Abstract: A method for playing back data stored on a recording medium and a recording medium play back apparatus using the same are provided. A method includes determining a section of data to be updated, among the data stored on the recording medium, transmitting information of the section of data to be updated to an external server, receiving new data to substitute for the section of data to be updated from the external server; and substituting the section of data to be updated with the new data and playing back the substituted new data at a point when playing back the section of data to be updated starts.

Abstract: A method and apparatus for multitrack recording of audio information using handheld digital electronic devices are described. Recording of video tracks complementing the audio is also contemplated. One device serves as master; others, slaves. Transmission of start and stop recording signals by the master may facilitate synchronization of the tracks. Slaves may begin preliminary sampling of audio information prior to the start signal, preparing to promptly begin actual track recording. Upon receiving the command to start recording, each slave chooses as first frame that sample closest to the signal to record. The task of stopping recording is typically handled similarly. A recording device may store an indicator for determining the offset of its first frame, facilitating time interpolation of samples in its track. In this way, all audio tracks, for example, might be transformed to a common set of times. The master might also record a track.

Abstract: A PC-based system for monitoring and storing representative images from video cameras may be utilized for security or other monitoring applications. Camera inputs from digital or analog sources are individually and independently digitized and displayed at a first set of image sizes, sampling rates, and frame rates, and may be stored in digital form on various recording media at a second set of image sizes, sampling rates, and frame rates, and these two sets of sizes and rates may or may not be identical. Provisions are included for adding detection or alarm systems which will automatically alter image size, sampling rate and/or frame rate of an individual input source, or activate other physical responses. In addition to security system monitoring, further applications of the invention are disclosed for process monitoring in manufacturing environments and also for applications in videoconferencing.