Video standards and resolutions
Author: ffDiaporama Team

Standards and resolution are both fundamental properties which define a video.
Two associated properties are the geometry and the FPS number.

## Standard

Standards are a historic feature which continues today in spite of technological progress.
A rich literature on this subject can be found on the internet.
To simplify things we shall summarize as follows:

- PAL is effective in all the countries where the electricity network is 50 hz (which is the case, for example, for Western European countries)
- NTSC is effective in all the countries where the electricity network is 60 hz (which is the case, for example, for the United States of America)

## Geometry

The geometry is the ratio of Width to Height.

- 4:3 corresponds to screens that are almost square
- 16:9 corresponds to screens that are rectangular
- 40:17 corresponds to cinema screens in overall size

## Resolution

Unlike with photos, video resolution is not expressed in megapixels but in number of points (pixels) shown by the screen multiplied by the number of lines.
So, 320x240 corresponds to 320 points of width and 240 lines in height

## FPS (Frames per second)

Corresponds to the number of images shown every second. You should know that in cinemas, 24 images are shown per second and this figure of 24 images is recognized as corresponding to the maximum number of images which the eye is capable of differentiating:

- More images per second and the eye does not notice it
- Fewer images per second and the film appears jerky

## Matrix of combinations managed by ffDiaporama

The following table indicates all the combinations of geometry, standards and resolutions managed by ffDiaporama. For every combination, it indicates the number of associated FPS:

Name | Geometry | PAL | NTSC | Remark
Resolution | FPS | Resolution | FPS
RIM 240 | 4:3 | 240x180 | 24 FPS | 240x180 | 24 FPS | Special format used on Blackberry's very small screen
6:9 | 240x136 | 240x136
40:17
QVGA | 4:3 | 320x240 | 25 FPS | 320x240 | 29,97 FPS | Used mainly on the Internet and by first generation smartphones and mobile video players.
16:9 | 320x180 | 320x180
40:17 | 320x136 | 320x136
HVGA | 4:3 | 426x320 | 426x320 | Used mainly on the Internet and by second generation smartphones and mobile video players. Because this format does not respect the traditional video geometry, black bands appear to fill the screen to 480x320.
16:9 | 480x270 | 480x270
40:17 | 480x204 | 480x204
VGA | 4:3 | 640x480 | 640x480 | Used mainly on the Internet and by some smartphones.
16:9 | 640x360 | 640x360
40:17 | 640x272 | 640x272
SD-DVD | 4:3 | 720x576 | 720x480 | The old television format for cathode ray tubes. Note that this format was specifically created for equipment with oval points: It is the anamorphism of the points that determines the geometry. That is why it is absolutely necessary to avoid this format for anything other than television sets with cathode ray tubes.
16:9
40:17
WVGA | 4:3 | 640x480 | 640x480 | Used mainly on the Internet and by new generation smartphones and mobile video players. This format has become widespread and has replaced the old QVGA, HVGA and VGA format used in the years 2000-2010. Because this format does not respect the traditional video geometries, black bands appear to fill the screen to 800x480.
16:9 | 800x450 | 800x450
40:17 | 800x340 | 800x340
XGA | 4:3 | 1024x768 | 1024x768 | Historically this format was used only by computers (fixed or portable). Now we meet it more and more on tablet computers like the iPad.
16:9 | 1024x576 | 1024x576
40:17 | 1024x436 | 1024x436
720p | 4:3 | 960x720 | 960x720 | 23,976 FPS | Today, this format is widely used on the Internet, in particular by social networking and video-sharing sites. We also find it on certain "home cinema" devices.
16:9 | 1280x720 | 1280x720
40:17 | 1280x544 | 1280x544
1080p | 4:3 | 1440x1080 | 1440x1080 | This is the real "home cinema" format. It is used by the Blue Ray players and the "home cinema" devices.
16:9 | 1920x1080 | 1920x1080
40:17 | 1920x816 | 1920x816

Note that many other resolutions exists but which are not used by ffDiaporama.