For the longest time I’ve been trying to find the Holy Grail of encoding settings to get me decent sized screencasts. Most of the time, either the file size was too big, or the text was illegible. I had come across one screencast that was PERFECT. (It averaged about 2mb/min it was a full sized screen (1280×720) and the frame rate was 10 fps, while the data rate was 294 kbits/s)
The closest I’ve gotten was following the instructions from Matthew Pare on this Drupal post titled “Tips and Encoding Settings for Long Duration Screencasts“.
VIDEO
- Encoding: H.264
- Frame Rate: 10 fps
- Key Frame: 500
- Frame Reordering: Yes
- Data Rate Limit: No
- Encoding Mode: Multi-Pass
- Quality: Medium
AUDIO
- Encoding: AAC, 12 khz, Mono
SIZE
Here is the formula that he proposes, I will attach his actual notes below:
- Start with the (original width) x (original height)
- Pick a (desired width) (the height will adjust accordingly)
- Divide the (desired width) / (original width) = (result1)
- Now multiply the (original heigth) * (result1) = (desired height)
(you want to round the “desired height” to the closest even number)
MATTHEW PARE QUOTE
That explanation may be a bit confusing so let me give an example. I just have created a screen capture and my video has the dimensions of 1012 x 757. That’s way to big. My video is nearly two hours long, if I kept that size, my final video would be 250MB or even much larger than that. So I want to make this smaller, but still be able to read the text. I am going to say I want my final video to be as close to 800 x 600 as possible. As I have found that size still allows most text to be readable. So I am going to divide my desired output width of 800 by my source length of 1012.
800 / 1012 = .790513834
So now I need to determine the height for my final video. So I take the answer of the above equation multiply it by the height of my source video. So in my example I would multiply my source height of 757 by .79513834.
757 * .79513834 = 598.419
So I am just going to round this number off to 598.
My final video size will now be 800 x 598. Perfect!
