0612 TV, a sub-project of NERDfirst.net, is an educational RU-vid channel. Started in 2008, we have now covered a wide range of topics, from areas such as Programming, Algorithms and Computing Theories, Computer Graphics, Photography, and Specialized Guides for using software such as FFMPEG, Deshaker, GIMP and more!
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Disclaimer: Please note that any information is provided on this channel in good faith, but I cannot guarantee 100% accuracy / correctness on all content. Contributors to this channel are not to be held responsible for any possible outcomes from your use of the information.
Hello and thank you very much for your comment! Glad to be of help =) If you have anything you'd like me to clarify, feel free to let me know in a comment and I'll do what I can to help you!
Hello and thank you very much for your comment! Glad you like my videos! I've been too busy with work to make videos recently, but in the meantime, feel free to check out the channel to see if there's anything else you like!
The simplest logic gate is actually the buffer. It is a monadic logic gate just like the NOT gate, but it does not invert the output. The output is simply the input.
The symbol for the not gate is actually just the symbol for the buffer (a triangle) with an inverted output. Technically the not gate could be a triangle with a circle on the input because it does the same thing. What makes it a not gate is that it inverts the signal in the buffer, which can be done in both ways
Hello and thank you for your comment! Yes, when I made this video (13 years ago, goodness!) I wasn't aware of the buffer gate or that the little circle symbol just meant an inversion. I think in later videos I started using that convention myself as well.
Hello and thank you for your comment! This depends on both the physical layout of your keyboard and they keyboard language you have set on your computer. There are many possible answers, here are some of them: www.quora.com/How-do-I-get-a-pound-sign-on-a-keyboard
This is great! I love how the information is displayed with the colors. I started color coding my notes and it really helps break apart the information and categorize it, much more than with explanations for me!
Hello and thank you very much for your comment! Yes, colors are a really powerful way to create visual separation and groupings between things, and I find myself using it a lot to subtly convey certain ideas. Glad it worked well for you!
Hello and thank you for your comment! Yes it does. You can create multiple HTML pages and navigate between them as per normal. Just ensure that each page includes the eel.js script. There was a bug back then that may cause the backend to shut down if you navigate between pages too quickly, but in my recent use this didn't crop up anymore so I'm inclined to say it's probably been fixed.
From a technical perspective, all LCD does is to selectively block a rear layer of material, which can be a luminous color like green, to reflect as much light from the environment back to your eyes. Traditional displays even used mirrors to achieve this. But ultimately, without an active backlight, your writing can only look as bright as the light reflected from the environment. It's a limitation of the technology, especially since the low-power nature of such boards is a major selling point.
Hello and thank you very much for your comment! Glad you like my work! If there's anything you haven't completely understood, feel free to let me know and I'll try to explain it further for you.
I can only wish for more, Like how about talking about upsampling audio,how about talking about dekwantize audio along with those great graphical illustration as well?😁
Hello and thank you very much for your comment! Honestly this stuff isn't my strong suit since my background is in Computer Science, but I'll see what I can do! Many of these topics are really interesting!
Why dont computers store the signal as a composition of curves like it is in vector graphics? Isnt that a way that we could store the exact analog signal?
Hello and thank you for your comment! I think for storage and synthesis, this is certainly possible. However, I think this might be difficult when it comes to capture - Ultimately, all you could do is to take measurements of a signal at a fixed interval, and at that point you already run into aliasing concerns.
Hello and thank you for your comment! In my initial draft for this video, I did have framerate operations, but I scrapped it after it turned out to be less trivial than what it seems on the surface - Changing the framerate inherently affects speed, so if you just reduced the framerate for example, FFMPEG compensates by dropping frames, which isn't all that intuitive to me. I ended up covering speed and framerate changes with the SetPTS filter a long time later, in this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ckCuy7dmyPI.html
Nerd, I hope you know, means genius to many of us that appreciate your channel. I'm using a Video converter software (DVDvideoSoft) that has used Handbrake to give us editing and ffmpeg to convert files to my preferred format, .mp4. I have a new windows 11 computer running an Intel 7i. the ffmpeg when converting a list of files, usually 4-5 at a time, consumes 100% of my installed cpu and 26% of my memory. These are lower quality mp4 files that are being converted to 1280x720. I've never run into this before on my old Windows 10 computer. Do I just do 1 at a time or does a command line exist to put off the conversion by ffmpeg until a later time? Thanks, again, I'll be watching your other videos. I see this one is from 2015, I hope you're still active.
Hello and thank you very much for your comment! Glad you like my work =) If I'm understanding you correctly, what you'd like is to perform video conversion in the background in a way that won't tie up your CPU completely, so that you can continue to use your computer while the conversion is in progress? First thing to bear in mind is that FFMPEG will try to use up as much resources as it needs to, which means that switching to FFMPEG and processing one file at a time might still not be enough for your computer to be freed up enough to do other tasks while the conversion is running. This really depends on where the bottleneck in the process is (eg. If you're using a slower hard disk, the CPU may be largely idle while waiting for file reads and writes). To run a number of FFMPEG conversions sequentially in a batch, you can use the forfiles command. I've made a video on this before and is what I use if I want to convert multiple videos using FFMPEG: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1mTFYyfYBS4.html I am not familiar with any tool that can defer processing until a later time. Technically the command line has commands like sleep that you can use, or you can use the Windows task scheduler, but both of these don't really feel like great solutions in this context. I think a good starting solution to test out will be to use forfiles and process your videos sequentially, and see if it helps. If you really need to, you can also consider limiting FFMPEG to less threads, so other cores on your CPU remain free for other tasks. There's discussion on how to do this here: superuser.com/questions/792525/how-to-change-ffmpeg-threads-settings
@@NERDfirst I'm so impressed with your lengthy and thoughtful response to my question. I appreciate your time. I'll look into your ideas as I have a backlog of about 20 videos I need to convert. I'll test a few. I use task scheduler and as I use a program interface and not the direct cmd line to convert my files, I'll try that! My hard drive is a 2tb SSD so drive speed should not be a problem. Again, I 'll watch your suggested youtubes and thanks again for the help.
No problem at all! Your use case is interesting and it gave me a chance to learn something new as well. All the best, hope you can find a solution that works well!
is there a way to use space characters in the new name with this command? i tried surrounding the name in more quotes, as well as putting a backslash (escape character) before the space, but it always gave me an "incorrect syntax" error, so i just substituted them for underscores
I apologize, when I first saw your comment I thought this was on my other video about the FFMPEG command line application. I did a bit of digging and I was surprised to find that you might have run into a limitation of forfiles, and so what you want to do might actually be impossible. The reason is that forfiles always introduces quotation marks around the parameters (you can try a simple `forfiles /c "cmd /c echo @fname"` and you'll see that in action). If you introduce your own quotation marks, they clash since they're interpreted as a doubling up of quotation marks.
Nice work and explanation. Would be cool to see a CMOS or JFET version if you do a revisit since they make better switches. Just not as beginner friendly.
Hello and thank you for your comment! There's no such thing as "best" really. It all depends on what tradeoffs you're willing to put up with. For astrophotography, if you're stacking exposures and want a brighter overall image at the expense of more noise, "addition" might be a good choice. If you want to average out the effects of noise across multiple shots, you can also consider the Normal blending mode, playing with the opacity to get the effect you want.
@@NERDfirst Yes I am stacking between three and six images with each one being red, green, blue, if I have more than three then I have red, green, blue yellow. So all my images are a single color and then I just blend them together. So you feel that addition would be a good fit for that method?
Yes that sounds good. If each of your images are already RGB (in that, for example, the red image has the red channel populated while the other two are completely black), then using addition will even restore full color information. For combining your RGBY images, you'll have to play around with the opacities of the channels to make it look right since R+G=Y so there might be some overlap of color information.
You're welcome! I'm glad to be of help. The good news is, there really aren't any right or wrong answers. Once you've figured out the basics, the rest is about experimentation and making your art look the way you want it to! All the best with your astrophotography work :)
two related questions: 1. can you asterisk an address literal to get the value stored there? 2. does the code treat addresses differently than a string that looks like an address?
1. Do you mean to look at the address of the pointer variable (not its target, but its own address)? If yes, then you can. I briefly discuss this at 6:55. 2. Yes, they're not the same, but only because you said "string". In C, a string is a sequence of characters, where an address looks more like an int or a long. What this means is, you could technically take an int that represents a valid memory address, cast it to a pointer type, and then use it to access a memory location. This is not common practice and comes with many caveats and risks, but it _is_ something that is technically possible.
question: doesn't the variable name also need to be stored in a way that links it with that address? I'm guessing that's done by the compiler somehow, but how does that work?
Hello and thank you for your comment! Variable names are really just an abstraction for memory addresses, making it easier for us to understand the code. By the time the program is compiled into machine code, the variable names are substituted with memory addresses, and they disappear. The low-level instructions generated for the CPU only manipulate memory addresses, registers, and other low-level constructs.
If the wire acts like an antenna…why do random signals flowing between ground and the pin behave differently from the random signals from before (when there was no pull down resistor)? Your animation shows there’s noise on the wire either way. So how does that solve the problem? And why does the closed switch ‘overwhelm’ the path to ground? I believe you. I’m sure you’re right. I just would love if one of the 40 RU-vid videos on this topic would take a little more time and explain the why.
Hello and thank you for your comment! These are fair points, I'll do what I can to clarify! I'm not sure that my animation shows that there's noise on the wire - It shows an electrical connection between the pin and ground. The kind of random noise we experience when the pin is floating comes from sources like electromagnetic induction. These are typically very low energy signals and therefore, the current generated is miniscule. When a voltage source is connected, the current generated is significantly higher. It "overwhelms" the noise by being the higher-energy source, exerting a greater "force" on the electrons in the conductor. When we pull down to ground, all the stray currents have a low resistance path to ground, so they "drain" that way instead of registering on the microcontroller's pin. We can use the same line of reasoning to understand why the closed switch overrides the pull-down resistor. There are two paths for the current to flow - Through the resistor to ground, or through the microcontroller pin, which has next to no resistance. Hence, most of the current flows to the pin, allowing it to register the voltage. That's what I mean by "overwhelming" the path to ground. Let me know if this makes things clearer or if you need further clarification!
Thank you for the video. I`m building a arduino grbl cnc. I got alot of problems with limit switches, how "big" resistor should i use? Have tryed 10k with no luck. Thank you.
Hello and thank you for your comment! I'm afraid I don't know enough about your use case to properly advise. The best I can do is to refer you to the Limit Switch page of the GRBL documentation here, I see that resistor values are given: github.com/gnea/grbl/wiki/Wiring-Limit-Switches
Hello and thank you for your comment! I hope this is not in reference to me, as this was an original work, though I would admit, not particularly groundbreaking.
Hello and thank you for your comment! Do you mean that you want to stop the greenscreen effect before the video ends? If so, you probably can use timeline editing features (discussion starting at 9:06) - The "enable" option discussed might be useful.
Hello and thank you for your comment! We typically only include one i-frame in each group of pictures (so don't end on an "I"). Other than that, both are valid ways to do GOP.
Hello and thank you very much for your comment! Yeah this is from a loooong time ago, but at least I'm still here, lurking in the comments. Any specific topics you're interested in? I'll see what I can do.
