Comments by "Lawrence D’Oliveiro" (@lawrencedoliveiro9104) on "Technology Connections" channel.

  1. 4:18 This https://sistemaplastics.com/products/microwave/rice-steamer is what I use now. Nice and simple. Note the anti-splatter lid insert—helps keep the inside of your microwave clean!
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  2. 11:17 That was in the NTSC world. In the PAL world, we just had SP and LP. Tape speeds were slower on PAL VHS tapes, for some reason, so EP wasn’t considered necessary. We had 2- and 3-hour tapes, which could record double that in LP mode.
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  3. 2:52 “A minute”? HAH! Here in NZ, I would regularly set the end time 5 or 10 minutes after the scheduled end of the program. And heaven help you if there was any live sport on ...
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  4. We call it “hum”. What other word should we use?
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  5. 9:00 It’s all in the mind, you know.
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  6. Which MP3 encoder do you use? LAME seems to be the best.
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  7. On top of that, ground is often not at ground voltage. You can have these things called “ground loops”. Audio engineers know all about that. When you hear a hum coming through the speakers, when there’s not supposed to be any sound? That’s a ground loop.
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  8. Sigh He was so careful to keep emphasizing “band-limited”, and yet the ill-informed responses are so predictable ...
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  9. 5:01 100,000 times is also a common figure for sector rewritability on flash storage.
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  10. 21:38 I have a number of electronic appliances, here in my office and in my living room, with no power switches. Some are even plugged into multipoint adapters with no power switches.
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  11. Remember that audio CDs came out soon after the whole quadraphonic fad went bust. So I think they were concentrating primarily on delivering high-quality 2-channel stereo sound, because that’s what the market clearly wanted. CDs were designed for audio first, and general computer data second. Whereas with DVDs it was the other way round. Thus, it was easier to add new audio and video formats on DVDs, just by adding new file format options.
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  12. Surround sound is more realistic. I think the problem was that 4 channels wasn’t enough; that’s why you have 5.1, or even 7.1 or more nowadays.
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  13. What do you use to count them? A comptometer?
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  14. My previous car CD player couldn’t cope with zero pregaps. The current one can, though.
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  15. 2:07 That depends on which country you’re in. When I came here to NZ, I was surprised to discover that the digits 1-9 were arranged the opposite way, so dialling 1 produced 9 pulses, and dialling 9 produced just one. Correspondingly, whereas the emergency number in the Old Country was 999, here it is 111.
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  16. Yes, there is a point. Raising the amplitude of a quiet signal, or resampling a signal to a different sample rate -- digital numeric operations all have rounding errors.
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  17. No, it won’t be OK. You cannot magically recreate information that was never captured in the first place. And you cannot escape rounding errors. This is all basic Computing 101.
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  18. It matters when you do any kind of processing to the audio.
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  19. And what do you fill the extra bits with? Where do you magically create the information from, out of thin air?
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  20. OK, let’s use a simple example. Say you have captured a signal at 16 bits per sample. That gives you a noise floor of -90dB. Supposing the signal actually has a level of -45dB. You want to boost that to something closer to 0dB. But at the same time you end up boosting the noise floor to -45dB. How do you fix that?
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  21. 14:12 Are there any stats to back that up? Maybe ratio of deaths to electric shock events, or something.
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  22. 7:35 Well, the original photons destructively triggered chemical reactions in the film, which gave rise to other destructive reactions during development and duplication, and then a further set of reactions to print the slide. The end result being (you hope) that the final physical manifestation of those reactions will produce a similar effect on illuminating light as that which impinged on the original negative in the first place. Still think digital is so bad?
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  23.  @xNYCMarc  I have listened to lots of AM. I live in a country which had no FM for several years after I first got here. So don’t try to tell me how good or bad AM can be.
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  24.  @xNYCMarc  Maybe because all the AM you listen to is crap.
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  25.  @xNYCMarc  So, has DAB taken off in the US yet?
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  26. Remember he actually said “perfectly reconstruct original band-limited signal”. That’s the key point.
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  27. If the D/A converter is not band-limited, then it cannot be reconstructing the original signal, can it?
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  28. You did notice he was careful to keep emphasizing throughout that the signal was “band-limited”, did you not?
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  29. 14:33 Sony made good VHS machines, by the way. I have an SLV-757NC from about 1989. It does trick play, picture-in-picture, and has an editing jog shuttle. It normally keeps the tape threaded (Beta-style) for fast-wind, for fast switch to play mode, but slower fast-winding. There is an extra-fast-rewind button you can press which is supposed to unthread the tape, but I never measured any noticeable speed increase with it.
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  30. Vinyl fans are snobs. But audiocassettes ... are cool. ;)
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  31. Bravo! Good explanation. But to preempt the inevitable disbelievers, and paraphrase Michael “Brexit” Gove: “I think the audiophile public has had enough of experts”. Tell them to go back to their oxygen-free cabling ... maybe that lack of oxygen has gone to their heads ...
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  32. 13:50 Aaah ... “Enhanced CD” ... would that explain it? Prior to that point, CD-ROMs stored their data in what looked to an audio CD player as track 1. There would be a warning label somewhere telling you not to put the disc in an audio player. Or there might be discs with data in track 1 and regular audio in the remaining tracks, where the warning was just not to play track 1. I tried once, and it sounded like a chainsaw was cutting through my speakers ...
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  33. 13:34 I think that is an inevitable stage in the evolution of every large corporation. For example, I would say Microsoft is entering that stage now.
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  34. I just found out in the last day or two that the Hollywood Screen Actors’ Guild had a policy, at least as of the 1980s, banning the showing of bloopers, because it somehow undermined the dignity of their members.
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  35. It’s easy to do that kind of thing on a computer nowadays. By the way, the imperfections in typewriter output were sufficiently distinctive to particular typewriters to be almost like a fingerprint. This was well-known to people working in forensics back then.
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  36. 6:21 See, those numbers are denominators too, yet everybody understands that the larger denominators actually represent smaller numbers, unlike with f-stops.
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  37. 5:17 I thought the “I” stood for “Incremental” (as in it’s the changes that are important, not the levels).
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  38. 23:45 Just to add to the irony, many of the same populations that use these for illumination will have access to mobile phones by now. So they don’t have access to a reliable electrical grid for home lighting and other appliances, but they can still charge their phones via solar cells or other portable means. And they don’t have a landline phone system, they have jumped straight to wire-free telephony, and will very likely stay that way.
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  39. CIRC can correct a whole lot of errors -- a lot more than Hamming. But you need a lot of redundant bits to do it.
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  40. 6:53 You didn’t mention that, after the original C-60 tapes, there were also C-90 and C-120 cassettes using thinner tape to hold up to 1½ and 2 hours of audio respectively. While the C-90 tapes seemed to work OK, I had a fair bit of trouble with the handful of C-120s that I did buy. They were probably pushing the format a little too far.
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  41. Did anybody else buy those CD-R blanks that were made to look like vinyl records? I think they came initially from Verbatim, then a few other vendors copied the idea. You can’t get them any more.
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  42. 2:39 Hence that incredibly-useful invention known as the “steam engine”. Which James Watt did not invent.
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  43.  @DFX2KX  He didn’t have anything to do with the “steam engine” at all. What he did was improve Newcomen’s “atmospheric engine”. It wasn’t a “steam engine” because it ran off the pressure of the atmosphere, not of steam. It took a later bunch of Cornish mining engineers to figure out how to actually harness the power of steam pressure to create the “steam engine”.
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  44. 12:11 Ah, the good old flashing “12:00” from folks who didn’t know how to set up their VCRs. ;)
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  45. 0:21 And boy, was the Ipod fussy about the type of video it would play. Way back then, I implemented a system for a client for automatically generating videos in various formats (including for inclusion in DVD-Video, and playing on Ipod). Thank goodness for FFmpeg’s ability to convert anything to anything!
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  46. I have come across people insisting it did.
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  47. 10:06 But you would want the twin-fibre cable to be a crossover, where transmit at one end connects to receive at the other end and vice versa. Whereas the actual single-fibre TOSlink connector is the same at both ends (RCA connectors have that property too), and doesn’t prevent you from connecting an output to an output, or an input to an input. So basically there would be no compatibility with such a hypothetical twin-fibre connection anyway, and it would be pointless to try to incorporate any such into the design.
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  48. The effect of that is to lower the amplitude of the higher frequencies close to the Nyquist limit. The same thing happens with scanned digital images, because of the nonzero size of the pixel samples, and the cure for this is the well-known “unsharp mask” filter. The same kind of equalization filtering can be done to sound.
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  49. So what you are saying is that the response of the human ear is not linear, that it is subject to distortion.
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  50. Hearing aids have to do with sensitivity and frequency response.
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