When I try to play a video, the video player cries out for some codec.
Multimedia files always employ some kind of compression to make them smaller. Smaller files download faster across the Internet and take up less space on hard drives. Some compression is mild, with very little (if any) loss of the original data, while other compression is very aggressive, with notable loss of the original data. A codec (short for compressor/decompressor) provides the instructions needed for an application (e.g., Windows Media Player or a video-capture program) to compress or decompress the data for a particular file format. Popular codecs include MPEG, Indeo, and Cinepak.
First, reinstall the video player application from scratch. As a rule, suitable codecs are installed along with the drivers and application software on your system. For example, if you install DVD movie-making software, the MPEG-2 codecs (and others) should install with the software. If the trouble persists, check your audio or video codecs for duplicate entries. Open the System control panel, click the Hardware tab, click the Device Manager button, and then expand the “Sound, video, and game controllers” entry. Right-click the Audio Codecs (see Figure 3-3) or Video Codecs (see Figure 3-4) entry and click Properties to see your codecs. Right-click any duplicates and select Remove.
Figure 3-3. Audio codecs include tools for speech, telephony, sound, and music.
Figure 3-4. Video ...