Temporal Preprocessing - A Practical Guide to Video and Audio Compression - page 546

Fields swapped within same frame

Odd Even Odd Even Odd Even

Odd Even

Odd Even Odd Even

Fields delayed by one frame

Odd Even

Odd Even Odd Even

Odd Even Odd Even Odd Even

Figure 33-10 Field-dominance errors.

quality of your compressed video any good. The synchronization must be correct in order
to digitize the video properly. The compression algorithms work very inefficiently with
video that has the field dominance accidentally reversed, and the resulting output is unat-
tractive at best and will normally appear to be seriously degraded.

33.8 Other Frame-Rate Issues

There are also time-base artifacts that may be introduced during modification of the time
base. Figure 33-11 shows the difference between the 50- and 60-Hz field rates. You can see

50 Hz

60 Hz

Figure 33-11 525i30 and 625i25 timing.

Relative field timing differences