Can someone please explain H.264 in layman's terms? Is it a codec? A compression? A container?
Basically, it is a compression format and is also referred to as MPEG-4/AVC or MPEG-4 Chapter 10. In the case of QT, the codec is also known as the "H.264" codec but there are other codecs (e.g., x264) which can produce the same or nearly the same files. In QT, H.264/AAC compressed data can be stored in three primary file containers -- the MOV, MP4, or M4V file type. MOV, for instance is a generic file container which can hold any QT or non-QT compression format for which you have the proper QT component support installed. The MP4 file container is limited to MPEG-4 compressed audio and video compression formats -- e.g., MPEG-4/AAC and H.264/AAC data. The M4V container is even more restrictive being limited to H.264/AAC and may be either "protected" or "unprotected."
Is there a way to convert a 1280x720 30fps HD video to a 848x480 30fps H.264 video using quicktime pro?
Sure. You can use either the "Movie to MPEG-4" or "Movie to QuickTime Movie" export option as long as you choose the proper settings.
I'm asking because I have two digital cameras, a Casio that records it's videos in 848x480 30fps H.264 format and a Panasonic that records in 1280x720 30fps HD format. Quicktime Pro opens both. I like the fact that the Casio's videos are smaller yet as clear.
File size is determined for the most part by the video data rate. The higher the data rate, the larger the end file size. In general, smaller displays require less data to maintain the same level of quality. This, of course means you can lower the data rate to make your file smaller and still retain equivalent quality between your 720p and 484p files.
