For the past few years I’ve been creating weird videos that (often) celebrate retro-computing with modern day low-power computing by making a Raspberry Pi connected to an old Apple display monitor play videos. You may rememberApple Watch andApple Wait from past years of Maker Faire Milwaukee .
I’ve struggled a bit with the process of using modern software to create low-resolution videos, and I’m sure there is more than one way to do it, but I thought I’d document my process so that the next time I do it I’ll have a simple guide to follow. I’m calling this my “Guide to creating Standard Definition Video files for Raspberry Pi”.
When I create a new video file in Final Cut Express (yeah, I’m still using it) I just pretty much assume I’ll want an HD version, so that’s what I create, even if I plan to have a standard definition video as my final output. Video files get created at 1920×1080, also known as “1080″, for short. Let’s make a 1920×1080 file in Photoshop.
Our final file will be 640×480, but since SD is 4:3 versus HD which is 16:9, we need to adjust for that. If we put in 480 for the height of the file, we see it proportionally scales down the width to 853. (I remember this number from my video editing days!)
853 isn’t what we want… we want 640, so subtract 640 from 853 and what do you get? Well, it’s 213. Maths, duh! (Remember, we’re going from 16:9 to 4:3 aspect ratio, so we need to lose some of the image.)
Divide that 213 in half and we get 106.5, but since we need an integer and not a floating point, we will use two numbers, 107 and 106. Those are the number of pixels we need to crop from our video file.
I still use MPEG Streamclip because, wow, it’s awesome and it works. I’ve highlighted all the important settings I need to care about. We are loading in our full HD (1080) video file, and then scaling it down to 853×480 and also cropping it, 107 pixels on the left, and 106 pixels on the right. (Selecting “Deinterlace Video” can help too, depending on the look you want.)
If the export preview from MPEG Streamclip looks wrong, you probably did something wrong. If it looks right, then you are probably in luck! Once your MP4 file is saved, you can check it out.
I open it with QuickTime Player to check the resolution. It’s 640×480, so everything is good. So now I’ve got a Standard Def 640×480 MP4 video file that is all set to be played on a Raspberry Pi connected via composite video to an old fashioned 4:3 video display.
#tags: raspberrypi , video
Posted on Sunday, August 26th, 2018 at 9:32 pm. Subscribe to the comments feed . You can leave a comment below.