GIFV is an alternative to the animated GIF format for presenting animated images on a web page. It is not a unique file format, but rather an approach to serving video files using the HTML5 <video> tag. It uses the H.264 or WebM video formats, which have widespread support in modern web browsers.
When you view a GIFV file on a site such as Imgur, you are actually viewing a video file, which would normally have the file extension .mp4 or .webm. The server is configured to serve the video using the extension ".gifv," but the video's file format is unchanged.
Advantages of using GIFV
Advantages of using video instead of a traditional animated GIF include:
|Loading time||The entire GIF must be downloaded before playback can begin.||Video/GIFV can begin playing as soon as it begins to download.|
|File size||GIF uses run-length encoding, which only significantly reduces file sizes when there are large areas of solid color.||Video compression settings can be tweaked to create a file size as much as 95% smaller than an animated GIF.|
|Color depth||GIF uses only 8 bits to encode color information, which provides a fixed palette of up to 256 colors. Diffusion can be used to simulate greater variation in color, but this can produce a grainy result for photographic images.||H.264 and WebM support 24-bit true color (eight bits each for red, green, and blue values), which can produce up to 16,777,216 different colors.|
|Frame rate||GIF frame rates are limited to whole numbers, such as 30 frames per second.||Videos can be encoded with fractional frame rates, such as 29.97 frames per second, which is the standard frame rate for NTSC video.|
Here's an example of an animation presented as an animated GIF (on the left) and an H.264 video (on the right):
|Animated GIF||H.264 video/GIFV|