I want to know if the iTunes AAC encoder has changed since 7.0.2.16? If so, are the changes -- overall -- for the good or bad? I don't want to upgrade if the current version of the encoder has some bad tweaks in it.
Moderation: Fixed typo in topic. ACC -> AAC. To help future searches.
A new AAC-LC codec is available in the new Mac OS X 10.5 (code named as Leopard) which will be released in Oct. 26. It has some significant sound quality improvement and bitrate mode enhancement. Since iTunes and QT use the AAC codec built natively in the OS X, these enhancements will be reflected in these Apple applications as well (doesn't matter you have upgraded these individual applications or not). You can also use the following commandline tools available in the OS X 10.5 to access the codec:
$> afconvert - perform various audio file conversions, including AAC encoding and decoding.
$> afplay - play back an audio file (compressed or uncompressed).
$> afinfo - display information about an audio file.
i wonder if iTunes will be able to do multiple file conversions at once.
doesn't matter you have upgraded these individual applications or not
Acutally since I'm on a PC then I think it does for me, but thanks for the heads-up anyhow!
Thanks skuo for the info. I just ordered my Leopard (Mac OS X 10.5) OS software for my Mac mini today. I will try out the new commands and AAC encoder/decoder when I receive it.
Are you allowed to report what version of FLAC (if any) comes bundled with the new Mac OS X Leopard yet or do you have to wait until October 26th for the NDA to expire?
Maybe for the original poster (and other Windows users), they will update Quicktime and iTunes for Windows to match the new Leopard audio encoder/decoder AAC (and maybe FLAC) support that will be coming with the new Mac OS due out on October 26th.
Maybe for the original poster (and other Windows users), they will update Quicktime and iTunes for Windows to match the new Leopard audio encoder/decoder AAC
Yup, that's true, and the Windows updates for these Apple applications have not been announced yet.
A new AAC-LC codec is available in the new Mac OS X 1.5 [sic] (code named as Leopard) which will be released in Oct. 26. It has some significant sound quality improvement and bitrate mode enhancement. Since iTunes and QT use the AAC codec built natively in the OS X, these enhancements will be reflected in these Apple applications as well (doesn't matter you have upgraded these individual applications or not). You can also use the following commandline tools available in the OS X 1.5 [sic] to access the codec:
$> afconvert - perform various audio file conversions, including AAC encoding and decoding.
$> afplay - play back an audio file (compressed or uncompressed).
$> afinfo - display information about an audio file.
Are you certain that Apple is planning a major iTunes update and that this is not just rumor?
If you check Apple's Leopard website that purports to list the 300+ features being added in OS X 10.5, neither iTunes nor Core Audio is listed.
See for yourself...
http://www.apple.com/macosx/features/300.html (http://www.apple.com/macosx/features/300.html)
iTunes and QuickTime are not on the same release schedule as OS X.
(I don't know if it's updated, but if it is, it would be under NDA anyway!)
I spotted an AAC-LD Codec in the whatsnew list.
I spotted an AAC-LD Codec in the whatsnew list.
AAC-LD is going to be included in the new version of iChat... because LD stands for low delay... because it's a codec that's tuned for online chat i.e. two-way communications. You're not going to be encoding your music in AAC-LD.
still no high efficiency aac in Leopard?
Has Apple any plan to include aacplus?
still no high efficiency aac in Leopard?
Has Apple any plan to include aacplus?
They should have - if they don't then iTunes will be the only music application left that is unable to play HE-AAC webradio.
I thought that a new version of iTunes and QuickTime would be released around the same time as Leopard. It might be built into Leopard (though I thought iTunes was part of iLife) but I am not sure. Last time they did something like this, it took Apple about a week to come out with Windows downloads. That was around the time Panther was released, it took them about a week or so to come out with Windows equivalents.
I thought that a new version of iTunes and QuickTime would be released around the same time as Leopard. It might be built into Leopard (though I thought iTunes was part of iLife) but I am not sure. Last time they did something like this, it took Apple about a week to come out with Windows downloads. That was around the time Panther was released, it took them about a week or so to come out with Windows equivalents.
Guarantee there will be a new version of iTunes and QuickTime released in the next week...maybe even by Friday. QuickTime obviously due to the reported encoder updates. iTunes will probably get a minor update just with any last minute Leopard-specific fixes.
Apple always keeps the Mac and Windows versions in sync (unless there is a specific Mac or Windows fix that only applies to 1 platform)...I doubt they will stop now. So expect those who have earlier OS X versions or Windows to get an update as well.
I'll let you guys know when I get Leopard on Friday what version of QuickTime comes with it and see if I can find anything interesting...
Guarantee there will be a new version of iTunes and QuickTime released in the next week...maybe even by Friday. QuickTime obviously due to the reported encoder updates. iTunes will probably get a minor update just with any last minute Leopard-specific fixes.
Apple always keeps the Mac and Windows versions in sync (unless there is a specific Mac or Windows fix that only applies to 1 platform)...I doubt they will stop now. So expect those who have earlier OS X versions or Windows to get an update as well.
I'll let you guys know when I get Leopard on Friday what version of QuickTime comes with it and see if I can find anything interesting...
While I'll admit that it is very possible iTunes/Quicktime updates are part of the + in the 300+ updates, I haven't been able to find any information on the Apple website that these are pending for next week. Don't get me wrong, I'd love to see updates/improvements to the Apple encoder and, in fact hope I'm wrong on this one... but I think that if these updates were coming, they'd have included them in the feature list... as telling people that iTunes was going to support HE-AAC is sort of a big deal.
I suppose we'll have to wait and see. Can anyone even point me to an article from somewhere like slashdot, digg, AppleInsider, MacRumors, etc. that implies these updates are coming this week?
A new AAC-LC codec is available in the new Mac OS X 1.5 (code named as Leopard) which will be released in Oct. 26. It has some significant sound quality improvement and bitrate mode enhancement. Since iTunes and QT use the AAC codec built natively in the OS X, these enhancements will be reflected in these Apple applications as well (doesn't matter you have upgraded these individual applications or not). You can also use the following commandline tools available in the OS X 1.5 to access the codec:
$> afconvert - perform various audio file conversions, including AAC encoding and decoding.
$> afplay - play back an audio file (compressed or uncompressed).
$> afinfo - display information about an audio file.
I just received my copy of 10.5 and a nice new feature is that iTunes lists the actual bitrate of AAC VBR files, albeit only ones encoded in Leopard. The encoder is indeed updated as well since the bitrates are completely different on some test encodes I did compared to the previous version. I haven't had time to do abx tests yet though.
FLAC doesn't seem to be supported.
I just received my copy of 10.5 and a nice new feature is that iTunes lists the actual bitrate of AAC VBR files, albeit only ones encoded in Leopard. The encoder is indeed updated as well since the bitrates are completely different on some test encodes I did compared to the previous version. I haven't had time to do abx tests yet though.
FLAC doesn't seem to be supported.
Is it now a true VBR mode, or does it still have the bitrate floor? i.e. Other than digital silence, it doesn't encode below the nominal bitrate, only above it.
The encoder is indeed updated as well since the bitrates are completely different on some test encodes I did compared to the previous version. I haven't had time to do abx tests yet though.
You should hear the sound quality improvement as well.
Although Apple applications offer a convenient way to access Apple AAC codecs, for Mac users, the best way to access the full functionality of the codecs is through those af* commandline tools (afconvert, afinfo, afplay). All other applications only use a subset of it. For instance, iTunes only uses ABR and VBR_Constraint encoding modes. QuickTime is better, it accesses most of the feature set, but it can only encodes to a set of pre-determined discrete bitrates (afconvert can encode to any arbitrary bitrate as long as it is within the supported bitrate range).
FLAC doesn't seem to be supported.
No, it's not in the supported codecs for consumers. It's only supported through SDK.
HE-AAC is not supported yet as many have figured.
Is it now a true VBR mode, or does it still have the bitrate floor?
The newly released Apple AAC encoder offers four encoding modes:
Constant Bit Rate (CBR)
-- Recommended for live streaming --
This mode achieves a constant target bit rate and is completely compliant to the CBR mode specified in the MPEG-4 standard. This mode is suitable for constant-bit-rate network transmission when decoding in real-time with a fixed end-to-end audio delay.
Average Bit Rate (ABR) - Default Mode
-- Recommended for controlling file size --
A target bit rate is achieved over a long term average (typically after the first few seconds of encoding). Unlike CBR mode, this mode does not provide constant delay when using constant bit rate transmission, but this mode provides almost best global quality while still being able to strictly control the resulting file size and with less complexity than the CBR mode.
Variable Bit Rate (VBR)
-- Recommended for controlling the audio quality --
The audio signal is encoded with constant (and settable) quality and virtually no bit rate constraints. This is the best mode to achieve consistent audio quality across many files with the smallest file size to achieve that quality. It also has the lowest complexity of all the encoding modes.
Variable Bit Rate But Constrained (VBR_Constrained)
-- Recommended as a compromise between VBR and ABR --
This mode is similar to VBR but limits the average bit rate variation. The lower limit is the user-selected bit rate. Higher bit rate is adapted for difficult tracks and can generate up to 10% larger files than the ABR mode.
Note that QuickTime and the commandline tools on Mac can access all these four encoding modes. However, iTunes can only access ABR and VBR_Constrained.
AAC-LD is going to be included in the new version of iChat... because LD stands for low delay... because it's a codec that's tuned for online chat i.e. two-way communications.
Yup, I believe people will be very pleased by the significant sound quality improvement in iChat (especially for music) when both parties are running on Leopard (Mac OS X 10.5).
Anyone know what version of FLAC is being supported for developers on Mac Leopard (OS X 10.5) in the SDK? We should get more Apple Mac FLAC supporting apps right?
It is nice to hear that a new AAC encoder is being implemented in iTunes/QuickTime. I wonder when Windows users and older Mac OS X users will get this update. I am glad that they are implementing a true VBR encoding mode now as that has always been a major gripe against iTunes in that it used a constrained VBR encoding mode.
Although Apple applications offer a convenient way to access Apple AAC codecs, for Mac users, the best way to access the full functionality of the codecs is through those af* commandline tools (afconvert, afinfo, afplay). All other applications only use a subset of it. For instance, iTunes only uses ABR and VBR_Constraint encoding modes. QuickTime is better, it accesses most of the feature set, but it can only encodes to a set of pre-determined discrete bitrates (afconvert can encode to any arbitrary bitrate as long as it is within the supported bitrate range).
I played around with the command line to access the true VBR mode in order to get high quality VBR files, but I'm not sure if I got it right;
afconvert -f m4af -d aac -s 3 -q 127
This setting produced vbr files with a fairly low bitrate (80-140kbps), and the bitrate option (-b) didn't make any difference.. Is there a way to make the true vbr mode aim for transparency and higher bitrate files?
Correct me if I'm wrong... but wasn't it stated above that iTunes still only uses VBR_constrained? I'm not sure much as changed. I was under the impression that full VBR was always available in Tiger through command line or CoreAudio, which is what programs such as Maxx use to encode AAC.
Is there a way to make the true vbr mode aim for transparency and higher bitrate files?
The command line for the true VBR mode is as follows:
afconvert -f m4af -d aac -s 3 -u vbrq 127
In VBR mode (-s 3), bitrate option (-b) is ignored because the mode is configured by sound quality which is set by "-u vbrq <sound_quality>" where <sound_quality>: 0-127. Note that the ABR and VBR modes are new features supported in Leopard. CBR and VBR_Constrained modes were in previous Mac OS X.
Anyone know what version of FLAC is being supported for developers on Mac Leopard (OS X 10.5) in the SDK?
FLAC 1.2.0 is the version that the SDK is tested against, however, it should work just fine with any other FLAC versions.
In fact, it's pretty easy for people to build FLAC codec from the SDK provided in Leopard install DVD. Once you have installed those developer tools, all you have to do is to follow the steps given in /Developer/Examples/CoreAudio/AudioCodecs/Codecs/FLAC/README.txt to build and install the FLAC codec to the system to make it accessible via af* command line tools.
Great info. Thank you.
Too bad you can't access the true VBR mode from iTunes itself.
Great info. Thank you.
Too bad you can't access the true VBR mode from iTunes itself.
Hopefully this comes soon, but it seems Apple like keeping the iTunes settings simple.
I suggest people send a feature request suggesting an ADVANCED tab that reveals full customisation of the AAC encoder.
http://www.apple.com/feedback/itunesapp.html (http://www.apple.com/feedback/itunesapp.html)
If this happens then it would make it possible to conduct listening tests to determine and what setting the VBR mode is transperant 95%+ of the time. My guess is it would produce files with sizes closer to 100 Kbps than 128 Kbps, thus enabling excelleng space saving compared to iTunes 128 Kbps default setting.
In fact, has the new iTunes in Leopard changed the default to ABR rather than CBR? Or is it still CBR (which I understand isn't actually true CBR due to the way AAC uses the bit resivour).
Many thanks for the info skuo. It is very helpful.
Is there any way to set the quality rate higher? I've been playing around and see no effect in tuning the numbers to higher than 127. This seems to give a 192 kbs type file.
Is there a way to make the true vbr mode aim for transparency and higher bitrate files?
The command line for the true VBR mode is as follows:
afconvert -f m4af -d aac -s 3 -u vbrq 127
In VBR mode (-s 3), bitrate option (-b) is ignored because the mode is configured by sound quality which is set by "-u vbrq <sound_quality>" where <sound_quality>: 0-127. Note that the ABR and VBR modes are new features supported in Leopard. CBR and VBR_Constrained modes were in previous Mac OS X.
Hmm.. for some reason I can only make it work with AIFF files, converting alac files gives this message: "Error: Couldn't set audio converter property ('prop')".
Anyway, this setting is probably exactly what I've been looking for since it seems more or less like an equivalent to the V2 setting in LAME for producing true VBR files around the 192kbps mark.
Is there a way to make the true vbr mode aim for transparency and higher bitrate files?
The command line for the true VBR mode is as follows:
afconvert -f m4af -d aac -s 3 -u vbrq 127
In VBR mode (-s 3), bitrate option (-b) is ignored because the mode is configured by sound quality which is set by "-u vbrq <sound_quality>" where <sound_quality>: 0-127. Note that the ABR and VBR modes are new features supported in Leopard. CBR and VBR_Constrained modes were in previous Mac OS X.
Hmm.. for some reason I can only make it work with AIFF files, converting alac files gives this message: "Error: Couldn't set audio converter property ('prop')".
Anyway, this setting is probably exactly what I've been looking for since it seems more or less like an equivalent to the V2 setting in LAME for producing true VBR files around the 192kbps mark.
any idea how to pick up this new encoder for us windows folks? and does it work in foobar?
I imagine you would have to wait for a new Windows QuickTime version.
Apple have their iTunes 7.5, together with QuickTime 7.3 for windows available. Can someone confirm if these product included the latest aac codec?
I don't know if is the latest aac codec but is a different version than the previous version of iTunes. I could not prove it in depth, but at first glance I notice that bitrates are higher when using VBR. I do not know whether this has a direct impact on the quality...
Well in theory, you would think that the QuickTime 7.3 version will have at least the same if not newer AAC codec compared to the one that shipped with Leopard. Else it would be a downgrade for us Leopard users
Is there a frontend or AppleScript available that one could use to batch encode a few files with the afconvert command?
I'm pretty confused over what portion of the AAC encoding is OS dependent, and how much of it (if any) has to do with updating QuickTime. An earlier post states that the codec versions are embedded in the OS; other posts indicate that they are updated via QuickTime. Does anyone know which surmise is the correct one?
I'm still running Tiger, as I haven't yet come up with enough reason to substantiate an immediate move to Leopard. Earlier this evening I ran the new iTunes and QT updates.
Now, running the new iTunes and QuickTime on Tiger (10.4), here is what I notice:
- The MP4 music export options in QT 7.3 (Pro) are 'None', 'CELP (Speech)', 'AAC-LC (Music)', 'AAC-LC VBR (Music)' and 'Pass Through'. However, each option aside from 'AAC-LC (music)' is greyed out. Seems that I cannot choose any of these other options. What's up with that? Guess I need 10.5 in order to use those?
- With iTunes 7.5, the 'VBR' checkbox for AAC encoding is still there, and still works. Now, why can I choose a VBR option in iTunes but not with QuickTime? This is really confusing.
EDIT: Never mind. I found the new options. I was looking in the wrong place.
- I haven't yet checked thoroughly enough to find out about the actual AAC encoder. It does seem to be different, and a cursory encoding test of the 'glockenspiel' test WAV shows that the AAC encoder may now be fixed. At least the glockenspiel WAV doesn't appear to be tripping up the AAC encoder like it had in the past. But I need to run a few more tests before I am can say that with any degree of real certainty.
Just where are the AAC codecs located, and how to tell which versions they are? For what it's worth, the MPEG component now found in the QT Library folder is version 7.3.
EDIT: Never mind. I found the new options. I was looking in the wrong place.[/b]
Where's the right place?
EDIT: Never mind. I found the new options. I was looking in the wrong place.[/b]
Where's the right place?
Export -> Movie to QuickTime Movie -> Options -> Sound -> Format (Choose AAC) -> Encoding Strategy (that's where you'll find the four options)
QT's screwy export menu is the same non-intuitive mess it's been since the stone age. I wonder why no one at Apple has ever shown the slightest inclination to redesign its user interface?
Oh, what a mess to get a true vbr encoded mp4 file. You have to encode with true vbr mode to a mov container (please tell me it's not the only way to access true vbr mode) and then export it with standard mp4 container format.
Export -> Movie to QuickTime Movie -> Options -> Sound -> Format (Choose AAC) -> Encoding Strategy (that's where you'll find the four options)
QT's screwy export menu is the same non-intuitive mess it's been since the stone age. I wonder why no one at Apple has ever shown the slightest inclination to redesign its user interface?
Ah well, how screwy is that!
The files QT generates appear to be identical with what you get from the command line.
How much easier it would have been to extend the same funtionality to iTunes.
Thanks for the heads up. I never would have even thought of looking there.
Apple have their iTunes 7.5, together with QuickTime 7.3 for windows available. Can someone confirm if these product included the latest aac codec?
I can confirm that aac encoder from iTunes 7.5 (Win) is exactly the same as the new one from iTunes 7.4 (Mac) shipped with Leopard. The encoder will appear in SoundExpert 256kbit/s page in a few days.
So I don't know who else has looked into this yet... but I'm not entirely happy with the results I'm getting with the new encoder. I don't think the encoder has necessarily gotten worse... but the old settings I use are no longer producing acceptable results. I've tested this across many tracks. With both the old and new versions, I've encoded using iTunes at 128 AAC w/VBR.
For example, AC/DC - What Do You Do For Money Honey? encoded with iTunes 7.4/QT 7.2 produced a 143 kbps file that I could not ABX from the WavPack source with any reasonable consistency. Encoding the same file with the same settings with iTunes 7.5/QT 7.3 produced a 138 kpbs file with a noticeable artifacts in the high end (primarily ringing and smearing in the cymbals) that was easily ABX-able 100% of the time.
I'm not saying that the new encoder is worse... just that the same setting produce worse results. Your millage may vary. Has anyone else been experience this type of behavior with the new codec?
So I usually avoid bumping my own posts... but I have a lot of files to encode and I'm trying to figure out if the quality problems I'm experiencing with the new AAC encoder are unique to my system or the fault of the encoder.
Has anyone else had quality problems encoding with the new iTunes 7.5 / QuickTime 7.3 128 AAC VBR_Constrained (iTunes with VBR checked) encoder?
I'm (temporarily I hope) swithching to the iTunes encoder as Nero Digital encoded AAC files will not play on the Creatize ZEN 16 GB flash player. How can I access VBR mode via command line using Windows XP? I have a large collection in FLAC and use Foobar to bulk convert to AAC. I searched for the afconvert executeable and can't find it.
I'm (temporarily I hope) swithching to the iTunes encoder as Nero Digital encoded AAC files will not play on the Creatize ZEN 16 GB flash player. How can I access VBR mode via command line using Windows XP? I have a large collection in FLAC and use Foobar to bulk convert to AAC. I searched for the afconvert executeable and can't find it.
I can't answer your question about encoding with the iTunes encoder on the command line.
However, it's possible to encode with the iTunes encoder using dbpoweramp as your secure ripper and itunesencode. Details here:
http://forum.dbpoweramp.com/showthread.php?t=14103 (http://forum.dbpoweramp.com/showthread.php?t=14103)
Thanks. How would I utilize the true VBR mode from the lastest iTunes/Quicktime encoder from Windows XP command line?
I'm (temporarily I hope) swithching to the iTunes encoder as Nero Digital encoded AAC files will not play on the Creatize ZEN 16 GB flash player.
Have you already tried the "Optimize MP4 Layout" switch, available in both MP3tag and foobar2000? This one's reported to fix the Nero AAC problems with several hardware devices. The extension also has has to be set to .m4a instead of the default .mp4 one in many cases (though I guess you're already aware of this old "problem").
Is there a frontend or AppleScript available that one could use to batch encode a few files with the afconvert command?
I've posted a basic AppleScript wrapper for AAC CBR here (http://dougscripts.com/itunes/scripts/ss.php?sp=ripaacoldschool). I'm not happy with the "C" of it though.
I've posted a basic AppleScript wrapper for AAC CBR here (http://dougscripts.com/itunes/scripts/ss.php?sp=ripaacoldschool). I'm not happy with the "C" of it though.
AWESOME! Any plans for changing that C to a V? Or could one modify the script so that it encodes using the new VBR? Also, I've noticed that it seems to be intended for ripping only, and not converting already ripped files... is that right?
I'm currently trying to figure out how to streamline the encoding process with QT.
Has anyone been able to figure out how to get files encoded with Quicktime (using the new VBR mode) to go from being MOVs to M4As? I encoded in OS X, the tried simply changing the extensions (in Windows, mind you), but foobar doesn't recognise them as playable media files.
Has anyone been able to figure out how to get files encoded with Quicktime (using the new VBR mode) to go from being MOVs to M4As? I encoded in OS X, the tried simply changing the extensions (in Windows, mind you), but foobar doesn't recognise them as playable media files.
Try to convert the .mov to mpeg4, and for audio select passthrough.
Xlossless decoder will convert lossless files to true VBR format using quicktime and coreaudio. It's a GUI app.
http://tmkk.hp.infoseek.co.jp/xld/index_e.html (http://tmkk.hp.infoseek.co.jp/xld/index_e.html)
Xlossless decoder will convert lossless files to true VBR format using quicktime and coreaudio. It's a GUI app.
http://tmkk.hp.infoseek.co.jp/xld/index_e.html (http://tmkk.hp.infoseek.co.jp/xld/index_e.html)
Good GRAVY! Works like a charm!
(Busemann: Thanks for the tip too!)
Max should also support the new VBR mode soon, but for now I'm ripping to FLAC and converting to AAC with XLD
Max should also support the new VBR mode soon ...
Sounds like it might be a little while yet from what Max's developer says (http://sbooth.org/forums/viewtopic.php?f=4&t=1780#p6076).