Diff b/w Raw & composite Video signal

1. Diff b/w Raw & composite Videosignal • Raw video signal: Raw video is the signal created by the tube or imager of the camera.  Raw video on an average, measure 0.6 volts peak-to-peak with high peaks of 0.8 volts. • Composite video signal: Composite video is the complete video signal including the Raw Video Information Pedestal, and Sync Line.  Composite video is measured form the sync line to the peak of the raw video average composite video with any camera system should be 1 volt peak-to-peak.  Composite video signals may have high peaks of as much as 1.4 volts, which represent hot spots or very bright points within the video picture.

2. Composite Video Signal …contd

3. Interlaced scanning

4. Concept of Interlaced scanning • The analog video signal includes synchronization pulses that control the scanning line by line from left to right and field by field from top to bottom. • The pulses that control the line-by-line scanning are called the horizontal synchronization pulses (H-Sync). The pulses that control the vertical scanning are called the vertical synchronization pulses (V-Sync). • Two interlaced fields compose a complete frame. The first field, called the odd field, scans the odd lines of the video image. The second field, called the even field, scans the even lines of the video image. The process repeats for every frame.

5. How to know Even or Odd field? • At the end of an odd field, there is an extra half line of data that is sent indicating the following field is even. Similarly, the last line of the even field is a full line of active video data, indicating the following field will be odd. See interlaced scanning pic

6. Cont..