Viewers of digital televisions that receive their signal from over the air or directly from a cable often have no recording equipment attached to their televisions.
Prior art exists for the estimation of position in a recorded video stream while the stream is being played back under viewer control and the viewer has transitioned to fast forward or fast reverse and initiates a play state. U.S. Pat. No. 6,850,691 specifically teaches methods to correct overshoot; where the viewer initiates a play state and because of human delays in pressing the play button on a remote control device, the point that the video stream begins playing is not the point the viewer wanted. 691 specifically identifies the transitions where the invention is to be used. These may include entering play state after fast forward or reverse. 691 teaches several methods for determining the correction factor. These include: predicting where the transition to play should start by adding a fixed offset to the play resume point, learning from the viewer's corrections to the play resume point after play mode starts, allowing the viewer to set a sensitivity to the correction offset, and testing of the viewer's reaction time.
U.S. Pat. No. 6,295,094 Cuccia teaches a methodology for instant replay including freeze frame. 094 teaches the storage of compressed video frames to maximize the use of solid state memory. This methodology includes an area of memory used for storage of metadata where each metadata tag points to the start of a video frame. The metadata tag includes the frame type (I, B, P) and if the frame type is not an I-frame, the location of the nearest I-frame. When the viewer initiates an instant replay event, an offset to the current frame of 1800 frames adjusted to the nearest I-frame, is generated and video frames starting at that frame are sent to the decoder. Adjustment to the nearest I-frame ensures that the video starts cleanly with a full frame and no picture macro blocking. 094 makes no provision for the viewer to adjust the replay point nor for stepping forward or backward once the replay event has been initiated.
U.S. Pat. No. 4,914,516 Duffield teaches a methodology for automatically presenting a single smaller picture on top of a larger television background picture or a series of pictures arranged as a matrix of various numbers of rows and columns. '516 teaches this methodology using a single analog tuner and sampling and digitizing circuitry that stores the digitized pictures in a solid state memory module. '516 teaches the technique of multiplexing a single analog tuner with 3 auxiliary video input sources such that the viewer has the option of selecting a secondary source as the picture to be presented as the picture in picture. The solid state memory is scanned and converted into signals compatible with presenting onto the screen of the television. '516 hence addresses the issues of capturing single frames from analog television.
U.S. Pat. No. 5,194,954 Duffield teaches an improved methodology over that presented in 516 for automatically presenting a matrix on the television screen with a single picture from a number of different channels. 954 gives the viewer the capability of building a scan list of favorite channels that will be presented in the picture-in-picture matrix. 954 methodology effectively freezes a single frame from each channel. 954 teaches the technique of commanding an analog tuner to tune to a channel and once the signal is stable, sampling and digitizing the signal into solid state memory. The solid state memory is scanned and converted into signals compatible with presenting onto the screen of the television. 954 addresses the issues of capturing single frames from analog television broadcasts.
U.S. Pat. No. 4,528,585 Bolger teaches a technique for sampling and digitizing a series of analog frames into solid state memory then mathematically processing the image contained in the memory for the purpose of magnifying a portion of the image contained in the memory. 585 effectively freezes successive frames of analog television such that a magnified portion of those pictures presented on the television screen remain in a magnified state.