Bluetooth accessories

[jaguarx]

Just to muddy the water further...
Take a look @ this

"A Hardware Accelerated MP3 Decoder
with Bluetooth Streaming Capabilities"

Iit goes though the MP3 spec, the decoding process and the Bluetooth spec in detail.

 

[nixd2001]

Re: Uh... Bluethooth?

Originally posted by Glossybear
But back on topic...

What other cool BT gadgets are out there?

Sony Ericsson P800 - currently not supported by iSync 😡

Sony Ericsson HBH-30 BT headset.

DLink DWB-120M USB/BT adaptor

If the P800 and iSync worked together, the P800 would be so amazingly cool we'd have a new ice age. But it doesn't work at present, so global warming will continue...

 

[wdodd]

Originally posted by LosJackal
So I'll believe what you are saying if you can tell me this: after letting the computer decode whatever format it plays, say a 128kbps MP3, how big is the music that you are saying is too big for bandwidth limitations?

Well, if you were sending it to the PCM decoder in your receiver so that it appeared to be a normal CD player for compatability, you're basically decoding back to uncompressed CD audio. Uncompressed CD audio data requires a transfer rate of 1,411.2 kpbs (16bits/sample x 2 channels x 44,100 samples/sec).

If you wanted to decode to analog and send that to a device that hooked up to the analog inputs on a receiver, then you could create your own method. Wireless speakers that I've seen use about 2 MHz of spectrum in the 900MHz range. I don't have any details on how they encode the signal though.

 

[filipp]

Originally posted by LosJackal
You have a good point with regards to being open for several formats.

So I'll believe what you are saying if you can tell me this: after letting the computer decode whatever format it plays, say a 128kbps MP3, how big is the music that you are saying is too big for bandwidth limitations?

I believe you will have to send it in raw format, which is 700kbit per second per channel. That would be 1,4mbit/s for stereo stream not encoded.


But check this out, if you after decoding on the computer always encode in same format, say ac3 or mp3, then you only need one decoder in the stereo.

What do you think about that?

Sorry wdodd, I missed your post when I replied. You described it much better than me. I dont really know how this PCM-encoding workds, but that's what I was referring to by raw.

edit: typo

 

[LosJackal]

Originally posted by filipp

Sorry wdodd, I missed your post when I replied. You described it much better than me. I dont really know how this PCM-encoding workds, but that's what I was referring to by raw.

Good. Well, I think we're done with the discussion then. I don't know what PCM is either, but it sounds like a digital audio format that requires 1.4 Mbps, which is indeed too large for Bluetooth.

So given that you'd need some kind of Bluetooth receiver plugging into your stereo, it would behoove the device maker to not use PCM audio.

Anything else beyond this is speculation....so thanks for the education! Let's let the thread get back on topic.

 

[NavyIntel007]

Ok, here's a big question. Assuming I have bluetooth and VPC. I need to dial into a PBX telephone system through a serial port where i've attached a bluetooth to serial adapter. The PBX software is x86. Would VPC pick up the bluetooth in windows as a com port?

 

[alset]

Originally posted by LosJackal
Where do you get that x10 multiplier? Just a guess regarding the compression?

MP3 128 bit is compressed 12:1. Uncompressed PCM audio runs approximately 10 MBs/minute.

Dan