There are zillions video converters on the net, free or for sale. But I would like to have:

1. Lossless trimming and joining
2. Optimum conversion quality, e.g. when I download an flv file and I want to convert it to lets'say an AVI-file, the converter should automatically find for me the AVI-output that comes the closest to the quality of the original flv source. It's easy to overdo it yourself: converting a shitty source file to a huge output file (from 5mb to 50 mb) is very common.