Flash Video Encoding with jpg thumbnails
I have been searching all over the web looking for a batch flv encoder that would also generate jpg thumbnails for the video encoded. The Adobe Flash Video Encoder lacks both the watch folder as well as the jpg thumbnails features. On2 Flix Pro comes close. It can batch encode flv with On2 VP6 and also generate thumbnails. But it lacks a watch folder feature which I also want. Sorenson Squeeze has everything but lacks jpg thumbnails generation. I also searched for flv encoders from other 3rd parties software but none has all the features I want in one package. There is always something missing, or that the codec lacks On2VP6 support, etc. I can’t believe that none exists. Very frustrating.

google “ffmpeg thumbnail” and use cron.
As J suggests you can use ffmpeg for the job. I would suggest using inotify if you are on linux instead of a cron.
My search for ffmpeg so far was that it doesn’t support On2VP6 codec. I hope I am wrong on this.
No, ffmpeg does not support encoding of VP6 officially.