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, C, 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 summary of the monochromatic standards can be seen on this table:
ITU-R defined video standards
|Number of lines||405||625||625||625||819||819||625||625||625||625||625||525||625|
|Field Rate (Hz)||50||50||50||50||50||50||50||50||50||50||50||59.94||50|
|Frame Rate (Hz)||25||25||25||25||25||25||25||25||25||25||25||29.97||25|
| Color Subcarrier Frequency
(on associated color std)
|-||4.43 MHz||-||4.43 MHz||-||-||4.43 MHz||4.43 MHz||4.43 MHz||4.406 MHz||4.406 MHz|| 3.579545 MHz (NTSC)
or 3.575611 MHz (PAL)
|Channel Bandwidth (MHz)||5||7||7||8||14||7||8||8||8||8||8||6||6|
A color TV system is obtained by adding a color subcarrier encoded by 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. The frequency of the color subcarrier is generally
Example: PAL-I, the I television system with PAL color is used in Britain.
SECAM (Sequential Couleur A Mémoire) is a color standard used on France, Russia, and few countries at Central, East Europe, America, Africa and Asia. It is generally associated with monochromatic standards B, G, D, K and L (so, its typical resolution is 625 Lines, 25 frames per second). See SECAM page on Wikipedia for much more detail.
NTSC (National Television System Committee) is used in USA, Canada, and Japan. It is generally associated with monochromatic standard M (NTSC/M), so, its typical resolution is 525 Lines, about 30 frames per second. Less quality then PAL, therefore sometimes called Never Twice the Same Color, since the colors can shift as the phase of the color subcarrier shifts on broadcast. ;-) See NTSC page on Wikipedia for much more detail.
PAL (Phase Alternating Line) is the most widely used color standard for analog TV in the world, used on almost everywhere. It is generally associated with monochromatic standards with resolution of 625 Lines, 50 half frames per second. It can also be associated with M standard (PAL/M), having a resolution of 525 lines, about 30 frames per second. It is generally associated with 4:3 aspect. There is a 16:9 extension of PAL called PALplus. See PAL page on Wikipedia for much more detail.
Analog TV Hardware and Framegrabber cards
For analog TV, those are the currently supported boards:
- Conexant (Brooktree) based analog TV cards using the bttv driver - very stable, good support but no hardware MPEG Encoder;
- Conexant cx18 driver - it is a recent driver. Supports analog and digital TV. It also supports MPEG encoder;
- Conexant cx88 driver - stable, good support. A few boards have MPEG encoder;
- Conexant ivtv driver = supports Hauppauge and similar cards based on the cx23415/cx23416 chip. These cards are really good and have an onboard MPEG encoder (both cards) and an MPEG decoder with TV-out (PVR 350 only).
- NXP (Philips semicondutor) saa71134 driver - stable, good support. A few boards have MPEG encoder. Supports saa7130, saa7131, saa7133, saa7134 and saa7135 devices;
- NXP (Philips semicondutor) saa7146 driver - stable.
- Zoran driver - stable.
- Zoran 36120 driver - driver broken kernels 2.6. Removed due to that.
- Empia em28xx driver - stable, good support.
- Hauppauge PVR USB2 pvrusb2 driver - stable, good support.
- Trident tm5600/tm6000/tm6010 tm5600 driver - currently being developed. Not working yet.
- Nogatech NT1003/1004/1005 usbvision driver - stable, good support.