| 摘要 |
<p>The PCM codec transmission system, for PAL and NTSC signals, allows sub-sampling techniques to be applied to NTSC signals as well as PAL signals and moits the usual second comb filter at the input of the codec. The chroma signal is separated from the luminance signal and modified before adding back to the luminance signal at the PCM codec's input. The codec receives a PAL signal whose colour phase is the same in the lines of consecutive full pictures. At the output of the comb filter the colour phase is brought to the required state by further modification of the subcarrier. In a second method the sampling points of complete pictures and/or lines are altered in a specified way.</p> |
