I was using opus@96kbps for music storage, with opus version 1.1.
Now I updated to 1.2, it's said to be much improved ( https://people.xiph.org/~jm/opus/opus-1.2/ ). I was testing a bit and even 32kbps music sounds decent, and has stereo (in 1.1 was mono with similar quality). 48kbps sounds good, some songs are transparent, while at other I can notice small differences in some sounds. At 64kbps, only 15-25% songs seem to have very small artifacts at specific instruments. 64kbps is almost transparent. I am testing on headphones.
So what bitrate should I now use for storage of music? 64kbps? 75-80kbps? or 96kbps like before (with opus 1.1)?
I am listening to music mostly on speakers. So what's the point of 96kbps? Size matters for me. 96kbps is 50% bigger than 64kbps.
Here is some info how it sounds at different bitrates, but it could be outdated:
http://wiki.hydrogenaud.io/index.php?title=Opus
https://wiki.xiph.org/Opus_Recommended_Settings
tl;dr
was using opus1.1@96kbps for music storage. now updated to opus1.2, what bitrate should I use?
What I need is NOT "transparent quality at 100% songs"
What I need is "(near)transparent or high quality at 90% songs, on medium class speakers and headphones"
At higher bitrates, you need to add a lot of filesize to get small effects. So what's optimal quality/size
I think what you need to do is test for yourself. What is transparent and (near)transparent is something you can only decide with proper ABX testing.
I think what you need to do is test for yourself. What is transparent and (near)transparent is something you can only decide with proper ABX testing.
I am not sure if ABX tests are good for my question, as I don't mind if song sounds a little different on few samples, as long as it's not annoying or crappy. I did some not blind tests in the past with opus 1.1, and decided that opus@96 is transparent for 90% or more songs. But since opus 1.2 came out and claims much improvement, was looking for advice how much bitrate can I lower to get same quality as opus 1.1?
Is a storage limitation the reason for this?
Is a storage limitation the reason for this?
Yes and no.
I like efficiency, I want to use lowest bitrate and size that sounds good.
Also I have a lot of music, and want to keep it on mobile device at same quality like on PC, so it works as a backup too.
Another reason is one platter 2.5" mechanical HDDs are limited to 1TB of size at the moment. And I need to store much more things than just music, like videos.
Opus 1.2 has improvements at low bitrates mostly.
Just some rough idea
1.2 32 kbps ~ 1.1 40-45 kbps
1.2 48 kbps ~1.1 56 kbps.
For 64 kbps and higher it's likely just a matter of a few kbps.
Some have said that 80kbps is a good rate to go for and I have to agree with that. Its roughly equivalent to 128kbps mp3, while 96kbps Opus is roughly on par with 160kbps mp3.
At the moment 64 kbps is a bit too low since certain killer samples (guitars, harmonicas etc) will still mess with things. I hope a future update will focus mainly on 64kbps improvements since being able to market this as an mp3 successor with only half the bitrate would be really great. Pretty sure Spotify would change to 64kbps Opus and ditch 96 kbps Vorbis streams if the quality were polished up a bit. A lot of mobile network providers also throttle down to 64kbps once a users quota has been reached so its still the golden value I would aim for for further improvements.
But if I were squeezing every bit out of my Music collection due to storage constraints right now, 80kbps with Opus 1.2 would be it.