Multiplexed Analogue Components (MAC) – Europe; obsolete Multiple sub-Nyquist sampling encoding (MUSE) – Japan NTSC – United States, Canada, Japan EDTV-II "Clear-Vision" - NTSC extension, Japan PAL – Europe, Asia, Oceania PAL-M – PAL variation, Brazil PAL-N – PAL variation, Argentina, Paraguay and Uruguay PALplus – PAL extension, Europe RS-343 (military) SECAM – France, former Soviet Union, Central Africa CCIR System A CCIR System B CCIR System G CCIR System H CCIR System I CCIR System M An analog video format consists of more information than the visible content of the frame. Preceding and following the image are lines and pixels containing metadata and synchronization information. This surrounding margin is known as a blanking interval or blanking region; the horizontal and vertical front porch and back porch are the building blocks of the blanking interval. Computer displays Computer display standards specify a combination of aspect ratio, display size, display resolution, color depth, and refresh rate. A list of common resolutions is available. Recording Early television was almost exclusively a live medium with some programs recorded to film for distribution of historical purposes using Kinescope. The analog video tape recorder was commercially introduced in 1951. The following list is in rough chronological order. All formats listed were sold to and used by broadcasters, video producers or consumers; or were important historically. 2" Quadruplex videotape (Ampex 1956) VERA (BBC experimental format ca. 1958) 1" Type A videotape (Ampex) 1/2" EIAJ (1969) U-matic 3/4" (Sony) 1/2" Cartrivision (Avco) VCR, VCR-LP, SVR 1" Type B videotape (Robert Bosch GmbH) 1" Type C videotape (Ampex, Marconi and Sony) Betamax (Sony) VHS (JVC) Video 2000 (Philips) 2" Helical Scan Videotape (IVC) 1/4" CVC (Funai) Betacam (Sony) HDVS (Sony) Betacam SP (Sony) Video8 (Sony) (1986) S-VHS (JVC) (1987) VHS-C (JVC) Pixelvision (Fisher-Price) UniHi 1/2" HD (Sony) Hi8 (Sony) (mid-1990s) W-VHS (JVC) (1994) Digital video tape recorders offered improved quality compared to analog recorders. Betacam IMX (Sony) D-VHS (JVC) D-Theater D1 (Sony) D2 (Sony) D3 D5 HD D6 (Philips) Digital-S D9 (JVC) Digital Betacam (Sony) Digital8 (Sony) DV (including DVC-Pro) HDCAM (Sony) HDV ProHD (JVC) MicroMV MiniDV Optical storage mediums offered an alternative, especially in consumer applications, to bulky tape formats. Blu-ray Disc (Sony) China Blue High-definition Disc (CBHD) DVD (was Super Density Disc, DVD Forum) Professional Disc Universal Media Disc (UMD) (Sony) Enhanced Versatile Disc (EVD, Chinese government-sponsored) HD DVD (NEC and Toshiba) HD-VMD Capacitance Electronic Disc