FI107491B - A method for compatible transmission of additional signal type information - Google Patents

Description

107491

The present invention relates to a method for the compatible transmission of signal type supplemental information in television signal lines.

For the consistent transmission of a color TV signal in a 16: 9 widescreen format at a conventional line rate and half-10 (the future PALplus norm), it is known that three lines from each of the four consecutive lines are Signal). 15 In order for a widescreen receiver to re-develop the original color TV signal from the received letter-box signal, additional digital information referring to the original picture content must be transmitted to it in the letter box strips. Because existing telecommunication 20 vision channels carry both standard and letterbox signals at least during a certain transition time, each type of signal must be identifiable by a suitable identifier. Other tags refer to the source of the source signal (camcorder or movie player) and the reported presence of motion in the image content. The corresponding identification signals (status bits) must be transmitted as additional signal type information. Since all said signal type additional information (PALplus additional information) is exactly correlated with its associated image content, it must be transmitted permanently attached to the image signal. For this purpose, however, no free lines are available in the current PAL standard for field extinguishing intervals. For example, in Germany, line 16 (data line) is reserved for VPS signals and other control signals 35 within the radio system. Lanes Nos. 17, 18 and 19 are reserved for 2,107,491 measurement signals. Lines 11-15 and 20-21 transmit teletext-related information. Line 22 is reserved for disturbance distance measurements. Other reservations are used in other European countries. Lines 1-10 cannot (yet) be used for additional information given the sync properties of older television receivers.

The present invention is based on the object of proposing improvement opportunities for transmitting additional signal type information without altering or interfering with the use of field-off intervals to date. This problem is solved by the method set forth in claim 1.

Preferably, the 16-to-9 receiver of the letterbox signals (PALplus receiver) should be able to distinguish between the following compatible television signal types: (a) standard signals; (b) letter-box signals without further information; (c) letter-box signals together with additional information; d) interlaced scan source signal (camera); E) Film Scanning Source Signal ('Progressive' ori: Original); (f) static or dynamic image content.

In order to ensure this distinction and to select the corresponding decoding and playback, it is preferable to have a corresponding identifier transmitted on the transmitter side. This ·· signal type identifier should be uniform throughout Europe. Such a signal type identifier may advantageously be transmitted in a compatible manner at certain points in the FBAS signal used in the same manner regardless of the respective standard 30.

107491 3

In principle, the method of the present invention comprises: for co-ordinating transmission of additional signal type information (16) on the television signal lines,: generating this additional signal type information from a data packet having preamble, preamble, and utility information; step-by-step recovery and initial information serves to assign useful information 10 and selectively indicate the beginning of the useful information, and the data signal is transmitted in the unselected half of the first or last active picture line of the television signal, whereby information, or: an identification signal is applied to the television signal at least 20 lines prior to transmission and / or recording in the black posterior region; the per-image and additional signal type information included therein are utilized by the improved 16: 9 receivers, wherein: the additional signal type information comprises at least two of the following 25 television signal types: - standard signal (no Letter box, no additional picture information); - a letter box signal without additional picture information; - a letter box signal from a film source together with additional picture information; A letter box signal from the camera source together with additional image information, in particular with the difference between the static and moving image content interpreted as half or full images.

Preferred further developments of the process of the present invention are disclosed in the appended dependent claims.

Embodiments of the present invention are explained by the drawings. In the drawings: FIG. 1 illustrates a signal placement diagram at field-off intervals of a PAL television signal; FIG. 2 is a block diagram of a signal limiter stage of a 16: 9 receiver used by additional digital signal type information transmitted in accordance with the present invention; Fig. 3 shows a portion of the contents of a non-broadcast te broadcast line with a standard data signal; Fig. 4 shows a portion of the contents of a non-broadcast TV semicircle with a data signal formed in accordance with the present invention; FIG. 5 is a block diagram of a receiver-side circuit detail for detecting an error in received digital signal type information transmitted in accordance with the present invention: FIG. 6 shows a portion of a known FBAS signal line and transmission points according to the present invention for signal type identification.

The diagram of Fig. 1 shows the current signal content of the field blanking intervals of the PAL color television signal used in Germany, where the numbers of the television lines concerned are shown in the direction of the chart's abscissa. As is clear from this, the first 5 107491 halves of line 23 are used to place PALplus signal type data. Line # 10 transmits the reflection measurement signal 101 and line # 16 the source data 102. Line # 17 is the source measurement line, and lines # 18 and 19 are the measurement lines of portions 54. Line # 22 serves the noise measurements of the part. background 105, and lines marked with FT can be used to move television text. The payload information of the PALplus signal type information 106 is structured in the form of a plurality of data packets. The first data packet contains pre-information and initial information. The pre-information serves for the timely recovery of the payload information at the data rate in the receiver. For example, eight sine fields are the prerequisites for common data signals, of which only three waves are shown in Figure 3. The sine waves in particular synchronize the PLL (Phase Locked Loop) in a 16: 9 receiver. The pre-information of the PALplus signal type information of the present invention is discussed in more detail below.

20

The start information serves to indicate the payload information and to selectively indicate the start of the payload information at the receiver. The 16: 9 receiver detects the presence of a placed tag, which is represented by initial information. As soon as the receiver detects the desired tag in the receive signal, it can retrieve the next useful information in a timely fashion and process it.

For example, the utility information is biphasic, which provides the advantage of simple error prevention inherent in the code. In addition, the signal is DC free, which is advantageous in magnetic recording. To enhance error prevention, the payload information may be transmitted using 35 higher redundancies, for example by transmitting its 6,107,491 non-inverted and inverted waveforms of each data packet sequentially, as further described in connection with FIG.

Figure 2 shows a block diagram structure of a signal limiter stage of a PALplus signal type data receiver. The limiter 23 receives a video signal 201 at its analog input which contains data signals of the PALplus signal type at dedicated time slots. The incoming vi-10 deosignal is compared in the limiter 23 to the reference voltage Uref acting on the second input of the limiter 23. The limiter generates an "digital" random signal from the image signal portion of the incoming video signal, followed by attenuation in the following interpretation. From the perspective of utilization 15, only the portion of the data signal processed by the limiter 23 in the incoming video signal is of interest. If the amplitude of the data signal contained in the video signal is greater than the reference voltage Uref, the output voltage of the digital signal output 202 corresponds to a logical "up" state. Conversely, if the amplitude of the data signal is smaller than the reference voltage Uref, the output voltage of the digital signal output 202 corresponds to a logical "down" state. Since the error-free limitation of the data signal depends solely on the reference voltage Uref, careful design of the respective units by J '25 is particularly important. In addition, the video signal is also fed to a first peak voltage meter 21 which produces at its output a maximum signal amplitude Umax of the video signal 201 in a time delayed manner. Similarly, a second peak voltage meter 22 operates to which the video-30 signal 201 is also applied. Similarly, at the output of the second peak voltage meter 22, the smallest signal amplitude Umin of the video signal 201 is delayed. The best possible limitation of the data signal contained in the video signal is present when the reference voltage Uref 35 is 50% of the sum of the maximum and minimum amplitudes 7 107491 of the video signal. The reference voltage Uref is generated by a generator 24 whose inputs are supplied with a maximum signal amplitude Umax and a minimum signal amplitude Umin. A reference voltage Uref is set at the output of the generator 24, the level 5 of the data signal in the stabilized state being (Umax + Umin) / 2.

With each change in the amplitude of the video signal 201 at peak voltage meters 21 and 22, there is a change phenomenon illustrated in Figures 3 and 4 by data signals containing different pre-information.

Figure 3 shows the waveforms of the pre-information commonly used in data signals. The voltage waveform of the largest signal amplitude Umax is represented by curve A, while curve B illustrates the waveform of the smallest signal amplitude. Curve C shows the waveform of the comparative voltage obtained from the minimum and maximum signal voltages. It is noticed that the optimal reference voltage is available only after the time interval T1. Since the voltage of the reference 20 determines the cut-off threshold of the limiter 23, interfering signal type data signals during time slot T1 do not achieve an error-free conversion to digital signals. In contrast, in Fig. 4, a pre-information pulse having a duration T2 of a level corresponding to the maximum amplitude Umax of the data and having a width multiple of a cycle is placed in the pre-information. By means of this pulse, the operation of the first peak voltage meter 21 is influenced so that the optimum reference voltage Uref is already achieved within a substantially shorter time period T2. In this case, the limiter 23 already functions as an actual pre-information; at the beginning of the transfer.

*

Figure 5 illustrates a simple arrangement for detecting transmission errors in the utilization of serial data signals, the data packets of which are transmitted in the above manner.

O

in an uninverted and an inverted signal form. The arrangement shown comprises a delay circuit 51 having a signal propagation time T corresponding to the signal propagation time required to transmit one data packet. At the inputs of the applied summing stage 52 after the delay circuit 51 5, the non-inverted and inverted signal of the data packet 501 appear to be simultaneously and correctly phased. Thus, during the transmission time of the associated data packets, a simple error check can be performed in each of the second half of the transmission time slot, since no signal is present at the output 502 of the adder 52 during the transmission of error free data signals. If other error prevention measures, such as biphasic coding, have been implemented in the data packets, then corresponding correction measures may be used when error signals occur at the output of the adder stage 52.

Figure 6 shows a portion of the FBAS signal on a television line containing a sync pulse 11, a burst signal 12 20, and an image signal 13. The first portion 15 of the black aftertaste can receive a signal type identifier. Likewise, it is possible to mix the signal type identifier with the burst signal in the second part 14 or use the first and second parts to transfer the signal type identifier.

25

The signal type identifier must meet a number of criteria to ensure compatibility with conventional receivers. It must not adversely affect the pacing and color demodulation or locking of standard receivers. These boundary conditions are met if the identifier signal is converted into a digital data signal using DC-free coding and if the data frequency is less than the color carrier frequency, e.g.

1 Mbit / s. Due to the narrow bandwidth of the conventional receiver color PLL, this has no detrimental effect on color demodulation or color reproduction.

If a standard PAL-5 letterbox track signal is received by a 16: 9 receiver, the signal type identifier allows control of the format changeover switch, which produces a full-frame presentation without letterbox tracks. A simple implementation of such detection could, for example, comprise a variable number of burst signal oscillation cycles, whereby the 16: 9 receiver, by determining the number of oscillation cycles, e.g. Separating letterbox information with additional information is advantageous because future 16: 9 receivers (PALplus) use different processing algorithms for color depending on the source (film or camera). These types of processing can then be triggered directly by the signal type identifier.

20

Usually, the number of letterbox lines is known, so the receiver only needs to indicate the ID once per full image, e.g. once per half image. However, to ensure authentication, duplication of the tag should be desirable. The positioning of the tag signal in the first 15 and / or second portions 14 of Fig. 6 may preferably take place in the vertical sweep area or even during field extinction.

30 a simple embodiment, for example the ability to half the color carrier frequency of a few lisävärähtelyjen through the first part 15 shows kentänpaluujuovilla fol-predominant table. (0 line without lisävärähtelyä of 1 line, which is lisävärähtely): 107 491 10

Line n Line n + 1 Signal type 0 0 Standard signal (no letter box, no additional information); 0 1 Letter box signal without additional information; 1 0 Letter box signal source with additional information; 1 1 Letter box signal from camera source with additional information.

10

Taking into account other bands could identify other types of signal mentioned above.

The signal type identifier can also be generated by a recognition signal distributed over a plurality of lines per image, which can improve the detection reliability of the receiver.

Motion pictures transmitted in a television system may have various source image formats. Correspondingly, the letterbox stripes have different widths. It is now also possible to include different letter-box formats in the signal type identifier and to transfer the identifier signal as format information. This format aid information then acts as a transition from standard PAL signals having a letter box according to (b) to a full-field representation at the 16: 9 receiver by changing the vertical deflection amplitude or performing the corresponding digital processing.

30

For recording Type-d) or Type-e) Letter Box PAL signals on S-VHS or Hi8 Recorders respectively PCT / EP91 / 00676 and DE 41 11 979, it is appropriate to indicate by means of the added signal type identifier that 35 previously recorded Letter Box The PAL signal is provided to a 16: 9 receiver for playback. This signal-type identifier can preferably be inserted into the FBAS signal after playback from the tape. It indicates to the receiver that partial decoding of the letter-box PAL signals and additional information according to PCT / EP91 / 00676 and DE 411 11 979 for recording has already been performed.

The solutions of the present invention for transmitting the identification signals 10 are useful in both NTSC and SECAM systems.

Claims (6)

A method for compatible transmission of supplementary information (16) in lines not belonging to the field signal of a television signal, the additional information being utilized in improved receivers, characterized in that in half of the first or last active picture line in the television pictures which does not contain image signals, as additional information, a data packet containing advance, beginning and utility information is transmitted, the advance information on the receiving side functions to ater the utility information data rate at the correct stage and the starting information functions to enter utility information and selectively the -30 detecting the beginning of the utility information, wherein the supplemental information detects at least two of the following television signal types: - a standard signal (not letter read, not supplementary information); A letter-loading signal without image-addition information; - a letter read signal from a film source, as well as image supplement information: - a letter read signal from a camera source, along with image supplement information, especially along with separation of half or all of the static or movable interpreted image contents of images. Method according to Claim 1, characterized in that a pulse whose amplitude 10 corresponds to the data max level (Umax) and whose width is a multiple of the data rate period is placed in the advance information. Method according to claim 1 or 2, characterized in that the useful information is transmitted so that in each data packet (501) its non-inverted and inverted signal form is transmitted successively and that on the receiver side (52) is added to each inverted signal form the associated non-inverted signal form. to detect transmission errors, wherein the resulting signal sum that deviates from zero indicates the transmission error. 20 Method according to one or more of claims 1 to 3, characterized in that for the additional information or the identification signal, a coding without a DC voltage is selected on a data frequency below the color carrier path. Method according to one or more of claims 1 to 25, characterized in that the supplementary information or identification signal detects several different letter leather formats. Method according to one or more of claims 1 to 5, characterized in that, when repeating letter-read television signals stored with image recording devices, the television signal is placed with such additional information or an identification signal which detects partial decoding of the letter-read supplementary information which has already occurred in connection with the signal. .