A progressive standard-definition picture for regions that kept the 625-line broadcast raster of Phase Alternating Line (PAL). SECAM uses the same count of active lines. About 720 by 576 stored pixels make each frame, and every line goes out in one pass, commonly at 50 Frames Per Second (FPS). The number is the vertical line count. The letter p means that pass is a complete frame rather than one field of a split picture.
The interlaced form of that line count is 576 Interlaced (576i). It divides the frame into two fields, so a moving edge can comb across them. With no field split, motion stays cleaner, because one pass already holds the whole picture. The result remains Standard Definition (SD). It is not High Definition (HD), and it is not High Definition Television (HDTV).
How the Complete Frame Is Built
- Line count. 576 names the active vertical lines and does not name the width. The usual stored width is about 720 samples.
- One pass. Progressive scan emits every line of the current frame before the next frame begins.
- No weave. Interlaced video places odd lines in one field and even lines in the next. A single progressive pass does not weave two moments together, so a still is already a full picture.
Display Shape and Timing
- Shared grid. Both 4:3 and 16:9 use that stored sample array.
- Non-square pixels. The samples are stretched horizontally by different amounts so the displayed shape is 4:3 or 16:9. That correction is pixel aspect, not Pixels Per Inch (PPI), which measures density on a physical screen only.
- Usual timing. 50 frames per second matches the 50 Hz cycle used with PAL.
Countries that standardized on National Television System Committee (NTSC) video use a shorter raster: 480 Progressive (480p) or 480 Interlaced (480i), each with about 480 active lines.
Steps Above Standard Definition
- Next step up. 720 Progressive (720p) stores 1280 by 720 and still paints a full frame on each pass. It is the common step from this raster into high-definition television.
- 1080-line class. Full High Definition (FHD) covers that class. 1080 Progressive (1080p) keeps one complete frame per pass. 1080 Interlaced (1080i) splits the same line count into fields.
- Taller rasters. Quad High Definition (QHD) is 1440 Progressive (1440p), typically 2560 by 1440. Ultra High Definition (UHD) at 3840 by 2160 is the broadcast picture of Ultra High Definition (4K), and that vertical count is 2160 Progressive (2160p). 8,000 Pixels (8K) is 4320 Progressive (4320p) at 7680 by 4320.
These labels fix line count and scan only. They do not choose dynamic range, so the same frame size can use Standard Dynamic Range (SDR) or High Dynamic Range (HDR). They do not require one color encoding, such as Red Green Blue (RGB). High-Definition Multimedia Interface (HDMI) can carry this standard-definition progressive frame as well as the taller ones. Society of Motion Picture and Television Engineers (SMPTE) timing documents are the studio reference for the 720-line and 1080-line progressive formats, while this 576-line frame stays in the standard-definition group.
| Mode | Typical Pixels | Scan | Usual Rate |
| 480i | 720 by 480 | Interlaced | About 60 fields per second |
| 480p | 720 by 480 | Progressive | About 60 frames per second |
| 576i | 720 by 576 | Interlaced | 50 fields per second |
| 576p | 720 by 576 | Progressive | 50 frames per second |
| 720p | 1280 by 720 | Progressive | 50 or 60 frames per second |
| 1080i | 1920 by 1080 | Interlaced | 50 or 60 fields per second |
| 1080p | 1920 by 1080 | Progressive | 24, 50, or 60 frames per second |
| 1440p | 2560 by 1440 | Progressive | 60 frames per second |
| 2160p | 3840 by 2160 | Progressive | 24, 50, or 60 frames per second |
| 4320p | 7680 by 4320 | Progressive | 24, 50, or 60 frames per second |