What's Opus like for day-to-day use? Do you notice any battery hit on Android from it being decoded in software? (assuming AAC is done in hardware - could be wrong)
What kind of quality/filesize do you use? If I'm used to ~170kbit VBR AAC/MP3 for headphone use, what settings would I need for Opus?
No significant battery hit, I really don't care. There is an ARM-optimized version of libopus that seems to use vector operations, I don't think it gets much better than that.
I'm using 72-96 kbit/s as bitrates, I've been playing around with that actually. 72 kbit is too little sometimes, 80 is fine, 96 is safe. Encoding is done in foobar2000, copy everything into a playlist, right click -> encode. My archive structure is this: At the top, there is one folder "Lossless", one folder "Lossy", each with subfolders for artist and album. foobar2000 and any other players syndicate their library from both folders.
I have separate versions of my music archive on my laptop and on my phone, each of which are complete. For the laptop, Lossless gets converted to Opus, Lossy remains the same, folders get merged. On the phone and tablet with tighter space constraints, I just re-encode everything to opus and merge. I won't notice the artefacts of re-encoding MP3 to Opus when there's a train humming in the background and people talking.
My best headphones for use with my phone are the 50€ Shure earphones. I also have some large open headphones from Thomann. Both are kinda good, but not studio quality good, so some details will escape me. I could maybe find some differences between Flac and Opus in some recordings if I tried very hard, but frankly I hate paying attention to audio quality. It's a very draining task that I restrict to comparing amplifiers/DACs and speaker setups, and I'll always use Flac for that anyways.
What kind of quality/filesize do you use? If I'm used to ~170kbit VBR AAC/MP3 for headphone use, what settings would I need for Opus?