MXPA98005686A - Method and apparatus for improving the effects of modifications of the color burst in a sign of vi - Google Patents

Abstract

In the known process of color strip to avoid the recording of video signals, the burst of color present in each line of the active video is modified so that any subsequent videotape recording shows variations in color fidelity that appear as bands or stripes of color error. The color strip process is improved by a combination of modifying the phase of the color burst over only a part of the color burst. Additional improvements were obtained by incorporating techniques of widening the normal color burst envelope to the trailing edge of horizontal synchronization and to the start of active video. These techniques are useful to improve the execution of the process of the color strip both in the PAL system and in the NTSC system. However, further improvements are described in the PAL system where the phase modifications are controlled to avoid the confusing presence of the so-called PAL ID pulse. This inhibition of the impulse PAL ID improves the reading of the signal of the color strip in the P format

Description

METHOD AND APPARATUS FOR IMPROVING THE EFFECTS OF MODIFICATIONS OF THE COLOR BURST IN A VIDEO SIGNAL CROSS REFERENCE WITH RELATED APPLICATION This application is a request for continuation in part of the Serial No. 08 / 438,155, registered on 09/05/95 entitled METHOD AND APPARATUS TO DELETE THE EFFECTS OF THE MODIFICATIONS OF THE COLOR BURST IN A SIGNAL OF VIDEO, by Ronald Quan and John O. Ryan. This application claims the benefits of the Provisional Applications Serial Nos .: 60/010015, entitled A METHOD AND APPARATUS IMPROVED TO MODIFY COLOR BURST TO PROHIBIT THE RECORDING OF A VIDEO TAPE by William J. Wrobles i; recorded on 1/16/96; Serial No. 60 / 010,779 entitled AN ADVANCEMENT COLOR BURST AND APPARATUS TO MODIFY THE COLOR BURST TO PROHIBIT THE RECORDING OF A VIDEO TAPE by William J. Wrobleski., Recorded on 1/20/96; Serial Number 60 / 014,246 entitled ONE SYSTEM AND METHOD FOR THE PROTECTION AGAINST COPYING OF A VIDEO RECORDING USING A DIVIDED AND ADVANCED COLOR BURST SYSTEM by William J. Wrobleski recorded 3/26/96; Serial Number 60 / 024,393 entitled METHOD OF PROTECTION AGAINST COPYING OF A PAL COLOR VIDEO SIGNAL by William J. Wrobleski, registered 6/28/96; and Serial Number 60 / 021,645 entitled Pl 99 / 98MX IMPROVED PROTECTION METHOD AGAINST COPIES OF A PAL COLOR VIDEO SIGNAL by William J. Wrobleski registered on 12/12/96. All previous co-pending applications are incorporated here for reference.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a method and apparatus for processing a video signal, and more particularly to the improvement of the effects of phase modulation of the color burst component of a video signal. video (for protection against copying videos).

DESCRIPTION OF PREVIOUS TECHNOLOGY Several techniques have been developed to modify a video signal and avoid protection against copying or to reduce the entertainment quality of a copied video cartridge (effectiveness), while the same signal is produced on a receiving screen or monitor, a presentation with a minimum of visible artifacts or without artifacts. The protection against the copying of videos is defined as a system in which a video signal protected against copying is visible with a minimum of visible artifacts or without artifacts, where it is not Pl_99 / 98MX possible reading a recording of that signal or a signal that has a fairly degraded entertainment value. Copy protection must be differentiated from video mixing. Video mixing means that a video signal is not visible. A mixed video signal can be recorded, but unless it has been demixed, the reading of this recording is not visible. A well-known scheme for protection against copying for video signals includes the disclosure in U.S. Patent No. 4,631,603 ('603), by John O. Ryan, issued December 23, 1986 and assigned to Macrovision, incorporated herein. as reference. The '603 patent is directed to the modification of an analog video signal to inhibit the acceptable recording of the video therefrom. It is described to add a plurality of pulse pairs for the otherwise unused lines of a vertical extinction range of a video signal, each pair of pulses is a negative forward pulse followed closely by a pulse of positive advance The effect is to confuse the AGC (automatic gain control circuitry) of a VCR (video recorder), which records that signal, so that when the recorded signal is read it is not visible due to the presence of an excessively dark image. Another well-known copy protection is P1 99 / 98MX the one disclosed in U.S. Patent Number 4,577,216 ('216), "Method and Apparatus for Processing a Video Signal", by John 0. Ryan, issued on March 18, 1986 and incorporated here as a reference, which discovers the modification of a color video signal to inhibit making acceptable recordings from it. A conventional television receiver produces a normal color image from a modified signal. However, the subsequent color image that results from the recording of a video tape shows variations in color fidelity that appear as color error strips. Colloquially, the modifications are called "Colorstripe M System" or the "Colorstripe ™ Process". The commercial modalities of the teachings of this patent have limited the number of video lines per field having the color induced error or color strips. The teachings of the '603 patent can be used in an analogue duplication of the video cartridge and in various digital transmissions and recording reading systems such as DVD, DVCR and satellite services using a separate decoder of the monitor. The teachings of the '603 patent depend on the actions of the AGC of a recorder. The recorders used in the arrangements for the duplication of video cartridges are modified in a special way to operate without depending on P1 99 / 98MX the action of the AGC and, in this way, can record the signal protected against copying. The ColorstripeTM system depends on the recording system based on time and color of a recorder-, of a video cartridge. Economically, it is not possible to modify the video cartridge duplicating recorders to record a signal with the teachings of the '216 patent. In this way the ColorstripeTM system is used, mainly, in transmission systems; at the output of DVD recorders and reading machines; and at the output of DVCR machines. A more detailed description regarding the modality of the ColorstripeTM system within these systems is provided below. Color video signals (both in the NTSC system and in the PAL TV system) include what is called a burst of color. The color strip system modifies the color burst. The suppression of the color subcarrier signal in the TV transmitter requires that the color TV receiver include an oscillator (in NTSC a 3.58 MHz oscillator) (and in PAL a 4.43 MHz oscillator), which is used during demodulation to continually reinsert the color subcarrier signal and restore the color signal to its original shape. Both the frequency and the phase of this reinserted subcarrier signal are critical for color reproduction. Therefore it is P1399 / 98MX need to synchronize the local 3.58 MHz or 4.43 MHz oscillator of the color TV receiver so that its frequency and phase are in accordance with the subcarrier signal in the transmitter. The synchronization is achieved by transmitting a small sample of a 3.58 MHz subcarrier signal or 4.43 MHz of the transmitter during the back-end interval of the horizontal extinction pulse. Figure IA shows a horizontal extinction range for a NTSC color TV signal. Figures IB and IC show the details of the color burst in two lines of a video signal. The phase of the color burst in successive lines in the NTSC are 180 degrees out of phase with each other. The horizontal synchronization pulse, the front threshold and the duration of the extinction range are essentially the same for black and white TVs. However, during the transmission of color TV, (both broadcasting and cable) of 8 to 10 cycles of the subcarrier of 3.58 MHz (in NTSC) of the color synchronization signal to be used are superimposed on the front threshold. This color synchronization signal is called a "burst of color" or "burst". The peak-to-peak amplitude of the color burst (40 IRES for NTSC TV as shown) is generally the same amplitude as the sync pulse P1 99 / 98MX horizontal. Fig. IB shows an amplified view of a part of the waveform of Fig. IA that includes the actual cycles of the color burst. During the color TV extinction intervals, such color burst is transmitted following each horizontal synchronization pulse. In a PAL signal, similar characteristics are found for both the horizontal extinction interval and the color burst. The differences between PAL and NTSC are described in more detail below. The phase relationship of the color burst and the color components of an NTSC signal are shown in Figure ID. The NTSC color system operates on a quadrature modulation system based on an R-Y (red-yellow) and B-Y (blue-yellow) system or on an I-Q system. For ease of description, the R-Y and B-Y system will be explained. As can be seen in Figure ID, the R-Y axis is the vertical axis and the B-Y axis is the horizontal axis. The Color Burst signal has been set to be on the B-Y axis and is at a point at 180 degrees, relative to a 0 degree point, as shown in Figure ID. The process of demodulating the color modulation depends on its phase relationship between the different color components shown in the vector diagram of Figure ID, and the reference subcarrier represented by the signal of P1399 / 98MX burst of color. The color strip processes described in the '216 patent and the material below represent a modification of this phase relationship that creates a copy-protected signal that is effective because it produces a recording of the signal that has lost its entertainment value, while which presents the copy protection signal without artifacts in a TV receiver or monitor (reading). Figure 2C shows the phase relationship of the color burst and the color components of an unmodified PAL signal. The PAL color system as its NTSC counterpart operates through a quadrature modulation system based on a U axis and a V axis. As can be seen in Figure 2C, the U axis is the vertical axis and the V axis is the horizontal axis. One of the main differences between the NTSC color system and the PAL TV system is the location of the color burst vector. The PAL Color Burst signal has been adjusted to be +/- 45 degrees from the U axis relative to a 0 degree point as shown in Figure 2C. Based on each alternating line, the V signal changes phase by 180 degrees. The burst of color of each of these changes is in synchronization. On lines with a + V signal, the color burst is + 45 degrees relative to the U axis. On lines with a -V signal, the color burst is at -45 P1 99 / 98MX degrees relative to the U axis. The process of demodulating the color modulation depends on the phase relationship between the different color components shown in the vector diagram of Figure 2C, and the reference subcarrier is represented by the color burst signal. The so-called oscillating burst is used to generate a PAL ID pulse within the demodulation process to switch the demodulation process to respond to the line-by-line change in the V portion of the signal. Due to the unique characteristics of the PAL TV signal, there is a need for an improvement in the color strip process described in the '216 patent, to improve and create a copy-protected signal having the effectiveness to produce a recording of The signal that has lost its entertainment value along with the signal of protection against copying, and to improve the presentation of the signal without artifacts by means of a receiver or TV monitor For more details of the Color TV PAL system you can consult "Color Television ", by Geoffrey Hutson, Peter Sheperd, and James Brice, published by McGraw Hill Book Company, (UK) Limited, Maidenhead, Berkshire, England In the modalities of the color strip process, no modification appears (fringe) of the color burst phase in the video lines, which have a P1 99 / 98_.X color burst signal during the vertical extinction interval. These are lines 10 to 21 in an NTSC signal and the corresponding lines in the PAL signal. The purpose of maintaining these modified lines is to improve the reading of the modified signal. Because these lines are not visible when reading a recording, the effectiveness of modifying these lines is not reached. The previous commercial modalities with modifications in the color bands (modulation of the color burst phase) are presented in bands of four to five video lines of a visible TV field, followed by bands of eight to ten video lines. without the modulation of color strips. The location of the bands is fixed (stationary) field by field. It has been found that the color strip process is effective for cable television, especially when combined with the teachings of the '603 patent described above. In NTSC TV, the start of the color burst is defined by the zero crossing (positive or negative slope) that precedes the first half circle of the subcarrier (color burst, which is 50% or greater than the burst amplitude of the subcarrier). It should be understood that the process of color strips changes the phase of the color burst cycles in relation to their nominal (correct) position shown in Figure IB The phase color burst with change is P1_99 / 98MX shows in the Figure ID. The amount of the phase change shown in Fig. 1C can be as large as 180 ° (the maximum possible). In addition, the amount of the phase change in the color strip process may vary from e.g. 20 ° to 180 °; The greater the phase change, the greater the visual effect in terms of color change. In a color strip process for PAL TV, a slightly larger phase shift (e.g., 40 ° to 180 °) is used to be effective. In any copy protection system, there is a need for an appropriate balance between the effectiveness of a copy-protected signal in the formation of a damaged copy, against the need for no visible effects on the reading of a copy-protected signal . However, certain television sets can produce some reading problems during the presentation of the signal with the modalities of the '216 patent. In particular, it has been found that the visibility of the color strips in a television receiver is particularly noticeable in some "frame by frame" ("p-i-p") portions of the TV presentation. These systems use analog-to-digital conversion techniques and digital-to-analog conversion techniques to achieve the "p-i-p" characteristic that can sense the phase errors of the '216 mode. Therefore, it is a P1399 / 98MX object of the invention to provide an improved method and apparatus for modifying a color video signal for a conventional television receiver to produce a normal color image including the frame-by-frame portion of the modified signal, while the Recording a video tape made of a modified signal exhibits annoying interference of color, inhibiting the recording of the signal. Other variations of the ColorstripeTM process are also possible.

SUMMARY OF THE INVENTION The present invention is directed to a method and apparatus that meets the need for an improved method and apparatus for modifying the color video signal for a conventional television receiver to produce a normal color image, and include the frame-by-frame portion from the modified signal, while the videotape recording made with the modified signal exhibits annoying interference of color, and thus inhibits the recording of the signal. The present inventors have determined that some improvements are possible from the teachings of the aforementioned U.S. Patent No. 4,577,216, especially those pertaining to the reading of the signal P1_99 / 98MX on a television receiver or monitor. In a first embodiment, it has been found that it is not necessary to completely modify a burst of color. With commercially available television and VCR devices, it has been found that modifying or modulating only part of the bursts of color is effective to make the signal protected against copying, while the reading on television receivers or monitors is improved. A second embodiment improves the reading of the modified signal by extending the forward color burst signal within what is known as the fuzzy portion of the television signal. Additionally, a third mode improves reading by extending the burst of color beyond the final normal point just before the active video. With the first and second embodiments, some combinations of modified or modulated burst signal with unmodified or unmodulated burst signal are used to optimize the effectiveness of copy protection and reading of a modified signal. Within the NTSC color system, each of the first three modes, the phase of the modified versions is generally 180 degrees from the nominal burst position. You can also use other angles of P1399 / 98MX phase. These three modes are also useful for the PAL color system. However, it is described that some specialized modalities take advantage of the difference in the PAL system in relation to the NTSC system. In PAL incorporations modalities, the modified lines comprise a phase change of either + 90 degrees relative to the burst phase angle of a normal line or -90 degrees relative to the burst phase of the burst phase of a normal line. The differences between the different PAL modes is the sequence of the line modifications. It should be understood that in each of these modalities it has been found that it is not necessary to modify or modulate the entire burst of color strips in particular.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects and advantages of the present invention will be more readily understood with respect to the following description, appended claims and accompanying drawings in which: Figures IA to IC show the normal waveforms of NTSC TV; Figure ID shows a vector diagram of a P1399 / 98 X NTSC signal unmodified; Figure 2A shows a normal TV PAL waveform; Figure 2B and 2C show a vector diagram of an unmodified PAL signal; Figures 3A to 3E show waveforms illustrating various versions of a first embodiment of the color strip process according to the invention; Figures 4A to 4B show waveforms illustrating various versions of a second embodiment of the color strip process according to the invention; Figures 5A to 5D show waveforms illustrating various versions of a third embodiment of the color strip process according to the invention; Figures 6A to 6C show the waveforms of a modality using the split burst concept without any modified burst; Figure 7 shows an example embodiment combining the modality described in Figures 3A through 3C, Figures 4A and 4B and Figures 5A through 5C; Figures 8A to 8D show the vector diagrams illustrating a first PAL mode of the process of the color strip according to the invention; Figure 9 shows a series of diagrams P1399 / 9BMX vector illustrating a second PAL mode of the color strip process according to the invention; Figure 10 shows a waveform of an example embodiment of the PAL version of the invention; Figure 11 shows a waveform illustrating several versions of a fourth PAL mode of the color strip process according to the invention; and Figures 12A and 12B show block diagrams illustrating a general and exemplary embodiment of the apparatus covering the different modes of the color strip process according to the invention.

DETAILED DESCRIPTION OF THE INVENTION The following describes various number of modalities for an improved method and apparatus for modifying a color video signal, so that a conventional television receiver produces a normal color image including the frame-by-frame portion from the modified signal, while a tape recording made from the modified signal exhibits annoying interference of color and thus inhibits the recording of the signal. First, there is a description regarding the waveforms and methods. Next, there is a description of several related circuits.

P1 99 / 98MX Description of the method The following are some methods of color stripes according to the invention. A main inventive concept in each of the described modalities is that it has been found that it is not necessary to modify or modulate the whole burst of color strip in particular. It has been found that modifying or modulating only a portion of a color burst is also effective as a copy-protected signal for a typical VCR. Also, it has been found that reducing the portion of the burst that is modified or modulated improves the reading of the copy protection signal on television receivers or monitors. This modification or modulation of only a portion of a specific color burst signal is called a split color burst signal. The variations in the concept of the split color burst comprise the different modalities described below. Figures 3A to 3G show several versions of a split color burst signal that are contained within the normal position of a color burst signal. This normal position of a color burst signal is shown in Figure ID (for NTSC) and in Figures 2B and 2C (for PAL). Figure 3A shows a burst of color with a P1_99 / 98_.X Modification or full burst modulation (shading denotes a modified burst signal). Figure 3B shows a color burst signal with about half the first portion of the normal burst duration and the remaining portion of the normal color burst duration has a modified or modulated burst phase, as shown by the shading. The amount of phase modification can be as small as 20 degrees from the normal phase to a maximum of 180 degrees from the normal phase. This replacement may be only a portion of a particular color burst. For example, of the eight to ten normal cycles of the NTSC color burst, the last five cycles, the first five cycles, the last five cycles, or any other group may be replaced, for example four to six cycles. The replaced cycles do not need to be consecutive; Alternating cycles can be replaced, leaving the "good" (corrected) cycles spaced between the "bad" cycles (color band). It is also possible to add the color burst corrected cycles out of their normal location and overlap the horizontal synchronization pulses, since these will be detected by a VCR. The recognition of the present inventors should be understood in relation to that only a portion of a particular burst of color that P1399 / 98MX needs to be replaced as part of the invention. In addition, the partial replacement is also applicable in the other modalities described later. Figure 3C shows a version of a split color burst wherein the modified portion is within a first portion of the normal duration of the color burst and the unmodified portion is in the last portion of the normal duration of the burst. Figures 3D and 3E show where the unchanged color burst portions and the modified cclcr burst are located in sandwich fashion within the normal duration of a color burst. Figure 3D shows the unmodified portions to be at the extremes of the normal burst duration with the modified portion that is in the middle. The amount of portions modified against the unmodified portion is adjusted for an optimum balance between effectiveness and reading as described above. Figures 4A and 4B show modalities of a version of the color stripe process, which, in colloquial terms, is called forward split burst. In these versions it was determined that the reading was improved by advancing the area within the frontal threshold where the color burst would exist (modified or unmodified). Figure 4A shows a basic combination of the P1-99 / 98MX breakthrough concept with a split color burst. In this particular version, the envelope of the burst extends forward towards the trailing edge of horizontal synchronization. As shown in Figure 4A, the color burst comprises a burst of color modified or modulated from the trailing edge of synchronization through and within a portion of the normal burst duration. The surplus of the normal burst duration has an unmodified portion of burst. Figure 4B shows another version of the forward split color burst. Here, the envelope of the color burst begins during the duration of the horizontal synchronization and continues within the normal duration of the color burst. As in the previous version of the forward split color burst, the remaining color burst signal within the normal color burst duration is a burst of unmodified color. One of the advantages of having the forward split color burst in the NTSC system is that the detection area of the color burst signal in the VCR tends to be closer to the back edge of the horizontal synchronization than is the detection area of the color burst on a television receiver or monitor. Therefore, in the NTSC system with a split-forward color burst, the VCR tends to catch on a signal P1 99 / 98MX modified and the television receiver tends to catch on an unmodified signal. Figures 4C and 4D show the forward split color burst system with the unmodified or unmodulated version in the first portion of the forward color burst. It should be understood, as will be shown later, that a combination of the forward split color burst can use the "sandwich" concept described above, is another possible variation of the color strip system. Figures 5A to 5D show another embodiment of the split color burst system. As shown in Figures 4A to 4E, there are advantages of having a normal burst envelope that extends forward to a point that can extend as far as the front threshold area of the horizontal extinguishing area. Some advantage has also been found by extending the normal color burst envelope beyond the normal burst period to the active image area. This extension of the normal one is limited only by the maximum horizontal extinction area and the start of active video. Figure 5A shows a burst of normal unmodified color. Figure 5A shows an extended color burst indicating the end of the normal color burst. The extended period may have a normal color burst or modified or modulated color burst. The figure PX399 / 98MX 5C shows an example of a color burst signal having the front portion with the normal color burst and the last portion including the extended portion containing the modulated or modulated color burst. Figure 5D shows the opposite. The point at which the switching between the modified color burst and the unmodified color burst is variable and subject to experimental results for the maximum balance between effectiveness and reading as described above. Figures 6A through 6C show a modification mode of a color burst where the modified burst area does not exist. However, the concept of a split color burst prevails when the envelope width of the normal color burst narrows. In this mode, the number of color burst cycles is reduced. As shown in Figures 6A to 6C, the shortened color burst varies in this position within the normal color burst window. In the lines that contain this modification, confusions will be presented in the fidelity of the color, during the recording of the signal, but the reading is maintained inside the receiver or TV monitor. Each of the embodiments described in Figures 3A through 3G, Figures 4A and 4B, Figures 5A through 5D, and Figures 6A through 6C are applicable for the color format.

P1399 / 98MX NTSC and for PAL color format. Figure 7 shows an example modality of NTSC that combines the elements of the modality identified above. The example mode of NTSC, called Advance Commutated Burst (ASB) has the ability to program several combinations of the modalities described above. The envelope of the burst comprises three zones. Zone 1 (burst start) starts 4.96 μsegs. After the leading edge of the horizontal synchronization. Zone 1 ends 1.48 μsegs after the start of the normal burst. Zone 2 begins and ends at the end of Zone 1. In this particular modality, Zone II does not exist per se. Zone III begins after the point in Zone II and extends 1.48 μsegs at the end of the burst. Therefore, in this particular mode, the color burst has a width of 4.96 μsegs. The area of Zone 1 will have a modified subcarrier (inverted 180 °). The normal phase subcarrier is used in Zone 2 (duration zero and Zone 3). As described above, the number of lines containing the modified or inverted carrier in the color burst area is limited to groups of lines followed by larger groups of lines that do not contain a modified or inverted subcarrier in the color burst. The example modality described above is suitable for both versions P1399 / 98MX basic. One is called the 2-line version and the second is called the 4-line version. Table 1 shows the example modality of ColorstripeTM measurements for NTSC. The example modality is the result of experimental work aimed at finding the optimal reading and effectiveness mix, as mentioned before.

Table SUMMARY OF MEASURES 525/60 / NTSC Note 1: Start and end points should be P1 99 / 98MX such that the total burst duration for the default configuration is 2.96 + 0.15 / -0.07 Table lb LINE NUMBERS THAT INCORPORATE THE FORM OF DIVIDED AND ADVANCED BURST WAVE Strip No. 1 2 3 4 5 6 7 9 10 11 12 13 P1599 / 98MX As described above, these modes can be applied in both the NTSC system and the PAL system. However, because PAL uses the burst of color in a somewhat different way from NTSC, four modes are described below only from the PAL color strip systems. The normal PAL color signal has some significant differences from the regular NTSC signal. Some of these differences are related to the scanning standard used. These exploration differences create the need for a different frequency of subcarrier. However, the most important difference is the use of the oscillating burst and the alternating phase relationship between the adjacent lines within a field. Figure 2A shows a horizontal extinction range for a PAL color TV signal. Figures 2B and 2C show the vector presentation of the details of a colcr burst with color bar signal in a PAL system. A person with technological ability will fully understand that there is a 180 degree change in the V component of each color component on a line-by-line basis. Additionally, as can be seen in Figure 2C there is a corresponding change of phase in the color burst signal on a line-to-line basis. The color burst component and the color components P1399 / 98MX that appear when the burst is at a point at + 45 degrees relative to the U axis, are the so-called NTSC lines. The color burst component and the color components that occur when the burst is at a point at -45 degrees relative to the U-axis are the so-called PAL lines. In the NTSC system, the phase of the color burst is at 180 degrees with reference to the grade 0 phase of color signals. However, for a PAL signal, the color burst must also identify the V portion of the subcarrier phase, which is switched during transmission at 180 degrees in alternating lines. Therefore, the burst phase is also switched on alternating lines and is at 135 degrees on the NTSC lines and at 225 degrees on the PAL lines. The identification of a PAL line in the receiver can be achieved by phase detection at 180 +/- 45 degrees switched or oscillating burst. As can be seen from Figure 2B, the chromatic saturation signal is switched on the U-axis, so that, for example, a blue signal appears at approximately 350 ° relative to 0 ° on the line when the color burst It is at 135 °. A blue signal is approximately 10 ° relative to 0 ° on the line when the color burst is at 225 °. One embodiment of the invention uses the four-color strip group as described above.

P1399 / 98MX In an unmodified signal, the four lines of the group of four lines would have a so-called NTSC burst angle at 135 degrees as shown in Figure 3A. The second line of the four-line group would be the so-called PAL burst angle at 225 degrees as shown in Fig. 3b. The same scheme is repeated in the third and fourth lines of the four-line scheme. The leftover lines follow the same normal pattern. However, the embodiment of the invention has the phase angles in the modified four-line scheme as shown by dotted lines in Figures 8A and 8D. The so-called NTSC burst angle of line 1 and 3 moved at 90 degrees to a 45 degree angle. The so-called PAL burst angle of lines 3 and 4 moved from 90 degrees to 315 degrees. The invention is not limited to a sequence of four lines. It is possible that a sequence of 2, 4, 6, 8 or more lines is effective. The advantage of this copy protection method is that it does not change the so-called PAL ID pulse scheme generated by +/- 45 degrees from the U axis. The television receiver is not affected by the changes in the phase angles to the V axis as shown in Figures 8A through 8D. However, the time-based color process in a recording VCR is confused by this variation from the regular signal. The variations of P1_99 / 98MX this mode can include other changes of phase angles than the 90 degrees, while the impulse ID PAL is not disturbed. Another embodiment shown in the vector diagrams in Figure 9, has a modification of one line of the color burst signal between the lines having the normal color burst signal. With experimental tests, it has been found that the reading of a modified signal can be improved by using the variations of a one-line version of the signal modification. As an example, in a five-line portion of a field, the first line can be a modified NTSC line, followed by an unchanged PAL line, and this in turn, followed by a modified NTSC line, followed by an unmodified line and finally followed by another modified NTSC line. This sequence of five lines is shown in Figs. 4 A-E- The sequence of five lines can have modified PAL lines with unmodified NTSC lines. The sequence of five lines can also be with a smaller number of lines or a greater number of lines. Through experimentation, it has been found that there is no need for approximately 34 groups of unmodified lines for the purpose of reading on a TV monitor. The advantage of this method of protection against P1399 / 98MX copied is that it does not change the so-called PAL ID pulse scheme generated by the +/- 45 degrees from the U axis. The television receiver is not affected by the changes in the phase angles with respect to the V axis as it is shown in Figs. 3, 3B and 4. However, the time-based color process on a recording VCR causes color phase errors due to this variation of the normal signal. Variations of this mode may include other phase angle changes than 90 degrees, as long as the PAL ID pulse is not affected. Table 2a and Figure 10 show an example modality of the color strip measurements for PAL. Table 2B shows both configurations of number of lines. In Table 2a, the number of lines indicates the first line in a sequence of two or three lines. In the two-line sequence, there are two lines that contain the modified color burst followed by 32 burst lines of unchanged color. In the sequence of three lines, there are three lines containing a burst of modified color followed by 31 burst lines of unmodified color. Other combinations are possible. The example modality is the result of experimental work aimed at finding the optimal mixture of reading and effectiveness described above.

P1399 / 98MX Table the Summary of Measures 625/50 / PAL Note 1: The start and end points must be such that the total burst duration for the default configuration is 2.25 + 0.15 / -0.07 P1399 / 98MX Table 2b LINE NUMBERS INCORPORATING THE COLOR STRIP FLASHWAVE SHAPE Strip No. 1 2 3 4 5 6 7 8 NOTES: 1. This table uses the CCIR line numbering convention 625/50 / PAL. Subtract 313 from the previous nones line numbers from the Divided Field to obtain the line numbers in the "Non / Ll Field" for the "Field non / L312" format. 2. The line numbers listed in the table are the first lines of a sequence of 2 or 3 lines according to P1399 / 98MX is appropriate. 3. The above configurations are within the programming range Rev. 6.1.

Figure 11 shows another embodiment for a PAL color strip system. This embodiment includes the concept of split burst with the modified portion in the last portion of a normal color burst envelope. The phase of the modified area is at 0 ° or a -U in relation to the average position of the normal signals of the burst phase. In the previous mode, the modified phase angle does not affect the so-called ID PAL pulse in the modified area. In this mode, the PAL pulse is maintained in the unmodified portion, while the subcarrier phase Color is affected by the modified color burst having a phase angle of 180 ° far (opposite) from the mean value of the oscillating burst. This modality is an effective system of protection against copying. Figure 12 shows another embodiment of the PAL color strip system. This embodiment includes the concept of split burst with the modified portion in the last portion of a normal color burst envelope. The phase angle of the unmodified area is the normal oscillating burst angle for the particular line. The P1399 / 98MX modified portion has a phase angle set to be 180 ° from the oscillating burst angle [0A or 0B] of the opposite oscillating burst angle [(0A) or (0B)]. For example, on line 1 as shown in Figure 11, the unmodified burst area has the normal burst angle, (135 °) and the modified burst area has the angle of 45 ° (180 ° from the 225 ° angle of the oscillating burst of the opposite line). On line 2 of the sequence, the unmodified burst is at a normal angle of 225 °. The modified portion has a burst phase angle of 335 ° (180 ° from the 135 ° angle of the oscillating burst of the opposite line). In the above embodiments, the modified phase angle did not affect the so-called ID PAL pulse in the modified area. In this mode, the PAL pulse is maintained in the unmodified portion, while the phase of the color subcarrier is affected by the modified color burst having the 180 ° phase angle away from the average value of the oscillating burst. This modality is an effective system of protection against copying. In each of the embodiments described above involving an extended or advanced color burst envelope, the lines with the normal burst signals through the burst envelope have a normal burst width. However, this discovery is not limited P1 99 / 98MX for that condition. There may be conditions in which all lines have a burst signal of advanced or extended burst envelopes depending on whether or not the burst has some modification or modulation. Another additional modality is to modify the position and / or the width of the horizontal synchronization. An example would be to narrow the width of the synchronization from 1 to 2 μsegs and fill the extended area of extinction with extended burst. Another example is to extend the horizontal synchronization from 1 to 2 μsegs, and fill the horizontal synchronization with extended burst. Another variation is to move the leading edge of the horizontal synchronization 1-2 μsegs and then the extended front threshold with the modified color burst. Each of these additional modalities are designed to improve reading with minimal effect on the effectiveness of copy protection. Digital video tape recorders and digital reading devices are commercially available for consumer use. To maintain compatibility with analog video broadcast signals and analog video tape recorders, these digital video recorders and recorders will be "hybrid" and analog digital systems. These systems will have the capabilities of a recorder P1 99 / 98MX analog conventional video cartridge, to record and read analog signals, while maintaining equivalent digital capabilities. In this way, these new hybrid digital tape recorders will have the internal capacity to convert the analog input signals into digital signals, and record the digital signals as a stream of digital data on the tape or disk. During the reading of the digital data stream from the tape or the disc, they will be available either as a digital signal for the presentation by a digital television device (not yet commercially available) or they can be converted back into the hybrid video tape or tape recorder, in a conventional analog video signal (such as the NTSC signal used in the United States). The ability of the internal system to convert the received analog signals into digital data streams will be important, since currently there are no sources available to the consumer (whether tape or broadcast) of digital video program material. Hybrid video recorders employ a digital "consumer" recording format that is different from the standards of current professional digital systems. The digital video recorder will include a "front end" RF tuner and an RF modulator on the output side, as do the analog VCRs P1399 / 98MX conventional. (Analogue video refers to NTSC, PAL, SECAM or YC). The digital recording standard for consumers is essentially a data structure representing a video signal as a stream of data bits (binary) together with an error cloaking coding, together with a physical standard of the tape.

Problems Related to Digital Recordings Because the digital video or tape recorders and digital reading devices will have the capacity of a high fidelity reproduction, which in turn favor copying, it is important that these recorders for consumer use are designed to inhibit unauthorized reproduction. For this reason, it is important to avoid the use of recorders to illegally duplicate the video material with reserved rights, and also to avoid reading illegally duplicated material. Current protection techniques against analog video copying are not useful within digital reach. Therefore, there is a need for a copy protection system suitable for use with hybrid digital and analog video tape recorders, where the material recorded on the tape is a stream of digital data. A very common situation that should be P1399 / 98MX to avoid is the use of a hybrid video tape recorder to copy an output signal from a conventional VCR VCR, where the tape reading from the VCR VHS has a conventional copy protection process applied on it . The problem is to prevent the new analogue-digital hybrid video tape recorder from copying the material from that tape. Otherwise, the existence of these hybrid recorders favor the violation of copyrighted material. A hybrid digital video recording system is described in U.S. Patent No. 5,315,448 by Ryan, issued May 24, 1994 (incorporated herein by reference).

Use of the Integrated Circuit A first embodiment of an apparatus comprises having the color strip technology together with the copy protection technology within an integrated circuit. The other copy protection technology consists of the technology described in U.S. Patents 4,631,603 and 4,819,098 issued to Ryan on December 23, 1986 and April 4, 1989, respectively (incorporated herein by reference). Generally, the integrated circuit includes a digital-to-analog converter to convert the video current P1399 / 98MX digital in an analog video stream, which is encoded within the NTSC format; PAL or YC. The copy protection technology is added to the encoder level and combined with the encoded output. The technology used in integrated circuits is usually of the ASIC variety, which uses gate crowds to produce the output waveform for the desired copy protection. The three specific applications for this integrated circuit that incorporate the technology of protection against copying are the Recorders and Readers of Digital Video Discs, recorders and readers of digital video cartridges and digital adjustment boxes used in the industry of cable and industry from satellite to home. These specific applications include the programming of the integrated circuit that allows a change in the parameters of the waveform. In the case of a transmission system, the bits that change the missing values of the waveform are transmitted with the signal. In the case of a DVD Recorder / Reader and the recorder / reader of the digital video cartridge, the bits are included inside the disc or the tape of the cartridge. Figure HA is a general block diagram of the integrated circuit implementing the embodiments of the invention and the teachings of the '603 patent.

P1399 / 98MX General Circuit Figure 11B shows a second mode of the device implements the different modalities described above. Usually, an apparatus for producing the different color strip modes described above comprises: 1) a subcarrier processor, 2) a burst gate generator and 3) a line generator. Figure 11B illustrates an exemplary circuit for producing a color strip signal of the different embodiments described above. A copy protection apparatus 50 has an unmodified video input signal 52. This signal can be an analog signal of PAL or NTSC or a stream of digital data representing a video signal to be protected against copying. The input signal is input into a copy protection inserter 60, a subcarrier processor 54, a burst gate generator 56, and a line selector 58. The subcarrier processor 54 detects the color burst signal within the video input signal 52 and generates a subcarrier of 3.58 MHz or 4.43 MHz (depending on whether it is processing a PAL signal or an NTSC signal). The burst gate generator 56 is programmed to generate the appropriate gate signals for the P1399 / 98MX copy protection inserter 60 to instruct the copy protection inserter to insert the normal phase subcarrier or a modified phase subcarrier. The line selector 58 is programmed to instruct the burst gate generator 56 and the copy protection inserter, which lines will produce a modified burst and which lines will reproduce a burst signal present in the input signal 52 Of video. The '603 patent teaches that the apparatus 50 may be combined with the appropriate circuitry to produce pseudo-synchronized AGC pulse pairs.

Example Circuitry Figure 10B illustrates an apparatus for implementing the different modalities described above. An improved color strip system is implemented within the different elements of system 10. Each element within the system performs well-known functions for those enabled in video engineering technology. A signal 11 composed of video is inserted into an input amplifier 12. The amplifier 12 adjusts the level of the video signal to an appropriate level for the leftover elements of the color strip system. A first output of the input amplifier 12 P1399 / 98MX is coupled to the synchronization separator 14. The synchronization separator 14 removes horizontal and vertical synchronization signals from the composite video for later use in the enhanced color strip system. The outputs of the synchronization separator 14 are coupled to the inputs of the burst gate generator 16 and the line counter 18. The burst gate generator 16 uses vertical and horizontal synchronization pulses from the synchronization separator 14 to produce a burst gate signal. In the NTSC format, the normal burst gate signal would start at approximately 5.3 microseconds after the leading edge of the horizontal synchronization and end after the 9 equivalent cycles of the subcarrier (2.52 microseconds). The burst gate generator 16 is programmed to produce a widened burst gate in those lines, where the advanced and / or extended burst gate is desired. The line counter 18 uses the horizontal and vertical synchronization pulses of the synchronization separator 14 and is programmed to determine which lines will contain the color strip information. An output of the line counter 16 is coupled to the burst gate generator 16 to instruct the burst gate generator 16 on which lines require a burst gate P1399 / 98MX widened. In one embodiment, the proportion of lines that have the color strip signal against that of the lines that do not have the color strip is 4/16. This is four lines out of twenty in each field have the color stripe signal. In addition, the line counter is arranged so that the comparable lines in each field contain the color strip signal. These pairs of color strip portions increase the visibility of the color strip in the reading of the recorded signal. A first output from the burst gate generator 16 is coupled to the modification gate 20. The modification gate 20 determines which portions of the color burst signal will contain the inverted phase color burst. The modification gate 20 may be programmed to provide four inverted phases of color burst in one or more parts of the color burst signal as shown in the different previous modes. A second output of the input amplifier 12 is coupled to the color saturation separator 24. The chromatic saturation separator 24 consists of chromatic information and high frequency luminescence information within the video signal. Since the luminescence information does not exist during the burst portion of color, there is only color information P1399 / 98MX during the color burst portion of the output of the color saturation separator 24. The output of the chromatic saturation separator 26 is coupled to the burst separator 26. The burst separator 26 also has a burst gate input from the burst gate generator 16. The output of the burst separator 26 only contains the color burst signal recovered from the input signal 11 through the color saturation separator 24 and the burst separator 26. The color burst signal from the burst separator 26 is coupled to a subcarrier oscillator 40 to produce a subcarrier signal synchronized with the incoming burst signal (3.58 MHz in NTSC and 4.43 MHz in PAL). An output of the subcarrier oscillator 40 is coupled to the subcarrier generator 42. The burst generator 42 also receives a burst gate signal from the burst gate generator 16. The width of the burst signal generated by the burst generator 42 is determined by the burst gate generator. This can be varied by the combination of the burst gates in the lines that do not have modifications that are of a width and the lines with modification of burst that have a different width. These variations are determined by a combination of burst gate generator 16 and line counter 18.

P1399 / 98MX The output of the burst generator 42 is coupled to the phase changer 28 and the first input of the switch 30. In the NTSC system, the phase change is generally 180 °. In the PAL format, the phase inverter can have an input from the line meter 18 to instruct the phase inverter to produce different phase changes in different lines as described above. Generally, the phase modification in PAL in some lines is + 90 °, and in other lines it is -90 °. The output of the phase changer 28 is coupled to the second input of the switch 30. The reversing gate 20 and the line counter 18 are coupled to the gate 22 Y to produce a control signal 21. When the gate 22 Y produces a signal indicating the requirement to modify the burst phase. The control signal 21 places the switch 30 in a position to pass the normal color burst. When the gate 22 Y produces a signal indicating the need for the color burst phase modification, the color signal 21 places the switch 30 to pass the inverted color burst. The output of the switch 30 is coupled to a first input of the burst inserter 32. A third output of the input amplifier 12 containing the processed input signal is coupled to an input of the burst blocker 32. A third P1399 / 98MX output from burst gate generator 16 is coupled to burst blocker 32. The burst blocker 32 blocks all color burst information from the video signal 13 using the burst gate signal from the burst gate generator 16. The output of the burst blocker 32 containing the video signal 15 is input into a first input of the burst inserter 34. As described above, the video signal 15 has no color burst information. The output of the switch 30 has the color burst of the color strip generated by a combination of elements 24, 26, 28, 12, 14, 16, 18, 20, 22 and 30. With experimental tests, it has been determined that the Effectiveness and reading of the modified signal are affected by the silhouette of the waveform of the color burst. Therefore, the output of the switch 30 is coupled to a burst-shaped former that controls the rise and fall time of the color burst waveform. The output of the burst shape former is coupled to the burst inserter. The burst inserter 32 inserts the color fringe color burst with the video signal 15 that does not contain color burst information, to produce a composite video signal containing the burst of color of the enhanced fringe and its information composed of P1399 / 98MX related video. The output of the burst inserter 32 is coupled to output amplifier 36. The output amplifier 36 provides the appropriate signal processing to produce a composite video signal with the correct levels and output impedance for use in a video system. This discovery is illustrative and is not limiting. Other modifications will be apparent to a person skilled in the art and are intended to be within the scope of the appended claims.

P1399 / 98MX

Claims (29)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A method to inhibit an acceptable video recording of a signal from being made. video having an improved reading of a modified video signal, the video signal includes a plurality of video lines, each video line includes a burst of color having a predetermined duration and phase, the method is characterized by the steps of: modifying a minor phase to the entire portion of the duration of each burst of color to be different from the predetermined phase, thereby inhibiting an acceptable recording of a video signal from being made.
2. 2. The method of Claim 1, wherein the step of modifying includes the step of changing the predetermined phase by 180 °. The method of Claim 1, wherein the step of modifying includes the step of changing the predetermined phase by at least 20 °. 4. The method of Claim 1, wherein at least 60% of the duration of the color burst is modified. P1399 / 98MX 5. The method of Claim 1, wherein the duration of the color burst is eight to ten cycles of a color subcarrier signal, and the step of modifying includes modifying more than four cycles. The method of Claim 1, wherein in each video field, at least one band of video lines is subject to the step of modifying a portion of the color burst, followed by a band of video lines that do not are subject to the step of modifying a portion of the color burst. The method of Claim 1, wherein a modified portion precedes an unmodified portion of the color burst. The method of Claim 1, wherein an unmodified portion precedes a modified portion of the color burst. The method of Claim 1, wherein a first unmodified portion precedes a modified portion and a second unmodified portion follows a modified portion. The method of Claim 1, wherein a first modified portion precedes a modified portion and a second modified portion follows an unmodified portion of the color burst. 11. The method of Claim 1, wherein P1399 / 98MX the video signal is an NTSC signal. The method of Claim 1, wherein the video signal is a PAL signal 13. A method for inhibiting acceptable video recording of a video signal with improved reading of a modified video signal, the video signal includes a plurality of video lines, each video line includes a burst of color having a predetermined duration, the method is characterized by the steps of: extending the duration of the color burst; and modifying a phase of one or more portions of the extended duration of each burst of color to be different from the predetermined phase, thereby inhibiting acceptable video recording of the video signal from being made. The method of Claim 14, wherein the step of increasing the duration of the color burst comprises: increasing the duration of the color burst. The method of claim 14, wherein the step of increasing the duration of the color burst comprises: starting the duration of the color burst before the normal duration. P1399 / 98MX 16. The method of claim 14, wherein the step of increasing the duration of the color burst comprises terminating the duration of the color burst after the normal duration. The method of claim 14, wherein the step of increasing the duration of the color burst comprises beginning the duration of the color burst before the normal duration of the color burst and ending the duration of the color burst. after the normal duration. 18. The method of claim 14, wherein a modified duration of color burst begins at the trailing edge of horizontal synchronization. 19. The method of claim 14, where a modified duration of the color burst starts between the leading edge of horizontal synchronization and the trailing edge of horizontal synchronization. The method of claim 14, wherein one end of a modified burst duration is at the beginning of the active video. The method of claim 13, wherein the step of changing the duration of the color burst comprises: increasing the duration of the color burst by adding a first portion to the duration of the burst of color between the back edge of synchronization P1399 / 98MX horizontal and at the beginning of a normal duration of the color burst; increase the duration of the color burst by adding a second portion that follows the normal duration of the color burst that ends before the start of the active video. The method of claim 21, wherein the step of the phase modification consists of: modifying a phase of a first portion of the modified duration of color burst; and retaining a normal burst phase in a second portion of the modified color duration. 23. The method of claim 14, wherein the video signal is an NTSC signal. 24. The method of claim 14, wherein the video signal is a PAL signal. 25. An improved method for inhibiting an acceptable recording of a PAL video signal, the video signal includes a plurality of video lines, each video line includes a burst of color having a predetermined duration and phase, the method it is characterized by the steps of: modifying the phase of the color burst so that the average in the plurality of lines having the phase vectors of the modified signals is P1399 / 98MX approximately 180 ° opposite the average in the plurality of lines having the phase vectors of the appropriate signals of the color burst, thereby inhibiting the acceptable recording of a video signal. 26. The method of claim 25, wherein the step of modifying the phase of the color burst comprises the step of: modifying an NTSC burst of the video signal PAL to -90 °. The method of claim 14, wherein the step of modifying the phase of the color burst comprises the step of: modifying the PAL burst of the PAL signal to + 90 °. 28. An apparatus for modifying a video signal to inhibit acceptable video recording of a video signal, the video signal includes a plurality of video lines, each video line includes a burst of color having a duration and a predetermined phase, characterized by: a burst gate generator for producing a burst gate signal which is coupled to a copy protection insert apparatus; a line selector to produce a line count to indicate to the copy protection insertion device which lines of the video signal are going to P1399 / 98MX modify; a subcarrier processor that modifies a portion (s) of the predetermined duration of the color burst signals; and a video input for the copy protection insertion device, wherein the combination of the inputs from the subcarrier processor, the burst gate generator and the line selector modify the video signal to produce a video signal of protection against copying, which inhibits making an acceptable recording of the video signal. 29. An apparatus for restricting the analog recording of a digital video signal that has been pre-recorded in a medium and the digital video signal is read and output as an encoded analog video signal characterized by: the arrangement of an integrated circuit for add the copy prevention signals whose phases are controlled so that the average of the phase vectors of the appropriate signals of the color burst, which are originally placed in a plurality of lines, is approximately 180 ° opposite the average in the plurality of lines having the phase vectors of the color burst signals modified for a plurality of consecutive lines of the analog video signal. P1399 / 98MX