Skip to main content

Mac OS X: make a screen cast with no additional software

I recently learned that on Mac OS X (> 10.6) it is possible to create decent screen casts using only the built in utilities (From hints here and here):

For the basic screen Quicktime is sufficient. Open up Quicktime and go to File->New Screen Recording. A small control panel will open that allows you to control recording. The small dropdown arrow on the right gives access to various recording options, including sound. When you are ready hit the record button. QT will tell you to click to start right away recording the whole screen, or drag your mouse and select a part of the screen to record from. Then you get a 'start' button which you should click to start recording. If you have activated voice recording you can see your voice level in the control panel.

If you want to visualize your keystrokes on the screen (and don't want to spend money on separate software that does this in a fancy way) you can do the following: Go to System Preferences->Keyboard. Check 'Show keyboard and character viewers in menu bar'. This shows a flag on your menu bar corresponding to the current language. Click the flag and check 'Show keyboard viewer'. This will show a schematic keyboard on your screen which lights up with the keys you press. There is no persistence, so it is not as apparent as specialized software made for screen casts.

Additionally, if you have a cluttered desktop, from a hint here, you can hide all the icons as follows: In a terminal type defaults write com.apple.finder CreateDesktop -bool false And then restart Finder. To unhide the icons type defaults write com.apple.finder CreateDesktop -bool true And then restart Finder

Comments

Popular posts from this blog

A note on Python's __exit__() and errors

Python's context managers are a very neat way of handling code that needs a teardown once you are done. Python objects have do have a destructor method ( __del__ ) called right before the last instance of the object is about to be destroyed. You can do a teardown there. However there is a lot of fine print to the __del__ method. A cleaner way of doing tear-downs is through Python's context manager , manifested as the with keyword. class CrushMe: def __init__(self): self.f = open('test.txt', 'w') def foo(self, a, b): self.f.write(str(a - b)) def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.f.close() return True with CrushMe() as c: c.foo(2, 3) One thing that is important, and that got me just now, is error handling. I made the mistake of ignoring all those 'junk' arguments ( exc_type, exc_val, exc_tb ). I just skimmed the docs and what popped out is that you need to return True or...

Store numpy arrays in sqlite

Use numpy.getbuffer (or sqlite3.Binary ) in combination with numpy.frombuffer to lug numpy data in and out of the sqlite3 database: import sqlite3, numpy r1d = numpy.random.randn(10) con = sqlite3.connect(':memory:') con.execute("CREATE TABLE eye(id INTEGER PRIMARY KEY, desc TEXT, data BLOB)") con.execute("INSERT INTO eye(desc,data) VALUES(?,?)", ("1d", sqlite3.Binary(r1d))) con.execute("INSERT INTO eye(desc,data) VALUES(?,?)", ("1d", numpy.getbuffer(r1d))) res = con.execute("SELECT * FROM eye").fetchall() con.close() #res -> #[(1, u'1d', <read-write buffer ptr 0x10371b220, size 80 at 0x10371b1e0>), # (2, u'1d', <read-write buffer ptr 0x10371b190, size 80 at 0x10371b150>)] print r1d - numpy.frombuffer(res[0][2]) #->[ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] print r1d - numpy.frombuffer(res[1][2]) #->[ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] Note that for work where data ty...