77 karma · joined September 23, 2021
Throw away your CPU and RAM then.
No, this is nowhere near pseudoscience, psychoacoustics is an established field of science.
Of course there are other ITU tests that work without hidden references, looping or even A/B comparison. They require a much bigger listener pool, are more expensive and take longer, thus used less often during development.
Modern codes like opus are much more efficient. At high bitrates they are fully transparent and anybody who claims to be able to hear a difference is full of shit. Put them in a controlled setting and they fail every time.
VoIP in general experiences full packet loss, meaing if a single bit flips the entire packet is dropped. For radio links like Bluetooth it's possible to deal with some bit flips without throwing the entire packat away.
Until 1.5 Opus PLC was in my opinion it's biggest weakness, compared to other speech codecs like G.711 or G.722. A high compression ratio causes bit flips to be much more destructive.
As for making moeny, Bluetooth codecs have no license fees.
I did a quick test with the Google implementation (https://github.com/google/liblc3) which is about 2x faster than Opus. To be honest, I expected a bigger difference, though it's just a superfical test.
A few things that also might be of relevance why they picked one over the other:
- suitability for DSPs
- vendor buy-in
- robustness
- protocol/framing constraints
- controlThis is hearsay: Bluetooth SIG considered Opus but rejected it because it was computationally too expensive. This came out of the hearing aid group, where battery life and complexity are a major restriction.
So when you compare codecs in this space, the metric you want to look at is quality vs. CPU cycles. In that regard LC3 outperforms many contemporary codecs.
Regarding sound quality it's simply a matter of setting the appropriate bitrate. So if Opus is transparent at 150 kbps, and LC3 at 250 kbps thats totally acceptable if that gives you more battery life.
Lots of people treat PEP8 as the word of god, but apparently have not bothered to read it. "Many projects have their own coding style guidelines. In the event of any conflicts, such project-specific guides take precedence for that project."
How can those microphones even capture fricatives or plosives in decent quality? Most of the vocal tract lies behind the throat. I looked for some examlpes and they all sound terrible.
If you want good and cheap audio, get an off-brand USB large diaphragm condenser mic, for example this:
To counter your anecdotal evidence, let me offer mine.
My AKGs are almost 20 years old now. I only had to relpace the plug once which was a cheap repair I could do myself.
Especially the audio jack is a hard sell when their mission statement is sustainability.