AACplus/HE-AAC playback on Ipod 5G Video

[Febs]

Yeah, but that's just one test, and AAC has progressed since that time anyway. Look at this test or this one (that second one being by far the most recent), and it's clear that AAC beats out MP3, especially using good settings for the encoder.

Actually, the first test that you cite is from 2003.  This test, conducted in 2004, shows that LAME and iTunes AAC tied.

[Gamesoul Master]

::Sigh:: I was not the one to start throwing tests. I showed those merely to point out that anybody can show tests to prove anything. If you tried, you could probably find a test that says MP3 beats HE-AAC in quality. I'm not big with seeking tests, because I'm not that lazy (no offense, but that's simply how I feel about searching test results when you could just run your own tests really easily).

I apologize for stating opinions as fact. To be honest, I was reading reviews and tech papers about the MP3 and MP4 formats, and everything I read kept pointing to MP3 not having much more optimization left, while MP4 is still in its earlier stages and has room for much improvement in terms of the encoders these days. Some of the things I read were certainly backed with solid reasoning, but some of it was beyond what I know. Basically, I was reading what you asked if I did (about researching it). But I do apologize, as you are right... I provided almost no proof of the "statements" I was making.

"Technically superior" I meant in terms of quality only, as you are right... AAC is more resource-intensive.

But again, I do apologize. I guess I got a bit defensive because in all the testing I've done on my own, I have never found MP3 to be as good as AAC. But of course... it's just a personal test of personal preference. So I shouldn't have been so forceful with my opinion. I apologize humbly to anybody I might've angered because of that...

@Febs: Ahh... I didn't notice that. Sorry, I just sort-of grabbed the tests without looking at them too closely. As I said, I'm not much for reading other peoples' tests. I noticed just about all the tests I've been looking at (yeah, now I'm just sort-of browsing them out of curiousity of being on this topic... XD), they're all pretty much outdated by at least 2 years. I guess people got tired of trying to compare them

[Llorean]

Though to be fair, that's iTunes AAC, which should be LE. HE-AAC is more advanced (for lower bitrates) because of SBR and parametric stereo. In all honesty, HE-AAC should be expected to perform better than Standard MP3 (it should be compared to MP3Pro) at low and very low bitrates, though as you progress up to the transparency point it probably shouldn't be expected to be superior near or past there (in fact, it may be possible that it's inferior higher up since it may be more likely to add artifacts, though this is little more than a guess). For all practical purpose, HE-AAC should be considered a separate codec, and should NOT be referred to simply as "AAC"

In the end, though, the only test that matters is "Have you tried it in a blind ABX yourself" and then you pick the one that works for you.

There are objective points in how advanced the techniques used, but the phrase "technically superior" doesn't mean much, since some people would consider a technically superior codec one that "can be run on a very slow processor with a minimum of resources and still provide high quality sound at fairly low bitrates" which certainly applies to MP3 much much much more than HE-AAC, for example.

[Febs]

@Febs: Ahh... I didn't notice that. Sorry, I just sort-of grabbed the tests without looking at them too closely. As I said, I'm not much for reading other peoples' tests. I noticed just about all the tests I've been looking at (yeah, now I'm just sort-of browsing them out of curiousity of being on this topic... XD), they're all pretty much outdated by at least 2 years. I guess people got tired of trying to compare them

Actually, the folks at Hydrogen Audio pretty much stopped doing tests at moderate to high bitrates because the codecs became good enough that most codecs were transparent at those bitrates.  You can't conduct a test comparing codecs when the people taking the test can't hear any difference between them.  That's why you now tend to see tests like this 64kbps multiformat test, which is currently in progress.

[Gamesoul Master]

True. I tried iTunes AAC and didn't really like it. Nero AAC is great though. I just wish I could use HE-AAC, but as it was already said... it's too much for the iPods to try and process. Comparing HE-AAC to MP3Pro wouldn't be much better, since they are both optimized from their original format by the same technology created by the same company... LOL. Although HE-AAC v2 has SBR *and* PS... doesn't MP3Pro only have SBR? Though it's not too useful... I have nothing besides maybe one or two media players that can play HE-AAC v2 (my Sanyo phone can only handle v1, which is still nice).

@Febs: You mean... they've pretty much decided that all the current codecs/formats are too close to transparent at 128 kbps to be distinguished? Wow... I don't think I could go down to 64 kbps for MP3 or LC-AAC, as the quality would irritate me to no end. I'm basically hoping for something around 96 kbps so as to be able to fit over 600 songs on my 2 GB Nano...

[Llorean]

At 96kbps, Ogg/Vorbis should probably be a good choice. That actually seems to be one of the popular encoding bitrates for it, I believe.

[soap]

Possible. Though I really don't care... the initial point I was trying to make was that AAC is technically superior to MP3.

I don't care one-way or another about the format "wars", and won't even bother taking a side.
The one point I feel is critical in this discussion, though, is that encoder maturity is very important:
See LAME vs (just about any other)
See AoTuV vs Xiph
and can make up much ground for the "technically inferior" codec (at least) until the newer one matures. (If it ever does, history is littered with codecs which never caught on, regardless of merits.)

[Gamesoul Master]

@Llorean: But see... I have to stick to what the iPod natively supports, since I have a Nano 2G. And if I do end up getting the 5G Video, I can use something like VBR MP3 (to save on processor usage, thus battery usage). On my computer I keep all my music stored as MP3 VBR ~200 kbps (a good balance since I only have about 260 GB of hard drive space to work with for music storage).

[Llorean]

Is there some rule that says you have to use the same format on your 2nd Generation Nano, as on your 5G iPod?

By the way, Ogg/Vorbis runs faster at most bitrates (especially the 'transparent' range ones) on iPod than MP3 does at the moment (at least according to the last test_codec runs made).

As this is the Rockbox forum, I'm of course only talking about what you should run on a player running Rockbox, and NO discussion should be happening regarding things not related to Rockbox.

[Gamesoul Master]

LMAO... a full page and some extra of this thread was completely unrelated to Rockbox. But I see your point... and in that light, I'll definitely consider OGG for if/when I get the 5G Video.

Your first statement... sort-of eludes me. I was saying I'd use AAC for my Nano because it's the best format for my music at lower bitrates, and MP3 on the 5G Video for faster decoding times. But since I keep forgetting to consider OGG (that's from years of ignoring it), your testimony is enough for me to take a closer look into it.

[saratoga]

Don't quote those SoundExpert tests.  They're completely worthless.

[TexasRockbox]

For compression I used Sony's ATRAC (including ATRAC 3Plus) for so many years and was amazed that anything resembling music could be recorded and played back (and that was with ATRAC 1!) with it.  I recorded a lot of live shows using that format.   All subjective, of course, but MP3 just sort of dissapoints me.   I'm sure there is room for continual development.  It now appears that ATRAC (Minidisc) is finally breathing its last -- not a bad run, almost fifteen years.   Vorbis had impressed me with some early tests but for portable use only had a buggy iriver IMP-550 that would play it.  The Archos AV500 is a fine piece of equipment and has some enormous capability but is CODEC challenged, in my view.  No Vorbis happiness there.  Rockbox has finally allowed me to use a player that will allow some large storage and a wide choice of audio CODECs.  I'm very happy with the Rockbox 5G system -- a nice balance between the comfort of a "tested" hardware and the excitement of a "cutting edge" firmware.

[Chronon]

I encoded the sample file from the CodecPerformanceComparison wiki page into HE-AAC at several different bitrates ranging from approximately 63 kbps to 128 kbps.  It looks like it decodes the slowest out of all the codecs I tested, but the Gigabeat still manages around 220% of real-time.  Visit the wiki page for the complete results.

[Gamesoul Master]

Wow... yeah... that most definitely means that the iPod could not even come close to HE-ACC playback (not even at <=32 kbps). Your results clearly show the superior processing power of the Gigabeat as compared to an iPod (even if not directly comparable, still comparable enough to make estimates I'd say).

[Llorean]

Actually, according to the official numbers a 67mhz ARM core can play back certain bitrates of HE-AAC, though it was ARM9 I believe, and doesn't specify if that's running only the decoder or if that's the minimum expected to be needed in a device.

As once we're running dual core we might have a single 80mhz ARM7 core sitting around for decoding, it might be possible for some bitrates of HE-AAC to be realtime on iPod, though by no means is this any guarantee or promise until both testing and optimization have been done. They'll of course be lower bitrates, but once you reach 128kbps or so, there's much much less advantage to these types of formats anyway.