Encoding

About video/audio encoding

Since today’s technology does not permit the economical streaming or capturing (to solid-state memory) of wideband digital video signals, it is necessary to compress the video and audio signals for these applications.

Encoding is the process of compressing the original signal into a signal small enough to be useful for these applications. The SA- DV6000 uses ISO MPEG-4, revision 1.04, the most widely accepted variant of the MPEG-4 algorithm, supported by industry leaders, such as Microsoft. The audio encoder uses the ITU-T G.726 algorithm (for Windows Media Player mode) and ∝law algorithm (for Quick Time mode).

With MPEG-4 video, the bit rate (amount of data per second), frame rate (number of frames per second) and the image size can be changed as necessary.

However, these parameters directly influence the picture quality. When lowering the bit rate, for example, the picture quality will decrease but will have lesser load on the network and longer recording is also possible.

When lowering the frame rate, smooth video playback will be suffered but the picture quality will increase since the larger data volume per frame. The same effect can also be observed when reducing the image size.

The selected encoding parameters affect both the streaming capabilities and the amount of video that can be stored on a CF memory card, but does not affect the VTR’s outputs or the video recorded to tape. Please refer to the table on Page 8 for the encoding values supported by the SA-DV6000.

Note

The selected encoding parameters are independent of, and do not affect the DV recording or VTR’s outputs.

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