2024 – My Point of View

Video Recording

I am looking for a simple audio / video recording solution that can help me to capture computer screens.

I am planning to use OBD software. It’s free and open source. Here is a good tutorial on this tool.

download from here; It’s free.

Set base resolution = 30fps, video will be crisp. I am leaving it to default.

OBS file extension is mkv. We need to remux to get MP4. The reason mkv is default, a lecture of 2 hours terminates after 1 hour then we would have the video up-to the point of failure. If we set default to MP4 then risk of loosing 2 hour lecture is very high. Leaving it to default. You will be Happy doing remux as a second step.

OBS start and stop buttons are visible. We can edit it in editing software or we can use shortcuts to start and stop the video. We can add Hot keys if we want. The path is Settings -> Hot Keys. Add your favorite keys here; Press

ALT + F2 = Start/Stop

ALT + F3 = Pause/Resume

#-1. To resize video of me, click on Video Capture device, press ALT key and resize. This will crop the image.

#-2. To record a specific area of screen, Click on Display Capture, Press ALT and zoom in to screen area. This will record that screen area.

#-3. I can add a logo by dragging and dropping inside recording screen. I can make it smaller or larger.

#-4. To add a border around my face, add color source that match up with my logo. Add a color source.

#-5. To hide source from video, simply click (toggle) on the eye and my video or color source will go away.

#-6. To lock items, simply click on lock and now all of my sources are locked.

#-7. To have a cleaner interface, click on video, logo and color and make a group. Press shift, select sources and select “Group selected items”. Name them “Logo and Video”. This helps organizing my resources a little bit better.

#-8. This is trick. I am explaining and doesn’t want my face to show up. Click on Scene on the top. This will just show the desktop. When I am done with full desktop and wanted to bring back my face on the desktop, I can click on my focused scene “Proxmox performance – IPERF3”.

#-9. When I switch screen from scene to scene, it makes a hard cut. What if I want to add a transition? Click on Scene transitions and pick “Swipe”.

#-10. I don’t want OBS to shift my scene. Create following hot keys. Alt + F5.

#-11. I can add audio filters for example “Noise suppression”. This can help to suppress the noise of dog or lawn mower outside.

#-12. I can transform my resource. Click on the group and you can see transformation there.

#-13. We can re-arrange UI. To reset UI, click on View and Reset UI.

#-14. We can create profiles. Profile will store video specific scenes, for example “YouTube profile” etc.

#-15. Studio mode help us to preview without recording. The left side is live recording and right side is preview. We can make changes to the right side and when done click to swipe it to live view.

Now comes Video editing part;

There is another open source audio / video editing software, DaVinci Resolve. Here is the URL

https://www.blackmagicdesign.com/products/davinciresolve

This can be installed using admin account but wouldn’t be visible to user’s other than Admin. To make it visible to say Shahzad user account, copy admin profile to a user-defined folder e.g c:\video\blackmagic folder. Open folder and run it from there. took me some time to figure out this work around.

This one talks about cut page

pexals.com has free videos and audios that I can use in my videos.

Dafonts.com can be used to download fonts.

Here is a 2 start. This one talks about adding text.

This one has more views;

Here is how to add audio on existing recording

https://www.makeuseof.com/davinci-resolve-how-to-record-voiceover-audio

The best thing is to use your iPhone for voice recording. Laptop voice sucks. In my simple case, I don’t need to buy any voice recorder.

Treegrid Row Filter

When we apply filters in treegrid, Row property is set to true. Let’s say we have 100 records of VA and DC equally distributed 50/50. If we don’t apply any filter then Row Visible property of all records is true.

If we apply VA filter then 50 records visible property will be true and remining 50 will be false.

The twist is hidden rows. Let’s say we have 2 DC records selected. We apply VA filter then row visible property of 52 records will be selected. To get a clean picture we need to reset DC hidden rows.

For custom implementation OnAfterValueChanged Event. This is a generic event and can be used for anything (cells, rows etc).

Here is a sample code snippt;

$.each(grd.Rows, function (index, row) {
   if (row.Visible == true) {
     grd.SetValue(rw, 'Select', val, true);
   }
}

Reference

https://www.treegrid.com/Doc/RowAPI.htm

JavaScript equivalent to C# String.Format

From ES6 onward, you could use template strings:

let soMany = 10;
console.log(`This is ${soMany} times easier!`);
// "This is 10 times easier!"

Here is the reference;

https://stackoverflow.com/questions/610406/javascript-equivalent-to-printf-string-format

UBUNTU disk size increase

To increase disk size, first we need to see disk status;

df -h

If it’s a VM, make sure VM has allocated enough space before performing next actions.

Here’s the list of steps for a simple scenario where you have two partitions, /dev/sda1 is an ext4 partition the OS is booted from and /dev/sdb2 is swap. For this exercise we want to remove the swap partition an extend /dev/sda1 to the whole disk.

As always, make sure you have a backup of your data – since we’re going to modify the partition table there’s a chance to lose all your data if you make a typo, for example.
Run sudo fdisk /dev/sda
- use p to list the partitions. Make note of the start cylinder of /dev/sda1
- use d to delete first the swap partition (2) and then the /dev/sda1 partition. This is very scary but is actually harmless as the data is not written to the disk until you write the changes to the disk.
- use n to create a new primary partition. Make sure its start cylinder is exactly the same as the old /dev/sda1 used to have. For the end cylinder agree with the default choice, which is to make the partition to span the whole disk.
- use a to toggle the bootable flag on the new /dev/sda1
- review your changes, make a deep breath and use w to write the new partition table to disk. You’ll get a message telling that the kernel couldn’t re-read the partition table because the device is busy, but that’s ok.
Reboot with sudo reboot. When the system boots, you’ll have a smaller filesystem living inside a larger partition.
The next magic command is resize2fs. Run sudo resize2fs /dev/sda1 – this form will default to making the filesystem to take all available space on the partition.

That’s it, we’ve just resized a partition on which Ubuntu is installed, without booting from an external drive.

https://askubuntu.com/questions/116351/increase-partition-size-on-which-ubuntu-is-installed

nameof expression (C# reference)

A nameof expression produces the name of a variable, type, or member as the string constant. A nameof expression is evaluated at compile time and has no effect at run time. When the operand is a type or a namespace, the produced name isn’t fully qualified. The following example shows the use of a nameof expression:

Console.WriteLine(nameof(System.Collections.Generic));  // output: Generic
Console.WriteLine(nameof(List<int>));  // output: List
Console.WriteLine(nameof(List<int>.Count));  // output: Count
Console.WriteLine(nameof(List<int>.Add));  // output: Add

List<int> numbers = [1, 2, 3];
Console.WriteLine(nameof(numbers));  // output: numbers
Console.WriteLine(nameof(numbers.Count));  // output: Count
Console.WriteLine(nameof(numbers.Add));  // output: Add