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by thrdbndndn 807 days ago
New advancement of media compression seems always focusing on low bitrate, be it audio, video or image.

Which is totally fair given their applications, but I always wonder how much improvement they bring in high bitrate scenario. For example, are there codecs that have much better (perceptible) quality than Apple AAC 256kbps (or achieving similar quality at, say, 160kbps?) How much better are AV1 at 10Mbps compared to H265/264 (the improvement of H265 compared to H264 in "transparent" encoding was pretty disappointing IMHO).
2 comments
apt-get 807 days ago
> are there codecs that have much better (perceptible) quality than Apple AAC 256kbps (or achieving similar quality at, say, 160kbps?)

Opus achieves ABX transparency at around 128kbps (as in, the threshold where the vast majority of users taking a fidelity test are unable to tell the difference between the opus-encoded and lossless version).

https://abx.digitalfeed.net/opus.html

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thrdbndndn 807 days ago
Thank you! The note there:

> NOTE:Opus doesn't support 44.1kHz sample rates, so encodes to 48kHz sample rate. As this causes browser playback issues, it has been resampled back to 44.1kHz. This may affect the sound quality, so this test should be taken with caution.

Is very surprising to me, in two ways.

Firstly I knew 44100 is a relic due to historical reasons, but it's still a quite widely used sample rate in audio world. I have no idea Opus does not support it.

Secondly, it seems to imply browser can't playback 48kHz audio properly. I didn't dig the details, but this sounds weird. Just like 44100, 48k is a very common sample rate, I can't imagine browser would have trouble with it (or any arbitrary sample rate, to be honest).

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tripflag 806 days ago
Like jasomill mentions, the browser playback issues statement has not been true on desktops for a long time. The most recent (or only) example I know of is iPhones, which finally added passable support for non-44.1kHz audio somewhere between iOS 15.7 (late 2022) and last august. Until then they'd sound like a broken vinyl deck when playing 48 kHz audio, oscillating in playback rate and crackling like crazy -- especially when passing through an AudioContext.
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jasomill 806 days ago
Opus doesn't support 44.1 kHz because compatibility and effort/benefit ratio:

https://github.com/xiph/opus/issues/43

The browser audio limitation is presumably a workaround to some bug or performance limitation that was relevant at some point in history (the site was created in 2014).

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phoboslab 807 days ago
Kinda related, I was exploring how much complexity you really need with https://qoaformat.org/ - compresses at 278 kbits/s, but is much simpler than even MP2.
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