Nice, I'm looking forward to seeing how this performs in practice. FFmpeg's previous AAC encoder produced poor quality output and often had irritating chirping artifacts, so I've always had to install Apple's Core Audio encoder on any computer I do video recording on to get decent sound. I've done A/B/X comparisons and found that a 320kbps MP3 sounds better than a 320kbps AAC encoded by FFmpeg, but about the same as a 256kbps AAC encoded by Core Audio. If installing Core Audio is no longer necessary, that'll be a huge improvement and people who use something like OBS to do screen recordings or streaming will get a massive sound quality boost the next time they update.
[−]repelsteeltje · 2026-07-01 Wed 17:49 UTC ·
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Why not use a lossless codec if you care about quality? Or use Opus, descent for specht and works pretty much anywhere these days.
You can care about quality to the extent that a lossy codec allows. Lossless is not always necessary or wanted. This is like saying “why care about transcoding quality when you can keep the video as is?”. There’s a myriad of use cases and preferences at play here.
[−]cosmic_cheese · 2026-07-01 Wed 18:17 UTC ·
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There are a ton of older, but still perfectly usable devices that support AAC well but not Opus.
In the Hydrogenaudio discussion thread's metrics table, the new encoder scores better than Core Audio. But this is at constant bitrate (CBR) [edit: maybe not? see lesscraft's reply below]. Core Audio also has variable bitrate modes (TVBR) which the new encoder lacks.
So maybe Core Audio will continue to be the best when TVBR is available, but I'm hopeful the new FFmpeg encoder will be "good enough", especially if more folks find and contribute problem samples to help tune it.
A useful project related to Apple's Core Audio is qaac - it wraps iTunes Windows DLL's in a standalone encoding tool with a CLI interface. I believe it even works under Wine on Linux: https://web.archive.org/web/20250814194428/https://www.andre... So you don't need a Mac or even a full iTunes installation to get high quality AAC encoding.
[−]winstonwinston · 2026-07-01 Wed 19:35 UTC ·
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I was using FDK AAC encoder, I didn’t know Apple encoder was available for systems other than Apple. Though I have once compared AAC FDK to Apple AAC at 192kbps, and couldn’t tell the difference, while the old FFmpeg AAC encoder fall apart at this bitrate.
It gets installed when you install iTunes. If you don't want to install iTunes, you can pull out the codec installer by opening an old version of the iTunes installer in 7-zip and extracting the MSI. Here's a copy I keep around for whenever I have to do a screen recording on a new computer, it's signed by Apple so you don't have to trust me. https://www.infochunk.com/obs/AppleApplicationSupport64.msi
(1) Lossy codecs are transparent at half the file size (or less) of FLAC/ALAC.
(2) AAC (strictly, AAC-LC) is universal, where FLAC and Opus are not yet there.
So maybe Core Audio will continue to be the best when TVBR is available, but I'm hopeful the new FFmpeg encoder will be "good enough", especially if more folks find and contribute problem samples to help tune it.