re: Test
"Tony Langdon, VK3JED" <vk3jed@...>
At 03:24 AM 8/2/2012, you wrote:
------------------------------------Little bit of power supply hum there, and some signs of RF feedback. ;) 73 de VK3JED / VK3IRL http://vkradio.com
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Re: Bridging the digital voice and data gap
"qrv@..." <qrv@...>
This one tickled my fancy ...
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Perhaps one could modulate the 5v line? Just sayin' ... ;-)
Tony Langdon, VK3JED wrote: (have you ever managed to get an analog --
Thanks! & 73, KD4E.com David Colburn nevils-station.com I don't google I SEARCH! duckduckgo.com Network: groups.yahoo.com/group/qrv Restored to design-spec at Heaven's gate 1Cor15:22
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Re: Bridging the digital voice and data gap
"Howard Small" <howard@...>
Hmm. Not sure how they do it but the IC-7200 passes the audio over a USB connection in parallel with the CI-V commands.
Howard VK4BS
From: UniversalDigitalRadio@... [mailto:UniversalDigitalRadio@...] On Behalf Of qrv@...
Sent: Thursday, 2 August 2012 12:01 To: UniversalDigitalRadio@... Subject: Re: [UniversalDigitalRadio] Re: Bridging the digital voice and data gap
This one tickled my fancy ...
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Re: Bridging the digital voice and data gap
Ian Wade G3NRW <g3nrw-radio@...>
___Original Message_________________________________________
From: "Tony Langdon, VK3JED" <vk3jed@...> Date: Thu, 2 Aug 2012 Time: 07:32:08 There is no analog audio near a DV Dongle (have youYup. I do it every day. On my TS-590S. Mostly analog data tones, but sometimes analog DV tones. Audio codec in the radio, codec driver in the PC. USB cable in between. Works very well. :-) -- 73 Ian, G3NRW The TS-590S Resources Page: http://homepage.ntlworld.com/wadei/ts-590s.htm The TS-990S Resources Page: http://homepage.ntlworld.com/wadei/ts-990.htm
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Re: Bridging the digital voice and data gap
"Tony Langdon, VK3JED" <vk3jed@...>
At 12:30 PM 8/2/2012, you wrote:
Hmm. Not sure how they do it but the IC-7200 passes the audio over a USB connection in parallel with the CI-V commands.Well, that one's easy, the audio is still in digital form, it's rather like a serial dongle and a sound fob on the one USB hub. :) 73 de VK3JED / VK3IRL http://vkradio.com
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Re: AW: Bridging the digital voice and data gap
"siegfried jackstien" <siegfried.jackstien@...>
Usb soundcard?!?
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Dg9bfc Sigi
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Re: Bridging the digital voice and data gap
Matthew Pitts <daywalker_blade_2004@...>
From: Tony Langdon, VK3JED ; To: ; Subject: RE: [UniversalDigitalRadio] Re: Bridging the digital voice and data gap Sent: Thu, Aug 2, 2012 10:56:09 AM
At 12:30 PM 8/2/2012, you wrote:
>Hmm. Not sure how they do it but the IC-7200 passes the audio over a >USB connection in parallel with the CI-V commands. Well, that one's easy, the audio is still in digital form, it's rather like a serial dongle and a sound fob on the one USB hub. :) 73 de VK3JED / VK3IRL http://vkradio.com
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Re: Bridging the digital voice and data gap
"Tony Langdon, VK3JED" <vk3jed@...>
At 06:59 PM 8/2/2012, you wrote:
___Original Message_________________________________________But you are NOT passing analog audio down the USB cable. You're passing digital PCM to a USB sound device built into the radio. Semantics are important in this discussion, and my point still stands, there are no analog signals around a DV Dongle, just an AMBE coded bitstream and a PCM bitstream (plus commands to the dongle and status/responses back). 73 de VK3JED / VK3IRL http://vkradio.com
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Re: Bridging the digital voice and data gap
Tyrell Berry <kd7kuj@...>
Fair enough, I stand corrected. Even as I hit send, I more or less knew I was wrong and should have said simply "uncompressed audio". Still, every time you convert to a lossy format, audio data is lost, and we don't have much to work with from the get-go.
On Aug 2, 2012 3:22 PM, "Tony Langdon, VK3JED" <vk3jed@...> wrote:
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Re: Bridging the digital voice and data gap
Matthew Pitts <daywalker_blade_2004@...>
From: Tyrell Berry ; To: ; Subject: Re: [UniversalDigitalRadio] Re: Bridging the digital voice and data gap Sent: Thu, Aug 2, 2012 10:52:00 PM
On Aug 2, 2012 3:22 PM, "Tony Langdon, VK3JED" <vk3jed@...> wrote:
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Re: Bridging the digital voice and data gap
"Tony Langdon, VK3JED" <vk3jed@...>
At 08:52 AM 8/3/2012, you wrote:
Fair enough, I stand corrected. Even as I hit send, I more or less knew I was wrong and should have said simply "uncompressed audio". Still, every time you convert to a lossy format, audio data is lost, and we don't have much to work with from the get-go.True, but in my experience, there is still a big difference between transcoding to PCM and going all the way to analog and back. With the latter, you add a D/A and A/D converter, you're relying on the antialiasing/reconstruction filters to be good, and the quality of the intervening audio stages (which can be suspect in 2 way radios). You are right that there are still losses converting between the formats. Only one way to find out if it's too bad or not. ;) 73 de VK3JED / VK3IRL http://vkradio.com
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Re: Bridging the digital voice and data gap
"Tony Langdon, VK3JED" <vk3jed@...>
At 10:29 AM 8/3/2012, you wrote:
Depending on what the bit rate is for NXDN, there may only need to be a conversion to and from D-Star's bit rate; does anyone know that information off-hand? The nice thing is that we probably won't need more than one chip as long as there isn't a need to handle full-duplex digital voice.Well, what could be useful here is an interface in the UDR56K that presents the raw digital audio data, so it can be processed by an external AMBE (or whatever) decoder, making an external transcoder easier to implement. Just contributing in the brainstorming spirit. 73 de VK3JED / VK3IRL http://vkradio.com
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Re: Bridging the digital voice and data gap
Bryan Hoyer <bhhoyer@...>
The UDR56K has an expansion interface which is designed for an optional ambe vocoder (it is NOTcompression).
DVSI chips are TI DSPs that are factory programmed with their code. The interface is 2 SSPs or synchronous serial port which connect directly to the Marvell SOC. The interface and drivers wil be documented. Bryan
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Re: Bridging the digital voice and data gap
Tyrell Berry <kd7kuj@...>
Again, I'm not an audio engineer, and I have been wrong before... but isn't saying that the chip is a vocoder and it is not compression kind of like saying MP3 is a Muscoder and is also not compression? Is it somehow true that because someone chooses to use a different vocabulary that the principles of which I speak somehow cease to apply? It has been said several times before, and I will agree: it's entirely possible that transcoding through back to back vocoders may produce legible audio... Only one way to find out, and I look forward to hearing recordings of the results.
On Aug 3, 2012 6:51 AM, "Bryan Hoyer" <bhhoyer@...> wrote:
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Re: Bridging the digital voice and data gap
"John D. Hays" <john@...>
Hi Tyrell,
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Vocoders and other codecs are different beasts. Two short articles: http://en.wikipedia.org/wiki/Codec
In layman's terms, a codec converts an analog stream into a coding format. Some coding formats are lossless and produce a true representation of the orignal analog stream in a digital format, but most such as MP4 and AAC, use compression to get a lower data rate. A vocoder is considered a type of codec, in that it is converting "analog" voice to what is usually a very low data rate bitstream and back. However, it's methodology is fundamentally different than traditional audio lossy and lossless codecs. AMBE and CODEC2 both approach the problem by detecting and recognizing phonemes (the basic sounds that make up human speech) and such things as frequency slope, amplitude, and inflection in the analog stream. The vocoder then represents the phonemes and modifiers as digital codes (e.g. 0x3E might represent the 'th' sound), which are transmitted digitally, where the receiving end uses those codes to synthesize the original speech. This process is focused on human speech and has the side effect of mostly ignoring sounds that are not human speech.
The semantic is important to differentiate both the technique and result of the method of encoding and decoding speech. If you transcoded an MP3 (lossy) music stream into AMBE or Codec2 the result would likely be unrecognizable. It may be that transcoding between two similar vocoders would exhibit less deterioration of a voice signal, since they would both be looking for the same attributes in the "audio" signal. We won't really know until someone tries it in the real world.
Everything else on the "data" side of a complex DV radio protocol can probably be handled, in one form or another, though there would be mismatches. For example, going from D-STAR to DMR, "callsign addresses" and unit identifiers could be mapped to one another. On the other hand, there is no equivalent to D-STAR's ancillary data (e.g. comment text, D-PRS, etc.) in IRLP's network, though a SIP link could send it as a message in the control channel.
John D. Hays K7VE PO Box 1223, Edmonds, WA 98020-1223   
On Fri, Aug 3, 2012 at 7:00 AM, Tyrell Berry <kd7kuj@...> wrote:
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Re: Bridging the digital voice and data gap
Matthew Pitts <daywalker_blade_2004@...>
From: Tyrell Berry ; To: Subject: Re: [UniversalDigitalRadio] Re: Bridging the digital voice and data gap Sent: Fri, Aug 3, 2012 2:00:31 PM
On Aug 3, 2012 6:51 AM, "Bryan Hoyer" <bhhoyer@...> wrote:
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project
"Chris B" <brizey02@...>
This still alive?
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