14

I've been seeing several YouTube videos that show the news hosts' eyes are doing crazy things. Sometimes their eyes change dramatically after what looks like a strange inner eyelid blinks, their eyes change color, or their pupils look vertically elongated. A common explanation seems to be that they are reptilian shape-shifting aliens, of course.

I was thinking that perhaps there could be another explanation.

My thoughts are that there was a change in the signal strength at some point in the broadcast, causing encoding fragments. I assume there is much proprietary signal processing done to the news streams so that the signal degrades as gracefully as possible. This could trigger all sorts of visual changes. Furthermore, facial tracking might give higher priority to certain parts of the image in the case of fluctuating signal strength. Plus people do look and act weird anyway.

I was hoping someone here might know more about how news signals are handled and processed. Could that be a plausible explanation of these videos? If so, is there any way to prove this?

Is there any scientific reason for believing that they are in fact reptilian shape-shifting aliens?

Or maybe some other explanation?

Thats only three but I just can't bear looking through so many stupid videos to find more. I hope these are a good enough examples.

  • Yes please link some videos :) – Sklivvz Apr 20 '11 at 7:13
  • 1
    Are you possibly watching "They Live" starring Rowdy Roddy Piper? youtube.com/watch?v=7Lwlx3GnLGs – Paul Apr 20 '11 at 7:21
  • 14
    Oh this is positively the stupidest conspiracy theory I have ever heard of. I love how elaborate some of the commenters are in their explanations, as well. Observation: I can't see a thing. Conclusion: Dinosaurs. – David Hedlund Apr 20 '11 at 8:56
  • 10
    I am constantly amazed by questions like these. I open them up thinking "nobody could really believe that!" to actually find out that I'm wrong. :-) – Sklivvz Apr 20 '11 at 9:51
  • 4
    @Sklivv, I doubt that many people truly believe this, though I'm sure that some people do. Probably not even the people who post the videos believe it. Even less likely that users of a skeptics site are believing it. Most people who claim to believe this are likely just patronizing the idea in jest. Still, I thought it would be nice to develop a rational explanation for this phenomena. I feel it's obviously compression/encoding issues but I personally lack knowledge and experience to confirm that feeling. I wish someone who did believe it would give a rational argument as to why they do though – logicbird Apr 21 '11 at 1:05
24

http://en.wikipedia.org/wiki/Statistical_multiplexing

Multiplexing is a common compression technique. Basically, when a video sequence is somewhat static, the bandwidth to that image decreases to allow bandwidth to increase on other channels on the same frequency with more dynamic video sequences.

Cable companies pump anywhere between 3 and 15 channels down each 6mhz frequency band. More channels per frequency = more multiplexing.

As the static to dynamic ratio changes bandwidth is allocated back and forth between channels, which can cause all kinds of artifacts, the most common being pixelization. You might notice during sporting events that as the camera sweeps from one end of the field to another the resolution drastically decreases for a brief moment. This is a direct result of multiplexing.

But in answer to your question... yes, facial images are the first thing to degrade generally, especially in the case of a talking head, because almost everything else in the video sequence is static except for the face of the newscaster. That would be the first place you would notice compression artifacts.

http://www.ciscopress.com/articles/article.asp?p=106971&seqNum=3

MPEG-2 is a lossy video compression method based on motion vector estimation, discrete cosine transforms, quantization, and Huffman encoding. (Lossy means that data is lost, or thrown away, during compression, so quality after decoding is less than the original picture.) Taking these techniques in order:

Motion vector estimation is used to capture much of the change between video frames, in the form of best approximations of each part of a frame as a translation (generally due to motion) of a similar-sized piece of another video frame. Essentially, there is a lot of temporal redundancy in video, which can be discarded. (The term temporal redundancy is applied to information that is repeated from one frame to another.)

MPEG-2 Artifacts

What are MPEG artifacts? In practice, all lossy encoders generate artifacts, or areas of unfaithful visual reproduction, all the time; if the encoder is well designed, all these artifacts will be invisible to the human eye. However, the best laid plans sometimes fail; the following are some of the more common MPEG-2 artifacts:

If the compression ratio is too high, there are sometimes simply not enough bits to encode the video signal without significant loss. The better encoders will progressively soften the picture (by discarding some picture detail); however, poorer encoders sometimes break down and overflow an internal buffer. When this happens, all kinds of visual symptoms—from bright green blocks to dropped frames—can result. After such a breakdown, the encoder will usually recover for a short period until once again the information rate gets too high to code into the available number of bits.

Another common visible artifact is sometimes visible in dark scenes or in close-ups of the face and is sometimes called contouring. As the name suggests, the image looks a little like a contour map drawn with a limited set of shades rather than a continuously varying palette. This artifact sometimes reveals the macro-block boundaries (which is sometimes called tiling). When this happens, it is usually because the encoder allocates too few quantization levels to the scene.

NOTE

Macro-blocks are areas of 16-by-16 pixels that are used by MPEG for DCT and motion-estimation purposes. See Chapter 3 of Modern Cable Television Technology; Video, Voice, and Data Communications by Walter Ciciora and others, for more details.

High-frequency mosquito noise will sometimes be apparent in the background. Mosquito noise is often apparent in surfaces, such as wood, plaster, and wool, that contain an almost limitless amount of detail due to their natural texture. The encoder can be overtaxed by so much detail and creates a visual effect that looks as if the walls are crawling with ants.

There are many more artifacts associated with MPEG encoding and decoding; however, a well-designed system should rarely, if ever, produce annoying visible artifacts.

and further down in this link:

Statistical Multiplexing

Statistical multiplexing is a technique commonly used in data communications to extract the maximum efficiency from a CBR link. A number of uncorrelated, bursty traffic sources are multiplexed together so that the sum of their peak rates exceed the link capacity. Because the sources are uncorrelated, there is a low probability that the sum of their transmit rates will exceed the link capacity. However, although the multiplex can be engineered so that periods of link oversubscription are rare, they will occur. (See Murphy’s law!) In data communications networks, periods of oversubscription are accommodated by packet buffering and, in extreme cases, packet discard. (The Internet is a prime example of an oversubscribed, statistically multiplexed network where packet delay and loss may be high during busy periods.)

Video material has a naturally varying information rate—when the scene suddenly changes from an actor sitting at a table to an explosion, the information rate skyrockets. Although MPEG-2 is designed to compensate by encoding more or less detail according to the amount of motion, the encoded bit rate may vary by a ratio of 5 to 1 during a program.

  • 1
    FTR, former cable tech here with video engineering training. :) There is nothing odd at all about the videos you linked. Having played around with multiplexers, these are exactly the kinds of things you expect to see as the multiplexer kicks in. – erikthebassist Apr 20 '11 at 8:22
  • 21
    can you prove that Statistical Multiplexing wasn't created by reptilian creatures? – sal Apr 20 '11 at 13:40
  • 2
    @Sal I can't tell if you're serious. – erikthebassist Apr 20 '11 at 14:04
  • 14
    Yeah. They deliberately developed compression algorithms that produce precisely the sort of artifact that hides the truth. And to what end? So they could team up with Bigfoot and the Loch Ness Monster to fake the moon landing. Sheeple! Wake up – Lagerbaer Apr 22 '11 at 22:24
  • 1
    It's the only logical explanation for the facts at hand. – Joel Rein May 23 '11 at 14:16

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .