Is there a difference in ATRAC3 132kbps between MDLP and HiMD modes?

[Levanel]

Looking at the FAQ (http://minidisc.org/hi-md_faq.html), the only difference would be between MDLP and HiMD right?

And judging from that table above, the modes listed in SS 4.3 are slightly confusing.

352 kbps

256 kbps (ATRAC3plus)

192 kbps

132 kbps (ATRAC3)

105 kbps (ATRAC3)

66 kbps (ATRAC3)

64 kbps (ATRAC3plus)

48 kbps (ATRAC3plus)

They could've at least labeled an additional "plus" for 256, 64, and 48 respectively..

But what do the 352kbps and 192kbps bitrates refer to? Am I to assume 352kbps is Linear PCM? Because the table lists it as 1.4mbps which is clearly not 352kbps..

Edited December 6, 2008 by Levanel

[jpteasy]

From the bit of testing I've done Atrac3 recorded in MDLP or in HiMD mode is the same sound quality. Whether there is a slight difference because of the inner workings or not I'm not sure.

However from a disc capacity point of view the two are different.

LP2 MDLP 80min disc = 160mins

LP4 MDLP 80min disc = 320mins

LP2 HiMD 80min disc = 290mins

LP4 HiMD 80min disc = 590mins

I am currently creating a tool that estimates the no. of discs required and the difference threw me and made me dig out my old MZ-N510 manual.

[sfbp]

Am I to assume 352kbps is Linear PCM? Because the table lists it as 1.4mbps which is clearly not 352kbps..

I don't think it is possible to send 1411kbps PCM **to** any device so far manufactured (that is, using Sonic Stage; LPCM recording of digital signals is (only) possible using optical input at x1). 352 is merely the highest compression mode available under Atrac3+

As to the difference between 132kbps(Atrac3) on MD and 132kbps on HiMD, you've got me. Seems like the latter takes less space (almost HALF!!!) because of some other differences in the way signals are encoded, and also because the disk is used to capacity instead of wasting a bunch (20%?) for backwards-compatibility reasons.

Thanks for bringing this to my attention, I never even noticed it. My usual practice is to "render unto Caesar that which is Caesar's", so I have used LP2 on NetMD, and 256K on HiMD.

[Levanel]

Yeah, I always assumed the only way to get Linear PCM was by live recording, via line-in or optical toslink. Then perhaps you can "check in" via SS and get a 1.4mbit audio file. But then again, I'm also to assume that the DRM is in effect as well so you're limited to the number of copies you can "check out" with..

Come to think of it, the only recording modes on the RH1/M200 (without the use of USB) are Linear PCM (1.4Mbps), Hi-SP (246Kbps), and Hi-LP (64Kbps). That's a weird limitation considering there are other bitrates for importing music via USB.. what on earth did the Sony suits think by putting only these three encodings on this unit..

Edited December 7, 2008 by Levanel

[sfbp]

Yeah, I always assumed the only way to get Linear PCM was by live recording, via line-in or optical toslink. Then perhaps you can "check in" via SS and get a 1.4mbit audio file. But then again, I'm also to assume that the DRM is in effect as well so you're limited to the number of copies you can "check out" with..

Don't think there are any numerical limitations on anything to do with RH1. Earlier models, not sure.

Come to think of it, the only recording modes on the RH1/M200 (without the use of USB) are Linear PCM (1.4Mbps), Hi-SP (246Kbps), and Hi-LP (64Kbps). That's a weird limitation considering there are other bitrates for importing music via USB.. what on earth did the Sony suits think by putting only these three encodings on this unit..

You can still record SP, LP2 and LP4. So no mono, but surely 6 modes is enough to be going on with? I can see Sony's point here.

[Levanel]

You can still record SP, LP2 and LP4. So no mono, but surely 6 modes is enough to be going on with? I can see Sony's point here.

Probably for less complicated reasons..

[Avrin]

1. It IS possible to transfer LPCM to your Hi-MD unit using SonicStage, exactly as the wizard of oz says. The maximum time is 1 hour and 34 minutes per 1Gb blank, and 28 minutes per reformatted 80-minute MD blank. And you better do that using SonicStage, and not via optical recording, since SonicStage preserves the original PCM signal, while the unit, when recording via optical in, passes the signal through its level adjusting circuit, where it may get changed, even when the level is set to 23 (which is supposed to mean "no change").

2. 352 kbit/s is simply the highest possible ATRAC3plus bitrate. Very fortunately, Hi-MD devices support it (ATRAC CD players do not). Transferring this bitrate, along with 192 kbit/s, was not originally enabled in SonicStage. SONY enabled it only in SS version 3.3 or 3.4 and later. Both these bitrates may only be created in SonicStage (no realtime recording).

3. ATRAC3 132/105/66 kbit/s can be transferred in both MD and Hi-MD modes, and will have exactly the same quality in both modes (for each bitrate). The only difference is that in the MD mode the music is padded with additional bits for compatibility (without any effect on the original quality), so 132 and 105 kbit/s actually take up 146 kbit/s, and 66 kbit/s takes up 73 kbit/s. Also, 132 and 66 kbit/s can be recorded in realtime by the unit on an MD blank (without a computer). In the Hi-MD mode (on both 1 GB and reformatted MD blanks) the music is not padded, so it takes up exactly the specified amount of bits per second (forgetting about the small Hi-MD padding, which actually increases with the bitrate).

4. It is possible to record MONO to MD blanks in realtime on first-generation Hi-MD units (like the NH600).

Edited December 7, 2008 by Avrin

[sfbp]

Where on earth did you find that information, Avrin, about 23 being equivalent to no change?

Sorry about the misinformation, I could never figure out how to get WAV onto a HiMD (I guess you cannot). I guess it is one of those invisible options, since the 1411kbps never appears in the conversion menu - so you have have to use unmodified .oma files in SS. Are there any other restrictions, such as that they must be encrypted?

[sfbp]

3. ATRAC3 132/105/66 kbit/s can be transferred in both MD and Hi-MD modes, and will have exactly the same quality in both modes (for each bitrate). The only difference is that in the MD mode the music is padded with additional bits for compatibility (without any effect on the original quality), so 132 and 105 kbit/s actually take up 146 kbit/s, and 66 kbit/s takes up 73 kbit/s.

Here's where I am puzzled, then.

Why can you get 4hr 50 mins (290) on an 80 disk using HiMD whilst only 2hrs 40 (160) using MD mode? The difference in the padding doesn't account for this. I'm sure I read the answer somewhere but this seems like another one of those technological miracles.

[Sony_Fan]

Not to side track, but I noticed that the RH1 was probably designed to enhance the sound quality of low bitrate music. For example, for some reason, if I transfer a song in MP3 @ 192 vs MP3 @ 320, the lower bitrate track sounds much better. The higher bitrate track lacks bass and the highs seem to be less crisp. I know it sounds strange, but I do not think my ears decieve me. Since most music listeners use MP3 files @ 128 - 192, the unit enhances the sound quality. Sony may have been pushing the idea of using lower bitrates to fit more music on a disc, and still enjoy great quality sound. In my honest opinion, MP3 @ 192 played back on my RH1 sounds great!

And to add, LP2 on my NetMD sounds great as well. Almost identical to SP, almost.

[Avrin]

Where on earth did you find that information, Avrin, about 23 being equivalent to no change?

Setting the level to 22 and below decreases the level of recorded music when compared to the original CD. Setting the level to 24 and above increases it. While always 23 keeps the original level.

Sorry about the misinformation, I could never figure out how to get WAV onto a HiMD (I guess you cannot). I guess it is one of those invisible options, since the 1411kbps never appears in the conversion menu - so you have have to use unmodified .oma files in SS. Are there any other restrictions, such as that they must be encrypted?

1411 kbps never appears in the ATRAC conversion drop-down box. And it shouldn't, since there is no such bitrate for ATRAC. 1411 kbps "lives" in the WAV conversion box, and it is the only bitrate there, since Hi-MD only supports 44.1 kHz 16-bit PCM.

Here's where I am puzzled, then.

Why can you get 4hr 50 mins (290) on an 80 disk using HiMD whilst only 2hrs 40 (160) using MD mode? The difference in the padding doesn't account for this. I'm sure I read the answer somewhere but this seems like another one of those technological miracles.

It seems quite a miracle, but easily explained. Original MDs use simple "bit-by-bit" recording, while Hi-MD units use the PRML technique (Partial Response, Maximum Likelihood), which allows packing bits much closer together, and perfectly reading them after that. The technique actually came from computer hard drives. Here's a nice article on PRML: http://www.storagereview.com/guide2000/ref...m/dataPRML.html

[kino170878]

1. It IS possible to transfer LPCM to your Hi-MD unit using SonicStage, exactly as the wizard of oz says. The maximum time is 1 hour and 34 minutes per 1Gb blank, and 28 minutes per reformatted 80-minute MD blank. And you better do that using SonicStage, and not via optical recording, since SonicStage preserves the original PCM signal, while the unit, when recording via optical in, passes the signal through its level adjusting circuit, where it may get changed, even when the level is set to 23 (which is supposed to mean "no change").

This is very interesting. I was under the impression that digital recordings made through the optical in on the Hi-MD unit using PCM mode would be bit-for-bit identical to the original source?

Is it only the portable units which have this 23 setting feature applied to all real-time recordings? I take it that professional CD (MD) recording decks do not suffer from such complications when recording through the optical input. If they did then they would cease to be classified as professional equipment.

[Avrin]

Any recorder, be it a deck or a portable, a professional unit or not, has a level control, which is supposed to change the input signal level.

And the word "professional" nowadays is nothing but a marketing hype.

[Levanel]

This is very interesting. I was under the impression that digital recordings made through the optical in on the Hi-MD unit using PCM mode would be bit-for-bit identical to the original source?

I don't think that would be possible..

Think of it this way.. you've got a 60min audio CD being optically recorded to a 60min MD in SP mode. A CD roughly holds 650MB and a regular 60min MD only holds about 150MB. Of course there will be some transcoding taking place.. hmm, maybe my analogy is not that good..

Anyway, since 132Kbps is no different in a standard NetMD and HiMD in terms of audio quality, then I suppose there's really no need for me to "adapt" my entire music collection from standard to HiMD. Sure, the latter might open up more space on standard "converted" disks but rerecording everything would seem cumbersome and redundant, all for sacrificing backward compatibility with MDLP units..

Edited December 9, 2008 by Levanel