Topic: AAC Conversion--best practice? (Read 8427 times)

bspachman · « **on:** April 28, 2004, 11:51:24 pm »

I hope this is a relatively simple question:

I have ~10,000 tracks in APE/APL format & maintain a duplicate of all those tracks in MP3 format for use on my iPod & for cross-platform use on my various Macintoshes.

Now that AAC has become a more widely-used format, I'm interested in reconverting my APE/APLs to the AAC format for my cross-platform/portable uses.

I know MC10 can play AAC tracks (I've downloaded a few from the iTunes Music Store), but there isn't an option to encode to AAC.

Can a future version of MC10 hook into the same QuickTime libraries it uses for playback in order to encode to AAC?

If not, does anyone have pointers on the simplest way to convert a large number of APEs to AAC?

Will I need to be concerned about tagging issues?

Best,
Brad

paulr · « **Reply #1 on:** April 28, 2004, 11:54:09 pm »

I can't answer the MC questions, but dBPowerAmp Music Converter will handle conversion quite nicely I think (and it's free).

SteveG · « **Reply #2 on:** April 29, 2004, 09:40:35 am »

Brad,

At this time the licensing costs for AAC are prohibitive for us, so there is not a way to convert to AAC from within MC.

Steve

bspachman · « **Reply #3 on:** April 29, 2004, 09:45:18 am »

Thanks for the pointer. I'll check it out...

[later]

Hmmmm. It looks promising. However, I can't tell if the Monkey's audio decoder from dbPowerAmp wil read APL files. Anyone know?
--------
SteveG,

Yes, I guessed as much from older posts. I didn't know if there an API available to QuickTime that would allow you to use its built-in encoder. Too bad

Brad

IanG · « **Reply #4 on:** April 29, 2004, 05:57:14 pm »

Quote from: paulr on April 28, 2004, 11:54:09 pm

I can't answer the MC questions, but dBPowerAmp Music Converter will handle conversion quite nicely I think (and it's free).

I've just tried producing a few .AACs with this - quick and easy, but MC doesn't play or import them, even with .aac selected as an option. Is there something extra that needs to be done?

Ian G.

SteveG · « **Reply #5 on:** April 30, 2004, 09:59:42 am »

Ian G,

Can you import and play the files in QuickTime? If not, we will not be able to either.

Steve

bspachman · « **Reply #6 on:** April 30, 2004, 10:06:13 am »

It seems there is little agreement as to what an AAC file is in some quarters of the computer audio world.

Most are in agreement that it is the audio encoding used in the MPEG4 specification. More specifically, folks are used to using them with Apple's iTunes software (which was the first major piece of software to support the codec).

However, there are a bevy of filename extensions: .aac, .m4a, .m4p, .m4v, etc. etc.

For some converters, it seems to matter what you set the destination file extension to. I believe that dbPower Amp Converter treats .aac files as some kind of raw audio bitstream.

Although I haven't tried it yet, converting to .m4a (an audio mpeg4 file) may work better.

Best,
Brad

pank2002 · « **Reply #7 on:** April 30, 2004, 10:32:07 am »

all right, here's my guide to, how you make aac.
First, you need a command line AAC encoder or Nero aac encoder (commercial.)

if you choose Nero go ahead (

) and get the it. It like 25mb but you only need a couple of files. You'll also need nencode from
http://www.rarewares.org/aac.html
now go to Zrockers site here
http://www.1982transam.com/
and get the utility at the bottom of the page.

Alright, now we're ready.
* install nero
* after install, go to /program files/shared files/ahead/audioplugins and place the files from the nencode zip and from Zrockers files in there.
* run nencode once and choose your settings. I recommend you use one of the VBR preset. I think I use transparent, which, to me, sound just fine.
* start media center and go to tools->optioons->encoding and choose external encoder in the encoder list.
* click on advance
* in the exe path locate the zkr_exec.exe file, which you placed in the audio plugins folder
* in parament put the following: nencode.exe %IN %OUT
* extension should be mp4, and the encoder do support long names.
The reason to use zrockers program is that the command lines that way will pupup in the back instead of in the front.

now there's another (free) way too, but I'll have to read up on that one, as I don't use it. I'll post it in a bit.

pank2002 · « **Reply #8 on:** April 30, 2004, 10:49:59 am »

So, I'm not to sure about this, as I don't use it myself.

well, go to http://www.rarewares.org/aac.html and get FAAC.

Put faac.exe it in windows/system32.

in encoder option (still extern);
in exe just write faac
parament should be something like
-q [set quantizer qulity, 100 around 120kbps, max 500] -w %IN

file should be mp4 or m4a. I you remove the -w it should be aac. You can also use zrockesr program with this program.

I haven't tried it, so I don't know how good or bad it is, or even if this line work. If it dosen't work, try putting a - before the %IN.

Hope it helps.
- Rasmus

IanG · « **Reply #9 on:** April 30, 2004, 01:42:31 pm »

Quote from: SteveG on April 30, 2004, 09:59:42 am

Ian G,

Can you import and play the files in QuickTime? If not, we will not be able to either.

Steve

I tried it with iTunes and that wouldn't play it either. An AAC file produced by iTunes was fine in MC.

Ian G.

jeffh · « **Reply #10 on:** April 30, 2004, 09:49:52 pm »

I continue to have great success using quicktime as an external encoder for MC. It
takes a little work, but works great and files play anywhere apple aac file play.
I think that you have to have licensed quicktime. Here is the post where I
called out how I was doing it.

http://yabb.jriver.com/interact/index.php?board=3;action=display;threadid=16795;start=msg114780#msg114780

hans-jürgen · « **Reply #11 on:** May 02, 2004, 10:52:04 am »

Quote from: bspachman on April 28, 2004, 11:51:24 pm

If not, does anyone have pointers on the simplest way to convert a large number of APEs to AAC?

You could use the command line version of FAAC with the external codec plugin in MediaCenter which should work similar to e.g. using it in CD rippers like EAC, CDex or Audiograbber. If you would like to try out other applications for transcoding, you should have a look at foobar2000, dBpowerAMP or GX::Transcoder which can all use FAAC or other AAC codecs, either on the command line or with an own GUI.

Quote

Will I need to be concerned about tagging issues?

No more, because the release version 1.24 uses iTunes-compatible tagging switches now. You can find them on the console help screen (--help or --long-help) or on the Wiki page for FAAC:

http://www.audiocoding.com/wiki/index.php?page=FAAC

So if MediaCenter can import the tagging data from freeDB or CDDB and hand it over to the external codec plugin, it should be possible to tag the *.m4a or *.mp4 files on-the-fly. By the way, it should be enough to simply define these file extensions in the GUI, so using the -w switch is not necessary anymore, because these file extensions trigger the automatic wrapping to the MP4 container format which is mandatory for iTunes-compatible tags, i.e. you cannot tag *.aac files with them.

This should also explain the other problems mentioned in this thread, I guess. Files with the *.aac extension are not the same as *.mp4 or *.m4a files, because they use another container (ADTS or ADIF headers). See the Wiki for more info on this, e.g. the pages on MP4 or AAC and follow the links there.

hans-jürgen · « **Reply #12 on:** May 03, 2004, 01:08:59 am »

Quote from: pank2002 on April 30, 2004, 10:49:59 am

Put faac.exe it in windows/system32.
in encoder option (still extern);
in exe just write faac

That's right, you could also use any other directory that is included in the "path" or the main directory of Media Center.

Quote

parameters should be something like
-q [set quantizer quality, 100 around 120kbps, max 500] -w %IN

Yes, the default value for VBR quantizer quality in percent is 100 which should result in a ~120 kbps stereo 16bit 44.1 kHz file (if your input had these properties, too).

The -w switch is only necessary if you don't define either *.mp4 or *.m4a as the file extension for the output file on the command line, i.e. if you don't define an output file name with -o at all. In a GUI like the external codec plugin for Media Center (where you have to set the file extension separately from the command line) using the -o switch for output file name is mandatory, otherwise the GUI setting wouldn't be used. So -o %OUT is necessary, too (I'm just guessing that the placeholder for output file name is called %OUT in this plugin, because I don't know it).

Quote

file should be mp4 or m4a. I you remove the -w it should be aac. You can also use zrockesr program with this program.

Using *.m4a would enable to play the files directly in iTunes or on the iPod while *.mp4 should be recognized by QuickTime without an installed iTunes. It's correct that *.aac is the default file extension with FAAC, i.e. if you don't use -w or the other file extensions on the command line. These files play on hardware portables like some Philips Expanium CD players, some newer Nokia mobile phones, the RCA Lyra A/V Jukebox etc. as well as in Winamp 5.03 and in all other software players that use plugins based on FAAD2, the open source AAC/MP4 decoder.

Adding "zrockesr" (which I've never heard of) is probably not necessary, because it seems to suppress the console display of command line codecs in Windows. I guess that Media Center and/or the external codec plugin have a setting to do that like "silent operation" or the like?

Quote

I haven't tried it, so I don't know how good or bad it is, or even if this line work. If it dosen't work, try putting a - before the %IN.

Using a simple hyphen instead of the input file name is possible if the GUI enables direct piping of the input to the codec, i.e. without a temporary WAV file in between. FAAC can use this setting with several GUIs like foobar2000 or CDex, so I guess it should also work with Media Center, but probably there is a special setting for this mode in the plugin somewhere. Furthermore you don't need %IN then, because it substitutes the input file name.

The following line works in CDex's external encoder setting, so it should give you an idea how to adapt it for Media Center, e.g. the tag name placeholders in quotation marks will be different, I guess:

- -o %2 -q 100 --artist "%a" --album "%b" --title "%t" --genre "%g" --year "%y" --track "%tn"

Concerning the improved quality of the newer FAAC versions you could either do an own listening test or read the last AAC comparison where FAAC v1.23.5 was third closely behind Nero (which used ~140 kbps overall instead of 128 kbps) and not far away from the winner iTunes 4.2:

http://www.rjamorim.com/test/aac128v2/results.html

By the way, according to a few reports the brand-new iTunes 4.5 seems to have ringing problems caused by a higher cutoff frequency than v4.2 which isn't unusual for CBR codecs.

Sound-related changes in FAAC v1.24 since this comparison are enabled TNS (Temporal Noise Shaping) on default and automatically changing cutoff frequencies with different -q settings (e.g. -q 50 uses 10 kHz, -q 100 16 kHz and -q 150 22 kHz now) which can still be set individually with the -c switch.

pank2002 · « **Reply #13 on:** May 03, 2004, 06:22:40 am »

Quote from: hans-jürgen on May 03, 2004, 01:08:59 am

Quote from: pank2002 on April 30, 2004, 10:49:59 am
Put faac.exe it in windows/system32.
in encoder option (still extern);
in exe just write faac

That's right, you could also use any other directory that is included in the "path" or the main directory of Media Center.

Sure, if you think so, you can do it that way, but imo its a lot more work, if you use faac in other programs too.

Quote

parameters should be something like
-q [set quantizer quality, 100 around 120kbps, max 500] -w %IN

Yes, the default value for VBR quantizer quality in percent is 100 which should result in a ~120 kbps stereo 16bit 44.1 kHz file (if your input had these properties, too).

The -w switch is only necessary if you don't define either *.mp4 or *.m4a as the file extension for the output file on the command line, i.e. if you don't define an output file name with -o at all. In a GUI like the external codec plugin for Media Center (where you have to set the file extension separately from the command line) using the -o switch for output file name is mandatory, otherwise the GUI setting wouldn't be used. So -o %OUT is necessary, too (I'm just guessing that the placeholder for output file name is called %OUT in this plugin, because I don't know it).

Quote

Proberbly. I don't use faac myself, so I don't know. I just guessed from the help in the program

Quote

file should be mp4 or m4a. I you remove the -w it should be aac. You can also use zrockesr program with this program.

Using *.m4a would enable to play the files directly in iTunes or on the iPod while *.mp4 should be recognized by QuickTime without an installed iTunes. It's correct that *.aac is the default file extension with FAAC, i.e. if you don't use -w or the other file extensions on the command line. These files play on hardware portables like some Philips Expanium CD players, some newer Nokia mobile phones, the RCA Lyra A/V Jukebox etc. as well as in Winamp 5.03 and in all other software players that use plugins based on FAAD2, the open source AAC/MP4 decoder.

Quote

.mp4 do play on the iPod. All aac my files are named .mp4 and play just fine on the iPod.

Quote

Adding "zrockesr" (which I've never heard of) is probably not necessary, because it seems to suppress the console display of command line codecs in Windows. I guess that Media Center and/or the external codec plugin have a setting to do that like "silent operation" or the like?

Zrocker is a user on this board, who've made a small program which does, that commandline windows will be minimized, instead of popping up. Its quite useful. Its possible that the external encoder have option to do "silent operation" but why search in each an every encoder to find the needed string, when you can use a simple program? Its double work imo.

Quote

Using a simple hyphen instead of the input file name is possible if the GUI enables direct piping of the input to the codec, i.e. without a temporary WAV file in between. FAAC can use this setting with several GUIs like foobar2000 or CDex, so I guess it should also work with Media Center, but probably there is a special setting for this mode in the plugin somewhere. Furthermore you don't need %IN then, because it substitutes the input file name.

In MC - which seems like you haven't use - %IN is your file. Fx i you have a list of files it will put the diffrent files in for %IN... Sorry if this bad explained. Hope you get the picture.

Quote

The following line works in CDex's external encoder setting, so it should give you an idea how to adapt it for Media Center, e.g. the tag name placeholders in quotation marks will be different, I guess:

- -o %2 -q 100 --artist "%a" --album "%b" --title "%t" --genre "%g" --year "%y" --track "%tn"

MC should transfer the tags from YABB, or wherever you got 'em, to the file without faac.

Quote

Concerning the improved quality of the newer FAAC versions you could either do an own listening test or read the last AAC comparison where FAAC v1.23.5 was third closely behind Nero (which used ~140 kbps overall instead of 128 kbps) and not far away from the winner iTunes 4.2:

http://www.rjamorim.com/test/aac128v2/results.html

I think I've seen it already. I the glad owner of Nero AAC anyway, so...

Quote

By the way, according to a few reports the brand-new iTunes 4.5 seems to have ringing problems caused by a higher cutoff frequency than v4.2 which isn't unusual for CBR codecs.

Sound-related changes in FAAC v1.24 since this comparison are enabled TNS (Temporal Noise Shaping) on default and automatically changing cutoff frequencies with different -q settings (e.g. -q 50 uses 10 kHz, -q 100 16 kHz and -q 150 22 kHz now) which can still be set individually with the -c switch.

I don't like iTunes.

BTW Hans, do you know of any program like nencode for the quicktime encoder?

Cheers, Rasmus

hans-jürgen · « **Reply #14 on:** May 03, 2004, 08:33:41 am »

Quote from: pank2002 on May 03, 2004, 06:22:40 am

.mp4 do play on the iPod. All aac my files are named .mp4 and play just fine on the iPod.

Then this might have changed from the early iPod versions, but anyhow it's good to know that you wouldn't have to rename them from *.mp4 to *.m4a (in iTunes).

Quote

In MC - which seems like you haven't use - %IN is your file. Fx i you have a list of files it will put the diffrent files in for %IN... Sorry if this bad explained. Hope you get the picture.

That's how I understood it from your first posting, but what about the output file name placeholder, is it called %OUT like I guessed?

Quote

MC should transfer the tags from YABB, or wherever you got 'em, to the file without faac.

That would mean that MC can already handle iTunes/iPod compatible M4 tagging, so if it does - even better... But do you know if it's possible for the external codec plugin to use tagging switches on the command line?

Quote

I don't like iTunes.
BTW Hans, do you know of any program like nencode for the quicktime encoder?

There is a compiled script called "Quitobat" or something similar which enables batch encoding with QuickTime from the command line, but as far as I know it isn't very convenient and/or fast.

pank2002 · « **Reply #15 on:** May 03, 2004, 09:22:54 am »

IE Just ade my reply:

Quote

Then this might have changed from the early iPod versions, but anyhow it's good to know that you wouldn't have to rename them from *.mp4 to *.m4a (in iTunes).

jep, you can use both. I've been using mp4 since v2.01 (iPod firmware.) MC use QT engine to play aac files.

yes, %OUT work as you figured.

Quote

That would mean that MC can already handle iTunes/iPod compatible M4 tagging, so if it does - even better... But do you know if it's possible for the external codec plugin to use tagging switches on the command line?

MC do support iTunes tagged files, but I'm not sure if iTunes can read MC tags... I don't use iTunes. I don't know if you can tag via command line. However you can get tags from the file location fx artist/album (year)/# - title or artist - title.

Good to know about Quitobat... so far I'm perfectly happy with Nero.

hans-jürgen · « **Reply #16 on:** May 03, 2004, 11:59:11 am »

Quote from: pank2002 on May 03, 2004, 09:22:54 am

yes, %OUT work as you figured.

OK...

Quote

I don't know if you can tag via command line. However you can get tags from the file location fx artist/album (year)/# - title or artist - title.

Sure, using appropriate file names is always possible, so a player/masstagger can create tags from there (like foobar2000 or Media Center). But some tags may be too difficult or impossible with this method like cover art, i.e. including a GIF, JPG or PNG image from your HDD in the tagged MP4 file. That's why using tagging switches with the encoder make sense, and FAAC does this the same way as iTunes. Here's the list of possible tags:

--artist "X" Set artist to X
--writer "X" Set writer to X
--title "X" Set title to X
--genre "X" Set genre to X
--album "X" Set album to X
--compilation Mark as compilation
--track "X" Set track to X (number/total)
--disc "X" Set disc to X (number/total)
--year "X" Set year to X
--cover-art "X" Read cover art from file X
--comment "X" Set comment to X

hans-jürgen · « **Reply #17 on:** May 06, 2004, 12:47:51 am »

Quote from: pank2002 on May 03, 2004, 09:22:54 am

Good to know about Quitobat... so far I'm perfectly happy with Nero.

Sorry, I didn't remember the correct name for this tool, it's "Qutibacoas - QuickTime Batch Conversion Assistant", available on http://www.rarewares.org/mp4.html

hans-jürgen · « **Reply #18 on:** May 07, 2004, 01:50:21 am »

Having a closer look at the available plugins for Media Center it seems that the only existing DSP plugin turns it into a DirectX host. This might also support the 3ivx DirectShow filter suite for full MPEG-4 content including multichannel AAC/MP4 encoding with their audio encoder which is based on FAAC. The DS filter suite is free for one month, and then you have to pay US$ 19.99 if you want to use both audio codecs (US$ 6.99 for the decoder only).

JimH · « **Reply #19 on:** May 07, 2004, 08:33:29 am »

Quote from: hans-jürgen on May 07, 2004, 01:50:21 am

Having a closer look at the available plugins for Media Center it seems that the only existing DSP plugin turns it into a DirectX host. This might also support the 3ivx DirectShow filter suite for full MPEG-4 content including multichannel AAC/MP4 encoding with their audio encoder which is based on FAAC. The DS filter suite is free for one month, and then you have to pay US$ 19.99 if you want to use both audio codecs (US$ 6.99 for the decoder only).

MC has DSP built-in. You should be able to find it in MC Help.

hans-jürgen · « **Reply #20 on:** May 07, 2004, 10:49:36 am »

Quote from: JimH on May 07, 2004, 08:33:29 am

MC has DSP built-in. You should be able to find it in MC Help.

Thanks for the information. Is it possible though to use external DS filters through the DSP plugin for DirectX support? Could the 3ivx DS filter suite be used for encoding MPEG-4 content in Media Center this way?

INTERACT FORUM

Author Topic: AAC Conversion--best practice? (Read 8427 times)