I hear a lot about streaming video and audio. What does that mean?
A1:
In the past, video and audio files took minutes and sometimes hours to retrieve through most modems, which severely limited the inclusion of video and audio on web pages. The goal that everyone is moving toward is streaming video or audio, which plays while the data is being received. In other words, you don't have to completely download the clip before you can start to watch it or listen to it.
Streaming playback is now widely supported through most media players, in both standalone versions and plug-ins. When you embed a media object using the <object> tag, the underlying media player will automatically stream the media clip if streaming is supported in the player.
Q2:
How do I choose among audiovisual file formats such as QuickTime, Windows AVI/WAV, RealVideo/RealAudio, and MPEG? Is there any significant difference among them?
A2:
QuickTime is the most popular video format among Macintosh users, though QuickTime players are available for Windows as well. Similarly, AVI/WMV and WAV/WMA are the video and audio formats of choice for Windows users, but you can get players for the Macintosh that support these formats. MPEG is another popular audio and video standard. MPEG-3, or MP3 for short, is already extremely popular as the high-fidelity audio standard of choice. One other audio format that is based on MPEG is Apple's AAC format, which may be more familiar to you as the native iTunes music format.
How do you choose? If most of your audience uses Windows, pick AVI/WMV for video, or WAV/WMA or MP3 for audio. If your audience includes a significant number of Macintosh users, pick QuickTime or RealVideo/RealAudio, or at least offer it as an alternative; MP3 is also a viable option for Mac audio. If cross-platform compatibility is essential, consider going specifically with MP3 for audio, or RealVideo/RealAudioalthough only those who download special software from http://www.real.com/player/ will be able to see RealVideo/RealAudio clips.
