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.
@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.
basse wrote: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.
Will it stream via uPNP?
@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 😉
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
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.
Uridium wrote: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.
Uridium wrote: 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.
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@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 😉
Excellent review, and thanks particularly for the tip about the Winamp encoder!
-Oren (Nokia S60 marketing)
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
great stuff! i only have one question though, wouldn't reencoding already compressed music (eg 192kbps mp3) to a different format (eg 64kbps wma or eAAC) cause the audio to loss even more quality.
Guys and gals, don't forget to check out my HE-AACv2 conversion tutorial posted some months ago. It's available at http://www.allaboutsymbian.com/forum//forum/thread/68361/ I too use WinAmp to convert; in the tutorial, I also present some screenshots so that you can even more easily find how it can be used for conversion.
You'll also want to read my other articles on HE-AACv2, explaining how it can be used to, for example, make it possible to transcode Internet radio streams into, say, 32 kbps, high-quality streams you can listen to even over plain GPRS connections. (GPRS connections aren't able to play back 40+ kbps streams at all.) It's available at http://www.allaboutsymbian.com/forum//forum/thread/68414/ , http://www.allaboutsymbian.com/forum//forum/thread/68540/ and http://www.allaboutsymbian.com/forum//forum/thread/68556/. (The first is a generic article; the second and third explains XM Radio and Siius Radio receiving / transcoding.)
Unregistered wrote:great stuff! i only have one question though, wouldn't reencoding already compressed music (eg 192kbps mp3) to a different format (eg 64kbps wma or eAAC) cause the audio to loss even more quality.
Don't use WMA at 64 kbps. HE-AACv2, preferably at 48 kbps, is the way to go.
Note that I don't recommend 64 kbps for HE-AAC. The sole reason for this is that there's no PS at speeds larger than 48 kbps any more. This is why I use, in general, 48 kbps to transcode my stuff - and 32 kbps for Internet radio transcoding so that I can listen to them over plain GPRS connections. Vodafone doesn't support EDGE and I have a flat rate Voda subscription. GPRS streaming consumes far less power than 3G (see my Radio Streaming Bible, linked above, to see some real-world N95 figures to see how economical GPRS is, power usage-wise); therefore, it's always preferable.
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
You're right. However, currently, HE-AACv2 is the best (and most economical) solution for low-speed, low-storage transcoding. Too bad so few mobile devices are (still) able to decode it (no Apples, no Zunes, no Windows Mobile devices w/o using some suboptimal apps with high power consumption and lack of AVRCP etc.)
olevine wrote:Excellent review, and thanks particularly for the tip about the Winamp encoder!
-Oren (Nokia S60 marketing)
BTW, I heavily recommend my tutorials posted in the N95 forum. You'll like them, I'm pretty sure. See my similar review / tip posted some 5 months ago.
Uridium wrote: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.
Actually, you can easily transfer your album art by, say, simply copying the (hidden) two standalone JPG files from the source (say, MP3) to the target directories. The N95 (or any other HE-AACv2-capable phone) will have no problems reading them.
neilhoskins wrote:Will it stream via uPNP?
It will - the audio stream format has nothing to do with the way you access / control it. For example, I've used HE-AACv2 streams / files in my UPnP Bible - see http://www.allaboutsymbian.com/forum//forum/thread/68115/ (I recommend it for anyone still not having read it) - and had absolutely no problems with playing back them over home stereo, using the N95 as the source.
Unregistered wrote:Large music collections are easier to organize in folders. MLauncher does this:
www.mlauncher.org
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.
ayush3090 wrote: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 ?
As Snoyt has already explained (and me too in some of my past articles - see the N95 forum for them), most A2DP solutions simply re-encode their input, regardless of their format, to 64 / 128 / 192 / 256 / 320 kbps streams. (Bit speed depending on the encoder and the environment. For example, when there's a wall between the headphones and the source, you'll most likely only have a very low-quality 64 kbps stream, if any.)
However, some (VERY few and, in general, older and no longer mainstream) headphones are also able play to directly play back MP3. With them, no transcoding (further decreasing the audio quality - no matter how little the audio quality loss is) needs to take place.
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
In my tests, I've found them exactly the same. Are you sure the 5700 codecs are "crappy"?
N which headphone under 100 dollars would u suggest to go along with BH-500 ?Thnx in advance
I recommend -if interested - my A2DP headphones reviews. I'll soon post a big review of three new A2DP headphones to the N95 forum - make sure you follow my articles there. Unfortunately, some headphones have inherent problems when used with a Nokia S60- for example, none of the Plantronics Pulsars are able to use all AVRCP functionalities. Therefore, it's always worth checking out my A2DP headphones tests before shopping for them to avoid having to, later, return the headphones to get a (more) compatible pair of headphones.
Hei Menneisyys,
Kudos for all the good work I stumbled upon on with Google while doing the background for the article 😉.
- About streaming. This is about not streaming, getting a better audio quality, saving batterypower and network load. Being independent of network coverage. It is also about saving you on the electricity bill and being green, reducing pollution. No 200 Watt PC at home is required to stay on 😉
- With proper ID-3 tags winamp can be told to refetch the album art easily. Far easier for most users.
- Perhaps no Apples, no Zunes, no Windows Mobile devices support eAAC+. But it is supported by Sony Ericsson and Nokia on their mobile platforms. Though with 32 microSD cards becoming affordable I might start coding into 128 kbps HE-AAC. However it is also one of the best codecs for lowbit rate streaming. Anyone commercially into streaming, will prefer to use it saving expensive bandwidth. With all you can stream music for xx buck a month eAAC+ will be demanded by mobile network operators.
Question: With all the posts on powercomsumption for media players, did you do any comparison of the powerconsumption on S60 3rd edition between 48 kbits HE-AAC v2 and other codecs? I could not find any. Is there tangible 'proof' around of HE-AAC v2 power efficiency on my phone?
Terve,
Snoyt
P.S. If we forget our 'past' we are bound to repeat old mistakes 😉
snoyt wrote:Hei Menneisyys,
- About streaming. This is about not streaming, getting a better audio quality, saving batterypower and network load. Being independent of network coverage. It is also about saving you on the electricity bill and being green, reducing pollution. No 200 Watt PC at home is required to stay on 😉
Yup, I just added streaming as the best example for the usability of HE-AACv2 for people that want to really extend their battery life but don't have EDGE access, only GPRS. (See Vodafone.) In there, HE-AACv2 is just unbeatable and not even some future standards like AMR-WB+ (note the +) can come close in terms of (non-voice) sound quality - see for example my remarks at http://www.pocketpcmag.com/cms/blogs/3/mwc_audio_encoding_news_roundup_skype_cr
snoyt wrote:- Perhaps no Apples, no Zunes, no Windows Mobile devices support eAAC+. But it is supported by Sony Ericsson and Nokia on their mobile platforms. Though with 32 microSD cards becoming affordable I might start coding into 128 kbps HE-AAC.However it is also one of the best codecs for lowbit rate streaming. Anyone commercially into streaming, will prefer to use it saving expensive bandwidth. With all you can stream music for xx buck a month eAAC+ will be demanded by mobile network operators.
Yup, a lot of radio stations have already started using HE-AACv2 as an alternative to RealOne / WMA or even MP3 / Ogg (SHOUTcast). I only wish its use became far more widespread, also with state funded broadcasters like YLE in Finland (currently WMA and RealOne only - meaning really crappy sound quality at 32 and 20 kbps, respectively) or BBC in the UK.
snoyt wrote:Question: With all the posts on powercomsumption for media players, did do any comparison of the powerconsumption on S60 3rd edition between 48 kbits HE-AAC v2 and other codecs? I could not find any. Is there tangible 'proof' around of HE-AAC v2 power efficiency on my phone?
Sure I've done several tests; see section "1.2.1 Symbian / Nokia" at http://www.allaboutsymbian.com/forum//forum/thread/67595/ :
"1.2.1 Symbian / Nokia
In this respect, the built-in Music Player in the Nokia N95 is far-far better. The following power usage shot shows the HE / HE2 / LC / MP3 / WMA playback power usage in Music Player. As can clearly be seen, HE-AAC v2 (again, the second in the chart) only consumes about 0.02-0.03W more than the �dumber� HE / LC versions. (Also see THIS for more info on how this graph should be interpreted.)
"
The case is, currently, far worse on Windows Mobile with only two, old and CPU-intensive players supporting the format. I haven't benchmarked BlackBerry 4.5 / 4.6 as yet, which has only now (with the latest OS version, still at beta) received out-of-the-box HE-AACv2 support.
(BTW, how come you speak Finnish? Based on the screenshots, you're Dutch 😊 )
Menneisyys wrote: I only wish its use became far more widespread, also with state funded broadcasters like YLE in Finland (currently WMA and RealOne only - meaning really crappy sound quality at 32 and 20 kbps, respectively) or BBC in the UK.
Patience, mobile internet will have its impact and perhaps with AAC becoming 'supported' in HTML5, its bretheren will gain more ground too 😉 It would be well if they became a 'free' standard.
Menneisyys wrote: The following power usage shot shows the HE / HE2 / LC / MP3 / WMA playback power usage in Music Player. As can clearly be seen, HE-AAC v2 (again, the second in the chart) only consumes about 0.02-0.03W more than the “dumber” HE / LC versions.
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.
Menneisyys wrote: (BTW, how come you speak Finnish? Based on the screenshots, you're Dutch 😊 )
My profile at snoyt.vox.com admits that I am dutch. I speak only a few words the suomen kielta. It has an interesting structure. I visited Finland several times for longer vacations. As such I made a small effort to be able read signs, understand older busdrivers and voice annoucements. I visited most larger cities and did some solo hiking through the Urho Kekkosen kansallispuisto and the Karhun Kierros. Finland is a beautiful country with great people and an interesting culture. It was a great period in my life.
In any case any scientist worth his salt, knows the value of owning a good library 😉 Don't be puzzled by snoyt, that is intranslatable.
Kiitos ja hei,
A 'man from the forest'.
How do I preserve the album art with WinAMP? the pictures are embedded into the mp3 with mp3tag.
When I convert them it keeps the tag info but not hte album art.
Also I have a problem with my N91 and eAAC+ files: When there are any special characters in the tag, for example ş, ı, �. etc, they show up as an � and a square block. It only seems to do that with eAAC+ files and not with MP3s.
RenkliArif wrote:Also I have a problem with my N91 and eAAC+ files: When there are any special characters in the tag, for example ş, ı, �. etc, they show up as an � and a square block. It only seems to do that with eAAC+ files and not with MP3s.
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.