Previewer is a native plugin for Adobe After Effects which enables you to quickly preview files selected in Project Panel. You can preview videos, images, audio or first frame of precomps.
Supported Formats On Mac
Previewer can read only those media formats for which your mac has a codec. Previewer uses codecs from QuickTime. Below are the media formats and codecs that QuickTime Player can open in Mac OS X v10.6.x or later:
If you are looking for more format, you can install additional codecs. You can get some here.
Supported Formats On Windows
Previewer can read only those media formats for which you have a codec installed. On Windows, Previewer uses codecs from DirectShow. Below are the media formats and codecs that are supported. Also, more info here.
As we found out, many of you use VLC player and do not have codecs installed. Mister Horse recommends to install the Basic pack of K-Lite Codec, which you can get for free here.
Compatibility
Adobe After Effects CS5 and above.