- As a straightforward download. The end user will have to wait until the file has downloaded before it can be viewed.
- As an HTTP "Fast Start" streaming file which does not require special server software and which will start playing as soon as sufficient data has arrived.
- As an RTSP streaming file which requires special server software.
QuickTime RTSP streaming
Like RealMedia files, QuickTime RTSP streaming video files need special server software which delivers data to the end-user on an as-needed basis. Playback is handled by the end-user's browser's QuickTime plug-in.
RTSP is suitable for live video or internet "radio" broadcasts. If the network becomes congested then the video and audio may stop for a while. The end-user will never see or hear the lost data because when replay resumes the broadcast will have moved on.
Disadvantages include ...
- Data is not saved on the end-user hard drive and so has to be downloaded again to be viewed a second time.
- Special server software is required.
Advantages include ...
- The end-user can choose to start playback from any point in the video.
- Because RTSP data does not download to the end-user's hard drive, it may be preferable for longer movies which will require greater amounts of free end-user hard disc space.
- Because no data is saved on the end-user system it may be preferable if copyright is an issue.
QuickTime HTTP streaming
HTTP streaming involves placing a QuickTime "Fast start" file in a web page. When the end-user clicks on it, the file downloads to the end-user's system from where it is replayed by either the browser's QuickTime plug in or the QuickTime Player. Because the file can start playing before download is complete this method can be considered streaming.
Advantages include ...
- No special server software is required.
- Once data has downloaded it can be viewed a second time without further download.
- Providing you don't mind the end-user waiting for sufficient download to replay to start, you can author higher quality files.
- HTTP allows additional data tracks, such as sprites and 3D.
Disadvantages include ...
- Files play from the start. The end-user cannot choose to view the file from any other point until it has downloaded.
- Because the whole file is downloaded, it can be redistributed and therefore copyright cannot be protected.
Authoring file with QuickTime Pro player
You can create HTTP and RTSP files with QuickTime Player Pro by either importing a file you have created in another application or by using the editing features of the application itself.
Use the File>Export menu and then use the Options button and Export and Use drop-down menus to select appropriate settings ("Fast start" for HTTP streaming). In preparing files you will need to consider ...
- End-user system
- Network
- Frame size
- Frame rates
- Compression settings (audio and video)
- File format
- Data rates
- Data size
Choosing approriate settingsare discussed on the page Choosing settings for optimising video & audio.