July 1, 2026
Codec wars: now with extra noise
FFmpeg 9.1's new AAC encoder
FFmpeg’s audio glow-up sparks cheers, codec wars, and one very nerdy 48kHz fight
TLDR: FFmpeg’s AAC audio encoder got a full rewrite, and its creator says it now outperforms other AAC options in quality tests. Commenters are split between cheering a huge open-source win, joking about ancient obscure bugs, and arguing that Opus still makes the whole AAC victory lap look awkward.
A developer just dropped a massive makeover for FFmpeg’s built-in AAC audio encoder — basically the part that shrinks music and sound into smaller files — and claimed it now beats big-name AAC rivals in listening quality tests. That alone would be spicy, but the real fun is in the peanut gallery. One commenter immediately faceplanted into classic internet housekeeping with “Flagged for the wrong link,” because of course even a major audio breakthrough can’t escape admin drama.
Then the comments swerved straight into delightful niche-chaos. The biggest laugh came from a user staring at a bug involving “stereo PNS” — a fancy audio trick most normal humans have never heard of — and joking that it has probably been ruining someone’s extremely specific setup for 20 years. That was the mood: awe mixed with nerd comedy. Another commenter was thrilled, hoping this finally means they can ditch the long-favored fdk-aac encoder. But not everyone was ready to hand FFmpeg the crown. One of the strongest hot takes was basically: cool rewrite, but Opus still clears. In other words, congratulations on winning the AAC race, but another format is still dunking on everyone at low file sizes.
And yes, there was even a mini culture war over sample rates after the developer bluntly declared “48kHz is the standard. Get over it.” The replies instantly turned that into a tiny referendum on whether the future has actually arrived. So the headline isn’t just “audio encoder improved.” It’s open-source swagger, codec rivalry, old bugs dragged into daylight, and audiophile bickering over what year it is.
Key Points
- •The article reports a full rewrite of FFmpeg’s AAC encoder, covering rate control, RDO, and coding tools including PNS, TNS, I/S, and M/S.
- •The author says benchmark results using Zimtohrli and ViSQOL show the new encoder outperforming qaac and fdk-aac in the AAC comparisons listed from 64 to 256 kbps.
- •The new encoder is described as primarily optimized for strict CBR use, with the author not recommending `-q:a` true VBR mode.
- •The article says a stereo PNS bug in FFmpeg’s AAC decoder, and possibly other AAC decoders, required an encoder-side workaround.
- •The encoder was mainly optimized for 48 kHz audio, tested on about 3,000 music tracks, and now prints additional tool-usage and quality-control statistics on uninitialization.