Video Definition and 724 Threads

Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode ray tube (CRT) systems which were later replaced by flat panel displays of several types.
Video systems vary in display resolution, aspect ratio, refresh rate, color capabilities and other qualities. Analog and digital variants exist and can be carried on a variety of media, including radio broadcast, magnetic tape, optical discs, computer files, and network streaming.

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  1. S

    Funny QM Video

    TL;DR Summary: Funny (but very well informed) video about QM. Hope this is not considered off-topic, but anyone so inclined and with 4+ mins to spare might enjoy this (intentionally funny) QM video by eigenchris:
  2. S

    Video Unavailabe. Watch on YouTube.

    What is happening and with the on-forum compositional code when we see a link for a video showing the normal front unplayed display and then when we click to play it, the video displays "Video Unavailable; Watch on YouTube"?
  3. H

    B Clever Geometry in this Video

    Something I never would have suspected.
  4. T

    Car tires, informative video of the finer details

    Cheers, Tom
  5. bhobba

    How Modern Video Codecs Work

    The easiest way to understand modern codecs is to look at the most common one in use today and the one most other codecs are based on, H264: Since then, several codecs have been developed and are in use (HEVC, VVC, AV1, EVC, etc). A big problem arose with licensing. As codecs became more...
  6. bhobba

    Why 8k Downscaled to 4k is very close to 8k Direct

    This is the first post in a series I plan on creating a Video Codec based only on AI. First a while ago now I did a post on 8k vs 4k https://www.physicsforums.com/threads/exploring-8k-vs-4k-how-to-choose-the-right-tv-size.982481/#post-6283071 One of the takeaways was: 'First despite what...
  7. Y

    Need suggestion of a site to download youtube videos

    Hi I want to get suggestion on a safe site to download youtube videos. I don't want to just take anything I find online. Anyone heard of JDownload? Thanks
  8. DaveE

    Excellent Mars Perseverance video

    https://mars.nasa.gov/resources/27873/perseverance-rover-zooms-in-on-ancient-mars-river/ Look NASA, Congress, no astronauts required...
  9. robphy

    B Video: Mathologer on visual logarithms (and hyperbolic trig)

    Mathologer (https://en.wikipedia.org/wiki/Burkard_Polster) has a nice video using known (but not well-known) geometric motivations of the natural logarithm and the hyperbolic functions... and he makes brief mentions of special relativity I've been using similar motivations to support geometric...
  10. S

    Embedded video "can't play here" --> Refreshing may help

    Just noticed that sometimes, if a youtube video embedded in a post is marked "This video can't be viewed here..." , it may get enabled if you refresh the page.
  11. D

    Why do my sprites turn into black squares after I show an AdMob video?

    Hi everyone I've made a game in Godot and added AdMob ads to it using the Shin-Nil plugins. The game works fine when I run banner ads. However, after I play a rewarded video, all my sprites turn into black squares. I've tried the following suggestions from ChatGPT and none of them work...
  12. BillTre

    Anomalocaris Video (Earth's First Predator)

    Here is a nice video (about 10 minutes) on Anomalocaris, a Cambrian animal known for its weird fossils. The video goes over how it was figured out from fossils (took a long time), how it worked as a predator (it could be two feet long and was the Cambrian's apex predator), how it...
  13. jedishrfu

    Great Youtube Video Review of the GPT-4 Paper

    Gets into a lot of stuff tucked away in the 98 page report from OpenAI on GPT-4. - GPT-4 can process a lot more text in queries than GPT-3.5 - training data cutoff was at 2021 same as ChatGPT but it seems that the ChatGPT cut off was later in the year. - in contrast Bing with GPT-4 can search...
  14. P

    A Popular Pseudoscience Video on General Relativity: Analysis & Criticism

    Here is the video: [link deleted by moderators] His basic idea is to take the spacetime interval and add a 5th term for the 5th dimension he is describing so it looks like: $$\Delta S^2 = c^2\Delta t^2 + c^2\Delta w^2 - \Delta x^2 - \Delta y^2 - \Delta z^2 $$ where w is the difference in time...
  15. DaveC426913

    Why Does My Wife's Zoom Video Keep Freezing and Corrupting?

    My wife has a bunch of Zoom meetings this week. Her incoming feed is fine but everyone sees her as this blocky frozen screen. It starts off OK but then starts to freeze and corrupt until it's just coloured stripes and blocks. I am on the same (Bell) network and my speedtest showed 100Mb+ for...
  16. Drakkith

    I Speed of Two Falling Ladders (Veritasium Video)

    Just saw this Youtube Short by Veritasium. The idea is that two identical chain ladders are dropped at the same time. One hits a table shortly after release, while the other continues to free fall. Curiously, after the bottom of the first ladder hits the table, the remainder still in free fall...
  17. S

    Motherboards that can transmit audio over video cables

    Are there motherboards for desktop computers that can transmit audio over DVI or HDMI cables to a TV when the TV is used as the computer's display? If so, what terminology is used in the specifications for such a motherboard to indicate this capability? For example, the manual for a Samsung TV...
  18. paulb203

    B Very basic acceleration problem (from a video on The Physics Classroom website)

    I'm confused after 2 minutes of this video on acceleration; It starts with telling us that a car acclerates at 8m/s/s for 5 seconds. Then it gives a data chart which includes the car's position at each time interval. The data is as follows. O seconds; O metres 1 second; 4 metres 2 seconds; 16...
  19. robphy

    Video: A Trip to Infinity (Sept 26, 2022 on Netflix)

    A Trip to Infinity https://www.netflix.com/title/81273453 (Sept 26, 2022 on Netflix) trailer: https://www.imdb.com/title/tt21929356/ lists the cast as: Anthony Aguirre Stephon Alexander Eugenia Cheng Moon Duchin Kenny Easwaran Delilah Gates Rebecca Goldstein Brian Greene Janna Levin...
  20. jedishrfu

    Great Sequence of Video Documentaries on Nuclear Disasters

    Youtuber Kyle Hill has created a great sequence of videos on nuclear disasters around the world: They include: - THERAC-25 Medical Device disaster where cancer outpatients received doses many times greater than what the doctors prescribed - The Demon Core: fissile material that scientists...
  21. DennisN

    Physics experiments that changed the world (video)

    If you enjoy both physics/science and history like me, you may enjoy this video from the Royal Institution. It's about groundbreaking experiments (no theoretical physics); X-rays, particles etc. I'm only 45 minutes in so I haven't seen the entire video yet, but I wanted to share it...
  22. phinds

    Video card in my workstation only shows background on fire TV

    I just got my first fire TV and in HDMI1 mode (show computer video) it only shows the background of what shows on the monitor. My previous TV with a firestick showed everything although I never did get the sound to work through the HDMI cable. In the NVIDIA control panel, it shows the fire tv...
  23. T

    I Voyager I and Voyager II informative video

    13 minutes of background and findings by the Voyager spacecraft s, at the popular level. Rather well done. Cheers, Tom
  24. C

    I Using Dimensional Analysis to derive an equation (Walter Lewin video)

    Hello everyone. I was watching the Walter Lewin lectures and I noticed in the talk he used something called dimension analysis to study the time it takes for an object to drop based on differing heights. I'm 22:07 minutes into the video. With some guess work on what's proportional to what...
  25. S

    Video demonstration of playing an invisible piano

    This is a demonstration on what he there calls a Graphene piano. I DO NOT BELIEVE THIS, in all honesty; unless someone here can instruct me differently:
  26. A

    I What Does Radiation Do to Space Ice?

    A little more clear: I'm looking for a video or animation where I can visualize/see radiation on space ice (Europa or the Galilean moons). I know that radiation is invisible, but what does the ice actually look like or how does it change visually when its bombarded with gamma rays? Because its...
  27. shivajikobardan

    Comp Sci Confusion on motion estimation block diagram-MPEG video compression-:

    My doubts are as follows-: -> Why frame n is not segmented to blocks? -> Why no inputs from (n-1) side for block matching? -> What do we do in prediction error coding? Source-: https://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/AV0506/s0561282.pdf I have read this many times but that...
  28. shivajikobardan

    MHB Confusion on motion estimation block diagram-MPEG video compression-:

    https://lh4.googleusercontent.com/g6wQjnQ6p3IVt86-_kwnNVwyOb_iUxUXWChyf0XZR5PO17uOnPbNhCxdpfUSScvU8sAR8Al2FNRMoeMEqLUUuJsvGOSnpFO94tutB2h-927rxVYRDUGzi-JF9FYs9hKivGdCvrAP My doubts are as follows-: -> Why frame n is not segmented to blocks? -> Why no inputs from (n-1) side for block matching...
  29. A

    Call recording permissions in video conferencing software

    Do the Host only get the permissions of call recording in video conferencing software? I.e. Teams, Google meet, Zoom, Skype etc. I mean the Host who creates the meeting and invite other participants to join the meeting on a specific date and time only has the permission to record the call. The...
  30. berkeman

    Exploring the Impact of Video Games on Dream Flying Experiences

    I haven't played many video games beyond the early Pong games in undergrad and some Flight Simulators after I graduated. But my kids and grandkids are definitely part of the video game generation, and after watching some of those games and some advertisements today on TV that had the players...
  31. M

    Using ffmpeg to extract every n frames from a given range of an m2ts video

    Hi PF! I have a video titled myvideo.m2ts that is 2 hours long at 60 fps. I would like to extract every second from 54 min to 55 min via ffmpeg. It looks like I would execute something similar to this: ffmpeg -i myvideo.m2ts -r 1 output_%04d.png except this will run the entire video. Any help...
  32. Borek

    Power surge video - why does the spark travel?

    Any idea what is the physics behind? Why does the spark travel down the line?
  33. VVS2000

    Alternative video analysis software for tracker

    Hello, I wanted to know some software used for plotting the positions of a point mass. I did an oscillation experiment and I used the tracker app, but I cannot get it to track my point mass Please mention if any alternative software exists for carrying out my experiment. Thanks in advance
  34. Iwanttolearnphysics

    Propagating Uncertainties in acceleration when using a video software

    Here's why I'm confused: I recorded a video of a ball moving across the floor and uploaded it to the video analysis software I used. I had to track the moving ball while it moved and I did this while the video was playing in slow motion through the video analysis software. put a dot in the...
  35. P

    Video lecture demonstrations for an online class

    I'm looking for a collection of physics video demonstrations (open sourced or licensed) for an online calculus-based class at the level of Halliday, Resnick, Walker textbook, covering EM waves, optics, special relativity, intro to quantum, and so on, basically the last third of the textbook. I...
  36. LarryS

    I Check out this YouTube video on EM waves in free space

    I've always had difficulty grasping why the electric and magnetic fields are in phase in EM waves in a vacuum. Of course, Maxwell's Equations imply that is the case, but I had a hard time intuitively visualizing it. Then I found this short video on YouTube. I would appreciate your opinion...
  37. PainterGuy

    I Video on imaginary numbers and some queries

    Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find...
  38. fluidistic

    Video games have become a joke (way too easy to finish)

    I've been somewhat of a gamer when I was younger (over 20 years ago), and I have recently played a few recent video games. I feel they have become a total joke, they are so much easier than before that there is no fun anymore. Back in the days, completing a level was a real challenge (super...
  39. bhobba

    COVID Peter Doherty On Covid with Informative Video That Is A Must Watch

    Hi All I mentioned I was reading Peter Doherty's book on Covid. Good book. But it turns out there was no need to buy it even though it was cheap. He has it all on his institute's website, plus stuff he has written since releasing the book. Here it is...
  40. BWV

    Sailing drone video from inside cat 4 hurricane

    https://www.saildrone.com/press-release/ocean-drone-captures-video-inside-category-4-hurricane The Saildrone Explorer SD 1045 was directed into the midst of Hurricane Sam, which is currently on a path that fortunately will miss the US East Coast. SD 1045 is battling 50-foot waves and winds of...
  41. E

    Interesting video on: Why are 2 logic gates faster than 1?

    Just saw an interesting video on youtube explaining Logical Effort very nicely. https://en.wikipedia.org/wiki/Logical_effort
  42. DennisN

    Brian Cox and Jim Al-Khalili about science communication (incl. video)

    I just saw a great discussion with Brian Cox and Jim Al-Khalili, which covered a number of topics including science communication and the role and importance of popularizations, e.g. documentaries, books etc, including criticisms and praise of such. They also touch a number of other topics...
  43. dlgoff

    Incredible Video Shows Nature's Beauty

    I just watched this video. How amazing is this:
  44. MichPod

    High School Physics online video courses and MOOCs?

    Hi Everybody, Could you please point me to some good video courses on Physics for the High School level and generally of the introductory level? What I could find meanwhile are: "How Things Work: An Introduction to Physics" from Coursera and "Intro to Physics" from Udacity. I am looking for...
  45. bagasme

    Playing Video Games in a Language You Don't Understand

    Hi, I have PlayStation(R) 2 gaming console on my house. It is considered legacy per today's standard (as there are new-generation PlayStation(R) 5), but still popular here. One of games that I installed on the console is Sengoku Basara. The gameplay is similar to Dynasty Warriors, but I won't...
  46. BvU

    I How big is a photon - Interesting video

    Bumped into this video after admiring the falling cat by @A.T. As an experimental physicist, indeed experienced a little of the 'hole in the brain' phenomenon!
  47. E

    Extremely rare "ball lightning" phenomena caught on video.

    Extremely rare ball lightning phenomena was captured on video.
  48. Strilanc

    I [video] Simulating a delayed choice quantum eraser in an online drag-d

    This is a follow-up video I made to a previous one on common misconceptions about the experiment. I'm interested in people's opinions here about how close the simulated experiment is to the real thing (e.g. there have to be some compromises due to the simulator not having free space propagation...
  49. Y

    How to make video files smaller

    I record a video on the phone and it's 65MB, it too big to send. How do I make it smaller? If I just send from the phone, it'll get smaller, but the quality is really bad. I want to find a compromised size so I can make it smaller but not looking too bad. I know there are downloads that can do...
  50. CPW

    Acceleration in Polar Coords, Intuitive Definition video

    Summary:: I wish this video (and YouTube in general) was around when I took intermediate level mechanics as an undergraduate physics student: I wish this video (and YouTube in general) was around when I took intermediate level mechanics as an undergraduate physics student:
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