Live data from Hacker News

FFmpeg 9.1's new AAC encoder

hydrogenaudio.org

71–80 of 162 posts

Re: FFmpeg 9.1's new AAC encoder

#71
post #20

Earlier quoted context omitted.

The biggest advantage for having a good AAC encoder isn't efficiency, it's that for nearly the past 2 decades the de facto standard for live streamed video has been RTMP with H.264 video and AAC audio. There is basically no support for any other codecs. If you want to send a video stream to Youtube or Twitch, you will be sending H.264 and AAC. If you want an idea of how ubiquitous this is, I just checked in OBS and i…

Plus, at 96+ kbps (assuming an Apple-quality AAC-LC encoder) Opus loses its quality advantage. So at higher bitrates, the benefit of choosing Opus is that encoders/decoders are royalty-free.

Am I reading that chart wrong? I see Opus ahead across every bitrate.

Re: FFmpeg 9.1's new AAC encoder

#72
post #20

Man what a showcase for Opus this is. Don't get me wrong, this sort of thing is a valuable exercise and we are better off with better encoders for these older codecs. But look at the numbers for Opus on this benchmark. It simply blows all the AAC encoders out of the water even at 64 kbps.

The biggest advantage for having a good AAC encoder isn't efficiency, it's that for nearly the past 2 decades the de facto standard for live streamed video has been RTMP with H.264 video and AAC audio. There is basically no support for any other codecs. If you want to send a video stream to Youtube or Twitch, you will be sending H.264 and AAC. If you want an idea of how ubiquitous this is, I just checked in OBS and i…

I think often of how all it would have taken was a bomb for the 10 or so people that years ago at some browser vendor consortium out of pure self centeredness went „nah lets fragment“. We could have saved many many collective years, electricity and eyeballs simply watching the most basic content.

Re: FFmpeg 9.1's new AAC encoder

#73
post #17

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…

i will never understand apples cuckoldry for proprietary codecs, if it wasn't for their adoption of h265 we would live in the av1 utopia

Re: FFmpeg 9.1's new AAC encoder

#74
post #38

Earlier quoted context omitted.

I think the biggest issue with Opus is the problem with its specification being lacking, see: https://nothings.org/stb/stb_opus.html This essentially causes opus to never be used in games or in things in stores that may have issues with specific licenses.

That’s going a bit far. I’m in the games industry and have used opus regularly, it’s a great codec for games, often the hardware decoding is so restricted that we’re using software regardless so we might as well use something like opus. The licensing restriction is unfortunate, but only restrictive for those with very specific goals, under normal conditions BSD is a wonderful license for game devs since you’re free t…

> under normal conditions BSD is a wonderful license for game devs since you’re free to use the code and only have to add an acknowledgement somewhere.

And it's not as though libopus is an outlier in using a BSD license. A lot of other commonly used libraries have similar licenses; a few examples that come to mind which are likely to show up in games are zlib, curl, Lua, and SDL.

Re: FFmpeg 9.1's new AAC encoder

#75

Earlier quoted context omitted.

That’s going a bit far. I’m in the games industry and have used opus regularly, it’s a great codec for games, often the hardware decoding is so restricted that we’re using software regardless so we might as well use something like opus. The licensing restriction is unfortunate, but only restrictive for those with very specific goals, under normal conditions BSD is a wonderful license for game devs since you’re free t…

> under normal conditions BSD is a wonderful license for game devs since you’re free to use the code and only have to add an acknowledgement somewhere. And it's not as though libopus is an outlier in using a BSD license. A lot of other commonly used libraries have similar licenses; a few examples that come to mind which are likely to show up in games are zlib, curl, Lua, and SDL.

libopus isn't even an outlier in using it for a media format specifically. See: everything coming out of the Alliance for Open Media

Re: FFmpeg 9.1's new AAC encoder

#76
post #20

Man what a showcase for Opus this is. Don't get me wrong, this sort of thing is a valuable exercise and we are better off with better encoders for these older codecs. But look at the numbers for Opus on this benchmark. It simply blows all the AAC encoders out of the water even at 64 kbps.

The biggest advantage for having a good AAC encoder isn't efficiency, it's that for nearly the past 2 decades the de facto standard for live streamed video has been RTMP with H.264 video and AAC audio. There is basically no support for any other codecs. If you want to send a video stream to Youtube or Twitch, you will be sending H.264 and AAC. If you want an idea of how ubiquitous this is, I just checked in OBS and i…

YouTube actually supports H.265 and VP9 ingest, depending on the streaming protocol. I can actually stream 4K@60 H.265 from my Mac Studio with https://developers.google.com/youtube/v3/live/guides/ingesti...

Re: FFmpeg 9.1's new AAC encoder

#77

Earlier quoted context omitted.

Say it or don't but "I have evidence otherwise but don't think I should say" is just as bad a flame war gateway as tempting the junk science audiophiles directly.

I know that with oscilloscopes, it’s recommended to use 5x instead of nuquist 2x of the highest frequency you want to use., but the most reasonable argument I’ve heard for higher than 48kHz sampling is digital audio effects. But for the end result 48kHz is more than necessary. I can’t even hear any frequency above 17kHz.

> I know that with oscilloscopes, it’s recommended to use 5x instead of nuquist 2x of the highest frequency you want to use.

For capturing analog signals, 2.5X is enough headroom.

The 5X recommendation is probably for digital signals where the frequency refers to the baud rate, not the highest frequency coming through. A fast switching digital signal will have components with higher bandwidth than the fundamental. Using a higher multiple of samples (assuming the bandwidth is there) will let you see the shape of the waveform and rise and fall times better.

Re: FFmpeg 9.1's new AAC encoder

#78

Older I get, more it seems it’s possible to ping pong between rewrites for good reasons (ex. here, metric maxes but I find it hard to believe VBR and not-48 kHz are silly things and not worth investing it)

I always encode my AAC with VBR. Why wouldn't you, right? I guess I'll stick to apple or fdkaac for now.

Re: FFmpeg 9.1's new AAC encoder

#79
post #72
post #20

Earlier quoted context omitted.

The biggest advantage for having a good AAC encoder isn't efficiency, it's that for nearly the past 2 decades the de facto standard for live streamed video has been RTMP with H.264 video and AAC audio. There is basically no support for any other codecs. If you want to send a video stream to Youtube or Twitch, you will be sending H.264 and AAC. If you want an idea of how ubiquitous this is, I just checked in OBS and i…

I think often of how all it would have taken was a bomb for the 10 or so people that years ago at some browser vendor consortium out of pure self centeredness went „nah lets fragment“. We could have saved many many collective years, electricity and eyeballs simply watching the most basic content.

At one point in I think 2012 three of us who normally all live in different countries were riding in the same car in Australia. We advised the driver to be extra careful (she was dating one of us, so incentives were aligned).

But it is nice to hear that you have been thinking of us, too.

Re: FFmpeg 9.1's new AAC encoder

#80
This is truly a representative of the old internet: somebody codes up the best AAC encoder ever, and the first response comes from some admin, and it's some bickering about 48Khz vs 44Khz.
Post reply on HN