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Announcing Bluetooth LE Audio

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Re: Announcing Bluetooth LE Audio

#71

Post by throw0101a »

nwah1 wrote: post #64
0-_-0 wrote: post #18

Earlier quoted context omitted.

Opus is not low complexity

Found this: LC3 at 32 kbps (LC3 32) provides significantly better audio quality than Opus-CELT at 32 kbps and complexity level 0 (OPUS_v114_c0 and COPUS_v114_c0). https://www.etsi.org/deliver/etsi_tr/103500_103599/103590/01...

I'm of the opinion that Codec 2 [0][1] should pause on trying to perform better at lower and lower bit rates, and put some work into higher ones.

Getting down to 700 and even 450 b/s is neat and all, but there seems (to me) to be a gap between 4000 and 10000 b/s in the patent-free space.

* [0] http://www.rowetel.com/?page_id=452

* [1] https://en.wikipedia.org/wiki/Codec_2

Re: Announcing Bluetooth LE Audio

#72

Post by lightedman »

TylerE wrote: post #38
lightedman wrote: post #4

This literally addresses none of my complaints regarding Bluetooth Audio. Latency needs to be on the order of single-digit milliseconds. LC3 can achieve around 20. One order of magnitude too high. Audio needs to not sound like it's being played underwater. And give me 100 feet of range.

20ms for playback of media is totally fine. (Hint: If you're standing on the opposite side of the room from a TV, you're already at about 15ms of latency...sound moves at approx. 1ft per ms) Many TVs are already delaying the audio by a frame or two anyway due to all the processing they do. It's a very very different set of requirements than real time recording/instrument playback.

"20ms for playback of media is totally fine."

Not when you're wearing headphones and playing along with the music with your guitar. 20ms is more than enough to throw off even the most professional musician's timing. It's enough to throw off opera orchestral performance (and I've had it happen performing at Forrest Lawn Glen Avon near Walt Disney's tomb.)

This is why I'm still using wired headphones. Latency is unacceptable in my hobbies.

Re: Announcing Bluetooth LE Audio

#73

Post by lightedman »

unlinked_dll wrote: post #37
klodolph wrote: post #17

Earlier quoted context omitted.

If you are a musician, try introducing a 10ms or 20ms delay and then play something on piano or guitar. Whether you notice it depends on a ton of factors which I’m not going to get into, but in general, at 10ms the music will feel sluggish and you will have difficulty playing on the beat. This can be verified with ABX tests if you like. The timing accuracy for professional musicians can approach 1ms under controlled…

You're not wrong, but I suggest you go out and measure the latency of pro audio wireless systems that have proprietary and specialized low-latency audio codecs. They push 10-15ms, depending on the source content. Often they trade fidelity for latency. They're also rather pricey, because it's a specialized use case. One of the tradeoffs in latency for fidelity is that the two major components of lossy codecs (the filt…

"You're not wrong, but I suggest you go out and measure the latency of pro audio wireless systems that have proprietary and specialized low-latency audio codecs."

I have a Shure wireless guitar/microphone transmitter - latency purely determined by device distance as it's totally analog and doesn't need/use a codec. That's pro-level audio equipment from the early 90s ($250 back then.) Literal atmosphere-limited light speed.

Today's stuff is literal garbage. Even the latest Shure wireless stuff can't keep up with the higher frequencies on my guitar and attenuates/dampens them.

Re: Announcing Bluetooth LE Audio

#74

Post by unsignedchar »

city41 wrote: post #63
Lammy wrote: post #51

Earlier quoted context omitted.

A bicycle is a road vehicle. You shouldn’t be riding on the sidewalk.

There are valid shared bike/pedestrian spaces, like bike trails. Zoned out pedestrians on phones/headphones are extremely common there.

Yes, they can be extra dangerous if they have, say, a curious dog on a long leash on the other side of said trail while they’re busy counting Facebook likes

Re: Announcing Bluetooth LE Audio

#75

Post by TylerE »

lightedman wrote: post #72
TylerE wrote: post #38

Earlier quoted context omitted.

20ms for playback of media is totally fine. (Hint: If you're standing on the opposite side of the room from a TV, you're already at about 15ms of latency...sound moves at approx. 1ft per ms) Many TVs are already delaying the audio by a frame or two anyway due to all the processing they do. It's a very very different set of requirements than real time recording/instrument playback.

"20ms for playback of media is totally fine." Not when you're wearing headphones and playing along with the music with your guitar. 20ms is more than enough to throw off even the most professional musician's timing. It's enough to throw off opera orchestral performance (and I've had it happen performing at Forrest Lawn Glen Avon near Walt Disney's tomb.) This is why I'm still using wired headphones. Latency is unacce…

Again, performing is not playback.

Re: Announcing Bluetooth LE Audio

#76

Post by lightedman »

TylerE wrote: post #75
lightedman wrote: post #72

Earlier quoted context omitted.

"20ms for playback of media is totally fine." Not when you're wearing headphones and playing along with the music with your guitar. 20ms is more than enough to throw off even the most professional musician's timing. It's enough to throw off opera orchestral performance (and I've had it happen performing at Forrest Lawn Glen Avon near Walt Disney's tomb.) This is why I'm still using wired headphones. Latency is unacce…

Again, performing is not playback.

You're making assumptions without all of the information.

WHEN YOU ARE PLAYING ALONG you need to have the timing right. That means if I set the orchestra off, hit play on my metronome, and my beat is half a measure off, we just screwed up, especially when we're doing things like musically-timed parts of the on-stage performance. Or when I hit play on our Silent Movie with original orchestral score made by local musicians nights. Timing goes off, everything feels wrong.

You'd need to be an actual performer to understand this, I suspect.

Re: Announcing Bluetooth LE Audio

#77

Post by lightedman »

ShakataGaNai wrote: post #26
lightedman wrote: post #14

Earlier quoted context omitted.

I play guitar. Timing is absolutely necessary. Anything past 15ms I can perceive and it is highly distracting and off-putting to my internal metronome.

Sure. Playing music makes sense. I was just curious why people cared about 10-20ms of latency on what I see as "movie on iPad on Plane". Clearly there are many other use cases.

"I was just curious why people cared about 10-20ms of latency on what I see as "movie on iPad on Plane""

At that latency I can see lips move before I hear audio. Very disconcerting.

Re: Announcing Bluetooth LE Audio

#79

Post by audunw »

lightedman wrote: post #4

This literally addresses none of my complaints regarding Bluetooth Audio. Latency needs to be on the order of single-digit milliseconds. LC3 can achieve around 20. One order of magnitude too high. Audio needs to not sound like it's being played underwater. And give me 100 feet of range.

Sounds like you want a magic solution. At least if you don’t want to compromise on anything else such as distortion due to packet loss and power consumption. Bluetooth Audio is not designed for your use case. You’ll just have to deal with that.

Re: Announcing Bluetooth LE Audio

#80

Post by nmstoker »

ShakataGaNai wrote: post #8

The "Broadcast" mode is really an interesting concept - depending on the available range. There are a lot of potential uses for this technology beyond the basic. Of course "I can share my headphones with you" is great, in the day in age of watching moves on iPads in say a plane. However I think in a business setting the broadcasts could be used for all sorts of cool bits. Remember the TV's in airports running news on…

The mass transit point would get my vote, specifically so you can ignore them more effectively than is currently possible (even with noise cancelling headphones).

On various modes of UK public transport, I regularly have to listen to people who shouldn't ever be given access to a PA system struggling to complete their obligatory yet pointless announcements.

There was a period a couple of years back when Waterloo station was going to have work done over the summer and there were times in the winter and spring months leading up to it when they would announce this at EVERY single station stop, day in day out on the way in and the way home. LE Audio would have been heaven for a scenario like that!

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