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Comment Re:But why? (Score 1) 209

So the phone may have the hardware for it, but not actually be wired up. The real question is why?

Because the circuitry required to utilize the shield (ground) wire on the headset as an FM antenna increases the ground impedance and causes left-right and capture-playback crosstalk. The latter can be fixed by the phone's echo canceler, but the former cannot.

That's why FM radio is mainly confined to lower-cost phones. Premium phone buyers tend to be more particular about the headset audio quality.

Comment Re:Solutions (Score 1) 385

Or, the sound server/mixer in the phone could switch from MP3/AAC passthrough to mix-and-reecode whenever there are multiple streams, and switch back to passthrough once the music is the only remaining sound.

Sure, that's technically feasible, but since nobody cares about mp3 passthrough anymore there's no incentive to implement it.

FLAC and OPUS are royalty-free nowadays, and OPUS is even a IETF standard. Bluetooth should consider introducing them to Bluetooth...

That would make many people very happy. No idea what BT SIG is up to these days.

Trivially possible, but it would have required a MP3 *codec* core, instead of a purely MP3 decoding hardware core as done back then, which would have risen the cost of the SoC and thus of the feature phone.

You have a funny definition of "trivial".

Correct me, if I'm wrong, but 25Mpbs figure is basically using AMP - Alternative MAC/PHY. Or in other words, using Bluetooth over a 802.11 transport (i.e.: over a Wifi transport).

Nope, you're not wrong. That's what I get for skimming the results for latest BT specs. Regular Bluetooth EDR is more like 3Mbps -- the data rate is one order of magnitude greater than hi-fi audio, not two. I stand by my assertion that faster radios aren't needed for high-quality audio.

Comment Re:Here's the problem with stereo Bluetooth: (Score 1) 385

Tons of headsets support mp3 over A2DP, but few sources do. It was intended to enable low-power operation by streaming the mp3 content directly from source to sink without transcoding. This seems perfectly sensible to somebody making a media player, but for smartphones it means you have to come up with something else to do with your UI tones and notifications and whatnot (because you can't mix them into the mp3 stream without decoding and re-encoding, defeating the purpose of mp3 passthrough).

For the same reason, ATRAC is also a defined A2DP codec: so your MiniDisc player could stream directly to an A2DP sink. I'm not sure if this was ever implemented by anyone.

I'm pretty sure all these codecs (except AptX) were part of the A2DP spec from the beginning. SBC was the first implemented because it's computationally trivial and royalty-free. I'm not sure it would have been practical to encode mp3 in real-time on a featurephone in 2004.

Anyway, the limiting factor of BT audio quality is the codec, not the radio. AptX is ~384Kbps for 16-bit stereo, and BT4.0 has a raw capacity on the order of 25Mpbs. Further increasing the interface speed isn't going to change the audio quality

Comment "Free" FM comes with a cost (Score 0, Offtopic) 34

The FM Receiver isn't enabled in most phones because the electronics required to use the headset shield as an FM antenna increase crosstalk on the 3.5mm jack. Phones without FM chose to emphasize 3.5mm audio quality over FM radio function.

This is trivially easy to confirm - just check the headset crosstalk numbers on any Android review site. You'll find a bi-modal distribution that correlates to presence of an FM receiver.

Comment Re:We've already got that. . . (Score 2) 460

It's got to be the stupidest time to set up a gas delivery business. Just as gas powered cars are going to be obsoleted. OK, they're not obsolete yet - but it's hardly a new business model that has a future.

Actually, this business model makes a lot more sense in an environment without a gas station on every corner -- people are much likely to pay a delivery fee for something they can't pick up conveniently themselves. If anything, I'd say they're jumping the gun on gasoline being a niche product.

Comment Re:$2,500 (Score 1) 242

(posting to undo moderation)

Got a citation for that? The only mention of a fee I could find was from a Car and Driver blog post


Tesla charges a one-time fee of $2500 to activate the Autopilot capability, but the Side Collision Warning is free.

I would have thought there'd be some communication from Tesla if they were selling an OTA update?

Comment Re:Razr v3 (Score 1) 313

Come now. MiniUSB isn't that unusual.

hacked tools are no longer readily available.(Motorola PST, Qualcom's tool, etc...)

You only need PST if you want to update the software, and there hasn't been an update for V3xx in quite some time. And Qualcomm never had tools for the V3xx, since there's no Qualcomm hardware in it. The V3xx was one of the last Moto phones with a Moto (Freescale) chipset. The only Qualcomm RAZRs were the CDMA ones.

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