How to: use eAAC+ to put FAR more music on your smartphone

[slitchfield]

Guest writer 'Snoyt' takes us expertly through the wonderful world of music compression, to explain how you can get thousands of music tracks on your smartphone, efficiently and in CD quality, using the eAAC+ codec rather than bog standard ol' MP3... Who needs an Apple iPod?

Read on in the full article.

well i hav my music cnverted in eAAC+ in my 5700, bt r u sure the bh-500 or other BT headphones/jacks dont use the built in DSP ?

N is better than 5700s DSP (which is crappy tho) ?

N wil it sound the same in 5700 as it would in n91 if i use the same BT headphones in both? coz im luking fr sm gud music headphones fr my 5700

N which headphone under 100 dollars would u suggest to go along with BH-500 ?

Thnx in advance

When searching for _the_ encoder to use, I wouldn't draw to drastic conclusions from the Hydrogen Audio comparison. It's from September 2005, and a lot has changed since then.

[snoyt]

@ayush3090: The hiss is most likely not the DSP but the D/A converter and subsequent electronics. The DSP (digital signal processor) converts a digital signal to another signal. The D/A converter reconstructs a 'wav' into an analoge signal used by you headphone.

I am not a A2DP expert, but A2DP transfers the sound digitally. The phone converts the eAAC+ music file to one of the following formats SBC (mandatory supported), mpeg I or II (optionally supported), or AAC in mpeg 2/4 (optionally supported). As such in some cases no recoding of the audio file is required.

Wether the 5700 and the n91 use the same dsp and algorithms for encoding to bluetooth I can not say. The BH-500 comes with headphones tough. Check Nokia website for more details and google for expert reviews. Which headset gives the best 'sound' is often a very personal choice, as is the case with stereo speakers. Also you might prefer over-the-ear headphones instead of in-ear plugs.

The BH-500 is a Nokia and charge on a standard Nokia mini-plug. It is water resistant and bluetooth V1.2. In comparison the Jabra BT3030 is V2.0. Not being an audiophile I simple choose for practical reasons and garanteed compatibility.

[snoyt]

Originally Posted by basse

When searching for _the_ encoder to use, I wouldn't draw to drastic conclusions from the Hydrogen Audio comparison. It's from September 2005, and a lot has changed since then.

@basse: We may surely hope that encoders will improve with time. However HE-AAC v1 and v2 will BOTH profit from improvements in SBR and AAC encoding. However in the hydrogen test the difference between 64 and 48 kbit lies in the usefulness of parametric stereo to reduce bit rates further.

eAAC+ is basically a mono signal, encoded in AAC with SBR, where a limited number of bits is used to assign stereo values for a range or frequency bands (the parametric stereo part). As such more bits remain for encoding the frequency spectrum. Encoding music from large orchestra with a complex stereo image suffers from more quality loss than music from a pop band with a simple stereo image of a few instruments. The point I made in the text and which is nicely supported by the hydrogen testresults.

In simple words HE-AAC v2 at 48bits has nearly the same bitrate for the frequency spectrum as HE-AAC v1 has at 64 bit. There is largely only a quality loss in the stereosound 'image'.

Yes, snoyt, I agree completely with everything you say. I obviously did not express myself clearly enough.

What I wanted to say is that you can use the HA comparison to evaluate the quality of (and the possible differences between) eAAC and eAAC+. On the other hand, you shouldn't use the comparison to judge the different implementations of the algorithms, ie. the different encoders. Back in 2005, Nero's encoder was not nearly as good as it is now.

[neilhoskins]

Will it stream via uPNP?

[snoyt]

@bass: www.soundexpert.info said they will add a 48 kpbs test with HE-AAC v2 with parametric stereo to their tests. A more recent comparison will hopefully soon be available.

The impression I got from the different test performances of Nero HE-AAC is that they are doing well in general over times past. Noticeable better than winamp as a rule of thumb. You however are right in pointing out that my remark that Nero is better than winamp is a too absolute ordering.

In the end perceived sound quality is dependent on far more than just mere encoding. And a true scientific solid comparison is impossible from the data supplied by HA or even soundexpert. They use 'unknown' listeners, each with their own music device and hearing.

However the general precepts for cramming your optimum of music on your phone will still be valid for most of the masses ;-)

[snoyt]

Yes, if and only if the client player can cope with eAAC+

Large music collections are easier to organize in folders. MLauncher does this:
www.mlauncher.org

[Uridium]

You forget to mention that any of the apps you suggest will rip out any embedded album art during the conversion process.

Additionally transcoding from one lossy format to another is never going to give anything better than dire output.

Disk is cheap. rip all your music to FLAC then if you really must carry 100's of tracks around at a time transcode to a medium bitrate aac using omething like DBpoweramp.

Originally Posted by Uridium

You forget to mention that any of the apps you suggest will rip out any embedded album art during the conversion process.

Another way to save diskspace ;-) Besides album art supported music browsing does not exist on the N95.

Originally Posted by Uridium

Additionally transcoding from one lossy format to another is never going to give anything better than dire output.

A mathematical unsound statement. A good lossy compression algorithm stops being lossy when there are suffcient bits. With 48 kbps being the target quality. I really doubt you would here the difference between straight from the CD ripped and recoded from 320 kbps mp3.

a

[snoyt]

@editor: If Apple can't take some friendly banter, boohoo! Still to keep the balance... My N95 is missing one particular accessory. A wooden back cover for my N95 replacing the plum plastic shell! I need something to gnaw on when the battery is drained ;-)

[olevine]

Excellent review, and thanks particularly for the tip about the Winamp encoder!
-Oren (Nokia S60 marketing)