6 ms·

I really wish Opus would make it into wireless speakers and headphones. From what I've read, it might not be the most power-efficient format, however, and thos

I really wish Opus would make it into wireless speakers and headphones. From what I've read, it might not be the most power-efficient format, however, and those tiny earbuds need to be /really/ efficient. But I also suspect that popular wireless codecs (i.e. Dolbly's AptX, MPEG's AAC, and Samsung's Scalable) are powered by marketing fluff. I'd love an informed opinion :D

LeoPanthera 6y ago
ALAC (Apple Lossless) was specifically designed to be power efficient, hence its use in AirPlay. Interestingly one of the most power efficient lossy codecs is still ATRAC, Sony's MiniDisc codec, specifically designed to sip lightly at your AA batteries.
- TD-Linux 6y ago
  Doesn't seem to be the case at least in Rockbox, ATRAC is less efficient than Vorbis or MP3: https://www.rockbox.org/wiki/CodecPerformanceComparison https://www.rockbox.org/wiki/CodecPerformanceComparison
  - kevingadd 6y ago
    Maybe ATRAC was designed for the purpose of being efficient when using dedicated hardware without making the hardware expensive to manufacture? It's from the minidisc era so I'm not sure it would have been common for them to use general-purpose CPUs to decode audio by then
    - LeoPanthera 6y ago
      Indeed. Sony made ATRAC ASICs, and I doubt there's one in anything Rockbox supports.
microcolonel 6y ago
Opus decoding in earbuds is totally doable. I've been working on an Opus mode for Bluetooth A2DP, it is a bit of work getting two implementations going, but I don't think Opus on earbuds is any more unreasonable than AAC. One big benefit to Opus on Bluetooth devices is that a lot of content, particularly Spotify, YouTube, and Netflix, is already in Opus; so presumably if one application is playing then it should be possible to just proxy the frames right over the wire without reencoding; switching to decoding and mixing when system sounds play is also pretty straightforward in that case. AptX HD is probably the most reasonable Bluetooth codec deployed right now, but it is proprietary to Qualcomm. LDAC is by far the silliest codec, it is very Sony, and designed for audiophools, but at least it's free and deployed on every Android device.
- neltnerb 6y ago
  As a point of reference, I'm designing some ear buds that have pretty big batteries (~300mAh Li-Ion) and at that power budget the idle current for the battery power controller chip is sufficient to drain the battery in about a month (or several hours of active use). I don't know if that's good enough to satisfy someone who purchases them, but it is what it is... I think you're probably right about active current consumption though, especially if you're using a modern MCU.
totetsu 6y ago
When I connect my headset to my android phone I get some marketing fluff notification about the codec.. and I cant dismiss this notification! so much for it being my phone.
telesilla 6y ago
APT-x is very good, low latency codec. It's been around a long time and is not marketing fluff. Some AAC codecs are also very well made for specific purposes. Opus is too high latency for headphones.
- sp332 6y ago
  The lowest number I can find for "low-latency Apt-X" is 32 ms end-to-end over Bluetooth. Opus frames default to 20 ms wide but can be configured as small as 2.5 ms, so I don't think it's going to slow things down very much.
- LeoPanthera 6y ago
  Opus is specifically designed to be low latency. I'm not sure where you got the idea that latency would be a problem. Of all the lossy codecs, there isn't much that is faster.

LeoPanthera 6y ago

ALAC (Apple Lossless) was specifically designed to be power efficient, hence its use in AirPlay. Interestingly one of the most power efficient lossy codecs is still ATRAC, Sony's MiniDisc codec, specifically designed to sip lightly at your AA batteries.

TD-Linux 6y ago
Doesn't seem to be the case at least in Rockbox, ATRAC is less efficient than Vorbis or MP3: https://www.rockbox.org/wiki/CodecPerformanceComparison https://www.rockbox.org/wiki/CodecPerformanceComparison
- kevingadd 6y ago
  Maybe ATRAC was designed for the purpose of being efficient when using dedicated hardware without making the hardware expensive to manufacture? It's from the minidisc era so I'm not sure it would have been common for them to use general-purpose CPUs to decode audio by then
  - LeoPanthera 6y ago
    Indeed. Sony made ATRAC ASICs, and I doubt there's one in anything Rockbox supports.

microcolonel 6y ago

Opus decoding in earbuds is totally doable. I've been working on an Opus mode for Bluetooth A2DP, it is a bit of work getting two implementations going, but I don't think Opus on earbuds is any more unreasonable than AAC. One big benefit to Opus on Bluetooth devices is that a lot of content, particularly Spotify, YouTube, and Netflix, is already in Opus; so presumably if one application is playing then it should be possible to just proxy the frames right over the wire without reencoding; switching to decoding and mixing when system sounds play is also pretty straightforward in that case. AptX HD is probably the most reasonable Bluetooth codec deployed right now, but it is proprietary to Qualcomm. LDAC is by far the silliest codec, it is very Sony, and designed for audiophools, but at least it's free and deployed on every Android device.

neltnerb 6y ago
As a point of reference, I'm designing some ear buds that have pretty big batteries (~300mAh Li-Ion) and at that power budget the idle current for the battery power controller chip is sufficient to drain the battery in about a month (or several hours of active use). I don't know if that's good enough to satisfy someone who purchases them, but it is what it is... I think you're probably right about active current consumption though, especially if you're using a modern MCU.

totetsu 6y ago

When I connect my headset to my android phone I get some marketing fluff notification about the codec.. and I cant dismiss this notification! so much for it being my phone.

telesilla 6y ago

APT-x is very good, low latency codec. It's been around a long time and is not marketing fluff. Some AAC codecs are also very well made for specific purposes. Opus is too high latency for headphones.

sp332 6y ago
The lowest number I can find for "low-latency Apt-X" is 32 ms end-to-end over Bluetooth. Opus frames default to 20 ms wide but can be configured as small as 2.5 ms, so I don't think it's going to slow things down very much.
LeoPanthera 6y ago
Opus is specifically designed to be low latency. I'm not sure where you got the idea that latency would be a problem. Of all the lossy codecs, there isn't much that is faster.