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Topic: Which AAC types among these versions has better quality? (Read 2145 times) previous topic - next topic

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  • meadseu
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Which AAC types among these versions has better quality?
1. AAC 320 KBPS
2. AAC v1 256 KBPS
3. AAC v2 256 KBPS

Re: Which AAC types among these versions has better quality?
Reply #1
I think you will mostly get answers that say those bitrates are above the threshold bitrate for transparency and that you could do ABX test to see if you can distinguish between original (lossless) and the AAC (lossy). Version 1 and two do use artificial high frequencies among other features and therefore MAYBE you can hear a difference even at high bitrates. Let's see what the others say but try to do an ABX test to see for yourself is you can hear the difference.

  • mpuzirew
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Re: Which AAC types among these versions has better quality?
Reply #2
2. AAC v1 256 KBPS
3. AAC v2 256 KBPS
It depends of what exactly you mean using terms "AAC v1" and "AAC v2" :) Usually, these terms point to so-called High-Efficiency AAC, which is not designed for such high bitrates as 256. НЕ-AAC is designed specially for lower bitrates  (internet radio etc). It does not provide high sound quality by design.
https://en.wikipedia.org/wiki/High-Efficiency_Advanced_Audio_Coding
P.S. AAC 320 kbps VBR or CBR? :) In fact, VBR@200kbps (and even lower) is usually enough to achieve transparency (if good lossless source and a good AAC encoder as Apple AAC or at least FDK AAC were used). IMHO.
  • Last Edit: 30 December, 2016, 08:54:53 AM by mpuzirew

  • Maurits
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Re: Which AAC types among these versions has better quality?
Reply #3
In addition to what has already been said about these bitrates being way above the transparency threshold, it is an odd comparison anyway.

HE-AACv1 and HE-AACv2 are not meant to produce 'the best achievable audio quality'. They are meant to produce 'the best achievable audio quality given a significant bitrate constraint'. They are meant to squeeze the last bits of quality out of a minimal amount of bits. To achieve that they open up a entire toolbox of gimmicks and tricks to make it sound as best as is possible with a less than ideal amount of bits per second. This is why you are more likely to find HE-AACv1 and v2 in audio streaming, digital radio etc. because every bit matters whereas in music download stores you are more likely to find AAC as the size is less important in those instances.

This is a bit of a shortcut but one could say that:
  • at 32 kb/s, HE-AACv2 will sound better than the other two because it is specifically developed for low bitrates.
  • at 64 kb/s, HE-AACv1 will sound better than the other two because it is specifically developed for medium bitrates.
  • at 128 kb/s and above AAC will sound better than the other two because it is specifically developed for high bitrates.

If you use a codec for something else than it was intended for you could run into audible issues. It simply won't have been developed, tested and tuned with such a bitrate in mind.
  • Last Edit: 30 December, 2016, 10:06:41 AM by Maurits
There is a hidden message in the song at approximately 4:32. If played at half speed, Waters can be heard to say, "That was pretty avant-garde, wasn't it?"

Re: Which AAC types among these versions has better quality?
Reply #4
1, 2 and 3.

  • meadseu
  • [*]
Re: Which AAC types among these versions has better quality?
Reply #5
Honestly, I have no idea on 80% of the terms you guys said :D I'm just familiar with lossy and lossless formats (FLAC and MP3, AAC etc.). I am encoding a video with audio through After Effects and shows me an option to which audio codec to use. I knew higher bitrate means better quality. And btw, I am talking about AAC v1, v2 = AAC version 1/HE-AAC. So what codec is better to produce the better sound quality like this: https://www.youtube.com/watch?v=WBdHOacDYwE.

  • Zarggg
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Re: Which AAC types among these versions has better quality?
Reply #6
YouTube uses LC-AAC for encoding audio streams, which is intended for higher bitrates.

If you want to figure out what bitrate is "best" for you, perform ABX tests with transcodes of varying quality until you find your personal threshold for transparency. HE-AAC (v1 or v2) is most likely irrelevant to your needs.

  • LithosZA
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Re: Which AAC types among these versions has better quality?
Reply #7
Quote
Honestly, I have no idea on 80% of the terms you guys said :D I'm just familiar with lossy and lossless formats (FLAC and MP3, AAC etc.). I am encoding a video with audio through After Effects and shows me an option to which audio codec to use. I knew higher bitrate means better quality. And btw, I am talking about AAC v1, v2 = AAC version 1/HE-AAC. So what codec is better to produce the better sound quality like this: https://www.youtube.com/watch?v=WBdHOacDYwE.
It is simple. YouTube transcodes anything you give it to LC-AAC and Opus streams. You have no control over this.
So upload the highest quality you can get to YouTube if you are paranoid about sound quality. It is even possible to upload FLAC or uncompressed PCM.
In the lossy AAC realm, LC-AAC will give you the best quality when using the highest bitrates.

Quote
YouTube uses LC-AAC for encoding audio streams, which is intended for higher bitrates.
YouTube also encodes Opus audio streams. If you are watching the videos through Chrome then there is a very large chance that you would get the Opus stream. Right click on the playing video and click on 'Stats for Nerds'. If it shows 249, 250 or 251 as a stream ID then you are getting Opus.

  • IgorC
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Re: Which AAC types among these versions has better quality?
Reply #8
Quote
YouTube also encodes Opus audio streams. If you are watching the videos through Chrome...
Firefox too (since version 47)