SubRip is a subtitle OCR program for Windows. It can take a (set of) VOB-files, and OCR from there, but it can also read in a pair of .idx/.sub files.
This last format comes in handy when you want to include the (bitmap) subs in an MP4 file, and OCR them later: MP4Box can extract a VobSub track from an MP4 file in to a idx/sub pair.
Unfortunately, I had problems with this workflow: after each subtitle image, SubRip added a ghost image. The ghost image contained half of the lines of the previous image, and thus looked interlaced.
This project is my quest to figure out what caused it, and to fix it. But since I don't have any Delphi experience, I can't fix SubRip itself, so I made a patch-script to fix it externally. Make sure that you configure SubRip to NOT "Use IDX's file offsets" (in Options -> Global Options).
The problem seems to be that the MP4Box output contains 0-length SPU's, which SubRip tries to parse. My guess is that SubRip doesn't clean up his memory before parsing a new SPU, and hence the ghost of the previous image.
This script just goes through the sub-file, and replace the 0-length SPU packets with padding packets.