bup to avi conversion is not possible, simply due the fact that .bup files do not contain video data, just additional data for a video DVD, such as info about tracks, subtitles and other type of metadata. These .bup files are pretty much just backup versions of .ifo files. You have to convert the actual DVD video file (.vob), which is covered under vob to avi conversion.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
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