480i

480i is the shorthand name for a video mode, namely the US NTSC television system or digital television systems with the same characteristics. The i, which is sometimes uppercase, stands for interlaced, the 480 for a vertical frame resolution of 480 lines containing picture information; while NTSC has a total of 525 lines, only 480 of these are used to display the image for DV-NTSC. Technical Detail For analog NTSC there are a total of 525 scanning lines of which originally 486 lines were active (243 complete lines per field) and later 480 (240 complete lines per field). A full frame is split into odd and even fields where an odd field starts with half a line and the even field ends with the other half of the line. By convention an NTSC video frame is considered to start with an even field followed by an odd field. The disparity of the line numbering compared to other systems is solved by defining the line numbering to start five equalising pulses (or 2 and a half lines) earlier than on all other systems (including Systems A and E even though they had no equalising pulses) on the first equalising pulse following an active line or half line. This has the effect of placing a half line of video at the end of the even (first) field and the beginning of the odd (second field). Thus the line numbers correspond to the real lines of the video frame. On all other systems, the field was considered to start with the falling edge of the first field pulse which gave the confusing position that the odd field (first) had a half a line of video occupying the latter half of a whole line and ended with a whole line of video but half a scanning line (and vice versa for the even field). The NTSC convention solved this confusion.1 For DV-NTSC only 480 lines are used. The digitally transmitted horizontal resolution is usually 720 samples (which includes 16 samples for the horizontal sync and horizontal blanking) or 704 visible pixels with an aspect ratio of 4:3 and therefore a display resolution of 640 × 480 (VGA); that is standard-definition television (SDTV) with a 4:3 aspect ratio.2345 The field rate (not the frame rate) is usually (60/100.1% ≈) 59.94 hertz for color TV and can be rounded up to 60 Hz. There are several conventions for written shorthands for the combination of resolution and rate: 480i60, 480i/60 (EBU/SMPTE) and 480/60i. 480i is usually used in countries that conventionally use NTSC (most of the Americas and Japan), because the 525 transmitted lines at 60 hertz of analogue NTSC contain 480 visible ones. 480i can be transported by all major digital television formats, ATSC, DVB and ISDB. See also Television portal 480p Enhanced-definition television (EDTV) References ^ Report 308-2 of the XIIth Planiary of the CCIR - Characteristics of TV systems. ^ rpsoft2000 - US HDTV, 480i, 480p, 1080i ^ AfterDawn.com - 480i ^ CNET - Glossary - 480i ^ TheFreeDictionary.com - 480i v · d · eBroadcast video formats  Television Analog 525 lines System M · NTSC · NTSC-J · PAL-M 625 lines PAL · PAL-N/NC · PALplus · SECAM Audio BTSC (MTS) · NICAM-728 · Zweiton (A2 / IGR) · EIAJ · SAP  · Sound-in-Syncs Hidden signals Captioning · Teletext · CGMS-A · GCR · PDC · VBI · VEIL · VIT  · VITC  · WSS  · XDS · EPG Defunct systems Pre-1940 · Baird-Nipkow · 180 lines · 405 lines · 441 lines · 819 lines · MAC · MUSE Digital Interlaced SDTV (480i · 576i) · HDTV (1080i) Progressive LDTV (240p · 288p · 1seg) · EDTV (480p · 576p) · HDTV (720p · 1080p) · UHDTV (4320p) MPEG-2 standards ATSC · DVB · ISDB · DMB-T/H · DVB 3D-TV MPEG-4 AVC standards ATSC 2.0 (A/72) · DMB · DMB-T/H · DVB · SBTVD · 1seg Audio AC-3 (5.1) · DTS · MPEG-1 Audio Layer II · MPEG Multichannel · PCM · LPCM · AAC · HE-AAC Hidden signals Captioning · Teletext · CPCM · Broadcast flag · AFD · EPG  Digital cinema 2540p · DCI  Technical issues 14:9 compromise · Moving image formats · MPEG transport · Reverse Standards Conversion · Standards conversion · Video processing · Video on demand · HDTV blur v · d · eDigital video resolutions Designation Usage Examples Definition (lines) Rate (Hz) Interlaced (fields) Progressive (frames) Low; MP@LL LDTV, VCD, HTV 240; 288 (SIF)   24, 30; 25 Standard; MP@ML SDTV, SVCD, DVD, DV 480 “NTSC”; 576 “PAL” 60; 50 24, 30; 25 Enhanced EDTV 480; 576   60; 50 High; MP@HL HDTV, BD, HD DVD, HDV 720   24, 30, 60; 25, 50 1080 50, 60 24, 30; 25 Ultra High UHDTV 4320   60