Abstract: In the known color stripe process for preventing recording of video signals, the color burst present on each line of active video is modified so that any subsequent video tape recording of the video signal shows variations in the color fidelity that appear as undesirable bands or stripes of color error. This color stripe process is improved by a combination of modifying the phase of the color burst on only part of the color burst. Additional improvements were obtained by incorporating techniques of widening the normal color burst envelope towards the trailing edge of horizontal sync and towards the beginning of active video. These techniques are useful in improving the performance of the color stripe process in both the NTSC and PAL color systems. However, additional improvements are described in the PAL system whereby the phase modifications are controlled so as to avoid disturbing the so-called PAL ID pulse.

Abstract: A video signal is modified so that a television/receiver still produces a normal picture from the modified signal, whereas videotape recording of this signal produces generally unacceptable pictures. Videotape recorders have an automatic gain control circuit (FIG. 2) which measures the sync pulse level in a video signal and develops a gain control correction signal for keeping the video applied to an FM modulator in the videotape recording system at a fixed predetermined level. A portion of the back porch intervals following the trailing edges of a substantial number of sync pulses are significantly raised and lowered to improve the playability of the original signal without reducing the effectiveness of the copy protection of the copied signal.

Abstract: A technique is disclosed for preventing unauthorized playback of scrambled video/audio signals recorded on, for example, a video tape cassette, which technique includes several cooperating processes and apparatus which further prevent the playback of recorded video/audio when the playback apparatus is in a still or pause mode of operation. The technique includes selected combinations of processes of inverting and re-clamping the luminance component of the video signal just prior to FM modulation; blanking an overscan portion, or portions, of the video signal and adding a video retrace signal to the overscan portion(s); inverting the normal control track signal and position modulating the normally unused edge; and selectively scrambling the audio signal and recording the scrambled audio signal in an audio track or in a Hi-Fi track. A selected user specific authorization code is recording in and recovered from the audio track.

Abstract: A method and apparatus is disclosed for disabling the effect of copy protection signals embedded in video signals, wherein the detection and modification of the copy protection signals is accomplished in the RF domain rather than in the baseband video domain as typically accomplished at the present time. To this end, various embodiments are disclosed for deriving a timing control signal from the modulated RF carrier signal, which timing control signal is indicative of the television lines which contain the copy protection signals. Several techniques in the RF domain responsive to the timing control signal are disclosed for replacing, attenuating, suppressing, pulse narrowing or otherwise modifying the modulated RF carrier signal during the interval of the copy protection signals to disable the affects thereof, to allow the making of acceptable recordings during demodulation subsequently by, for example, a record VCR.

Abstract: A technique for improving the scrambling concealment of a video signal and the like when displayed on a television set or monitor, includes the pulse width and/or pulse position modulation of a horizontal sync pulse in a horizontal blanking interval by time shifting the leading edge of the sync pulse while maintaining the trailing edge thereof stationary, by shifting the leading and/or trailing edge of the pulse, or by position modulating a sync pulse of specialized width. In modifications to the pulse width and pulse position modulation overlay techniques, the negative edge of the end of video lines may be modulated in the same way that the leading edge of the sync pulse is modulated, with the two edges locked together or modulated independently.

Abstract: Video signals in today's environment exist in both the analog domain and the digital domain. In many instances it may be desirable to delete or reduce the effectiveness of a video signal containing analog copy protection signals while the signals are in the digital domain. The invention uses digital techniques for defeating the effects of the analog copy protected signal while the signal is in the digital domain. The types of copy protection signals includes pseudo sync pulses and AGC pulses. Additionally digital techniques may be used for reducing or eliminating the affects of a chroma copy protection process. A digital video copy protection eliminator allows removal of substantially all pseudo sync pulses and/or AGC pulses in the digital domain. The location of pseudo syncs and/or AGC pulses are determined, while the signal is in the digital domain.

Abstract: In the known color stripe process for preventing recording of video signals, the color burst present on each line of active video is modified so that any subsequent video tape recording of the video signal shows variations in the color fidelity that appear as undesirable bands or stripes of color error. This color stripe process is defeated first by determining the location of the video lines including the color stripe process, either by prior experimentation or by on-line detection. Then some or all of the lines including the modified color bursts are modified so as to render the overall video signal recordable. The modification is accomplished in a number of ways, including phase shifting the color stripe burst into the correct phase, replacing some of the color stripe bursts or a portion of particular color stripe bursts so that they are no longer effective, and mixing the color stripe burst with color stripe signals of the correct phase so as to eliminate most or all of the phase error present.

Abstract: A method and apparatus for inserting source identification data into a video signal prior to its transmission, recording or display. The source identification data (Finger Print) is injected into the active picture area of a video signal without disturbing the viewing of the video signal and the data is retrieved by a data reader, called a Fingerprint Reader. The data injection or "fingerprinting" process consists of dynamically offsetting the video pedestal to carry information which can then be read back from any videotape made from the output of the data-injecting unit. In particular, the fingerprint carries the ID number of the unit used and the current date. The offset lasts for one entire field and has an amplitude of approximately 0.5 IRE--that is, a given field either has the nominal setup or a setup value differing from nominal by 0.5 IRE. The data is repeated every 128 fields in order to provide ample samples for the reader to detect and display the source identification data.

Abstract: A method and apparatus for copyright protection for various recording media such as Digital Video Discs (DVDs) uses a combination of a Video Finger Print Signal and an Authenticating Signature to permit the player to handle either copy-protected or non-copy-protected media, in a manner that is difficult to compromise. Both a Video Finger Print Signal and an Authenticating Signature are recorded on the media only when copy-protection is required. The nature of this Authenticating Signature is such that it will not be transferred to illicit copies made on CD recorders. When either an original protected or an original non-protected disk is played, the presence or absence of the Authenticating Signature causes the player to correctly play the program video. All original DVDs therefore play normally. When a copy of a non-protected CD is played, the absence of the Video Print Signal also causes the player to correctly playback the video signal data.