MP3 - AAC w/ ID tags. Impossible?

[Judas989]

I've been trying to convert a few MP3s to AAC w/ no luck. The specific problem is the ID tags aren't there when the final MP4/M4A (respectively, whichever encoding I'm using) is finished converting.

I really don't want to be doomed to be using iTunes to convert the files since I'll never be able to edit the tags outside of iTunes w/o corruption of the entire file.


Any help would be much appreciated. (BTW, I'm using the latest version and yes, preserve ID tags is ticked and I haven't unticked it since it was installed).

[xoas]

Re: MP3 - AAC w/ ID tags. Impossible?

Even though you are encoding, you need the AAC/mp4 decoder to manage tags. If you are using the AAC encoder, you need to install the aac.enc file as well (and it needs to be installed after you have installed the aac encoder codec). I have also installed the mp4>AAC/AAC>mp4 codec although I don't know as that is necessary.

So which mp4/aac codecs do you have installed and which have you tried?

Best wishes,
Bill Mikkelsen

[Spoon]

Re: MP3 - AAC w/ ID tags. Impossible?

Try holding the mouse over one of the converted files, it should show if there is a Tag.

[Judas989]

Re: MP3 - AAC w/ ID tags. Impossible?

Thank you Xoas, that makes sense, I'm going to try it out today.

The ENCODERS I've installed and tried are FAAC, Nero's AAC codec, and QuickTime's plugin. I've found FAAC to be the best at compression thusfar.


So... first I need to install FAAC, then the decoder? Or... LOL, I'm lost as to which order I need to install which plugins. =\


Thanks alot for the replies.

[Judas989]

Re: MP3 - AAC w/ ID tags. Impossible?

Ok, I've installed all the correct codecs to properly handle the AAC tags, but my new question has to do w/ FAAC. Does anyone know what the quality ranges mean? The default is 100, is that kbps? CBR or VBR? It doesn't say a whole lot. =\

[xoas]

Re: MP3 - AAC w/ ID tags. Impossible?

Just tried it out myself. It appears that 100 will encode at a vbr of around 100 kbs. (tag info shows a bitrate of 110 kbs. but dB Audio Player displays a variable bitrate readings as track plays, so I think VBR is a safe bet).

I noticed that the codec help file has not displayed right after installation, but I don't know if this is standard or even if there is a Help file for the FAAC encoder codec. It may require a restart for the help file to show, if there is one. Codec help for dBpowerAMP Music Converter can be found through Start>All Programs>dBpowerAMP Music Converter>Help>Codecs.

Hope this helps.
Best wishes,
Bill Mikkelsen

[Judas989]

Re: MP3 - AAC w/ ID tags. Impossible?

Hmm... I noticed that too, that the 150 setting will hover around 145 - 160 when playing (which is what Winamp reports at least) so I think I'll stick to the FAAC encoder.

Thanks for all your help Xoas, good to see helpful mods. =D

Now I have the dilema of dealing w/ a bunch of AAC tracks I ripped in iTunes... and the risk of corruption if I edit the tags within Winamp... or anything else that isn't iTunes. Damn Apple. =\ I wonder if I could convert them to FAAC? Hmm...

[xoas]

Re: MP3 - AAC w/ ID tags. Impossible?

Just a few notes and observations:
1 The FAAC encoder does not have a codec help file within dMC;
2. The FAAC encoder appears to consistently encode at a frequency of 48000 khz;
3. The FAAC encoder appears to consistently encode at avbr;
4. While the vbr bitrate appear to approximate the conversion setting at some settings (for example at 100 and at 150), in other cases the numbers are very different (a file converted at a setting of 60 actually is around 90 kbs., a setting of 10 results in a file of 60 kbs., a setting of 400 results in a file at 195 kbs).

As far as re-converting your iTunes aac files, good luck. It may be the case that iTunes has converted these to a protected format. Perhaps not but because iTunes seems to be very heavily into DRM protection of files I do not think I could ever advise to use iTunes as your primary conversion/storage tool. You will find some other threads discussing these issues.

Best wishes,
Bill Mikkelsen

[Judas989]

Re: MP3 - AAC w/ ID tags. Impossible?

Yeah, I have been reading alot about iTunes and what I've gathered is that it just uses a different type of tag, not DRM (when ripping at least).

And I noticed those things too about FAAC, I think I'll try Nero instead, as it has more functionality and control compared to FACC w/ dMC.

[xoas]

Re: MP3 - AAC w/ ID tags. Impossible?

I do have a few other observations about the FAAC encoder.
Given a mono (1 channel) file, it converted it to a one mono (1 channel) mp4/aac file at 22050 khz frequency. Bitrate was around 19 kbs.
Given a 6 channel wav file, it was converted to a 6 channel mp4/AAC file at 48 khz. The bitrate for the converted file at the "100" setting was around 350 kbs.
Ripping a cd at the "175" setting resulted in a files at 44.1 khz frequency with bitrates listing from 135 kbs to 162 kbs.

These results suggest that the FAAC encoder can claim a great deal of power and versatility, more than might be expected. For better or for worse, however, the codec deploys its features automatically and the user has only limited control. However, the codec does work very well. More documentation on this codec would be welcome.

Best wishes,
Bill Mikkelsen

[Spoon]

Re: MP3 - AAC w/ ID tags. Impossible?

>2. The FAAC encoder appears to consistently encode at a frequency of 48000 khz;

You would think this would lessen the quality, if you convert 44KHz to 48KHz...

[hans-jürgen]

Re: MP3 - AAC w/ ID tags. Impossible?

These results suggest that the FAAC encoder can claim a great deal of power and versatility, more than might be expected. For better or for worse, however, the codec deploys its features automatically and the user has only limited control. However, the codec does work very well. More documentation on this codec would be welcome.

Hi Bill, glad you like FAAC, thank you. The documentation/help screen can be found when simply typing "faac" in the DOS box for the command line version faac.exe, or with faac --long-help, too. I wrote a Wiki page about FAAC on Audiocoding.com, the homepage of the open source codecs FAAC and FAAD2 (the decoder):

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

I hope that most of your questions will be answered when reading it, but here are some remarks

* The -q setting defines a VBR quantizer quality in %, not a bitrate. It should result in ~120 kbps for a normal stereo input file at 44.1 kHz sample rate and 16bit sample size.
* The sample rate of the input file (or bitstream) is not changed by FAAC. If you want to resample while encoding (makes sense at low bitrates), you have to use an external resampler and/or a resampler that can be used during encoding like the SSRC module in foobar2000. I don't know if dbpowerAMP has this option, too.
* If you must use a bitrate instead of a VBR quality setting, you can use the -b switch on the command line which will result in a ABR file. The cutoff switch -c also influences the bitrate, see the Wiki page for more.
* A recommended setting for multichannel transcoding (AC3->AAC/MP4) of video soundtracks would be -q 75 which will result in ~230 kbps/6ch with a decent sound quality, at least to my ears. See the Doom9.org thread I've linked to on the Wiki page.

ZZee ya, Hans-Jürgen

[xoas]

Re: MP3 - AAC w/ ID tags. Impossible?

Thank you for your input. I appreciate all your posts today.
While this post does answer some questions about the dMC FAAC encoder, I am still left with some questions. In dMC (using the regular interface) the ONLY variable you can control during encoding is the vbr quantizer quality and the encoder handles bitrates, channels, frequencies automatically. And this may be a good thing (preventing bad choices or choices that just might crash the conversion) overall. But what about the situation where the user wants an ATYPICAL output (such as output files for a cell phone)? Is there anywhere a non-technical user could go to for the information on how to accomplish this (presumably, in this case you might have to convert an existing file to a new file with the right frequency, and maybe channels, for FAAC to convert to the right type of mp4 for the cell phone)?
Thanks for your insights.
Best wishes,
Bill Mikkelsen

[hans-j�rgen]

Re: MP3 - AAC w/ ID tags. Impossible?

The best way probably would be if Spoon extends the GUI he created for FAAC and adds some more options that the command line faac.exe has. I don't know if he uses a wrapper for the EXE or rather the libfaac.dll version which is not up-to-date in certain aspects, e.g. it cannot write MP4 files by itself nor tag them like faac.exe can.

Concerning the correct output for a cell phone you would have to output AAC files most of the time (not MP4 or M4A), because e.g. Nokia normally only knows this file format. To achieve this with FAAC you shouldn't use FAAC's built-in MP4 wrapper, because its default output format already is AAC. And probably there's an option in dbpowerAMP somewhere to choose the desired file format, right?

Other recommendations for cell phones would include lower VBR settings than the default 100%, e.g. 75% will certainly do it for these kind of portables, probably even lower than that. See the table on the Wiki page for a rough idea about resulting bitrates for these VBR settings. And using additonal resampling really makes sense then, too, but I don't know if dbpowerAMP has this ability.

[Spoon]

Re: MP3 - AAC w/ ID tags. Impossible?

I will note it down to look at. dMC has SSRC resampling.