Why is opus only good at 64/kbs Options

[Warning]

So I was very skeptical about opus when it sounded like a new OGG Vorbis hype where the codec is both free and crappy quality. I didn't think without SBR it would be able to compete with Nero HE-AAC. So I compared at different bitrates and opus always sounded worse. I decided to ABX at different bitrates, opus failed on 32 and 48 but not 64 where the treble was audibly brighter than Nero.

Ok you got me convinced that opus sounds better at 64 kb/s, why does it suck so bad at other bitrates? Also, why didn't you guys include WMA in your listening test along with opus? WMA has proven to be slightly superior quality to HE-AAC at 64 kb/s so maybe opus still has a competitor.

Also, fix your biased testing methodology and keep the bitrates as close as possible to the original! Jesus. My hypothetical codec produces output bitrates of 192 kb/s when my quality setting intends it to be half as less, I demand it to be nominated as capable of transparency at 16 kb/s.
Your unscientific results makes me keep clear of your website these days.

[Warning]

@seren
I don't use 32 kb/s for music, but I'm hoping it will happen someday. The original format of the song I uploaded is .MOD and it's only 15KB which gives it a bitrate of 1.2 kb/s and even lower when compressed.

@saratoga
I've explained myself numerous times, I won't do it a third. Also, choosing MP3 for quality isn't a wise choice given its inefficient block sizes and other numerous design flaws make it incapable of transparency at any bitrate.

@db1989
You're just being ignored, for now anyway. I intended to respond but posts concerning the original topic came back up so I went with the flow.

@greynol
I never said anything about archival quality.

@C.R.Helmrich
I increased Opus' delay to the maximum 60ms to produce that sample. Is this close to AAC's? I'm aware it was intended for VoiP but your latest listening test got my attention when I heard AAC has finally been made obsolete, so I was puzzled why this was only true for one bitrate? No I haven't ABX'd higher bitrates but since I do not intend to switch to Opus even if it is only slightly higher quality, I'm not wasting the time. USAC is due which will crush both AAC and Opus.

[C.R.Helmrich]

Good morning,

I increased Opus' delay to the maximum 60ms to produce that sample. Is this close to AAC's?

This I doubt. AAC-He is not really intended to be transparent.

OK, some clarification is necessary here.

HE-AAC has a frame length of 2048 samples in the normal dual-rate mode, and with its 50% window overlap, one frame spans 4096 input samples = 93 ms @ 44.1 kHz. Opus has very little frame overlap, which makes efficiency go down on tonal signals. So even 60-ms windows in Opus wouldn't be enough to get to the efficiency Level of HE-AAC. And IIRC Opus doesn't have 60-ms windows. I think the developers once mentioned here that the CELT block size can never be more than 20 ms, so a 60-ms frame just contains 3 blocks. Yes, if the block size were 40 ms, it would probably sound better.

HE-AAC is in fact intended to be transparent. In downsampled SBR mode, you can move your SBR start frequency up to 16 kHz or more, i.e. into (nearly) inaudible regions. But nobody uses it that way because then it gives no advantage over AAC-LC.

AAC will have better technical quality, retaining more inaudible, high-frequency parts

Hey Chris,

Are you OK with this? I'm not!

If you define technical quality as e.g. "maintaining efficiency on different input signal characteristics", I'm perfectly OK with this. The rest is mostly a sign of encoder tuning and has nothing to do with the particular formats.

Some last words to Warning: please stop the cursing! What's the point of calling people trolls etc.

And please upload a FLAC of 30 seconds of that MIDI-like item. And upload it in the Upload forum.

Chris

This post has been edited by C.R.Helmrich: Jan 27 2013, 13:10