Convert or extract TTC font to TTF - how to?
You can use onlinefontconverter.com site. It works fine and have plenty of output formats (afm bin cff dfont eot pfa pfb pfm ps pt3 suit svg t42 tfm ttc ttf woff). One of the advantages I saw, is that it export all the fonts contained inside the ttc at once (which is very convenient).
Assuming that Windows doesn't really know how to deal with TTC files (which I honestly find strange), you can "split" the combined fonts in an easy way if you use fontforge.
The steps are:
- Download the file.
- Unzip it (e.g.,
unzip "STHeiti Medium.ttc.zip"). - Load Fontforge.
- Open it with Fontforge (e.g.,
File > Open). - Fontforge will tell you that there are two fonts "packed" in this particular TTC file (at least as of 2014-01-29) and ask you to choose one.
- After the font is loaded (it may take a while, as this font is very large), you can ask Fontforge to generate the TTF file via the menu
File > Generate Fonts....
Repeat the steps of loading 4--6 for the other font and you will have your TTFs readily usable for you.
Note that I emphasized generating instead of saving above: saving the font will create a file in Fontforge's specific SFD format, which is probably useless to you, unless you want to develop fonts with Fontforge.
If you want to have a more programmatic/automatic way of manipulating fonts, then you might be interested in my answer to a similar (but not exactly the same) question.
Addenda
Further comments: One reason why some people may be interested in performing the splitting mentioned above (or using a font converter after all) is to convert the fonts to web formats (like WOFF). That's great, but be careful to see if the license of the fonts that you are splitting/converting allows such wide redistribution.
Of course, for Free ("as in Freedom") fonts, you don't need to worry (and one of the most prominent licenses of such fonts is the OFL).
If you've got a Mac the easiest way to split those would be to use DfontSplitter, available at https://peter.upfold.org.uk/projects/dfontsplitter
The Windows version they provide doesn't work with ttc files.
This is what worked for me for extracting TTFs from .dfont and .ttc files from Mac OS X: http://transfonter.org/ttc-unpack
The resulting TTFs work fine in Windows 7.