Difference between revisions of "Analog TV"
(Fix: PAL/SECAM/NTSC are color systems, not picture systems. Added ITU-T TV video systems.)
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=== PAL ===
=== PAL ===
PAL (''Phase Line'') system standard for analog . is widely used analog TV . resolution 625 Lines, 50 half frames per second, 4:3. There is extension of PAL called .
=== SECAM ===
=== SECAM ===
Revision as of 01:25, 29 April 2007
Analog TV is the predecessor of DVB. In some countries like Germany Analog TV is not available anymore and is exchanged by DVB-T, in other ones Analog and Digital TV are expected to live in peaceful coexistence for a while. If you own ancient hardware like analog camcorders or want to archive your old VHS archive you may be interested in using an analog framegrabber card in the future, too.
ITU-T defines monochrome television systems designated A, B, D, E, F, G, H, I, K, L, M, N. (A, C, E and F are no longer in use). They are esentially the same, but differ in the number of lines per field (405/525/625/819), frame rate (25/29.97), channel width, visual band width, vestigial band width, video modulation polarity (+/-), sound modulation type (AM/FM) and sound frequency offset (-6.5/-3.5/+4.5/+5.5/+5.996/+6.5/+13.5 MHz).
A color TV system is obtained by adding one of the three color systems: PAL, SECAM or NTSC. Theoretically one can combine any picture system with any color system. In practice only some combinations are used, and one color system is used mostly with one resolution and frame rate. (These are given below.)
Example: PAL-I, the I television system with PAL color is used in Britain.
PAL (Phase Alternating Line) is a color system standard for analog TV. It is the most widely used analog TV standard in the world, used almost everywhere except the USA, Russia and Japan. The usual resolution is 625 Lines, 50 half frames per second, 4:3, though some regional differences exist. There is a 16:9 extension of PAL called PALplus. See Wikipedia for much more detail
SECAM (Sequential Couleur A Mémoire) is a standard like PAL, but nowadays not widely used. (France, Russia, formerly used in Central and East Europe) Typical resolution: 625 Lines, 25 frames per second.
NTSC (National Television System Comitee) is widely used in America, Canada and Japan. Typical resolution: 525 Lines, 60 half frames per second. Less quality then PAL, therefore sometimes called Never The Same Color. ;-)
Analog TV Hardware and Framegrabber cards
For analog TV you can use
- Brooktree BT848/878 based analog TV cards using the bttv driver, good support but no hardware MPEG Encoder
- Hauppauge PVR 250/350 and similar cards based on the cx23415/cx23416 chip using the ivtv driver, please have a look at Chris Kennedys site. These cards are really good and have an onboard MPEG encoder (both cards) and an MPEG decoder with TV-out (PVR 350 only). Both of them are supported by ivtv. May these forum might be interesting for you too: link
- Hauppauge PVR cards, the predecessor of that cards mentioned before with an old-style unsupported Visiontech Kfir MPEG hardware encoder. Barely supported under linux with the pvr driver, better check the current project status before you spent too much money for these cards.
- Hauppauge WinTV USB and similar cards with the pvrusb driver
- Conexant 2388x chip (rather new) based cards driver link
- Zoran based cards like Pinnacle DC10 link
Please also check the video4linux homepage to get a complete overview of TV cards supported by the Video4Linux drivers.