Gaining a much wider use on the internet these days, the FLV or Flash Video file format is the format of choice in major internet sites like YouTube, Yahoo and Google Video. Previously known as the Macromedia Flash Player file, Flash Video can be played on the Adobe Flash Player as a format proprietary to the maker. It can be viewed on most operating platform, notably Windows and Mac, using the downloadable Adobe Flash player or a plug-in application for the browser. Third party multimedia players can also play them with the ffdshow filter support installed with the application.

Video support

The Flash player from Adobe is a multimedia and application player that plays FLV files from SWF files created by the associated Adobe Flash authoring tools as well as third party tools. As a browser add-on or plug-in, flash video players can be embedded in webpages to be viewed in browsers with the plug-in. This is what happens with the YouTube site.

The Flash Video files contain video bit streams which are slightly off from the H.263 video standard called as Sorensen Spark . Flash Player 8 and newer revisions support the playback of On2 TrueMotion VP6 video bit streams that can provide better visual quality than Sorenson Spark, especially at lower video bitrates. However, it is computationally more elaborate and may not run as well on certain older PCs. Recent trial versions of Flash Player 9 include support for H.264 video standard (also known as MPEG4 Part 10 or AVC) which while more computationally demanding provides significantly better quality/bitrate performance.

The FLV file format supports two versions of a so called ’screenshare’ codec designed for Screencasts. Both formats are bitmap based and can be lossy by reducing color depths lower than 8 bits for compression using zlib. The second version is only playable in Flash Player 8 and newer.

Audio in FLV files is often done in the mp3 format. However, FLV files recorded from the PC microphone use the proprietary Nellymoser codec. The most recent beta versions of Flash Player 9 support a number of profiles under AAC.

Most multimedia players based on the FFmpeg libraries can play back the FLV video format. Any player which plays back QuickTime formats also can but after installation of the required FLV software component. Below are some other media players that do:

• VLC multimedia player
• Mplayer (with FFmpeg)
• Xine (with FFmpeg)
• RealPlayer
• Any player which can use the ffdshow (based on FFmpeg) DirectShow codecs:
  • Media Player Classic
  • Windows Media Player
  • Windows Media Center (requires some registry hack)

Flash plans

Just recently, Adobe announced Update 3 of the Flash Player (currently in beta) that now will support the MPEG4 Part 10 standard, audio compressed using AAC (MPEG-4 Part 3), the MP4, M4V, M4A, 3GP and MOV multimedia container formats (MPEG-4 Part 14), 3GPP specification (MPEG-4 Part 17) which is a standardized subtitle format and parsing support for the ID3 equivalent of iTunes stored n the metadata. Adobe also will be gradually phasing out the proprietary FLV format to the standard MP4 format owing to functional limits within the FLV structure when streaming H.264.

Advantage of using FLV

More of a letdown than an advantage, Flash video files are embedded in SWF files when authoring from an associated Adobe software tool. The FLV needs to be decoded from the SWF file for playback to happen in the associated FLV player. Editing the video requires having the original SWF file or having it rebuilt.

FLV files have become popular because of the YouTube phenomenon belatedly copied by Google and Yahoo websites. Other than that, there’s really not much sense using FLV format or other formats that have already made their mark in the home PC entertainment industry. That should be pretty much obvious as YouTube is expected to convert their format into QuickTime formats soon enough to accommodate the huge demand for online video expected to be generated with Apple’s promise for YouTube access on its iPhone.