Problem Solver - A Practical Guide to Video and Audio Compression - page 639

A

Problem Solver

A.1 Solving Problems with Your Compression

This appendix lists some common problems when compressing video and provides some
advice about how to solve them. The information is presented in a Q & A style.

The Picture Keeps Jumping

Check the quality of your input video source. If you are using VHS, try connecting via an
S-VHS connector or add a time-base corrector between the VCR and the digital sampler.

My Compressed Output Has Noise All over It, Even on Still Pictures

If your source has background noise because it is of low quality, switch on a grain-removal
filter if you have one.

The Picture Looks Dull

Turn on the gamma correction and increase it a little. If that does not provide enough cor-
rection, look at modifying the brightness and contrast as well.

There Is Noise on the Black Background of the Credits Sequence

Set the black level with a calibration tool. Make sure you check the preview window to see
both raw and processed examples of the footage.

The Text in the Credits Sequence Is Unreadable

You will probably have to retype the titles and create some compression-friendly video as
still frames. Avoid scrolling text in credits. Perhaps the credits are good enough that appro-
priate still frames from them can be selected and reworked in your nonlinear editor or FX
power tools.

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