Newbie Questions regarding mp3 and AAC

[aliumalik]

I am just a regular music listener with some quries for you guys.
1) Does mp4(aac) have any advantages over mp3 coded files? All the music files on my computer are encoded at 128K CBR.
2) What's the codec for the future? I downloaded files from several online music stores and some are in aac some in wmv and some are in mp3. Which codec is most probable to be the dominant one in the future?
3) What is the ideal bitrate to rip CDs at in each fromat so that the filesize/quality ratio is reasonable.
I know these questions might sound childish to you but I really want to stick to one format and I think this is the best place that could help me.
Thanks a lot!

[E-Male]

1)he-aac should beat mp3 at low bitrates, it also has multi-channel capabilities
mp3 is much more supported in hardware atm (dvd-players, portable-players) [but that is likely to change, aac is getting more popular]
which sounds better for you(!) at a certain bitrate is something you should find out yourself

2)to much technical-research and political-BS plays into this, i daubt anyone can make a good prediction, but i think sooner or later mp3 will loose because of being outdated

3)you gotta try, it depends on how good your speakers and ears are and what kind of content you compress

[aliumalik]

low bitrates = ???
And is aac evolving at the moment or its released its climax. Cause if its improving there is no use convrting right now is it?

[E-Male]

ahead announced that they'll soon release a new aac-encoder

[Soulhunter]

Still evolving...

But ready to use, coz it compresses already better than mp3 !!!


Bye

[Tuning]

Originally posted by E-Male
.to much technical-research and political-BS plays into this, i daubt anyone can make a good prediction, but i think sooner or later mp3 will loose because of being outdated


I think it will not be outdated soon, coz of forthcoming 5.1 mp3 technology. Perhaps ac3 will be replaced by 5.1 mp3 @ higher bitrates. Who knows? :p

Source (http://forum.doom9.org/showthread.php?s=&threadid=72971&highlight=mp3+5.1)

PS: btw, I'm still fan of AAC..and looking for new ahead encoders.

[pogo stick]

Originally posted by aliumalik
1) Does mp4(aac) have any advantages over mp3 coded files? All the music files on my computer are encoded at 128K CBR.
Yes, it really is! Results of 128kbps Extension Public Listening Test (http://www.rjamorim.com/test/128extension/results.html)
See also Results of 64kbps Public Listening Test (http://www.rjamorim.com/test/64test/results.html).

[E-Male]

usefill link, nice

one thing about it:
i assume lame 128kb/s in that test was abr mp3, not cbr

[P0l1m0rph1c]

http://www.rjamorim.com/test/mp3-128/presentation.html

--preset 128, so, VBR.

[hans-jürgen]

Originally posted by aliumalik
low bitrates = ??? Whatever you personally consider as "low bitrates"... Some people think everything below 200 kbps/stereo is low (because they are used to LAME's bitrate explosions with their favorite music style), others might answer that 64 kbps/stereo is low, but 32 kbps/stereo is really low-down. Then again you'll hear praises about CD quality at 16 kbps/stereo = 40 kbps/6ch soon ("Check those names..."). ;)

And is aac evolving at the moment or its released its climax. Cause if its improving there is no use convrting right now is it? Right, to avoid the common monthly reripping of your whole CD collection you should rather use a codec which definitely is not developed anymore like Bonk. ;)

Now seriously: At the moment there is so much hype and BS flying around it's hard to give "definite" answers to questions like yours, and you should 1. do some own listening tests and 2. ask yourself what you really want and need, e.g. future hardware support for your favorite format and in which form (DVD player, FlashROM portable etc.). Then it will be easier to help you with further questions.

[aliumalik]

No hardware support really doesn't bother me much but I don't want it to be like after 1 or 2 months another aac codec comes along which is way better and I have t re-rip :(

[bond]

Originally posted by E-Male
[B]1)he-aac should beat mp3 at low bitratesno need to go for he-aac, even normal aac will beat mp3 by far at low bitrates

on normal bitrates, like 128kbps, aac should beat as good as any mp3 encoder by far too, BUT the new lame encoder has been heavily tuned and should now be able to keep up with aac again, but as rjamorims test showed lame is really the best mp3 encoder existing, most other mp3 encoders will not have a chance against it

[hans-jürgen]

Originally posted by aliumalik
No hardware support really doesn't bother me much but I don't want it to be like after 1 or 2 months another aac codec comes along which is way better and I have t re-rip :( Then use Bonk... or VQF, as it's closer to AAC... ;) There will always (for the near future) be "another AAC codec coming along" claiming to be "much better than anything you've ever heard", just like for any other format as well. That's why you need to do own comparisons to estimate where your personal "transparency level" lies and if you need to jump onto the next hype immediately.

And you should keep in mind that almost all new developments in any format (but especially in AAC) are done for very low bitrates in order to make them sound acceptable, but not necessarily indistinguishable from the original source. So if you are not interested/don't need these very low bitrates, because you don't do live-streaming with an analog modem or ISDN or listen to Digital Radio Mondiale over FM band, you can already relax a little. ;)

Last but not least, if hardware support is not important, you even could simply forget about using one format only, because your PC will always be able to decode the different formats of the online music services that you mentioned earlier. There it's more important that your computer is authorized to decode them at all.

[aliumalik]

A couple more questions
1) Which AAC codec is the best of the lot? (Ihave heard that the one used by Quicktime 6.5.1 is the best)
2) Do .mp4 files support tagging (Artist Name, Album, Picture etc)? And can these tags be read by all players?

[pogo stick]

Originally posted by aliumalik
1) Which AAC codec is the best of the lot? (Ihave heard that the one used by Quicktime 6.5.1 is the best)
Be careful. There is a forum rule against this kind of questions. There are no 'best' things.
I like Nero-BeSweet encoder. And, I think, it's the most popular way.
Originally posted by aliumalik
2) Do .mp4 files support tagging (Artist Name, Album, Picture etc)? And can these tags be read by all players?
I am not sure about 'standard' tagging for mp4.
I only tried to make tags with WinAmp. It was like mp3 tags.
I think, Bond can answer correct.

[hans-jürgen]

Originally posted by aliumalik
A couple more questions
1) Which AAC codec is the best of the lot? (Ihave heard that the one used by Quicktime 6.5.1 is the best) Well, there you go... The latest rumours on that codec are that it sounds worse than the previous version because of a higher cutoff at the same CBR setting, so it wasn't used in the latest comparison. Furthermore it can't do multichannel encodings which might not be important to you, but to many people in this forum. Last but not least it doesn't do VBR which also contributes to a lower overall bitrate especially when transcoding AC-3 to AAC/MP4.

But for standard stereo CD ripping it's a good choice if you install iTunes, too, because then it will be free unlike Nero AAC which you have to buy after the free demo period is over. If you don't like to download and install huge all-in-one apps (20 MB and more) just for one good AAC codec, you could also try FAAC, the open source AAC/MP4 codec that will work on any OS platform (older Windows versions, Linux, Mac OS X, FreeBSD etc.) and has been implemented in a lot of GUIs in the meantime, e.g. foobar2000, Winamp, CoolEdit, winLAME, HeadAC3he, Speek's "Ivan & Menno" and Multi frontend and more.

2) Do .mp4 files support tagging (Artist Name, Album, Picture etc)? And can these tags be read by all players? [/B] Yes, *.mp4 and *.m4a files (file extension used by iTunes and the iPod) can be tagged with their own MP4 tags that are not compatible with ID3 or APE tags. FAAC can even use them on the command line or within a CD ripper GUI like EAC or CDex.

All players with plugins that are based on the open source AAC/MP4 decoder FAAD2 can read and sometimes even edit these tags, and of course Apple's iTunes, too. The standard Winamp plugin is not able to do this, as far as I know, but you can easily replace it with the in_mp4.dll from Audiocoding.com, the homepage of FAAC and FAAD2. WMP can also read the tags in MP4 files when you install 3ivx DS filters, but cannot import them into its database, as far as I remember.

[aliumalik]

Now I know ID3 was the sandtard for tagging mp3 files but is there going to be a defacto stnadard for aac files. Secondly what about these different extensions floating aroun m4a mp4 m4p. I know some are just for apple but which one should we use for all apps?

[bond]

Originally posted by aliumalik
Now I know ID3 was the sandtard for tagging mp3 files but is there going to be a defacto stnadard for aac files.the defacto official standard for meta-data in .mp4 (like tags but much more) is specified in mpeg-7, still afaik its not finished and no tools for setting these tags exist atm
the inofficial tagging standard is the one apple uses

i would of course prefer the mpeg-7 way, but as not tool exist...

Secondly what about these different extensions floating aroun m4a mp4 m4p. I know some are just for apple but which one should we use for all apps?if you would have used search you would have found my faq where i describe all these things

.mp4, is the one and only extension specified in mpeg-4 (for files containing audio + video + subs + interactive content)
.m4a is used by itunes and some other tools for aac-only files. m4a = mp4 (the only difference is the extension)
.m4p is the extension used for songs bought in itunes with are drm protected.

[aliumalik]

bond can you please give me more infor about that mpeg 7 thing or gimme some links?
I have heard that the way in which iTunes tags files is only slightly different from the way they are supposed to be done in mpeg 7 standard, is this true?
Also does the profile LC/HE change automatically when you are coding using iTunes or Quicktime when you change the bitrate?
Another thing which codecs support AAC VBR?
Thanks a lot guys!

[hans-jürgen]

Originally posted by aliumalik
Also does the profile LC/HE change automatically when you are coding using iTunes or Quicktime when you change the bitrate?
Another thing which codecs support AAC VBR? Apple does not know the HE AAC profile, neither for encoding nor for decoding. The only publicly available encoder is Nero AAC, and all players using plugins based on FAAD2 can decode it like Winamp, foobar2000 etc.

If you encode with Nero AAC, the profile will automatically switch to LC for higher quality settings even if you set it to HE AAC which is only meant for lower quality files. If you decode HE AAC files with QuickTime or iTunes, they will only play the LC part of it, i.e. without the high frequencies = rather crappy.

AAC codecs with VBR are FAAC, Nero and compaact!.

[aliumalik]

Any chance of an Apple VBR codec coming out soon?

[aliumalik]

One last thing which decoder gives better quality decoding for AAC than the others. I have heard that the main ones are CoreCodecAAC, FAAD2 and 3ivx also plays aac files withut even the need of a parser. So which one offers the etter quality?
Thanks

[bond]

it doesnt matter which decoder to use qualitywise

[RadicalEd]

Originally posted by hans-jürgen
The only publicly available encoder is Nero AAC

You guys are forgetting about RA10's (HE)AAC codec, which is the only free one that can use sbr :|

[aliumalik]

Does 3ivx offer decoders as free downloads? because i can only find encoders and decoders in a trial version at their page.

[QuantumKnot]

A note about FAAC. Apparently from what I've heard, it is not as 'complete' as the modern AAC encoders. ie. it doesn't have a psychoacoustic model. The quality is quite impressive in that respect, but don't expect too many wonders from it either. :)

[hans-jürgen]

Originally posted by aliumalik
Does 3ivx offer decoders as free downloads? because i can only find encoders and decoders in a trial version at their page. No, you have to pay US$ 6.99 after one month for the decoder and US$ 19.99 for the encoder. If you're looking for free MP4 DirectShow filters, you can combine the CoreAAC filter with the 3ivx splitter or just use the mpegable DS decoder (no HE AAC or multichannel decoding though).

By the way, the only way you could experience a sound difference between AAC decoders is if you try to listen to HE AAC files with a player or plugin that only supports the LC profile (i.e. everything from Apple, mpegable and compaact!, the default Winamp plugin and almost all hardware decoders except the one in Siemens/O2's Digital Music Player). These decoders will play HE AAC files in a backward compatible way without the high frequencies generated by the SBR decoding.

[hans-jürgen]

Originally posted by RadicalEd
You guys are forgetting about RA10's (HE)AAC codec, which is the only free one that can use sbr :| I wouldn't call the SDK from RealNetworks for their Helix Producer "publicly available", because not everyone will get it, only software developers, as far as I know. Probably Coding Technologies would not have agreed on another licensing model which seems to be the same as for mp3PRO and the Gracenote SDK.

[hans-jürgen]

Originally posted by QuantumKnot
A note about FAAC. Apparently from what I've heard, it is not as 'complete' as the modern AAC encoders. ie. it doesn't have a psychoacoustic model. The quality is quite impressive in that respect, but don't expect too many wonders from it either. :) Apparently you prefer to rely on hearsay and spreading rumours than doing own listening test and/or looking into the source code. Does this have anything to do with your avatar maybe?

[aliumalik]

Originally posted by hans-jürgen
[B]No, you have to pay US$ 6.99 after one month for the decoder and US$ 19.99 for the encoder.
Strange because I have been using the K-Lite codec pack and it has both encoder/decoder and they have been working fine for about 2-3 months :confused: .

Originally posted by hans-jürgen
By the way, the only way you could experience a sound difference between AAC decoders is if you try to listen to HE AAC files with a player or plugin that only supports the LC profile
But LC Profile has a higher quality than HE right???

Thanks

[QuantumKnot]

Originally posted by hans-jürgen
Apparently you prefer to rely on hearsay and spreading rumours than doing own listening test and/or looking into the source code. Does this have anything to do with your avatar maybe?

If that is the sort of attitude I get here, maybe it was a mistake for me to come here in the first place.

Though I wasn't politely asked where I got this idea that faac wasn't as 'complete' as the other AAC encoders, I'll show you this thread by Gabriel, developer of LAME, as a matter of courtesy:

http://www.hydrogenaudio.org/index.php?showtopic=19295&view=findpost&p=190435

It seems to me that noise is uniform: no tonality estimation, not even a simple ath based shaping.

That is the source of my belief. And for your information, yes I have looked at the source code of FAAC as I do Vorbis development as well, hence the avatar.

As for quality of faac compared with other more 'complete' AAC encoders:

http://www.rjamorim.com/test/aac128v2/plot12z.png

It's quality is impressive (for its current implementation) but not as good as Nero or iTunes which have complete psymodels. Surely that listening test is good enough, yes?

Anyway, I think I'll spare you from my heresay, rumours, and vorbis propaganda. :rolleyes: This will be my last post here.

[hans-jürgen]

Originally posted by aliumalik
But LC Profile has a higher quality than HE right??? Yes, it's possible to achieve a higher quality with LC (indistinguishable from the original source) if you use it with higher bitrates than the ones where HE AAC was developed for, i.e. below ~96 kbps/stereo. That's also the reason why Nero AAC defaults to AAC LC when you use higher bitrates with it.

@QuantumKnot: The psymodel of FAAC is located in psychkni.c and psych.h, and the graph of the last AAC listening test does not show that Nero needed ~140 kbps for this result instead of 128 kbps (with a preset that is supposed to use ~100 kbps). Furthermore that test didn't have a low-quality anchor, so the differences between the codecs are exaggerated. Last but not least the tested version was FAAC v1.23.5, not 1.24 which uses TNS on default and automatic cutoff changes with higher quality settings now to further improve the sound while QuickTime was v6.5, not the problematic current v6.5.1. That's why I mentioned it's better to do own comparisons than only relying on a zoomed graph presenting an outdated test result when choosing a codec.

[QuantumKnot]

Originally posted by hans-jürgen

@QuantumKnot: The psymodel of FAAC is located in psychkni.c and psych.h, and the graph of the last AAC listening test does not show that Nero needed ~140 kbps for this result instead of 128 kbps (with a preset that is supposed to use ~100 kbps). Furthermore that test didn't have a low-quality anchor, so the differences between the codecs are exaggerated. Last but not least the tested version was FAAC v1.23.5, not 1.24 which uses TNS on default and automatic cutoff changes with higher quality settings now to further improve the sound while QuickTime was v6.5, not the problematic current v6.5.1. That's why I mentioned it's better to do own comparisons than only relying on a zoomed graph presenting an outdated test result when choosing a codec.

It comes down to our definition of what constitutes a psymodel. I've had a quick scan of those two files from the 1.24 source before but couldn't find anything obvious that implemented tonal masking, noise masking, or even ATH values that you can find in the psymodel of Vorbis and MPC source code. The only thing implemented seems to be for block switching only. And just because those files start with a psych* doesn't really mean it contains a proper psymodel. Again, another thread that talks about faac lacking a proper psymodel:

http://www.hydrogenaudio.org/index.php?showtopic=21767&view=findpost&p=212360

You asked for a listening test so I gave you the results of one. Note I never talked about choosing codecs in my first post or anything about the comparative quality so it's irrelevant to what my original point was. I'm not here to bash faac with ficticious points nor am I telling people to avoid it like the plague and go use the codec represented by my avatar. I was merely stating a fact about faac's psymodel (or lack of one) that has been discussed before in two threads and how generally (as Ivan Dimkovic says in that thread), lack of a proper psymodel will influence the quality, unless we are talking about extremely high bitrates.

If people want to choose whether to use faac or not and whether modelling the frequency domain to shape noise in time (temporal noise shaping) really made a difference in quality, then they should do their own listening tests. But that doesn't alter the fact that faac, unlike other perceptual transform coders like Musepack, Vorbis, and AAC, doesn't seem to take advantage of noise and tone masking. I mentioned that fact from a technical viewpoint and if no-one is interested in it, that's ok with me. But I see absolutely no justification why I am judged by my avatar, or how I am supposedly spreading rumours and hearsay. That is defamation.

[aliumalik]

Guys what about the 3ivx codec the codec packs are offering are those illegal???

[Stux]

Originally posted by hans-jürgen
No, you have to pay US$ 6.99 after one month for the decoder and US$ 19.99 for the encoder.

I'm sure you mean

"No, you have to pay US$ 6.99 after one month for the decoder or US$ 19.99 for the encoder."

If you decide to purchase 3ivx (and thus help support the development of our filtersuite and related technologies) for either decoding or encoding, you only need to purchase either the encoder or decoder as the encoder includes the decoder.

Thankyou.

[SeeMoreDigital]

I still would like to know if full 2pass encoding (or more) would help to increase the quality when generating 6Ch AAC streams?

As we all know, the technique works very well for video!


Cheers

[aliumalik]

Someone please answer the legality question about the codec packs please

[SeeMoreDigital]

Originally posted by aliumalik
Someone please answer the legality question about the codec packs please Well I guess, that will depend on what's in the codec pack!

Also, some codec packs only offer 'decoders'. While others offer 'encoders' and 'decoders'.

There really is no need to install such packs as they tend to cause more problems than they are worth!

As a rule of thumb, just install the codecs that you want to use ie: DivX, XviD, 3ivX, WMV9-VCM, VP6, Lame etc, etc and you'll get the both the encoder and decoder anyway.

One thing to note, most so-called 'codec packs' incorporate more than just codecs. Meaning you'll end up with a ton of crap you don't really want or need...

So don't do it!

Of course I'm not including GK in this analysis ;)


Cheers

[Tuning]

Originally posted by SeeMoreDigital
One thing to note, most so-called 'codec packs' incorporate more than just codecs. Meaning you'll end up with a ton of crap you don't really want or need...

And also it is possible to add 'Trojans' into these codecpacks, that will tamper your privacy on using computer. ;)


Again, if you only want to watch movies, then I would suggest MPC and FFDShow, nothing more. As these can decode most of formats.

[hans-jürgen]

Originally posted by aliumalik
Someone please answer the legality question about the codec packs please If you still can encode or decode AAC through DirectShow filters after one month and did not pay 3ivx.com or install other free DS filters like CoreAAC or mpegable (both only for decoding), then the codec pack obviously contains a cracked or a closed beta version of the 3ivx DS filters only available for certain testers.

@Stux: Right, I forgot to mention that paying for the DS encoder also includes the decoder of course.