Odds of "Hi-MP" / 128kbps Atrac3+

[moment42]

Does anyone know or have an opinion of the likelyhood that Sony will provide more bitrate options for Hi-MD in future versions of SonicStage? I'm currently using Hi-LP, and while it's ok for listening in noisy conditions like walking around in a city, it leaves a lot to be desired in better listening conditions. But to me, the space tradeoff for using Hi-SP isn't worth it (especially given the non-availability of Hi-MD discs). So for me going halfway, i.e. something like 128kbps (or, better still, a "custom bitrate" option in SS - don't see that happening anytime soon though) would be just peachy. And since there are also people who think Hi-SP isn't good enough, an even higher bitrate might also be desired.

I don't know if Sony have some deep marketing (or other) reason for keeping the LP and SP options so far apart in bitrate, but since SS already has the 48kbps option (does anyone use this?) it seems very likely that it's technically possible to use a wide range of bitrates. I'm personally going to send a message to Sony asking for this, and maybe if enough of us do, they'll listen.

Any thoughts?

/ Mats

[acidboy84]

I also just sent a mail to them asking why there is a big gap between LP and SP. We just need more people to amke them to work more.

[ROMBUSTERS]

the reason they dont offer you more bit rate choices is because the middle ground it already covered by the ATRAC3 codec. It offers 132kbps/105kbps/66kbps a nice middle ground between the major HiSP/LP modes

[Qwakrz]

I agree partly with Rombusters.

However the paper for Atrac3+ states that shorter blocks are used to handle transients in the music better, giving a much richer sound that better suits live recordings (or something to that effect).

Personally I think that Sony wanted a nice "It really will record xxxxx hours at near CD quality" and have pushed it a bit to far.

Sony give us freedome over Atrac3+ bitrates

[b.e.wilson]

However the paper for Atrac3+ states that shorter blocks are used to handle transients in the music better, giving a much richer sound that better suits live recordings (or something to that effect).  

To what paper do you refer?

According to the FAQ on this site (http://www.minidisc.org/mdlpfaq.html#_q61) ATRAC3+ uses a block size four times longer than ATRAC3.

[xispe]

I agree! More bitrates for Atrac3+

I think that Atrac3+ at 128 kbps would sound much better than Atrac3 at 132 kbps.

[streaml1ne]

Maybe the software can be suckered into using whatever bitrate you specify? Has anyone torn into whatever dll's or whatnot Sonic Stage is using to encode?

[Qwakrz]

Yes, you are right in that the time window for the long blocks are 4 times longer than before to allow better compression ratio's however they have also shortened the short blocks to allow for better music "atack" reproduction (short transient bursts).

Block sizes are explained in the link you supplied & I will endevour to find the link to the info (but its late here).

I would settle to say that Atrac3+ will produce alot better reproduction than Atrac3 at the same bitrate. Sony, give use a 128K Atrac3+ bit rate please.

[etotheix]

Me's argees wit als yous. Booyakasha!

[b.e.wilson]

Block sizes are explained in the link you supplied & I will endevour to find the link to the info (but its late here).

I googled up a link at Sony that says ATRAC3+ uses block sizes twice what ATRAC3 uses, but I'm still looking for variable block size info.

Here's the link: http://www.sony.net/Products/ATRAC3/tech/atrac3plus/

[moment42]

the reason they dont offer you more bit rate choices is because the middle ground it already covered by the ATRAC3 codec. It offers 132kbps/105kbps/66kbps a nice middle ground between the major HiSP/LP modes

Hmm, didn't think of that (I thought you couldn't use ATRAC3 on a Hi-MD formatted disc, but it turns out you can). I'd still like more options for Atrac3+, and I'd definitely like SimpleBurner to support direct encoding using ATRAC3, but at least it gives more options.

/ Mats

[Andy]

The optimal solution would be to make their hardware so that it can play back any bitrate (within some fixed range - there are minimums for these things and maximums which depend on chip speed) and then have an advanced encoding option both in SonicStage and on the unit itself which lets you select whatever bitrate you want.

Alternatively they could fix it up by supporting other formats like MP3, Ogg, AAC, WAV etc and make their hardware capable again but not care about sonic stage.

[Harper]

but since SS already has the 48kbps option (does anyone use this?)

Actually yes. As well as Atrac3+ at 64kbps. The 64 is very comparible to between 96 and 128kbps to my ears. And this is perfectly acceptable for use in normal conditions if you view it as somewhere between portable cassettes and portable CDs. We all use to use portable cassette players in all kinds of conditions and were ok with that. Most of my listening is done to enjoy or pass time more than it is for technical enjoyment.

As for the 48kbps, what is it good for? I honestly have not tried it for music but I do ALOT of ilstening to audio books and OldTimeRadio. I used to use a small mp3 player for this but now I can load the whole CD of shows (about 45 hours/CD) practically onto 1 HiMD disk and enjoy. My only small complaint is that without native MP3 support it takes an overnighter to leave the computer on and transfer the whole thing. ITs done when I get up the next morning. Not terrible bad.

But I actually figure it is a little better this way. Disadvandatages of MP3 native support for large volumes would probably be decreased battery life and decreased diskspace (Atrac seems to take less space than and equivalent mp3). So Ild only maybe get 35 hours of MP3s instead of 45hours in Atrac3+.

Advantage of MP3 native support would be noticed on small groups of mp3s of no larger than 1 or 2 albums. You could quickly transfer these from any computer. But for a larger Audio Collection Ill stick with Atrac. I only wish converting BOTH ways was easier. I am thankful for MarCs HimdRenderer.

:smile:

[moment42]

The 64 is very comparible to between 96 and 128kbps to my ears. And this is perfectly acceptable for use in normal conditions if you view it as somewhere between portable cassettes and portable CDs.

Well, depending on your view of "normal conditions", I agree. And I said as much in my post. My point was that in somewhat better conditions, 64kbps isn't good enough for me, but 256kbps seems a bit over the top most of the time (in pure storage terms, at least). But now that I've found that I can use 132kbps ATRAC3 on Hi-MD formatted discs, that's the perfect middle ground for me. And even though I haven't had time to do hardcore listening tests myself, I've heard some people say they think ATRAC3/132 often sounds better than ATRAC3+/256. Nevertheless, I still think Sony should provide more options.

As for the 48kbps, what is it good for?   ... audio books and OldTimeRadio. ...

Sorry, my bad. Not all source material is CD quality and/or music. Of course 48kbps is useful for these things.

/ Mats

[Christopher]

the reason they dont offer you more bit rate choices is because the middle ground it already covered by the ATRAC3 codec. It offers 132kbps/105kbps/66kbps a nice middle ground between the major HiSP/LP modes

You're dead on. They don't see the need to bring that over the ATRAC3plus codec. If they can improve the spectrum they've enlisted for the lowest and the highest bitrates with the codec, after a few generations of maturity, then it won't be that bad of a codec after all. I just don't honestly believe it will happen with ATRAC3plus; it's not in the ATRAC WORLD, n•code Professional ATRAC3plus Audio Encoding Tool [it says 132kbps there, but it's really ATRAC3 if you do some reading] or any other of those websites.

I just say use mature 132kbps ATRAC3 and be content with it. Would the difference between it and it being in a ATRAC3plus form really be a worthwhile endeavor? What I'm saying is that they made the right decision - low bitrate ATRAC and high bitrate ATRAC needed the most improvement. I'm excited to see what 256kbps ATRAC3plus will be like with a couple of revisions, and the same with 64kbps.

[ROMBUSTERS]

and this improvements would be on the encoder side right? so that as long as I still do everything through SS it'll sound better and better ?(because obviously i cant upgrade the encoder chip - which they should have allowed via firmware updates)

[Sbetsho]

I have tried 48k on music, at first it sounds horrible, but if you just let it play and forget about the bitrate and just enjoy the music it did turn out to be just (barely) acceptable.. but I still prefer Hi-LP anytime.

But it would have been nice to be able to record at 48k via analog, and even more at 128k, I'm sure 128k a3+ would be much better than 132k a3.

[xeroxide]

I just wish sony would allow us to record in 132kbps while in Hi-MD mode (and I mean live-recordings)

I would like that option to be able to go half-way and still be able to make a MD->PC transfer!!!

[ROMBUSTERS]

food for thought

All of the A3 modes include extra bits to allow for 'backwards' compatibility with non-MDLP players, telling them it wont work or playing back scilence. Wouldn't be safe to assume the 132-128 = 4 bits is wut is used for this reason? I noticed the same thing with LP4 66 and HiLP 64 (although I know they changed the way it encodes so this is kind of different)

[moment42]

Wouldn't be safe to assume the 132-128 = 4 bits is wut is used for this reason?

Erm, no. First of all it's 132kbps (kilobits per second), which means that the difference isn't 4 bits it's 4096 bits per second (or 4000 depending on your definition of kilo-). That's a lot of bits. And that's every second. What you're talking about sounds like it needs a bit or two in the header of the file, not several thousand per second.

Now, I don't know any details about ATRAC3 encoding, but I doubt there's anything magic about the number 132. It's probably just a point where they had a good "size"/"sound quality" ratio. It's very seldom the case that there's something special about powers of 2 either. It's just that programmers tend to pick them instead of purely random numbers (or powers of 10, or whatever), often out of habit, and sometimes to make it seem the number's special when it could really be anything. Of course there are occasions where powers of 2 are the best choice, but I doubt codec bitrates are one of them.

/ Mats

[jadeclaw]

The odd 132k for LP2 has a reason:

Old SP has a datarate of 292kBit.

Normally, it is possible to mark a track

as non-playable as a whole.

Problem: Not all manufacturers adhere to that, so that every sector of the track has to be mark as non-playable, resulting in 20 bytes of data that is not available for music, leaving the 132kbit over. (See the MD-FAQ for more)

Btw, 292 / 2 = 146.

[thebarnman]

The odd 132k for LP2 has a reason:

Old SP has a datarate of 292kBit.

Does the new ATRAC3plus SP 256kbps sound better than the older ATRAC-R SP of 292kbps?

I know they claim it does, but does it really?

As far as middle of the road bit rates, I think there are enough already. The only upgrade at this time I would like to see is the data trasfer from simple burner AND SonicStage is an ATRAC3plus SP 256kbps AND ATRAC-R SP of 292kbps trafer rate. That way I can get the best possable sound for my older MD car unit and my new Hi-MD portable recorder.

[jadeclaw]

Some here say Old-SP is better and with some critical sounds Hi-SP produces some nasty effects. However, none of my cds could trip up Hi-SP. And none of these trip up Old-SP.

To my ears, both are so close to the original, that I cannot reliably point out one or the other.

[exvaxman]

Glad to hear that there is someone else who uses MD for OTR. Due to a medical condition since middle-school, I need to have noise in the bedroom to mask the noise in my ears to get me to sleep. Unfortunatly, I have been conditioned that if there is not a noise, I wake up. 48K is so bad that even bad OTR recordings sound worse. 64 is what I use. Great for the old shows. I agree on the fact that I have no problem transcoding from the usenet groups that I download from - what gets downloaded today gets listened to tomorrow. I have several MP3 players, but the battery life and capacity of the hi-md has been a lifesaver. Many times I have been stuck in a hotel room as part of the job where radio reception is bad - and I cannot sleep. But with the older MDLP (waking up once to swap disks) and the now Hi-MD at 64 for "better" quality - I actually get to sleep without interruption (with the exception of the family cat that often needs petting & comfort at 4:AM - not all that bad since I usually get up at 6). Of course, being stuck a few times in an airport and laughing at the IPOD users whose batteries have died (I do carry a couple of adapters that allow for sharing of headphones - have been used more than a few times by bored IPOD people).

Only issue I have is with the crappy quality of the memorex disks. My father gave me a lifetime supply of the memorex disks (500+) i 80 minute format when his local "Best Lie" was closing them out. About 1/4 of them fail the Hi-MD formatting.

"As for the 48kbps, what is it good for? I honestly have not tried it for music but I do ALOT of ilstening to audio books and OldTimeRadio. I used to use a small mp3 player for this but now I can load the whole CD of shows (about 45 hours/CD) practically onto 1 HiMD disk and enjoy."

[samplehunter]

I agree! More bitrates for Atrac3+

I think that Atrac3+ at 128 kbps would sound much better than Atrac3 at 132 kbps.

←

Custom bitrates would be fine, yes.

But I'm rather dissapointed from the quality of this atrac3+ codec. I've tested all available codecs with some of the official EBU-Test Signals for lossy audio codecs (I think a link to these files was at minidisc.org) These signals are not (only) some synthetic waveforms to stress the encoder but also signals from natural instruments like a harpsichord, a glockenspiel (is it called this in english) and also a sppech sample. I found this quite useful because recording a single instrument is a not so irrealistic task one could do with this units.

The original file are uncompressed PCM-Wave files of course.

the harpsichord sample for Example gave quite strange results:

At 256k (Hi-SP), the atrac3+ codec sometimes sounds a bit grainy in the sustain phase

(I think, the a3+ codec is a bit new and the sony guys still have to tweak the parameters a bit. Sounds like the window size is a bit too small or the transitions between two windows are not smooth enough)

At 64k (Hi-LP), it has (very) little less high frequencies but very smooth sound(!)

with atrac3 LP2 this sample sounded the best for my oppinon.

atrac3 LP4 - well, forget it.

I haven't tried it with the atrac SP mode because you cannot really transfer in this mode. (I think sony knows why they didn't realize the original atrac codec as software...)

This sample tricks many encoders because the waveform has very soft high frequiency parts but these are very important to recognize the sound correctly.

Don't even try to encode this sample with the crappy wma-encoders :-)

with the speech sample you can hear the graininess of the Hi-SP mode very good while the Hi-LP mode with 64k is absolutely perfect for speech (well, dry speech without reverb). here you will hardly notice a difference from the uncompressed original.

For normal music the Hi-SP mode is ok and for recordings with the unit i normally use this mode (or PCM) but for transfers i prefer the LP2 mode because it sounds quite good and is about 3-4 times faster tha the Hi-SP codec on my PC.

Well, I miss the REAL atrac codec on Hi-MD...

[ROMBUSTERS]

does anyone remember if OpenMG (that POS program that shipped with old NetMD units) supported SP transfer? I remember there being a 'Stereo' option along with LP2 and 4 but is this the real SP or just another fake like SonicStage uses? I it is real, why doesnt SonicStage use it?

[zerodB]

According to Sony, ATRAC3+ is merley an extension of the ATRAC3 format.

Therefore ATRAC3 is like a subset of ATRAC3+, and should be viewed that way as such.

SonicStage gives you the option to use both ATRAC3 and ATRAC3+ bitrates when copying music to your device when in "hi-md" mode.

ATRAC3plus is the latest development in codec technology; while keeping compatibility with ATRAC3... ATRAC3 provides bit rates of 66Kbps, 105Kbps, and 132Kbps for compressing music. An enhancement of ATRAC3 technology, ATRAC3plus delivers low bit rates of 48Kbps and 64Kbps with extremely high quality sound (64Kbps ATRAC3plus rivals MP3 at 128Kbps) and a high bit rate option of 256Kbps.

Link: Sony - ATRAC3plus Overview

Edited January 11, 2005 by zerodB

[MAVickers]

But now that I've found that I can use 132kbps ATRAC3 on Hi-MD formatted discs, that's the perfect middle ground for me.

←

I don't know about anybody else here, but even with SS v2.3 I still regularly run across .mp3's that convert into silence when using ATRAC3 @ 132kbps. That is extremely annoying and means I have to go through the whole .mp3 -> Nero Image -> re-rip in SS process. The newest version of Simple Burner does not seem to support the regular ATRAC3 modes.

I have not run into that problem with Hi-SP. If anything, it would be nice to see a Hi-MD @ 128kbps so the .mp3 conversion process runs correctly.

Michael

[Christopher]

Why transcode at such a poor bit rate. You should try converting those same mp3's to 256kbps ATRAC3plus and see what happens.

EDIT: I just read that you have and it works better [mp3 to Hi-SP]. It's a sign from the bitrate gods trying to deliver kindness to your ears.

[ROMBUSTERS]

the higher the bit rate the less information is thrown out for Atrac (above and beyond what was already thrown out for MP3) and you get better quality

[jadeclaw]

I don't know about anybody else here, but even with SS v2.3 I still regularly run across .mp3's that convert into silence when using ATRAC3 @ 132kbps.

←

It happens here as well. A bunch of these doesn't even play in Windows Mediaplayer 10.

Solution: Use Winamp, activate the Diskwriter plugin and set a directory in there.

Then let Winamp play into wave files, import these wave files.

Just remember to switch off the EQ and set Volume to 100% and Balance to the center.

Winamp has the ability to play anything thrown at it....

To use Winamp normally, deactivate the plugin and restart the comp.

[ROMBUSTERS]

i wonder if these encoders that do not work, use an unlicensed version of the encoder system or emply tricks in order to improve sound but it ends up screwing up SS conversions

[MAVickers]

Why transcode at such a poor bit rate. You should try converting those same mp3's to 256kbps ATRAC3plus and see what happens.

EDIT: I just read that you have and it works better [mp3 to Hi-SP]. It's a sign from the bitrate gods trying to deliver kindness to your ears.

←

Thanks for looking out for my ears Most of my listening is done in the car or at work with cheap headphones on. I don't have the greatest ears (I think I have a slight case of tinnitus) either. I guess it's more important to pack more tunes on a disc than to have higher quality audio.

Besides, this bug has been around for eons, and seems to occur more frequently on my mp3s that are encoded at a higher bitrate (256kbps and up).

Michael

[Artstar]

The only thing I can't get my head around is why they went with a bitrate of 256kbps instead of 292kbps as per the older ATRAC3 MD-SP format?

I know Sony are trying to tell us that ATRAC3+ is a better sounding format overall, but given the anomalies that I've been able to ever so slightly notice as opposed to MD-SP, one would've thought that we'd be happy to come down from the 7+hrs to even 6 hours in order to accomodate the higher bitrate.

The real test for me I suppose will be in the live recordings. If it can give me the same sound in jazz, fusion, funk and heavy metal gigs, that'll be all I'll ever need since that's all I ever bought it (and my beloved Core Sounds mics) for.