Difference Among FLV, F4V, and HD FLV

FLV and F4V are also known as Flash video, which are popular
formats used to deliver video over the Internet using Flash
Player. But FLV usually refers to SD video (Standard-definition
video), which is compressed by H.263, MPEG video codec. F4V
usually refers to HD video (High-definition video), which is
compressed by H.264 video codec. F4V video has better video
quality and wider usages than FLV since F4V belongs to HD video.

HD FLV refers to a category of Flash videos which is compressed
by H.264 video codec.

At present, HD FLV is most popular on the Internet. Because it
delivers excellent video quality across the entire bandwidth
spectrum - from 3G to HD and everything in between (from 40 Kbps
to upwards of 10 Mbps). And Flash Player can play all the Flash
video included FLV, F4V and HD FLV.

For both enjoying web video on PC/devices and publishing video
to web, there are a lot FLV video converter software, and some
of them are completely free, safe and clean, like Sothink Free FLV Video
Converter, to freely convert between FLV, F4V and HD FLV,
and also can convert those Flash video to other video formats.

What is FLV?

FLV, also known as Flash video, is a popular format used to
deliver video over the Internet using Flash Player. Right now,
Flash Player supports H.264 video and HE-AAC audio, Flash video
contents can be embedded within SWF files. FLV format has
quickly established itself as the format of choice for embedded
video on the web; and FLV formats are used widely on mainstream
video website, for instance: YouTube, Google Video, Yahoo!
Video.

Flash video can be played freely on web without installing
additional codec requirements on most operation systems. The
people can enjoy Flash video via widely available adobe Flash
Player and web browser plugin, or one of several third-party
programs, such as MPlayer, QuickTime, VLC media player, Sothink
Free FLV Player Windows/Mac.

What is F4V?

F4V is a video file format which is developed by Adobe Flash.
F4V files belong to HD video. Since videos in F4V format are
usually encoded in H.264, the F4V format is based on the format
specified by ISO/IEC 14496-12: ISO base media file format. The
Adobe Flash Player has been able to play F4V files with SWF
files published for Flash Player 9 Update 3 (9,0,115,0). A large
part of the F4V format involves metadata. When Flash Player
loads an F4V file, various stream properties are made available
to a running ActionScript program via the NetStream.onMetaData
property. The available properties differ depending on the
software used.

What is HD FLV?

HD FLV is High-definition Flash Video, which generally refers to
Flash video system of higher resolution than standard-definition
(SD) video, most commonly at display resolutions of 1280×720
(720p) or 1920×1080 (1080i or 1080p). SD video is usually
encoded by standard H.263 or MPEG video codec, etc; HD video is
better video compression solution which adopts H.264 video
codec. The HD FLV in H.264 delivers excellent video quality
across the entire bandwidth spectrum - from 3G to HD and
everything in between (from 40 Kbps to upwards of 10 Mbps).

More about H.264:

H.264 is a standard for video compression, and is equivalent to
MPEG-4 Part 10, or MPEG-4 AVC. H.264 is the next-generation
video compression technology in the MPEG-4 standard, also known
as MPEG-4 Part 10. H.264 can match the best possible MPEG-2
quality at up to half the data rate.

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Detailed differences among FLV, F4V, and HD FLV.