Maximum bitrate of AudioStream

[Julius]

I‘m curious about the maximum bitrate AudioStream supports.
Currently my self-hosted music stack is configured to use 320kbps for new music discovery streaming and up to 1,400kbps FLAC files for titles which I actually added to my library.
Does AudioStream support these bitrates or am I only wasting space? 
Is it possible that high bitrates increase the audio dropouts (especially outside) because of higher data traffic?

Comparison:
- 128kbps: YouTube standard
- 320kbps: Spotify maximum
- 800kbps: Apple Music maximum
- 1,400kbps: CD quality, FLAC

[John Schulz]

I do not know exactly what the AudioStream uses but I believe it's G722 (since that's what ASHA uses) which has a max bitrate of 64 kbit/s. If I had to guess, it's likely not even using the highest bitrate.

[John F]

Now I wonder because I could’ve sworn I saw something about it streaming 128… hmm

 

Cannot find it in the Manual but need more coffee.

[John Schulz]

@MED-EL ModeratorCan you answer what the codec and bitrate of the AudioLink is?

 

@Julius Also, I mixed up the AudioLink and AudioStream when I typed my last reply. I don't get why Med-El didn't name them StreamRemote and StreamSleeve since these both satisfy the German/Austrian tradition of smashing words together but in a way that makes sense. I digress. The AudioStream uses G722 and the standard sample rate is 16kHz with each sample being eight bits so that would be 128kbps. I guess G722 is intended to not go above 64kbps since it's a phone optimized compression codec but there's nothing preventing it from being higher. @John F you were right!

 

https://source.android.com/docs/core/connect/bluetooth/asha#audio-packet-format-and-timing

[Julius]

So you mean AudioStream has twice the bitrate of AudioLink? Now that explains why I found the quality of AudioLink unbearable when trying it out for music streaming. 128kbps is still pretty low for todays industry standards though 😕

I‘m curious why they decided to settle at this bitrate and with this codec. Hoping for lossless support for the next generation / update!

[John Schulz]

1 hour ago, Julius said:

So you mean AudioStream has twice the bitrate of AudioLink? Now that explains why I found the quality of AudioLink unbearable when trying it out for music streaming. 128kbps is still pretty low for todays industry standards though 😕

I‘m curious why they decided to settle at this bitrate and with this codec. Hoping for lossless support for the next generation / update!

I don't know what the AudioLink streaming specs are. I think it should be roughly the same. My guess as to why it sounds bad is improper grounding within the processor that introduces a ton of static. The reason why the bitrate and codec was chosen was because it was intended for calls only but decided that it wouldn't make sense to block other streaming. Frankly, Google should roll out a revision to ASHA that uses LC3 since it would blow G722 a kilometer (0.6 mile) out of the water from what I can tell 😆. Bluetooth streaming will not be lossless in Cochlear Implants for a longgggg time (10+ years?). If you want lossless then use the 3 prong sleeve and AUX cable.

[John F]

BTLE which is what the AudioStream supports  has a limit itself on what is can support, add in that the sleeve hasn’t been updated (outside firmware) so it’s a bit outdated by like, 3 or 4 years.  Newer BT standards can support a higher rate.  I also highly doubt they designed the AudioStream solely for Phone calls knowing MedEl with Music an afterthought.  Most likely whatever the industry standards were when they released the AudioStream they went the Apple route and released them with a slightly older version of BTLE.  (Apple only recently began using current BT chips in new models and was well known for being behind in lots of hardware areas.)

 

AudioLink… I keep wanting to say it’s BT 4.2 but I don’t use it so not interested in much info.  Only know it was rushed and even employees are not keen on it as a whole.  

[John Schulz]

21 minutes ago, John F said:

BTLE which is what the AudioStream supports  has a limit itself on what is can support, add in that the sleeve hasn’t been updated (outside firmware) so it’s a bit outdated by like, 3 or 4 years.  Newer BT standards can support a higher rate.  I also highly doubt they designed the AudioStream solely for Phone calls knowing MedEl with Music an afterthought.  Most likely whatever the industry standards were when they released the AudioStream they went the Apple route and released them with a slightly older version of BTLE.  (Apple only recently began using current BT chips in new models and was well known for being behind in lots of hardware areas.)

 

AudioLink… I keep wanting to say it’s BT 4.2 but I don’t use it so not interested in much info.  Only know it was rushed and even employees are not keen on it as a whole.  

I meant ASHA as a whole was intended to be phone only then music became an after thought. As for the AudioLink, the MCU they used is the Silicon Labs WT32i-A-AI61 which is Bluetooth 3.0 (yikes!). The worst part is that they could've done general Bluetooth to Bluetooth streaming, not just phone calls only.

[John F]

7 hours ago, John Schulz said:

I meant ASHA as a whole was intended to be phone only then music became an after thought. As for the AudioLink, the MCU they used is the Silicon Labs WT32i-A-AI61 which is Bluetooth 3.0 (yikes!). The worst part is that they could've done general Bluetooth to Bluetooth streaming, not just phone calls only.

Ah yeah.  Apple doesn’t use ASHA so not something I think about much.

 

Knew the BT in the AudioLink was old but I’ve not the foggiest when it was even released.  BT 3.0 is way past its prime. Lol