Building a Standards Converter

[ppppenguin]

The horizontal axis size change probably needs more logic than the 625 to 405 conversion. you don't need linestores but the interpolator will need more multipliers to get a visually OK result. In the STB all this is done in LSI logic made in huge quantities so it's cheap. A bigger FPGA with more multipliers would add significantly to the cost of the 625 to 405 converter.