Files ending in H264 contain a video stream encoded using the H.264 method.
This process is also referred to as H.264 / MPEG-4 Part 10 or AVC (Advanced Video Coding) and is a standard for efficient, lossy compression of video data. It is mainly used for high-resolution material. For example, H.264 is used on BluRay discs, as a transmission format of HD channels and in Flash videos.
The bitstream contains only the encoded data without any further information, such as refresh rate or resolution. The file also contains no audio.
The extension is not necessarily recognized, but any player playing H.264 should be able to view the file. Occasionally, however, an H.264-capable container, such as MP4 or FLV because of the content with the extension H264 marked. This is wrong.
Most often resolving problems with opening H264 files is very simple. Just install an appropriate program that supports such files. All of the listed programs support H264 files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of H264 files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate H264 files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the QuickTime Player applications is not on the list, select "Browse" option in order to manually locate the directory where QuickTime Player has been installed.
Sometimes problems with opening H264 files may not lie with the application itself, but can arise due to other causes, such as: