Source Input Format

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Source Input Format (SIF) defined in MPEG-1, is a video format that was developed to allow the storage and transmission of digital video.

• 625/50 SIF format (PAL/SECAM) has a resolution of (360 or) 352 x 288 active pixels and a refresh rate of 25 frames per second.
• 525/59.94 SIF Format (NTSC) has a resolution of (360 or) 352 x 240 active pixels and a refresh rate of 29.97 frames per second.

When compared to the CCIR_601 specifications, which defines the appropriate parameters for digital encoding of TV signals, SIF can be seen as being reduced by half in all of height, width, frame-rate, and chrominance. SIF video is known as a constrained parameters bitstream.^[1]

The computer industry has defined square-pixel SIF to be 320 x 240 (QVGA) or 384 x 288 active pixels with a refresh rate of whatever the computer is capable of supporting.

See also

• Common Intermediate Format (CIF)

v • d • e Digital Video Resolutions Designation Usage Examples Definition (lines) Rate (Hz) Interlaced (fields) Progressive (frames) Low; MP@LL LDTV, VCD 240; 288 (SIF)   24, 30; 25 Standard; MP@ML SDTV, SVCD, DVD, DV 480 (NTSC, PAL-M) 60 24, 30 576 (PAL, SECAM) 50 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 This table illustrates total horizontal and vertical pixel resolution via box size. It does not accurately reflect the screen or pixel shape (aspect ratio) of these formats, which is either 4:3, or 16:9.

References