AAC LC vs. Opus which is better?

[Anonymous543]

AAC LC vs. Opus audio codec
Which one will give better sound quality?
I have seen mostly all video on internet are encoded with AAC LC codec ,but also readed somewhere that opus is good at lower bitrate

Any one know properly which codec gives best audio quality at lower bitrate?

[Atak_Snajpera]

Opus 64kbps sounds better for me than HE-AAC 64kbps.

[pandy]

Tricky question as audio subjective quality depends on encoder quality - simple AAC encoder may deliver sub-optimal quality where advanced AAC encoder may deliver same or better quality as Opus. Personally i would choose codec based on target i.e. what is your target device and how well both codecs are supported by your player.

You may try to search for subjective comparisons on hydrogen: for example https://hydrogenaud.io/index.php?topic=120166.0 and https://hydrogenaud.io/index.php?board=40.0

[non-vol]

From my limited knowledge, Opus was designed to scale down to to VERY low bitrates. AAC was not - it's an incremental improvement over MP3 which in turn is an incremental improvement over MP2 and other older MPEG spec codecs. IIRC, the design goals for MP2 were good quality, for stereo 44.1 khz, at 192 kbps, MP3 was designed to match that quality at 128 kbps, and AAC matches that at perhaps 96 kbps. Lower than that, they're not that good - weren't designed to be.

Opus was designed for low-bitrate and also for low-latency applications aka mostly internet telephony and such. With Opus, human speech still sounds very clear and intelligible at 16 kbps, possibly even lower, whereas MP3 or AAC at such low rates sounds horrible.

Vorbis is also a codec that performs substantially better at lower, sub 100 kbps, bitrates (but also can't compete with Opus at below 64 kbps) and curiously is the only serious audio codec I know of for which a proper "target quality" encoder exists. AAC encoders waste incredible amounts of space because they encode even complete silence at 32 kbps, if they have a variable/target quality mode at all.

Personally... I haven't been very worried about audio quality for a long time. Mainstream MP3 encoders ca. year 2000 were already really good for what they were supposed to do (close to cd-quality sound at 128 kbps). And people even these days have a tendency to use excessively high bitrates for almost everything. Honestly, ANY codec sounds good at 320 kbps. Most do not at 100 kbps.

To answer your question, it depends on HOW low a bitrate you're talking about. In my personal experience, for stereo music, movie soundtracks, etc., Vorbis beats AAC (LC) at least in the "about 80 kbps" range, possibly a little lower. Opus, I don't know enough to say. It's technically very different from the "competitors" and especially from AAC which is derived from stuff invented in the 1980's and all that is extremely well developed and fine-tuned since then. Opus is new and different. Comparing them yourself is indeed probably the best way to decide.