H.264 is a new video codec standard which can achieve high quality video in relatively low bitrates. You can think it as the “successor” of the existing formats (MPEG2, MPEG4, DivX, XviD, etc.) as it aims in offering similar video quality in half the size of the formats mentioned before. Also known as AVC (Advanced Video Coding, MPEG-4 Part 10), H.264 is actually defined in an identical pair of standards maintained by different organizations, together known as the Joint Video Team (JVT). While MPEG-4 Part 10 is an ISO/IEC standard, it was developed in cooperation with the ITU, an organization heavily involved in broadcast television standards. Since the ITU designation for the standard is H.264, you may see MPEG-4 Part 10 video referred to as either AVC or H.264. Both are valid, and refer to the same standard.
The latest version of ffdshow supports H264 playback. Pleaseremember, ffdshow is a DirectShow filter so after you install it you'll be able to play H264 in most video players you already have installed, including Windows Media Player. Alternatively you can download VLC player. It can play H.264 without need of any codec or DirectShow filter. Apple QuickTime players support H264 too, but their support is not so great for all formats, so don't use them for general H264 playback. Generally most players or codec packs nowadays include H264 support so you shouldn't have any problems. You may also watch your H.264 files on your Xbox 360 and PS3 with smooth playback.
You may come across all kind of file extensions and still the codec can be H.264:
*.avi - People also use .avi for H264 videos too!
*.mp4 - QuickTime use this format. Better than AVI as you can store AAC audio as well.
*.m4v - The standard file format for videos for iPods developed by Apple.
*.mkv - Matroska container - can support many video and audio formats.
*.h264 - Not commonly used, but you may download some video files with this extension name from Internet.
Related Software
WinX DVD Ripper: Free DVD to H.264 converter which is made for help users convert DVD to H.264, AVI, FLV, MPEG format with no fees involved.
WinX DVD Ripper Platinum: Advanced version of WinX DVD Ripper, apart from convert DVD to H.264 at fastest speed and excellent quality, also capable of converting DVD to H.264, MOV, iPhone, iPod, iPad, etc. Makes perfect 1:1 copy with 5 minutes. Constantly update to defeat upcoming DVD copy protections.
WinX HD Video Converter Deluxe: easily convert H.264 video to AVI, MOV, HD video, iPhone, iPad, iPod, PSP, ZUNE, etc, as well as convert them back to MPEG-4 format. Moreover, it builds 210 video and audio codec, a perfect multi-functional combination of HD Video Converter, DVD Burner & Website Video Downloader.
WinX DVD Ripper for Mac: Mac version WinX DVD Ripper Platinum, runs perfectly on Mac OS X Tiger/Leopard/Snow Leopard, convert DVD to H.264 MP4, MOV that are playable on Mac computer, as well as iPhone, iPod, iPad, Apple TV, etc.
WinX HD Video Converter for Mac: Excellent HD Video Converter for Mac, compatible with Mac OS X Tiger/Leopard/Snow Leopard. Fully support convert Blu-ray video, HD camcorder video, HDTV video to H.264 MP4, MOV, iTunes for playback on iPhone, iPad, iPod, Apple TV, etc.
Related Source
MPEG-4, AVC, MPEG, MP3, iTunes, iPod, iPhone, Mplayer, QuickTime, VLC
Related External Source
http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC
http://www.afterdawn.com/glossary/term.cfm/mpeg_4_part_10
http://en.wikipedia.org/wiki/M4V