QuickTime 3 Reference
During data storage, such as the capture of video and sound into a movie file, a a sequence grabber component isolates your application from the details of how to capture the raw data from a particular device. Therefore, during movie capture you do not have to directly use data handler components in your application, the storage of your data will be taken care of for you by the sequence grabber component you call. If, however, you are storing data onto a non-Macintosh or proprietary storage medium, or multiple storage media, you might need to write your own data handler.
The sequence grabber component calls the appropriate channel component, such as a video, sound, or text channel component, to retrieve the raw data from an input device, such as a microphone.
Figure 16-2 shows the relationships between an application, a sequence grabber component, two channel components, and a data handler while capturing movie data. Notice that the sequence grabber component intercepts the data from the channel components and then passes it on to a data handler, which writes it to a movie file. The sequence grabber controls the channel components and the data handler for your application.
