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Opus. Opus is a remarkable codec because it’s excellent at almost everything. The only areas where it’s being beaten are extreme narrowband, which it can’t do,

Opus. Opus is a remarkable codec because it’s excellent at almost everything. The only areas where it’s being beaten are extreme narrowband, which it can’t do, and narrowband, where it’s still not shabby (though some of this new stuff is redefining what’s possible). Opus tackled a broad field of competitors that were each somewhat specialised for their part of the field, and pretty much beat all of them at their own game. And in most cases the incumbents were high-latency, while Opus not only achieves quality superiority but also supports low-latency operation. https://en.wikipedia.org/wiki/Opus_(audio_format) https://en.wikipedia.org/wiki/Opus_(audio_format) has some good diagrams and explanation. https://upload.wikimedia.org/wikipedia/commons/8/8d/Opus_quality_comparison_colorblind_compatible.svg https://upload.wikimedia.org/wikipedia/commons/8/8d/Opus_qua... especially shows Opus’ superiority except in narrowband. Past about 16kb/s, Opus is pretty much just the format to use, except for extreme niches like if you want to represent over 20kHz (above which Opus cuts). Opus is so good there’s pretty much nothing left to improve for now (for now), and even if you improved things it probably wouldn’t be worth it. That’s why all the development is happening in narrowband, because that’s the only interesting space left. Perhaps eventually some of those techniques will be scaled up past narrowband. I don’t know.

makomk 5y ago
Yeah. In reality the main reason new audio codecs are developed post-Opus isn't technical, it's so that companies can get their patents into new standards and rake in the licensing royalties. There are better codecs for really low bitrates but that's quite niche these days; even telephony is going wideband and higher bitrate.
- sneak 5y ago
  I think you perhaps overestimate the bandwidth available to most telephone handsets in most of the world. I'm in a hotel in a schengen country right now and I am lucky to get 200kbps via the wifi. Other, less industrialized countries are frequently worse. It's safe to say a ~billion people's lives can be improved with better low bitrate codecs.
  - tialaramex 5y ago
    Let's assume for a moment that you're not stupid enough to confuse 200kBps (1.6Mbps) for 200kbps. Opus is fine down to 8kbps. It fits over a cheap, shitty mid-20th century analogue telephone line with room to spare. The ultra-narrow band stuff is very niche, and is consequently unlikely to have the broad impact you're imagining. In contrast there is continue enthusiasm for these pointless midband codecs that are similar in performance to Opus but have the "advantage" that somebody gets $$$.
    - zinekeller 5y ago
      "Pointless" is relative here. 8kbps is enough - when you don't spare anything anything to bit correction. Maybe in those cases, somewhat okay analogue audio is enough (for example, in long-distance raditelephony). But having a very impressive digital codec raises the bar significantly, especially the last time someone bothered with this is someone in Nokia trying to fit 6kbps using what was now rudimentary phone chips. Additionally, there are people in the world (including US) who are stuck using unreliable 28kbps lines. Having an option to do excellent audio and video is something that no-one seemed bothered to do.
    - sneak 5y ago
      That's 200kbps for a building with a few dozen people in it.
- vbezhenar 5y ago
  Why Whatsapp calls are so terrible even on 100 Mbps links?
diimdeep 5y ago
I just compared 730 kb/s Flac with 160kb/s Opus, I can see no difference even on spectrogram using 'mother of mp3' track: Tom's Diner (Live At The Royal Albert Hall, London, UK, November 18, 1986). Very surprising, will be migrating all my music to opus to save space.
- rokweom 5y ago
  Just as a side note, spectrogram are not in any way indicative of compression quality. Its interesting that you didn't see any differences between flac and opus, as opus has a hard 20 kHz low-pass filter and is 48kHz-only.
  - diimdeep 5y ago
    There is visible 20 kHz LPF, but it is meaningless for use case of music listening, right ? I did not liked degradation at 140-128kb/s and noise above 16kHz and some artifacts 10-16khz that is clearly visible and much more impactful. Here is spectrograms https://disk.yandex.com/d/PvQGSS2xBu7ucQ https://disk.yandex.com/d/PvQGSS2xBu7ucQ
    - rokweom 5y ago
      As I said, spectrograms are not indicative of compression quality. Codecs should be judged by ears only. What you see in a spectrogram will vastly differ between codecs and will not reflect their compression efficiency.
- jacquesm 5y ago
  Beware of phase differences, they won't show up on a spectrogram but could seriously upset your stereo impression. Before you compress all your Flac content and only figure this one out afterwards. That could be quite annoying.
  - Groxx 5y ago
    Yeah - definitely keep your backups in FLAC. Having a lossless source gives you infinite future flexibility, and that cannot be underestimated. Otherwise you're kinda doomed to hit https://www.youtube.com/watch?v=fZCRYo-0K0c https://www.youtube.com/watch?v=fZCRYo-0K0c eventually. For on-listening-device though, oh heck yes - Opus is great.

makomk 5y ago

Yeah. In reality the main reason new audio codecs are developed post-Opus isn't technical, it's so that companies can get their patents into new standards and rake in the licensing royalties. There are better codecs for really low bitrates but that's quite niche these days; even telephony is going wideband and higher bitrate.

sneak 5y ago
I think you perhaps overestimate the bandwidth available to most telephone handsets in most of the world. I'm in a hotel in a schengen country right now and I am lucky to get 200kbps via the wifi. Other, less industrialized countries are frequently worse. It's safe to say a ~billion people's lives can be improved with better low bitrate codecs.
- tialaramex 5y ago
  Let's assume for a moment that you're not stupid enough to confuse 200kBps (1.6Mbps) for 200kbps. Opus is fine down to 8kbps. It fits over a cheap, shitty mid-20th century analogue telephone line with room to spare. The ultra-narrow band stuff is very niche, and is consequently unlikely to have the broad impact you're imagining. In contrast there is continue enthusiasm for these pointless midband codecs that are similar in performance to Opus but have the "advantage" that somebody gets $$$.
  - zinekeller 5y ago
    "Pointless" is relative here. 8kbps is enough - when you don't spare anything anything to bit correction. Maybe in those cases, somewhat okay analogue audio is enough (for example, in long-distance raditelephony). But having a very impressive digital codec raises the bar significantly, especially the last time someone bothered with this is someone in Nokia trying to fit 6kbps using what was now rudimentary phone chips. Additionally, there are people in the world (including US) who are stuck using unreliable 28kbps lines. Having an option to do excellent audio and video is something that no-one seemed bothered to do.
  - sneak 5y ago
    That's 200kbps for a building with a few dozen people in it.
vbezhenar 5y ago
Why Whatsapp calls are so terrible even on 100 Mbps links?

diimdeep 5y ago

I just compared 730 kb/s Flac with 160kb/s Opus, I can see no difference even on spectrogram using 'mother of mp3' track: Tom's Diner (Live At The Royal Albert Hall, London, UK, November 18, 1986). Very surprising, will be migrating all my music to opus to save space.

rokweom 5y ago
Just as a side note, spectrogram are not in any way indicative of compression quality. Its interesting that you didn't see any differences between flac and opus, as opus has a hard 20 kHz low-pass filter and is 48kHz-only.
- diimdeep 5y ago
  There is visible 20 kHz LPF, but it is meaningless for use case of music listening, right ? I did not liked degradation at 140-128kb/s and noise above 16kHz and some artifacts 10-16khz that is clearly visible and much more impactful. Here is spectrograms https://disk.yandex.com/d/PvQGSS2xBu7ucQ https://disk.yandex.com/d/PvQGSS2xBu7ucQ
  - rokweom 5y ago
    As I said, spectrograms are not indicative of compression quality. Codecs should be judged by ears only. What you see in a spectrogram will vastly differ between codecs and will not reflect their compression efficiency.
jacquesm 5y ago
Beware of phase differences, they won't show up on a spectrogram but could seriously upset your stereo impression. Before you compress all your Flac content and only figure this one out afterwards. That could be quite annoying.
- Groxx 5y ago
  Yeah - definitely keep your backups in FLAC. Having a lossless source gives you infinite future flexibility, and that cannot be underestimated. Otherwise you're kinda doomed to hit https://www.youtube.com/watch?v=fZCRYo-0K0c https://www.youtube.com/watch?v=fZCRYo-0K0c eventually. For on-listening-device though, oh heck yes - Opus is great.