Speed, speed, speed

Posted on March 13, 2012 by Stephen Dawson

The other day I was playing a podcast on an iPod and had to stop listening for a while. When I resumed play some time later, the damned thing started again from the beginning. I had to search through to find where I had been up to, always an uncertain enterprise.

Panasonic SV-SD80 SD playerNow these were Econtalk podcasts and while I really ought to just get them in from iTunes, for historical reasons I have downloaded them as regular MP3 files and dropped them into the normal ‘Music’ section on the iPod. Since they are not tagged as podcasts, the property ‘Remember playback position’ is not checked by default. So I go in as I download them and click this on.

We’re talking about fairly intellectually intense discussions here of an average one hour in length, so being able to pop into and out of them at will is something to be valued.

Anyway, it appeared that I’d stuffed something up and a spot check revealed that at least some of them didn’t have the ‘Remember’ property ticked.

I could have gone through one by one and checked. I could have (I belatedly realised) checked this property for the files on the iPod. But I didn’t. Almost without thinking, I simply deleted the 34 podcasts from the iPod, checked the property in iTunes, and dragged and dropped them all back to the iPod. A little over a minute later the problem was fixed.

Diamond Rio 500Which brings me to the point of this post. Those podcasts were 64kbps MP3 files. So halving their run time for the purposes of comparison to 128kbps music content, they came to 1155 minutes (somewhat more than 19 hours). The transfer time was a touch over one and a quarter minutes. That comes to about 0.11% of the playing time of 128kbps content, a measure I’ve been using for years.

I have no doubt that my computer and setup isn’t optimal for the fastest possible transfer. Nonetheless, this shows how things have improved.

Let’s go back ten years. In 2002 I reviewed a Panasonic MP3 player. It came bundled with an SD card adaptor that plugged into your computer’s USB port. I wrote about it:

This works fast: a 128kb/s MP3 track takes just 7.6% of its playtime to download.

That was not so unreasonable, I suppose, in the context of what now seems to be a tiny 64MB SD card, which was what was supplied for storage. But, wow, 7.6%! Around the same time I did the Creative Nomad Jukebox. It was faster at 4.0%. And the Apple iPod? I did a first gen one. Apple loaned a Mac to me since the first gen iPods weren’t Windows compatible. It did the transfer at a lightening fast 0.34%, over Firewire.

Creative Nomad JukeboxIncidentally, the RRP of the iPod was then $895, in dollars that were worth rather more than today’s are.

But let’s press back even a little further, to the first two MP3 players I ever reviewed. The date: October 1999. The contenders: two CD players that also supported MP3 files on CD-ROM, two MiniDisc recorders, and two portable MP3 players. One of these was the Diamond Rio 500. USB transfers proceeded at a sprightly 3.3%, despite it being still back in USB 1.1 days. Impressive!

The other was the Grundig Mpaxx player. This poor thing was burdened by the use of a serial port (RS-232C) for transferring music to it. Oh. My. Goodness. It’s transfer time was an incredible 180%. Yes, it took longer than the playing time of a 128kbps track to shift it from a computer to the player.

Haven’t things gotten a great deal better?

Posted in Computer, Portable | 1 Comment

Free speech

Posted on March 5, 2012 by Stephen Dawson

The Australian government seems somewhat inclined to adopt a course of evil, in the form of media regulation. It is not for no reason that the first amendment to the US Constitution is phrased as ‘Congress shall make no law … abridging the freedom of speech, or of the press’. It is government from which free speech needs to be protected.

Under the proposals, I suspect even this blog would come close to its regulation.

Read Professor Bunyip on this evil. Sample:

In the Media section of today’s Australian, various heavyweights weigh in on the inquiry with balanced and nuanced appreciations of its worth, the general view being that the report is worthy of further discussion and refinement. Perhaps they cannot think beyond the report’s endorsement of taxpayer subsidies because they are already bending over, assuming the position. They do not object to being stuffed, apparently, just as so long as they retain the feeble right to negotiate how deep that violation will go.

Posted in Misc, Rant | 2 Comments

A 3D puzzle

Posted on February 27, 2012 by Stephen Dawson

I installed a shiny new 3D projector — DLP, which so far are the best kind for 3D performance. I popped into the player a demo Blu-ray 3D disc I always start with, and it only displays in 2D.

So I fiddle with the projector’s settings. Still 2D. I switch the receiver and player off, and then back on, with a view to them re-inialising their HDMI settings so that they can correctly detect that they are attached to a 3D system. Still 2D. I unplug and replug-in the external 3D sync transmitter. Still 2D.

I switch everything off, then plug the 3D Blu-ray player directly into the projector and switch it all back on. 2D. So far, all has been via HDMI 1.

I go through the projector’s menu system very carefully, item by item, to see if there is some kind of 3D enable/disable function. No. I consult the projector’s manual to see if I’ve missed something. Apparently no.

I try a different Blu-ray 3D player, plugged into HDMI 2. Eureka! 3D!

Time to plug the first Blu-ray player into HDMI 2, since HDMI 1 apparently doesn’t support 3D, although I can’t imagine why. As I switch the player on a thought occurs to me. I take action as a result.

Yes, we have 3D! I switch off the player, replug it into the home theatre receiver, and the receiver to the projector back into the original input, restoring the very first setup I had. I switch on the player, and yes we have 3D!

What action did I take to resolve the problem?

Answer over the fold.
Continue reading →

Posted in 3D, Blu-ray, Testing | Leave a comment

More reviews

Posted on February 23, 2012 by Stephen Dawson

I’ve been adding a few of my Blu-ray reviews to the site, here. These include a Blu-ray vs DVD comparison for The Crow. Had fun, of course, due to the different framing of the formats. The DVD is 4:3, but not pan and scan. Instead, its the full frame, whereas the Blu-ray has been masked down to 16:9. Here’s a full frame comparison between the two:

Aspect ratio of The Crow

BTW: free to a good home, ‘George Harrison: Living in the Material World‘ Blu-ray. Test disc, no box or slick. Australian addresses only. Ask in comments.

Posted in Blu-ray, DVD | 2 Comments

The things you can do with Lego

Posted on February 6, 2012 by Stephen Dawson

Via the Skeptics Guide to the Universe, here’s a harpsichord built entirely out of Lego. It looks beautiful, and it works. The MP3 on the linked page is the opening to Bach’s ‘Goldberg Variations’.

Posted in Misc, Music | 1 Comment

Money for Air

Posted on February 6, 2012 by Stephen Dawson

What do you reckon, good value for money?

Posted in Audio, Equipment | 1 Comment

Dirty glass, dull bulb

Posted on February 3, 2012 by Stephen Dawson

Well, that was disappointing. This evening I went to see Sherlock Holmes: A Game of Shadows at the local cinema. The movie was okay, but I fear that I failed to enjoy it because I was totally distracted by the horrible picture quality.

Now my local cinema is Limelight at Tuggeranong. This was a new startup a few years ago which took over the closed-down multiplex in the shopping centre, put in digital projectors, gave the place a bit of a brushover, and reopened selling movie tickets at much lower prices.

I’ve been impressed when I’ve been there previously. The black levels haven’t been up to the quality of a modern home theatre projector, but certainly adequate, while colours have been rich and engaging.

So what was going on in Cinema 3 tonight at the 8:20pm showing?

When they were running trailers, I was wishing that they’d turn down the house lights, because they were washing out the picture quite significantly. Then they turned down the house lights as the feature began. I couldn’t believe it. Totally washed out. Colours pallid. Contrast absolutely terrible. I don’t think I’ve seen a picture as low in contrast as this since Panasonic introduced the dynamic iris back around 2003!

I was hoping that perhaps this was something to do with the movie’s prologue, but no it continued throughout the movie. I would have guessed a contrast ratio of maybe 500:1. Not only were the blacks at best a dull grey, the bright parts weren’t especially bright. There’s a scene when some of the characters are chugging across the waters on a clear day in a paddle steamer. Dull, dull, dull!

So instead of being drawn into the picture, I’m wondering how a digital projector can lose contrast. As the lamp reaches the end of its life it dulls, but then the blacks should deepen commensurately.

And there were inconsistencies. When we got to a darker section of the movie, in those scenes where almost everything was dark, then the black levels didn’t actually look too bad. That’s not the behaviour you expect from a projector (or any other display) with a poor contrast ratio, unless it has a particularly aggressive dynamic iris. Which I don’t think cinema projectors have. If light is leaking through the LCD panels or whatever, it becomes even more obvious in dark scenes.

So what was going on?

I had a guess, but waited until the credits started to roll before checking it out so as not to irritate those behind me.

The first few credits of this movie are presented in a fancy script on a lightly coloured screen. When I turned back and looked at the projection booth, this was glowing brightly … on the glass of the booth, through which the projected image must pass.

The ideal glass would capture no part of the light. All would pass through unhindered to the screen for maximum brightness. This glass captured quite a bit of the light. Probably only a couple of per cent of it, to be fair, but the image was clear on the glass. A moment later when the normal scrolling white text on black background credits commenced, the text was obvious on this bit of glass (although, obviously, of quite soft focus).

So here’s my theory: the glass was dirty, and the lamp was dull, perhaps due to nearing the end of its life. I say the lamp was dull because I doubt that the glass — dirty or dusty though it may be — would itself be sufficient to reduce the overall brightness of the image.

But the dirty/dusty glass did, in my theory, far more damage. What it did, I think, was scatter part of the light.

Whenever there was a bright image, there was plenty of light to scatter into the darker objects on the screen (all the men wore dark suits). When there was a dark scene, there was nowhere near as much light being projected through the glass to scatter, so they looked surprisingly good.

So bright scenes looked washed out — including with pallid colours.

So that’s my theory. Next week I shall put that to the cinema proprietors and see what they think.

Now, I’m going to finish watching a movie on a large LCD/LED TV, and marvel at the rich colours and dark blacks.

Posted in Cinema | 1 Comment

Summer Wars

Posted on December 21, 2011 by Stephen Dawson

Do you like Japanese Anime? I have one copy of the Blu-ray for Summer Wars. No box. Ask for it in comments. Australian postal addresses only.

Posted in Blu-ray, Giveaway | 3 Comments

Can you even hear SACD/DVD Audio improvements?

Posted on December 20, 2011 by Stephen Dawson

Incidentally, while researching my piece on SACD, I came across a recent study in which double blind tests were conducted to determine whether people could pick between SACDs and DVD Audio discs on the one hand, and the same discs fed through a CD-standard (16/44.1) bottleneck on the other.

They could not. People could not tell the difference:

Claims both published and anecdotal are regularly made for audibly superior sound quality for two-channel audio encoded with longer word lengths and/or at higher sampling rates than the 16-bit/44.1-kHz CD standard. The authors report on a series of double-blind tests comparing the analog output of high-resolution players playing high-resolution recordings with the same signal passed through a 16-bit/44.1-kHz “bottleneck.” The tests were conducted for over a year using different systems and a variety of subjects. The systems included expensive professional monitors and one high-end system with electrostatic loudspeakers and expensive components and cables. The subjects included professional recording engineers, students in a university recording program, and dedicated audiophiles. The test results show that the CD-quality A/D/A loop was undetectable at normal-to-loud listening levels, by any of the subjects, on any of the playback systems. The noise of the CD-quality loop was audible only at very elevated levels.

The article is behind the Audio Engineering Society pay wall, but if you google a key phrase, you should be able to find it somewhere or other.

Now I imagine that there are plenty of criticisms of this study around, picking points of weakness and attempting to invalidate its results. And they may in fact be correct.

But having said that, the best way to overturn these results would be for someone to conduct a scientifically valid study which demonstrates that people can, in fact, notice the differences between formats.

Incidentally, the authors make this observation:

Though our tests failed to substantiate the claimed advantages of high-resolution encoding for two-channel audio, one trend became obvious very quickly and held up throughout our testing: virtually all of the SACD and DVD-A recordings sounded better than most CDs—sometimes much better. Had we not “degraded” the sound to CD quality and blind-tested for audible differences, we would have been tempted to ascribe this sonic superiority to the recording processes used to make them.

Why is this? They suggest — plausibly it seems to me — that the run of the mill CD release has been mixed and EQ’d for adequate performance on a wide range of mediocre equipment, whereas an SACD or DVD Audio has been created in the knowledge that the purchasers will all be careful listeners with respectable equipment, so considerable care is taken in creating the disc.

In short: buy SACD or DVD Audio where possible. It’s likely to sound better than CD, not because of high resolution digital formats, but because the recording has been prepared with love for your own fine system.

Posted in Audio, Codecs, Music, Mysticism | 2 Comments

I Hate Direct Stream Digital

Posted on December 20, 2011 by Stephen Dawson

Direct Stream Digital (DSD) is the digital format used by Sony in the Super Audio CD (SACD). But SACD is only one form in which it is used. I seem to remember that back in the day, Sony was promoting it as the best digital format for audio archiving. Something about robustness.

Perhaps. But my problem with it is accuracy. Namely, it isn’t very, compared to the alternatives (ie: PCM). Recently I did a piece (should appear early 2012) for Australian HI-FI in which I explain how DSD works (single-bit pulse density modulation: the more 1s, the higher the wave form at that point), and how it terms of resolution it comes in around the same as PCM at 117.6kHz and 24 bits, or 141.12kHz and 20 bits.

But Sony claims a ‘theoretical’ top end of 100kHz, which would imply a bit depth of just 14 bits!

Fortunately, Sony uses noise shaping to move all the quantisation noise up to the HF area were it is less noticable. If you measure the output of an SACD player, you will find that the output of the signal, looked at by frequency, falls away from the audible band up to maybe 25,000 to 30,000 hertz, and then starts to rise again. That rise is the level of HF noise DSD generates.

I measured snippets from the analogue outputs of an SACD player for a few SACDs to illustrate the point. So far as I know, there are no tools to even play an SACD in a computer, let alone extract its digital content for direct analysis.

However I have just been playing with the ‘Immersion’ box set for Pink Floyd’s ‘The Dark Side of the Moon’. One of the six discs contained therein is a Blu-ray which has three different versions of the album: the original 1973 mix in 2/0.0 (all are 24 bit, 96kHz PCM), the 1974 Quad mix in 2/2.0, and the 2003 5.1 mix in 3/2.1.

The 2003 version is clearly the same as the SACD version. So I ripped the audio out of this as six 24 bit, 96kHz PCM files and had a close look at the front left channel. Here is the frequency spectrum for this channel for the entire disc (ie. all ten tracks):

Dark Side of the Moon - Left Front Channel - Full scan

As you can see, this is only shown from around 2kHz. The bottom of the dip — the point at which the ultrasonic noise inherent in DSD overwhelms the signal — is around 32kHz.

Remember, the digital data being analysed here was carried on the disc in PCM format, which has no such problem. This is a DSD issue, and because the final mix was prepared in DSD, it carries through into PCM.

Just to show how inherent this quantisation noise is in DSD, here is the spectrum graph for the three seconds of near silence between the first two cash register ka-chings of the track ‘Money’:

Dark Side of the Moon - three seconds of silence

I used different software, obviously, and note that this one is the full spectrum, but with a linear rather than logarithmic X-axis.

Let me stress once again, had the mix been converted from analogue to PCM rather than analogue to DSD, then that rising noise would not have been there.

As for an archival medium, what a dreadful choice!

Posted in Audio, Codecs, Music | 8 Comments