Build a video parser

We are looking for someone who has experience in Video parsing with video libraries The project is to write a utility that pulls up a URL and searches the video / transcript for a keyword which is part of the argument. python function (URL, keyword phrase). Once the keyword is found, the parser will extract the 30 seconds of the video preceding the keyword and the 30 seconds after and feed it as output to the user. For now the keyword will be restricted to one phrase but in the future it will be able to use Boolean logic such as an OR string of multiple phrases. The project requires that a free, off the shelf tool be used and no original scraping technology is written. Preference is to use python. tool should be translatable to a php wrapper.