Scenario - High Quality videos over the Web
In this scenario we're going to explain a workflow that'll achieve:
- High quality 1280 x 720 video
- "Reasonable" bandwidth usage (suitable for well connected web clients)
- A high definition. e.g: suitable for describing type setting work
We'll be using iShowU HD to create the footage.
Preparation
We'll begin with the end product. The reason for this is that knowing what we want out the other end is critical to choosing the compression method, capture and output sizes. It may also influence the screen size you use to do the recording in the first place! In short, it's cruicial.
In our example, we're going to be showing clients typograpic corrections. This means we want very clear text.
The first problem is that the web is "generally" suited to 1280x720 (as of 2011) but that most of our computers run 1680x1050 or above. More likely, if we're typesetting we'll have screens capable of 1920x1080 (at least) or 2560x1600. If we intend to record full screen - we will very quickly run into the problem that when scaling down the footage for 1280x720 we'll introduce scaling artifacts. Bad.
Here's an example of some text taken from Wikipedia, and then scaled down. What you see below is equivalent to running a 1900 x 1200 screen and scaling the result down to 1280x720. Keep in mind that if you're using a 30" panel at 2560x1600 - your result will be even worse.
Going from 1900x1200 down to 1280x720 is a 67% reduction in size. You can see that the text on the right hand size is only JUST legible. That might be fine for other work, but given that we want to provide crystal clear video to our clients, it just won't fly.
Solutions
There are (at least) two ways to solve this problem.
- Change your screen resolution to 1280x720 (or as close as possible to that) and record your video footage at that resolution.
- Record at your native resolution of 1900x1200, and use a video editor to zoom in to the relevant parts.
We will cover solution (1) here. It is far, far simpler than solution (2). The later requires a video editor, and will take much more time to get right. Number (2) is a more flexible solution (you can zoom around the video, showing the user interesting things, highlighting those areas of important, and then zooming back out for context) but in our experience takes about ten times the amount of work.
Steps
1. Adjust the display resolution (from System Preferences | Display) so that the main display is at 1280x800.
This gets us mostly there, but we have the problem that 800 is more than 720. If we don't fix this, we'll end up with scaling in the final video, which we do not want.
To adjust for this, you need to specify an exact capture area in iShowU HD. What we'll now do is setup HD to capture exactly 1280x720. Before we do that however; lets get some content on the screen. For this example we'll capture some text from a wikipedia page. Here's what our screen looks like at 1280x800 (it's scaled down to fit in this document):
You can see that I have expanded out the Safari window to be full screen.
Now we're going to an area of this window to capture. We're aiming to slice a little off the bottom, so that our 1280x720 captures the full Safari frame. The way we're going to do this it to seutp HD to capture the true 1280x720 that we want, and then we're going to adjust the window to fit inside the preview.
The first step is to setup HD to capture a 1280x720 frame size:
This presets a dialog (not shown here). Type in 1280 for width, and 720 for height - then press the OK button.
The last bit is to position the capture area correctly. I want to fit the browser into the window, but not include the top menu bar.
To do this I click the "Choose" button on the left hand side:
Then I "drag" the overlay down a litte by clicking in the middle of it and dragging it downwards with the mouse, so that the top of the outline matches the top of the Safari window. Note the small circles that help define the outline. Don't drag these. If you do, you will adjust the capture size.
After having moved the capture area, our screen should look like this:
Notice the two "greyed" out areas. One above, and one below. Press the Enter key to accept the area.
With that done, we now have a 1280x720 capture, that is capturing the browser almost exactly as we'd like. It's not pefect though, since the bottom of the browser is off the bottom of the frame. To fix this, enable Preview mode in HD (if it's not already active) and resize the browser window so that it fits perfectly into the iShowU HD preview. Your final iShowU HD window should look like:
Almost done!
To finish, we need to set the Output Size of the capture to be 1280x720. This is very very important. If we don't do this we will get bluring and letterboxing (see the horizontal black bars in the preview above? that's letterboxing).
It's very simple. From the Output menu, choose 'Same as Capture size':
Now we'll end up with a perfect 1:1 capture of a 1280x720 area. Our iShowU HD window should now look like this:
Notice there are no black bars.
And that's it.
Although the above looks complex on first inspection, when you get the hang of it you'll be able to very quickly setup captures and produce perfect recordings.