Abstract: An apparatus and method for indexing data streams and generating an index file used during trick mode playback makes use of a demultiplexer that receives content formatted as a transport stream including a plurality of transport packets from a source. For each of the plurality of transport packets generates, the demultiplexer generates flag data indicating if the respective transport packet contains key frame data. A buffer includes at least one sub-buffer for storing the flag data and key frame data. An index processor parses the at least one sub-buffer to locate the flag data and uses the flag data to generate an index file including a position of each key frame in the transport stream to facilitate trick mode playback of the transport stream.