Choosing a correct frame rate
Movies on film are almost exclusively projected at 24 fps. Television, however, does not have an internationally accepted frame rate. In Europe and many other countries, PAL uses 25 fps, whereas NTSC video in North America and Japan uses 29.97 fps. 29.97 fps has been the NTSC standard of high definition video since 1953.
Converting video formats from one frame rate to another is technically challenging, and there are often unwanted visual side effects. This is especially true when the frame rates do not evenly divide. For example, converting 29.97 fps to 60 fps is fairly easy to do, but converting 29.97 fps to 25 fps is much more difficult. Making sure audio stays in sync throughout the conversion is yet another challenge.
Choosing a correct codec
H.264 or MPEG-4 AVC is relatively new technology and is taking the web video by storm. It is currently one of the most commonly used format for the video recording, compression, and distribution of video content.
The H.264 video format has a very broad application range that covers all forms of digital compressed video from low bit-rate Internet streaming applications to HDTV broadcast and Digital Cinema applications with nearly lossless coding. It is widely used by streaming internet sources, such as videos from Vimeo, YouTube, iTunes Store, Flash Player, and also various HDTV broadcasts over terrestrial, cable, and satellite.
AAC (Advanced Audio Coding) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.
AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications. AAC is the default or standard audio format for Vimeo, YouTube, iPhone, iPod, iPad, Nintendo, iTunes, PlayStation 3, Android, and webOS-based mobile phones.
AAC Low Delay (MP4 AAC-LD) is designed to combine the advantages of perceptual audio coding with the low delay necessary for two-way communication. It is closely derived from the MPEG-2 Advanced Audio Coding (AAC) format.