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Thread: Recording Technology Thread - HD vs mono vs stereo vs 3.1 5.1 DTS and beyond

  1. #1
    Campaign Veteran since9's Avatar
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    Jan 2010
    Colorado Springs, Colorado, USA

    Recording Technology Thread - HD vs mono vs stereo vs 3.1 5.1 DTS and beyond

    This thread piggybacks on the this thread.

    My interest in audio/video technology began decades ago, when I learned what we could do with the Amiga computer. To be blunt, we could do in the 80s with the Amiga what we could do with vastly more processing power in the 90s.

    The 90s were twenty years ago, and the 80s were 30 years ago. Both video and audio signal processing and manipulation have skyrocketed far beyond the ability of today's desktop or laptop computer to keep up, yet either of these two machines can wang-chung chunks across entire cities when it comes to what the Amiga could do 30 years ago.

    Get this: In 1984, the movie The Last Starfighter realized 1 frame per second with a Cray 1.

    That was the top of the line supercomputer in 1982, with the most massive amounts of memory and processors anyone could buy, and they did, for tens of millions of dollars.

    In 2013, I bought a laptop that surpassed the Cray1's capacity 30-fold. It was just a plain, old, floor-model laptop. Nothing exciting, and many more laps today outprocess it.

    Still, I like it, and it is mine, at least for the time being.

    When used in conjunction with Dolby's 5.1 schema, additional software does a very good job synthesizing surround sound.

    While doing the audio portion of the analysis, however, I was listening via headphones, as per the original recording, so I misspoke. I did have it in 5.1, on speakers, while reviewing the video. The interesting thing about translating 2.0 sound into 5.1 sound is that while the original is recorded with only two microphones, the better algorithms tend to reproduce the sound in such a way that our human ears, being the highly directional microphones they are, can easily place sounds in a three-dimensional sphere.

    Sort of scary how that works, but the accuracy of translating two monaural sources into 5.1 sound has been verified many times. As an aside to the main purpose of this thread, here's a description (source)

    Discrete: Some channels are considered "discrete" — that means that the sound information contained in each of the available channels is distinct and independent from the others.

    Matrixed: Other channels are considered "matrixed" — that means that the sound information in those channels is extrapolated from information in other channels. Though you'll notice more precise surround effects from discrete channels, you can still expect engaging sound from matrixed channels.

    Dolby Digital, strictly speaking, is simply a method of encoding audio information digitally.

    Like Dolby Digital, DTS® provides 5.1 channels of digital audio. However, DTS uses less compression than Dolby Digital. As a result, some say that the sound produced by DTS is slightly more accurate than the sound produced by Dolby Digital.

    ** I've audibly confirmed DTS is significantly more realistic than either Dolby Digital 5.1 and certainly more than Dolby 5.1. Alas, when upscaling from two stereo monaural sources, the most accurate representation stops at plain old Dolby 5.1. Most digital microphones these days are perfectly capable of recording all the way down to 20 Hz, and applying a counterweight to their frequency curve corrects for the microphone's response, delivering a flat signal for the recording.

    Most high-end smart phones with stereo recording already include this capability.

    My analysis of the audio signal reveals it's probably an...

    Aw, hell, people - chime in with your own analys. Please!!!
    I no longer have any confidence in the moderation or administration of this forum. Nonetheless, the First STILL protects the Second, and the Second protects the First! Together, they protect the rest of our Bill of Rights and other founding documents. If you're going to do anything at all, do it right!

  2. #2
    Moderator / Administrator Grapeshot's Avatar
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    On a simpler day-to-day basis my Realtek HD Sound Effect Manager, coupled with a 5 yo Logitech surround sound sound 5.1 system does more than my tired ears can detect.

    Patriotic music, cranked up! Oh yeah!
    Better to not open your mouth and be thought the fool, than to open it and remove all doubt.

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  3. #3
    Regular Member Maverick9's Avatar
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    Apr 2013
    I can't add a lot, but on a vaguely related topic, I just bought an SJ4000 (like a go-pro only more mounts).

    Should be here today. Going to record bike rides, underwater swims and some dash cam stuff. Only $80-$100 on Amazon. (Beware of cheap Chinese look-alikes now flooding the market.)

    What's the best or standard useful lapel cams? Which ones are cops starting to use?

  4. #4
    Regular Member OC for ME's Avatar
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    Jan 2010
    White Oak Plantation

    My little town's cop shop uses the upper left most photo type of camera.
    "I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it." - Thomas Jefferson.

    "Better that ten guilty persons escape, than that one innocent suffer" - English jurist William Blackstone.
    It is AFAIK original to me. Compromise is failure on the installment plan, particularly when dealing with so intractable an opponent as ignorance. - Nightmare

  5. #5
    Regular Member Contrarian's Avatar
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    Sep 2009
    Seattle,WA, , USA

    Unhappy Cop cams

    Seattle cops are looking at some style body cams, but the Union is not in favor of such devices.

    This idea was floated a few years ago, with similar results: cops don't seem to want the added protection that an audio/video record would provide.

    Course, these are the same people that the DOJ had to rule on...

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