Video search engine
A video search engine is a web-based search engine which crawls the web for video content. Some video search engines parse externally hosted content while others allow content to be uploaded and hosted on their own servers. Some engines also allow users to search by video format type and by length of the clip. The video search results are usually accompanied by a thumbnail view of the video.
Video search engines are computer programs designed to find videos stored on digital devices, either through Internet servers or in storage units from the same computer. These searches can be made through audiovisual indexing, which can extract information from audiovisual material and record it as metadata, which will be tracked by search engines.
Utility[edit]
The main use of these search engines is the increasing creation of audiovisual content and the need to manage it properly. The digitization of audiovisual archives and the establishment of the Internet, has led to large quantities of video files stored in big databases, whose recovery can be very difficult because of the huge volumes of data and the existence of a semantic gap.
Design and algorithms[edit]
Video search has evolved slowly through several basic search formats which exist today and all use keywords. The keywords for each search can be found in the title of the media, any text attached to the media and content linked web pages, also defined by authors and users of video hosted resources.
Some video search is performed using human powered search, others create technological systems that work automatically to detect what is in the video and match the searchers needs. Many efforts to improve video search including both human powered search as well as writing algorithm that recognize what's inside the video have meant complete redevelopment of search efforts.
It is generally acknowledged that speech to text is possible, though recently Thomas Wilde, the new CEO of Everyzing, acknowledged that Everyzing works 70% of the time when there is music, ambient noise or more than one person speaking. If newscast style speaking (one person, speaking clearly, no ambient noise) is available, that can rise to 93%. (From the Web Video Summit, San Jose, CA, June 27, 2007).
Around 40 phonemes exist in every language with about 400 in all spoken languages. Rather than applying a text search algorithm after speech-to-text processing is completed, some engines use a phonetic search algorithm to find results within the spoken word. Others work by literally listening to the entire podcast and creating a text transcription using a sophisticated speech-to-text process. Once the text file is created, the file can be searched for any number of search words and phrases.
It is generally acknowledged that visual search into video does not work well and that no company is using it publicly. Researchers at UC San Diego and Carnegie Mellon University have been working on the visual search problem for more than 15 years, and admitted at a "Future of Search" conference at UC Berkeley in spring 2007 that it was years away from being viable even in simple search.