Uncompressed video is digital video that either has never been compressed or was generated by decompressing previously compressed digital video. It is commonly used by video cameras, video monitors, video recording devices, and in video processors that perform functions such as image resizing, image rotation, deinterlacing, and text and graphics overlay. It is conveyed over various types of baseband digital video interfaces, such as HDMI, DVI, DisplayPort and SDI. Standards also exist for the carriage of uncompressed video over computer networks. Some HD video cameras output uncompressed video, whereas others compress the video using a lossy compression method such as MPEG or H.264. In any lossy compression process, some of the video information is removed, which creates compression artifacts and reduces the quality of the resulting decompressed video. When editing video, it is preferred to work with video that has never been compressed as this maintains the best possible quality, with compression performed after completion of editing.
Recording
A standalone video recorder is a device that receives uncompressed video and stores it in either uncompressed or compressed form. These devices typically have a video output which can be used to monitor or playback recorded video. When playing back compressed video, the compressed video is uncompressed by the device before being output. Such devices may also have a communication interface, such as Ethernet or USB, which can used to exchange video files with an external computer, and in some cases control the recorder from an external computer as well. Recording to a computer is a relatively inexpensive alternative to implementing a digital video recorder, but the computer and its video storage device must be fast enough to keep up with the high video data rate, which in some cases may be HD video or multiple video sources, or both. Due to the extreme computational and storage system performance demands of real-time video processing, other unnecessary program activity and asynchronous hardware interfaces may be disabled, and the process priority of the recording realtime process may be increased, to avoid disruption of the recording process. HDMI, DVI and HD-SDI inputs are available as PCI Express or ExpressCard, USB 3.0 and Thunderbolt interface also for 2160p. Software for recording uncompressed video is often supplied with suitable hardware or available for free e.g. Ingex.
