HydrogenAudio

Lossy Audio Compression => AAC => AAC - General => Topic started by: DaGrandMastah on 2012-05-03 14:51:04

Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-03 14:51:04
Hi all, I'm currently researching what the best route is to go with when converting over my CD library.  I realize that everyone loves Lossless (which I'll use for archiving the CD's) but I'm looking for "the best" lossy encoding.

I was originally planning to encode all my CD's into 320 CBR but it seems that almost everything I read states that this is a waste of space as their is nary a difference (except to the most trained ears) between 320 CBR and VBR v-0.  Ultiamtely, I don't mind the difference in space when on my computer hard drive but it does become more of an issue when uploading to my iphone for portable listening so then I switched course and started thinking I would go with VBR v-0 (I posted a similar question to this in the mp3 forum) but now I'm reading that I may even be better off going with AAC 256?

This may make the most sense for me being that I'm a Mac user (imac, iphone, ipad) and I'm going to playing all my music out of my itunes library.

Is there any reason I would regret the decision to go AAC over mp3?

Also, for those with experience with this, could you direct me to the best possible setting to use in XLD for encoding CD's/FLAC files to aac?
Title: Should I convert all my audio to 256 AAC?
Post by: pdq on 2012-05-03 14:57:06
As long as you still have the lossless files there is no wrong answer.

If you do some serious listening tests (i.e. double-blind ABX testing) you will probably find that even 256 kbps is very much overkill, especially for portable listening. I don't use AAC, but many people recommend 128 kbps for portable use.
Title: Should I convert all my audio to 256 AAC?
Post by: Porcus on 2012-05-03 15:01:03
Is there any reason I would regret the decision to go AAC over mp3?


You might encounter devices (like, a car stereo?) without AAC support. If you keep the lossless files, it is merely the nuissance there and then though.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-03 15:08:23
As long as you still have the lossless files there is no wrong answer.

If you do some serious listening tests (i.e. double-blind ABX testing) you will probably find that even 256 kbps is very much overkill, especially for portable listening. I don't use AAC, but many people recommend 128 kbps for portable use.


Yeah, the thing is that I have a LOT of music to convert....and it's not just converting but properly tagging with artwork and putting it in the exact format I like within the itunes file/folder structure so I'd like to avoid having to redo anything by researching the topic beforehand.

One thing I can say, and I am not an audiophile in the slightest, is that I can tell the difference in 128 kb mp3 and 256 kb mp3 on my iphone.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-03 15:52:27
Also, what are the best (recommended) settings for converting to AAC?  Is it 256 AAC CBR?
Title: Should I convert all my audio to 256 AAC?
Post by: pdq on 2012-05-03 17:25:07
Yeah, the thing is that I have a LOT of music to convert....and it's not just converting but properly tagging with artwork and putting it in the exact format I like within the itunes file/folder structure so I'd like to avoid having to redo anything by researching the topic beforehand.

I would think that this is simply a matter of making sure that the lossless files are all properly tagged and everything, then use software that duplicates all of this exactly when you convert to lossy. If at some time you are not satisfied with the quality or file size, simply repeat with the new settings.

Edit: I don't use itunes, but I thought it had the ability to convert on-the-fly from lossless to lossy as it downloads to your DAP? You could then use different settings at different times with no additional effort.
Title: Should I convert all my audio to 256 AAC?
Post by: felix26591 on 2012-05-03 19:14:50
Also, what are the best (recommended) settings for converting to AAC?  Is it 256 AAC CBR?


I woudn't really recommend 256kb AAC it's still too high you would still not notice the diference between 192kb or 168kb. Do a blind ABX test on the diferent qualities of AAC to know which one suits you best. As you are all apple AAC is the best way to go. You could get better quality of Vorbis but then you have compatability problems. Go AAC anywhere from 128KB-192KB which every suits you best.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-03 19:45:32
Also, what are the best (recommended) settings for converting to AAC?  Is it 256 AAC CBR?


I woudn't really recommend 256kb AAC it's still too high you would still not notice the diference between 192kb or 168kb. Do a blind ABX test on the diferent qualities of AAC to know which one suits you best. As you are all apple AAC is the best way to go. You could get better quality of Vorbis but then you have compatability problems. Go AAC anywhere from 128KB-192KB which every suits you best.


Thanks for the suggestion.  I'm still leaning more towards 256 as I'd like to eliminate the chances that, like has happened before, my hearing tastes change/improve and I regret not going higher.  Perhaps I won't notice it now, but maybe I'll notice it later?

So if I do end up going that route, would Tru-VBR settings be the way to go? 

Title: Should I convert all my audio to 256 AAC?
Post by: mixminus1 on 2012-05-03 19:55:21
If you're planning on ripping to lossless, pdq's suggestion is the way to go: rip to ALAC using XLD, make the ALACs your iTunes library, and then encode on-the-fly when you sync your devices.

You can try the different bitrates - 128, 192, and 256 - and see if you can even tell the difference.  You'll always have the ability to change your mind on a whim and use a different bit rate by just resyncing.
Title: Should I convert all my audio to 256 AAC?
Post by: Kohlrabi on 2012-05-03 21:01:07
Also, what are the best (recommended) settings for converting to AAC?  Is it 256 AAC CBR?

Please don't use CBR encoding, unless you have known bad decoders or are running a streaming site. It only wastes spaces, defeating the whole purpose of lossy encoding.

So if I do end up going that route, would Tru-VBR settings be the way to go?

Yes. It's advisable to do ABX tests to determine your sweet spot concerning the target bitrate/quality setting. For safety you might want to slightly increase the quality setting above that threshold when encoding your final files.

Lossless encoding will trade off HD space vs. not having to spend time on re-ripping if you find out that your lossy encodings are not appropriate.
Title: Should I convert all my audio to 256 AAC?
Post by: JJZolx on 2012-05-03 21:27:16
Yeah, the thing is that I have a LOT of music to convert....and it's not just converting but properly tagging with artwork and putting it in the exact format I like within the itunes file/folder structure so I'd like to avoid having to redo anything by researching the topic beforehand.


How many CDs do you have?

I'm just wondering if the space saving is worth all of the hand wringing.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-04 00:18:05
Yeah, the thing is that I have a LOT of music to convert....and it's not just converting but properly tagging with artwork and putting it in the exact format I like within the itunes file/folder structure so I'd like to avoid having to redo anything by researching the topic beforehand.


How many CDs do you have?

I'm just wondering if the space saving is worth all of the hand wringing.


I'm honestly not sure. Definitely over 100 but prolly less than 200.

I thought about possibly doing ALAC but I still think I'd prefer to go with AAC as the primary source.  That being said, I will likely rip to ALAC over FLAC just in case.

I'll have to look at the settings in XLD to determine what's best. Anyone have experience using that program on Mac?
Title: Should I convert all my audio to 256 AAC?
Post by: RobertoDomenico on 2012-05-04 01:09:32
Just listen to your lossless (ALAC) files in iTunes. When transferring to a portable have iTunes transcode it on the fly to AAC to either 128, 192 or 256 CBR. For me 128 is plenty for portables. By far the easiest simplest way to manage your music, one library and all your metatdata stays the same everywhere.
Title: Should I convert all my audio to 256 AAC?
Post by: JJZolx on 2012-05-04 01:38:34
Quote
How many CDs do you have?

I'm just wondering if the space saving is worth all of the hand wringing.


I'm honestly not sure. Definitely over 100 but prolly less than 200.


200 CDs encoded losslessly in ALAC (at 0.33 GB per CD) is less than 70 GB. At today's ~$100 for a 1 TB drive, that should cost you only about $7 in hard drive space. Unless you're really pressed for hard drive space, the space savings of using a lossy format (and its bitrate) shouldn't be much of a consideration at all. It might be different if you had 10,000 CDs and didn't want to pay for or maintain all the drive space required.


Quote
I thought about possibly doing ALAC but I still think I'd prefer to go with AAC as the primary source.  That being said, I will likely rip to ALAC over FLAC just in case.


ALAC over FLAC makes sense when your environment is mostly Apple and iTunes. In any case, if you choose a lossless format, you can readily convert everything to a different one at a later date, with no penalty and with minimal effort. That's not the case with lossy formats.

Where space and lossy encoding settings are an important consideration is in use on portables, like iPods. A lower bitrate means both better battery life and more songs that can be loaded load into limited storage space.

I would rip the CDs to ALAC, then keep a mirror library encoded in AAC or Mp3 if you want to load files onto an iPod. The disk space required for a lossy mirror library of 200 CDs should be less than 25 GB of space. And once again, if the main library is in a lossless format, the decision of which bitrate/quality level to use becomes much less unimportant, since you can always re-encode the library to another bitrate at a later date.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-04 02:03:00
Quote
How many CDs do you have?

I'm just wondering if the space saving is worth all of the hand wringing.


I'm honestly not sure. Definitely over 100 but prolly less than 200.


200 CDs encoded losslessly in ALAC (at 0.33 GB per CD) is less than 70 GB. At today's ~$100 for a 1 TB drive, that should cost you only about $7 in hard drive space. Unless you're really pressed for hard drive space, the space savings of using a lossy format (and its bitrate) shouldn't be much of a consideration at all. It might be different if you had 10,000 CDs and didn't want to pay for or maintain all the drive space required.


Quote
I thought about possibly doing ALAC but I still think I'd prefer to go with AAC as the primary source.  That being said, I will likely rip to ALAC over FLAC just in case.


ALAC over FLAC makes sense when your environment is mostly Apple and iTunes. In any case, if you choose a lossless format, you can readily convert everything to a different one at a later date, with no penalty and with minimal effort. That's not the case with lossy formats.

Where space and lossy encoding settings are an important consideration is in use on portables, like iPods. A lower bitrate means both better battery life and more songs that can be loaded load into limited storage space.

I would rip the CDs to ALAC, then keep a mirror library encoded in AAC or Mp3 if you want to load files onto an iPod. The disk space required for a lossy mirror library of 200 CDs should be less than 25 GB of space. And once again, if the main library is in a lossless format, the decision of which bitrate/quality level to use becomes much less unimportant, since you can always re-encode the library to another bitrate at a later date.


Thanks for the help.  So I got the lossy part down now...definitely doing ALAC.

Would these be good settings for my AAC encoding?  Should I go higher or lower on the target quality?

(http://i48.tinypic.com/261ln3c.jpg)
Title: Should I convert all my audio to 256 AAC?
Post by: RobertoDomenico on 2012-05-04 03:33:52
If iTunes is your music player of choice just transcode to AAC with iTunes. It will make your life 1000 times easier having to only manage one lossless library. iTunes will transcode to AAC on the fly.

If you must use XLD for AAC then i wouldn't use True VBR since i have found them to skip during playback on some ipod models. My personal opinion i would use 128 VBR Constrained.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-04 04:15:07
I heard that was only in the older apple models but doesn't occur anymore.

Wow.  I'm learning a lot from this thread.  Thanks a lot guys...you've been a great help here.

So I'm almost decided but I had a question.  I just spent some time testing the differences in size between mp3 vbr v0 and aac true vbr with target quality at 110 and i'm noticing that certain albums, the aac files come out slightly larger....and in other folders, the aac files are the smaller ones.

Is that because AAC true vbr allows for the file to exceed a specific rate while the mp3 vbr constrains the rate at 256?
Title: Should I convert all my audio to 256 AAC?
Post by: RobertoDomenico on 2012-05-04 05:24:56
Using LAme Mp3 they will not playback gapless over home sharing on iPod Touch and iPhones. Just keep that in mind (One day we can hope Apple will fix this)
Title: Should I convert all my audio to 256 AAC?
Post by: Engelsstaub on 2012-05-04 06:14:20
Most often I convert my lossless sources with XLD to AIFF and drag them into iTunes. From thence I let iTunes encode these files to the "iTunes Plus" settings and delete the AIFFs. (Many here will tell you that iTunes Plus bit rate is overkill, but I do it more for the sake of uniformity. I also subscribe to iTunes Match FWIW.)

When I do let XLD do the encoding it is 256 Kbps VBR constrained with "Encoder quality" set at max. I don't think it makes much difference either way at that bit rate.

If you plan on subscribing to iTunes Match in the future these may be the "optimal" settings. ALAC/encoding to the iPod on the fly, as some posters have encouraged, is also a good alternative. Me personally: as long as my files are archived lossless (as they are,) I would keep AAC files on the computer. It may matter if at a later date you want to migrate to, say, a MBA with limited SSD space.

Just my thoughts.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-04 12:28:56
Most often I convert my lossless sources with XLD to AIFF and drag them into iTunes. From thence I let iTunes encode these files to the "iTunes Plus" settings and delete the AIFFs. (Many here will tell you that iTunes Plus bit rate is overkill, but I do it more for the sake of uniformity. I also subscribe to iTunes Match FWIW.)

When I do let XLD do the encoding it is 256 Kbps VBR constrained with "Encoder quality" set at max. I don't think it makes much difference either way at that bit rate.

If you plan on subscribing to iTunes Match in the future these may be the "optimal" settings. ALAC/encoding to the iPod on the fly, as some posters have encouraged, is also a good alternative. Me personally: as long as my files are archived lossless (as they are,) I would keep AAC files on the computer. It may matter if at a later date you want to migrate to, say, a MBA with limited SSD space.

Just my thoughts.


Thanks for the info.  I don't notice any difference between true vbr or constrained at that bitrate either so I'm just gonna test out a couple more and go with whatever produces the smaller file size (which appears to be True VBR).

I plan on doing the same as you.  I am going to have my computer HD filled with all the AAC files and have a lossless backup of all my audio for archiving purposes.

Do you know what iTunes uses to encode their audio?  Just curious if they're going with vbr or cbr?
Title: Should I convert all my audio to 256 AAC?
Post by: Engelsstaub on 2012-05-04 12:43:40
...

Do you know what iTunes uses to encode their audio?  Just curious if they're going with vbr or cbr?


VBR.
Title: Should I convert all my audio to 256 AAC?
Post by: pdq on 2012-05-04 13:05:05
Is that because AAC true vbr allows for the file to exceed a specific rate while the mp3 vbr constrains the rate at 256?

mp3 vbr is not constrained to 256 unless you specifically tell the encoder to do so. Otherwise it is free to use as many 320 frames as it feels necessary.

There could be many reasons why, even if both encoders are targeting the same quality, one encoder could achieve that quality more easily than the other due to differences in the codec format.

Also, determining what is or is not a certain quality level is not an exact science. One encoder may use different criteria than another and so make different choices as to what it keeps and what it does not keep.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-04 16:07:27
You guys have been a tremendous help.  Ok so after weighing all my options I think I've decided on going with

VBR contstrained at 256 kbps with quality set to max to avoid any possible skipping on the true vbr. 

or

True VBR with quality set to max at 127

I was noticing that, while the constrained VBR is slightly higher in size then the true vbr, it is still significantly lower than 320 kpbs mp3 cbr.

My understanding is that, while it's not imperative that i match itunes settings, the rate I indicated above matches it closely and I've always found the quality of the music on itunes to be great.
Title: Should I convert all my audio to 256 AAC?
Post by: Ouroboros on 2012-05-04 16:44:32
Constrained VBR is still wasting bits. I'm sure that XLD's uses Quicktime for AAC encoding, and if Quicktime's true VBR skipped there'd be loads of posts about it.

Just go for true VBR, and let the encoding algorithm decide on the appropriate bit rate for each frame it encodes. Apple's encoders have been developed for a long time, and like LAME for MP3 there are very few bugs left, and they perform very well in the comparative listening tests. If True VBR had issues they would show up in the listening tests.
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-04 16:56:23
Constrained VBR is still wasting bits. I'm sure that XLD's uses Quicktime for AAC encoding, and if Quicktime's true VBR skipped there'd be loads of posts about it.

Just go for true VBR, and let the encoding algorithm decide on the appropriate bit rate for each frame it encodes. Apple's encoders have been developed for a long time, and like LAME for MP3 there are very few bugs left, and they perform very well in the comparative listening tests. If True VBR had issues they would show up in the listening tests.


So then the only question is....what target quality should I set?  Should I use 110 which is estimated at 256...or 127..which estimates it at about 320.

I noticed that the true vbr quality 110 was showing some files coming in as low as 180 kbps per second...but i'm assuming that's due to the complexity fo the song not requiring all those extra bits.
Title: Should I convert all my audio to 256 AAC?
Post by: Ouroboros on 2012-05-04 17:25:03
Exactly. If the music's complexity doesn't require lots of bits then the encoder produces smaller frames. Don't get hung up on the bit rate - it's an incidental outcome of the perceptual transparency ("quality") you are trying to achieve. For example, after lots of reading and lots of comparative listening tests (some ABX, some not) I settled on LAME V2 for most of my encoding, and on some albums get average bit rates around 130 kbit/s, while on others it will average around 220 kbit/s. I don't care, they still sound fine.

For XLD (Quicktime) encoding you have three choices when it comes to picking a quality setting:

1. Do your own listening tests with a range of quality settings
2. Read around to see what settings others are using
3. Use the default / recommended setting

1. takes time but will give you results that you know work for you, 2. relies on other people, not all of whom can be relied on to be impartial or accurate, 3. assumes that the developers have done 1.

Based on my experience with LAME - settling on V2, which is towards the top end of what many people recommend for casual or portable listening to non-problem genres, and is what many people would casually recommend - I'd suggest that some test encodes using the default settings (110?) might be worthwhile, but it all depends on how much time you want to spend.
Title: Should I convert all my audio to 256 AAC?
Post by: polemon on 2012-05-04 18:44:57
Hi all, I'm currently researching what the best route is to go with when converting over my CD library.  I realize that everyone loves Lossless (which I'll use for archiving the CD's) but I'm looking for "the best" lossy encoding.
[...]
Is there any reason I would regret the decision to go AAC over mp3?

Well, I don't know, but I personally think, that AAC isn't as much a replacement for MP3 as a lot of people would like it to. I mean. MP3 still isn't dead, and due to improvement in encoders like Lame, it kinda get's improved over the years, even though the codec is old, etc. I'd much rather see OPUS be the next "big thing", but I believe that this just wishful thinking :)
Title: Should I convert all my audio to 256 AAC?
Post by: Kohlrabi on 2012-05-04 18:59:14
I noticed that the true vbr quality 110 was showing some files coming in as low as 180 kbps per second...but i'm assuming that's due to the complexity fo the song not requiring all those extra bits.

Bitrate is no quality metric, but a size metric. You cannot compare file sizes of different material, encoded to a lossy format, to draw valid conclusions about quality differences of the resulting encodes. The variable bitrate or quality setting encodes every file to arrive at the same apparent quality, not file size.

I'd still advise to do an ABX test (http://www.hydrogenaudio.org/forums/index.php?showtopic=16295) to determine your encoder settings, but I was certainly content with my TVBR 70 encodes. To be fair, I only encoded for portable/casual use, not for archival, so your mileage may vary.
Title: Should I convert all my audio to 256 AAC?
Post by: flapane on 2012-05-11 11:24:24
Hi all, I'm currently researching what the best route is to go with when converting over my CD library.  I realize that everyone loves Lossless (which I'll use for archiving the CD's) but I'm looking for "the best" lossy encoding.


Two years ago I chose Nero AAC -q0.65 (via dbPowerAmp) for portable listening (TMo Vibrant and a pair of Yuin PK2 earphones), after having done some ABXs with similar bitrate VBR Lame encodings.
I'm happy with it, I barely notice any artifacts (mostly blues and jazz) but on some classical music files.
Needless to say, the advantage over my old LAME 128kbps CBR files is obvious.
I guess you could come to different conclusions, so you'd better do some blind tests with different encoders (and music genres) at similar bitrates.

Yeah, the thing is that I have a LOT of music to convert....and it's not just converting but properly tagging with artwork and putting it in the exact format I like within the itunes file/folder structure so I'd like to avoid having to redo anything by researching the topic beforehand.


I know what you mean, that's why I wrote a Bash script that parsed my thousands old 128kbps mp3 files ID3 tags and wrote them into my new aac files. I found a way to copy jpg covers too, but I can't find that version of the script atm.
Hope it helps
Code: [Select]
#!/bin/bash
#script per copiare le tag da un file mp3 nel file m4a con lo stesso nome
#script for id3 tag cloning from mp3 file into an m4a AAC file with same basename
#flapane.com 24jan10

for file in "$@"
do

title=$(id3v2 -l "$file" | sed -n '/^TIT2[^:]*:[[:space:]]*/s///p')
artist=$(id3v2 -l "$file" | sed -n '/^TPE1[^:]*:[[:space:]]*/s///p')
album=$(id3v2 -l "$file" | sed -n '/^TALB[^:]*:[[:space:]]*/s///p')
year=$(id3v2 -l "$file" | sed -n '/^TYER[^:]*:[[:space:]]*/s///p')
genre=$(id3v2 -l "$file" | sed -n '/^TCON[^:]*:[[:space:]]*/s///p' | awk '{print $1}' )
bandorchestra=$(id3v2 -l "$file" | sed -n '/^TPE2[^:]*:[[:space:]]*/s///p')
composer=$(id3v2 -l "$file" | sed -n '/^TCOM[^:]*:[[:space:]]*/s///p')
#publisher=$(id3v2 -l "$file" | sed -n '/^TPUB[^:]*:[[:space:]]*/s///p')
#track=$(id3v2 -l "$file" | sed -n '/^TRCK[^:]*:[[:space:]]*/s///p')

#echo $title
#echo $artist
#echo $album
#echo $year
#echo "$genre"
#echo $track
#echo $bandorchestra
#echo $composer
#echo $publisher

filemp4=$(basename "$file" .mp3).m4a

mp4tags \
-s "$title" \
-a "$artist" \
-A "$album" \
-y "$year" \
-g "$genre" \
-R "$bandorchestra" \
-w "$composer" \
"$filemp4"

done
Title: Should I convert all my audio to 256 AAC?
Post by: DaGrandMastah on 2012-05-14 15:32:48
Thanks a lot!  I'll check this out later on when I get home.

As a follow up, I'd like to thank everyone for giving me their opinions and helping me decide.

I'm now ripping my CD's to FLAC (for backup) and then converting the FLAC files to AAC True VBR 110.  The songs sound absolutely fantastic and it doesn't waste nearly as much space as 320 kbps. 
Title: Should I convert all my audio to 256 AAC?
Post by: F17 on 2012-05-14 21:19:18
Hi all, I'm currently researching what the best route is to go with when converting over my CD library.  I realize that everyone loves Lossless (which I'll use for archiving the CD's) but I'm looking for "the best" lossy encoding.

I was originally planning to encode all my CD's into 320 CBR but it seems that almost everything I read states that this is a waste of space as their is nary a difference (except to the most trained ears) between 320 CBR and VBR v-0.  Ultiamtely, I don't mind the difference in space when on my computer hard drive but it does become more of an issue when uploading to my iphone for portable listening so then I switched course and started thinking I would go with VBR v-0 (I posted a similar question to this in the mp3 forum) but now I'm reading that I may even be better off going with AAC 256?

This may make the most sense for me being that I'm a Mac user (imac, iphone, ipad) and I'm going to playing all my music out of my itunes library.

Is there any reason I would regret the decision to go AAC over mp3?

Also, for those with experience with this, could you direct me to the best possible setting to use in XLD for encoding CD's/FLAC files to aac?

____________________________________________________________________________

Just go with mp3(lame 3.98.4) using dbpoweramp V0 settings. It's easy with mp3 as u can find lot of tagging softwares and every hardware supports it.

Now could be irrelevant to this topic but why don't you try this maybe it will deliver some other new concept (http://www.noiseaddicts.com/2009/03/can-you-hear-this-hearing-test/)

best wishes


Title: Should I convert all my audio to 256 AAC?
Post by: greynol on 2012-05-14 22:06:18
Could be irrelevant to this topic?  No, try completely irrelevant to this topic.

FWIW, the test samples on that web page are fundamentally flawed, easily allowing for false positives depending on hardware and software configuration.

http://www.hydrogenaudio.org/forums/index....showtopic=93660 (http://www.hydrogenaudio.org/forums/index.php?showtopic=93660)
Title: Should I convert all my audio to 256 AAC?
Post by: F17 on 2012-05-15 16:30:54
Could be irrelevant to this topic?  No, try completely irrelevant to this topic.

FWIW, the test samples on that web page are fundamentally flawed, easily allowing for false positives depending on hardware and software configuration.

http://www.hydrogenaudio.org/forums/index....showtopic=93660 (http://www.hydrogenaudio.org/forums/index.php?showtopic=93660)



THNX
Title: Should I convert all my audio to 256 AAC?
Post by: FLAC plz on 2012-06-03 22:11:05
grandmastah, i think you should conduct some ABX tests to see what bitrate works best for you. your ears won't lie to you if it's a blind ABX test. i think you would be surprised how well AAC does a lower bitrates. i just wrote about this in another thread, but i used to encode at q100, and i realized that was overkill after doing some tests on myself. i now encode at q80 and it's perfectly transparent to my ears.

also, don't worry about the bitrate with the true vbr mode. sometimes when i encode at q80, i end up with some frighteningly low-bitrate files. sometimes i end up with files as low as 80kbps, but every time i try ABX'ing them with the original FLAC, i can't tell the difference.  of course, the tracks with these bitrates are generally pretty quiet and less complex sounding.

i hope you find out what works best for you!
Title: Should I convert all my audio to 256 AAC?
Post by: bigshot on 2012-06-26 08:07:18
I've been building a music server for the past few years. Right now, it stands at well over a year's worth of music, all ripped from CDs. When I started ripping, I did careful line level matched listening tests of various cdecs and bitrates and the original CD. I found that for 95% of music AAC 192 and MP3 256 were completely transparent. But I ran across a couple of CDs that had textures that artifacted like crazy. I found that in order to encode those troublesome tracks properly, it required AAC 256 or MP3 320 LAME. I settled on AAC 256 VBR and started in ripping my collection of CDs. I'm still working my way through it all.

I keep hearing shocked gasps from audiophile acquaintenes that I'm not ripping to lossless. I just don't see the need. I own the CD- it's in a box in the garage. The AAC file sounds exactly the same and it's emailable, ipod friendly and compact. Why do I want to mess with lossless?

The other day, someone said, "What if you want to transcode to another format in te future?" well, I haven't ever needed to transcode. AAC works in everything I own and it sounds perfect. So just for yucks I took a well recorded classical piece and encoded it and reencoded it ten times- ten generations of transcoding. It sounded fine.

Lossless is overkill for just simple music playback.
Title: Should I convert all my audio to 256 AAC?
Post by: Porcus on 2012-06-26 09:18:01
well over a year's worth of music, all ripped from CDs.
[...]
I own the CD- it's in a box in the garage.


That's OK if only one recording now and then has to be re-ripped at a higher quality. What you don't want, is to re-rip some 12000 (?) CDs. I did a job of half the size, and it took months (even with a carousel changer).
Title: Should I convert all my audio to 256 AAC?
Post by: Steve Forte Rio on 2012-06-26 17:31:14
Hi. Haven't read the whole thread, but answering the author's question I would recommend
Code: [Select]
qaac.exe --tvbr 127 -q 2
as the most qualitative VBR AAC mode.
Title: Should I convert all my audio to 256 AAC?
Post by: eahm on 2012-06-26 17:44:31
grandmastah, i think you should conduct some ABX tests to see what bitrate works best for you. your ears won't lie to you if it's a blind ABX test. i think you would be surprised how well AAC does a lower bitrates. i just wrote about this in another thread, but i used to encode at q100, and i realized that was overkill after doing some tests on myself. i now encode at q80 and it's perfectly transparent to my ears.

also, don't worry about the bitrate with the true vbr mode. sometimes when i encode at q80, i end up with some frighteningly low-bitrate files. sometimes i end up with files as low as 80kbps, but every time i try ABX'ing them with the original FLAC, i can't tell the difference.  of course, the tracks with these bitrates are generally pretty quiet and less complex sounding.

i hope you find out what works best for you!

Agree, -V100 is overkill. After this comment http://www.hydrogenaudio.org/forums/index....st&p=798420 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=85135&view=findpost&p=798420) I "redid" all my ABX and now I am truly happy with -V82 for random archival and portable use http://www.hydrogenaudio.org/forums/index....st&p=798905 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=95519&view=findpost&p=798905)

Hi. Haven't read the whole thread, but answering the author's question I would recommend
Code: [Select]
qaac.exe --tvbr 127 -q 2
as the most qualitative VBR AAC mode.

The command "qaac -V127" is enough. -q2 is set by default. "As you can see, iTunes is using either ABR or CVBR. If you want the same result as iTunes Plus, just use -v256 -q2 (-q2 is set by default, so actually -v256 is enough)" from https://github.com/nu774/qaac/wiki/Encoder-configuration (https://github.com/nu774/qaac/wiki/Encoder-configuration)
Title: Should I convert all my audio to 256 AAC?
Post by: yourlord on 2012-06-26 18:02:08
I rip to FLAC for a couple of reasons.

1st, I can directly play the FLAC file on my home network. I don't use any devices on the network that can't deal with FLAC so there's no reason to keep another lower quality copy around just to play.

2nd, in the lossy codec world I prefer OGG Vorbis, but I do occasionally wind up with a device that won't play Vorbis files. So, with my FLAC archive I can directly encode to whatever the target device supports. Vorbis for my portable DAP, mp3 for my car stereo, etc. This allows me to use devices that don't support my codec of choice, but when a device does support a modern codec I can use the space savings they afford. I almost ended up with a car stereo that would play AAC files and if I had bought it I could have then encoded to AAC to gain the advantages of that format over mp3, but the reviews for that stereo weren't as good.

3rd, CD's can get scratched by kids, eaten by dogs (it's happened!), burned in a fire, etc. Once converted to FLAC I have a perfect copy which I then backup on 2 separate machines at home, an external USB drive at home, and that I rsync with another machine of mine at my parent's house for off-site backup. With 3 local copies I also run a monthly checksum comparison between the 3 copies to monitor for drive errors to ensure I don't lose data that way.

4th, royalty free and open source. No one is going to come in and tell me I'm a criminal for using it. I have the source code and therefore will always be able to access my collection, even if the computer architecture changes. I can always port the code to any new platform that may emerge.


Anyway,

I'm now ripping my CD's to FLAC (for backup) and then converting the FLAC files to AAC True VBR 110.  The songs sound absolutely fantastic and it doesn't waste nearly as much space as 320 kbps. 


I personally dislike Apple, but if you're determined to use their wares then I would suggest converting to ALAC and just using that in your itunes library. Play the ALAC files directly, and you can transcode to AAC or whatever when you want to copy to your ipod, etc.
Title: Should I convert all my audio to 256 AAC?
Post by: bigshot on 2012-06-27 20:41:40
That's OK if only one recording now and then has to be re-ripped at a higher quality. What you don't want, is to re-rip some 12000 (?) CDs. I did a job of half the size, and it took months (even with a carousel changer).


AAC at 256 is audibly transparent. I don't see any reason to ever need to re-rip at a larger file size.

By the way, both AAC and ALAC are open source.
Title: Should I convert all my audio to 256 AAC?
Post by: Ouroboros on 2012-06-27 21:22:08
both AAC and ALAC are open source.

ALAC is open source, but I don't believe there's a good open source AAC codec. FAAC isn't - from the FAAC website (http://www.audiocoding.com/faac.htm):

Quote
Note that the quality of FAAC is not up to par with the currently best AAC encoders available


It's also not truly open source - it has patent restrictions.
Title: Should I convert all my audio to 256 AAC?
Post by: greynol on 2012-06-27 21:46:39
So just for yucks I took a well recorded classical piece and encoded it and reencoded it ten times- ten generations of transcoding. It sounded fine.

The infinite sample of one.

I realize we're talking about aac which has advantages over mp3 in terms of block size, but I have my doubts that transcoding in aac is immune to problems with pre-echo.  Not claiming that I am especially, but maybe you're just not sensitive to pre-echo?
Title: Should I convert all my audio to 256 AAC?
Post by: saratoga on 2012-06-27 23:37:38
both AAC and ALAC are open source.

ALAC is open source, but I don't believe there's a good open source AAC codec. FAAC isn't - from the FAAC website (http://www.audiocoding.com/faac.htm):

Quote
Note that the quality of FAAC is not up to par with the currently best AAC encoders available


It's also not truly open source - it has patent restrictions.


Being patented in some countries does not make source any more or less open.
Title: Should I convert all my audio to 256 AAC?
Post by: Ouroboros on 2012-06-28 00:44:02
You are absolutely right, and I meant to edit my post along those lines, but missed the edit time! It still limits what you can do with the source, but that makes it no better (or worse) than LAME in that regard.

But the point about FAAC being not the best encoder still stands!
Title: Should I convert all my audio to 256 AAC?
Post by: bigshot on 2012-07-01 04:08:12
So just for yucks I took a well recorded classical piece and encoded it and reencoded it ten times- ten generations of transcoding. It sounded fine.

The infinite sample of one.


Try it yourself, my man!