Much of the standards of web video are based on conventions that came out of film and video production that predates the digital technology that we currently use.

aspect ratio – ratio of the width and height of a video.  4:3 is common on old computer monitors and television sets.  16:9 is more common today for digital video.  Studio films often have larger ratios like 21:9 for widescreen formats.

4:3 dimensions: 480p (640 x 480 pixels “standard definition”)

16:9 dimensions: 720p (1280 x 720 pixels “high definition”), 1080p (1920 x 1080 pixels “high definition”)

Photoshop Film & Video presets are based on various digital video formats:

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frame rate – the number of frames (still images) per second of video.  Early films like super 8 were shot at 12, 16 or 24 fps.  Digital video is shot at 24, 25 or 30 fps.  Some video games and computer monitors run at 60 fps or faster.

interlaced videointerlacing video is a technique for making it appear to have a faster frame rate while using the same amount of data by switching the horizontal lines from frame to frame.

progressive scanningprogressive scanning is standard in computer monitors.  Each line of color is read after the next.

Web video formats

mp4 (h.264) – Supported by Microsoft and Apple.  Technically it is licensed but the development group does not charge.  Small file size, good quality.

ogg (Theora) – Open source, higher quality video, larger file size.

WebM – Owned by Google.  High quality, long encoding times.  Comparable to h.264.

Browsers support different formats, those standards are always changing.

You can use MPEG Streamclip to convert videos into new formats.

We can download some video from the Internet Archive and edit them in Photoshop.  Each video shows what formats are available:

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