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

43 replies · 10,546 views · Started 15 May 2008

snoyt wrote:I understand that AAC can implemented with about half the number of MIPS compared to MP3 at the same bitrate. Sadly this does not seem to give any improvements in battery life time. Similar eAAC+, would be decoding a monostream and stereofying, logically a less cpu-intensive operation than decoding two full stereo channels.

BTW, I've talked a lot to the CoreCodec folks (I've published several Bibles where CorePlayer was also featured) and they stated it has taken (and is still taking - they still haven't finished it, it seems) them about 10 times more time to come up with a decent HE-AACv2 decoder than with MP3.

Menneisyys wrote:BTW, I've talked a lot to the CoreCodec folks (I've published several Bibles where CorePlayer was also featured) and they stated it has taken (and is still taking - they still haven't finished it, it seems) them about 10 times more time to come up with a decent HE-AACv2 decoder than with MP3.

Algorithm design is as much an art form as it is a science. People like Donald_Knuth are very rare. Besides the complexity of a audio codec does not neccessarily mean it is slower. Sadly I can not recall the reference about the MIPS difference between mp3 and AAC.

Uridium wrote:*snip*

OFF: are you an Uridium-fan? Me too.. good old days of the C64 with me playing the game all the time, along with Archon, Adept, Wizard of Wor, Impossible Mission and Paradroid 😊

In my tests, I've found them exactly the same. Are you sure the 5700 codecs are "crappy"?

but bro im not happy with 5700's bass effect
it really lacks power

3250's was way better , even tho it didnt hav a dedicated audio chip 😞

ive heard that it uses a miniature version of n91's ASSAI (or something like that) chip, but its performance is nowhere near it

has nokia limited its use ??

snoyt wrote:Algorithm design is as much an art form as it is a science. People like Donald_Knuth are very rare. Besides the complexity of a audio codec does not neccessarily mean it is slower. Sadly I can not recall the reference about the MIPS difference between mp3 and AAC.

BTW, still as far as Nokia's codecs (at least the ones used in higher-end N-series models) are concerned, they are pretty well written, power usage-wise. I've done a lot of power consumption measurements (by running the battery down to zero) with my both v12 and v20 (that is, with the old- and new-generation firmware versions) N95 and, with the latter (the former, IIRC, was arond 5 or 6 hours - see my earlier N95 articles for the figures), I've measured about 7:30 hh:mm playback time (without A2DP), even with HE-AACv2 (!). This with the standard 900 mAh battery of the N95.

This is damn good a result, much better than anything I've ever measured on a Windows Mobile device, particularly with HE-AACv2 playback, where the CPU load is about 2-3 times higher than with MP3 played back in Windows Media Player (TCPMP/ CorePlayer / iPlay / Resco have about half the CPU usage at playing back MP3), which corresponds to really reduced battery life on some architectures like that of Marvel / Intel Xscale, even with the latest, 3x0-series platform. That is, kudos to the Nokia folks for implementing all these decoders really well.

I still have to test BlackBerrys (4.5 / 4.6 OS) and Zunes in this respect; of course, the latter doesn't support HE-AACv2 at all so I'll measure MP3 instead.

Menneisyys wrote:This means the chars are stored as UTF-8 in the files. If you know any programming language, you can quickly write a tool that converts these to 16-bit Unicode (if it can be used in AAC headers). Alternatively, google around for "aac utf-8" or "aac international characters" and the like. If you absolutely don't find anything, let me know and I quickly code such a converter tool.

I've tried finding such a program, but I kinda failed 😞

RenkliArif wrote:I've tried finding such a program, but I kinda failed 😞

I've looked in the AAC files WinAMP creates; it's using Unicode, not UTF-8. Could you make available at least a screenshot of the first, say, 1 kbytes of your AAC files in hex view so that I can see whether they're in Unicode or UTF-8?

[email protected].................................................@..................................*iods..........O.............

............e.trak...\tkhd.....U...U............X.................................................@.............ecmdia... mdhd.....U...U.....D..X........!

hdlr........soun...............e.minf....smhd...........$dinf....dref............url

......d.stbl...jstsd...........Zmp4a.........................D.....6esds........%[email protected].................._.stsz...................................Y...

x...........<...............................N...O...........................<...o...............................Z.......^.......................R...5.......................

{.......z...........I...............................F...`...

-.......................7..."...............................:...................;...$.......V...U......."...H...................v...........h...............................Y...q.......W.......i...D.....

..................R...................C...........1...........;.......u...........................................D.......T...............1.........../...............4.......6.......M.......................

C...!...w...0...............................i.......................J...........O.......C.......................o...........t.......................d.............................................................

......'.......X...........................................*...o...................*...........[.......l...............5.......6...................x...............o......

I have copied this from Hex Workshop. If I did anything wrong please tell me.

RenkliArif wrote:I have copied this from Hex Workshop. If I did anything wrong please tell me.

Well, it seems it's better if you send an affected AAC file in an e-mail so that I can see what the problem is caused by. werner AT pocketpcmag PISTE com, where change PISTE to a dot (.).

You can, of course, also upload it to somehwere else; even by attaching it in this very thread as a ZIP file (just remove it after I get it so that no (C) infringement takes place.)

Unregistered wrote:Anyone who believes that compressed music, in whatever format, sounds anything like uncompressed music is dreaming. A website with expert in the name and bar graphs does not prove anything. Compression is perfect for carrying around, the car etc but to say it is perfect is risible.

Guy

Stereo music does not do a live orkestra justice. Quality degrades already at limiting yourself to stereo, or even Dolby 5.1 surround. But in the end music is there to be enjoyed and the sound quality should be suffcient for the situation.

Compressed music can sound identical to the original. Transforming the storage format does not change the information contained. Note that compression is not the same as lossy compression where information is removed. And I really was talking about cramming music on a mobile platform.

Menneisyys wrote:So does WinAMP: it does preserve the original structure, assuming you have MP3 ID tags. ID tags, incidentally, get transferred to the target AAC files w/o problems.

MLauncher is an S60 application ...

How do you connect the headset to stereo to play MP3's from your phone over your hi-fi system?

Do you use a headset socket to headset socket to do it?

Thanks,

Saul

By the way which Nero version you are using ?
I think version 6 and 7 doesn't have eacc+ .