GB2262201A - Video recorder storing synthesized picture-in-picture signal - Google Patents

Abstract

A plurality of video signals V21, V22 are processed 201 to provide separate video signals V23, V25 and audio signals V24, V26. The video signals are synthesized in image synthesizer 203 and recorded onto recording medium (eg magnetic tape) 205, whilst the audio signals are convened into a single audio signal in audio synthesizer 204 before recording. On play back picture control selector processes the reproduced video signal and may produce a plurality of picture-in-picture or split screen effects or display one of the input video signals (figs 3a to 3e) via video output synthesizer 208. Audio control selector 207 may output any of the reproduced audio signals. <IMAGE>

Description

RECORDING/REPRODUCITON APPARATUS Th.s invention relates to the technology of TV signal processing, recording and reproducing. In particular, the invention relates to an apparatus for simultaneous multichannel TV signal processing, and for recording same on a carrier in predetermined formats, and for, according to the formats, selecting one or more or even all recorded TV signals and reproducing them simultaneously.

As is well know, general domestic 'v'CR's perform the function of recrding the rJ programs on magnetic tapes, and the function of reproducing the recorded programs through TV receivers. However, t.ae domestic VCR's currently available, have not been able to record simultaneously TV programs on two or more channels and to selectively reproduce one program with corresponding aurals on one set, or alternatively, to simultaneously reproduce a combinatlon or some of the programs; that is to say, the domestic VCR's currently available have not been able to function as the TV stes.And, they are unable to simultaneously reproduce or output TV Sig nals on more than one channel The object or the invention is to provide a recording/reproducing /R) apparatus, which can record and reproduced a TV program, and addition to that, which can simultaneously record two or more TV programs and can simultaneously reproduce all these TV picture signals together with the aural (audio signal) of one program, or alternatively, to select two programs to form a picture, overlaying a secondary image over a primary image, and to select to reproduce the audio signal of one program. This provides the "pic-in-pic" effects on an ordinary domestic TV set.

Another object of the invention is to enable said R/R apparatus to combine a number of programs recorded in one kind of desired formats, to form a TV signal output, together with the audio signal output of one channel.

Yet another object of the invention is to enable the R/R apparatus to perform like a recorder for a number of TV programs, and like a signal source of a plurality of TV signal outputs. A number of different program signals may simultaneously be provided for screening on a plurality of TV sets, through all the apparatus video output ports.

Accordingly, the present invention provides a recording/reproduction apparatus for simultaneously receiving and processing TV signals on a plurality of channels and for selecting one or more of the received TV signals for replaying, comprising: a plurality of V signal processors, each for processing a received TV signal and for outputting a video signal at a first output port of each individual processor and a corresponding audio signal at a second output port; picture synthesizer means for processing the video signals from the first output ports to form a synthetic picture signal for recording comprising selected ones of the video signals arranged in a predetermined format; audio synthesizer means for processing the audio signals from the second output port to form a synthetic simultaneously recordable audio signal; a recording/reproduction means for simultaneously recording the synthetic picture signal and the synthetic audio signal on a medium; picture control selector means for controlling, selecting and combining selected ones of the reproduced video signals comprising the synthetic picture signal into a format specified by input instructions to provide a specified video signal (on at least one channel); audio control selector means for selecting an audio signal in accordance with the input instructions; output video signal synthesizer means for combining the specified video signal and the selected audio signal into a composite video signal suitable for reproduction and viewing on a TV receiver; and control/select logic output circuit means for generating control signals to select a recording format and a reproduction format and for sending the control signals to the respective internal control circuit of the recording/reproduction means to operate the recording/reproduction means in accordance with predetermined control programs.

In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram representing the various components of one embodiment of the present invention; Figure 2 is a more detailed schematic diagram of the embodiment shown in Figure 1; Figure 3 represents various image formats which are made possible by one embodiment of the present invention; Figure 4 is a diagrammatic representation of a recording/reproduction apparatus according to a second embodiment of the present invention; Figure 5 is a diagrammatic representation of a recording/reproduction apparatus in accordance with a third embodiment of the present invention; Figure 6 is a more detailed diagrammatic representation of units 531 to 540 of Figure 5;; Figure 7 is a more detailed diagrammatic representation of the units 540 to 548 of the apparatus shown in Figure 5; Figure 8 is a diagrammatic representation of a recording/reproduction apparatus according to a fourth embodiment of the present invention; and Figure 9 is a diagrammatic representation of a recording/reproduction apparatus according to a fifth embodiment of the present invention.

As shown in Figure 1, the R/R apparatus comprises the following components: A multichannel TV signal processor 101, receiving one or more TV signals from external signal sources. These signals may be received by standard TV antennas, or may be provided by a number of video recorders or camcorders. Let V1, V2, ...Vn represent these signals. The function of the multi-channel TV signal processor 101 is to perform the processing of a number of TV signals separately and simultaneously.Under the control instructions from the control/select logic circuit 108, multichannel TV signal processor 101 selects from the n signals V1...Vn, to obtain some or all n signals, to respectively and simultaneously processes them in the multichannel TV signal processor 101 for heterodyne, amplification, detection, and to output channels 1...n complete video image signals and the corresponding channels 1...n aural signals. The i-n channels video image signals are sent to a picture synthesiser 102 via output port Vo, and the 1...n channel aural signals are sent to aural synthesiser 203 via output port Ao.

The picture synthesiser 102 further processes the one or more video signals thus received. Under the control instructions from the control/select logic output circuit, the internal CPU of the image synthesiser 102 samples the many video signals according to respective predetermined formats, and store the sampled digital signals in the respective areas in a field memory, according to specified formats. Thereafter, the image synthesiser 102 still need to process, in a unified manner (details of the processing method will be introduced later in the embodiment examples), the digitised video image signals of various channels stored in the + eld memory, in order to output the required digltised fleld image signals or analog field image signals, to satisfy the recording redire:nents of the RIR unit 104.Quite obviously, in order to form a unified video sIgnal for recording on a carrier, with these digital video image signals stored in the field memory the internal signal processing methods adopted by the picture synthesiser 102 are all different with respect to various ways of analog recording and of digital recording. One point must be achieved, is that, according to the various recording methods (digital or analog), the internal CPU of the picture synthesiser 102, following the format instructions of control/select logic output circuit 108, controls the internal circuit according to a predetermined format, to synthesise the input channel 1-n video image signals into a unified video signal of a single picture.

Corresponding to the picture synthesiser 102, the aural synthesiser 103 performs the function of processing, according to the instructions from the control/select logic output circuit 108, the multichannel aural signals from the multichannel TV signal processor 101, in order to output the multichannel aural signals in the reauired formats for recording by the R/R unit 104. It is similarly apparent that because of using different ways of recording, following the instructions from control/select logic output circuit 108, the internal CPU of the aural synthesiser 103 controls the internal electric circuits in the synthesiser, to process in different ways the multichannel aural signals. In this regard, details will be furnished in the embodiment examples later in the description.

The R/R unit 104 records the multichannel aural signals coming from the image signals from picture synthesiser 102 and the multichannel aural signals from the aural synthesiser 103. The principles of recording may be considered to be similar to that for an ordinary VCR. The main difference is, this time the recording is done on a carrier (for the time being, the carrier is a magnetic tape; and the carrier should be an optical disc when optical recording is intended.) to record multichannel coded input aural signals. If the signals from the picture synthesiser 102 and the aural synthesiser 103 are all analog signals, then the recording results in a magnetic tape with analog signals.It should be pointed out specifically that when only one channel is selected from the output of multichannel TV signal processor 101, then the R/R unit 104, under the control of the control/select logic circuit 108, may generate a magnetic tape for reproduction on any ordinary domestic VCR. However, when multichannel TV signals are present, the magnetic tape produced by the R/R unit can not be used on ordinary domestic VCRts, because these VCR's have no mechanism suitable for selection or identifIcation of an aural signal among mixed ones.

When the output is a digital signal from the picture synthesiser 102 and aural synthesiser 103, then the carrier generated from the R/R unit 10 could be a digital magtape. Of course, in this connection the output digital signals from the picture synthesiser 102 and aural synthesiser 103, may be utilised to modulate the laser beam of a laser disc recording system, under the control of the control/selet logic output circuit, to produce a video laser urs bearing the combined digital image and aural Information.

Consevtently, depending on the mode of digital recording to be selected, the R/R unit 104 can serve both as a magtape recording system, and as a laser disc recording system.

The following is a description of the performance of the picture control selector 105, aural control selector 106, and output TV signal synthesiser 107 of the reproduction portion of the circuit.

Picture control selector 105 determines most directly the final contents of the video signal output from the output video signal synthesiser 107. Under the control of the control/select logic output circuit 108, the picture control selector receives video signals from the R/R unit 104 and further processes them. When the input is a digital signal, the process in said unit mainly stores sigrials again into internal field memory, and later, the internal CPU responds to a select logic instruction from the control/select logic output circuit 108, and outputs corresponding control commands, using a predetermined format, to read from the field memory, digital data required for constructing the image, to yield, after further processing, the displayable analog video signals at the output ports.If the inputs are analog signals, then the picture control selector 105 still needs to change them into digital form and stored them into an internal field memory.

Subsequent processing is identical to the aforesaid processing when the input is digital.

Quite obviously, the format by which picture control selector 105 reads the data in field memory, decisively affects the displayed picture image. In general, under the control of control/select logic circuit 108, the memory has stored the selected video signals of a number of TV channels, according to the output formats of picture synthesiser 102. Of course, the formats of the signals output from the picture control selector, is not at all restricted to the output format of the picture synthesiser 102, and instead, the internal CPU may control to select one or a number of stored images as output.The more channels that the TV images representing by these stored digital signals belong, the more possibilities there are for combinations of the read formats; meanwhile, the more complicated the process will be in reading the digital signals of each selected channels line by line, in order to form one or more video signals line by line and field by field; and the more complex will be the extent of required internal control stored in the picture control selector 105 to be controlled by the CPU, according to various formats. The selection of output formats by the picture control selector 105, are to be elaborated later along with the embodiment examples.

Corresponding to the performance of the picture controller 105, the aural control selector 106 receives, from the R/R unit 104, all multichannel aurals from the output of the aural synthesiser 1G3.

Under the control of the control/select logic output circuit 108, the Internal CPU is synchronised with the internal CPU of picture control selector 105, and outputs via output ports the aural signals of the selected one or more channels.

Under the control of the control/select logic output circuit 108, the output TV signal synthesiser 107, synthesises the received one or more image signals and one or more aural signals, to form one or more composite video signals. To be cited as an example, a video signal and a corresponding aural signal may be modulated upon a RF carrier and output; or a number of received video signals and a number of corresponding aural signals may be modulated separately upon a number of different RF carriers and output.

It is seen from the above introduction that the operation of the whole apparatus, will not work without the control of the instructions from the control/select logic output circuit 108.

Said circuit decides the selection of a number of TV signals from V1 to Vn; the output format of the synthesised image and aural; the work format and output of the picture control selector 105 and aural control selector 106; and the work format of the output TV signal synthesiser 107. Besides, the control/select logic output circuit 108, must also be controlled by the internal CPU's of the aforesaid components, to coordinate the operation and synchronisation relationship between them. Control/select logic output circuit itself may be formed by combining logic circuits, the work format of each circuit being determined by decoding of output bits. The decoding is also used to invoke their internal control program in order to operate as required according to the selected work format.Quite obviously, the control/select logic output circuit needs to assemble to output two different kinds of instructions. One is for the circuit of the recording portion and t other is for the circuit of the output/reproduction portion.

In more concrete terms, the instructions of operation used by the recording portions decIde the selection of V1...Vn signals, and the modes of operation for picture synthesiser 102 and aural synthesiser 103; and the instructions for the output/reproduction portion of the circuit decide the work format of picture control selector 105, aural control selector 106, and output TV signal synthesiser 107. Besides, said circuit has to issue R/R instructions to the R/R units.The control/select logic output circuit '38 is controlled by external signals, which enters through pressing the keys on tne control panel of the apparatus, or is transmitted from infrared controller, and enters through an infrared sensing window and is received by the apparatus.

To make the concept of this invention more comprehensible, now with reference to Fig.2, a scheme of two TV program inputs is described. For the sake of convenience, the two TV signals are preusmed to have reached antenna TX, and have been fed via coaxial cables to TV signal processors 201 and 202. Also for simplicity in presentation, the control/select logic output circuit is omitted.

Yet it should be known that operation of all circuits have been functioning under the logic control of the control/select circuits.

In Fig.2, the two signals reaching the antenna are sens to two respective TV signal processors 201 and 202, and after being processed the signals come out as respective video image signals and aural signals at the respective video signal output ports and aural signal output ports. The two video image signals simultaneously go to the input image synthesiser 203, via V23 and V25. The two input video image signals coming into 203, are synthetically processed to form a single synthesised video picture signal that is recordable on an optional recording carrier, being magtapes or when the synthesised picture signal is in digital form, being optical discs. The synthesised picture signal is output through V31.

The two aural signals enter simultaneously into the aural synthesiser -204, via -V29 and V30, and synthetically processed within 204, to form one synthetic aural signal recordable onto magtape or optical disc, and are output through output port V32.

The synthetic video signal (analog or digital) from V33 and the synthetic aural signal from V34, are recorded by the R R unit 205 on a suitable carrier (magtape or optical disc) and played to reproduce the said signals at corresponding output ports V35 and V3.

Picture control selector 206 further processes the aforesaid input synthesised video signals, and follows the instructions from the control/selector logic circuit, which is not shown in Fig.2, to output a selectable, formatted, unified video signal, or alternatively, to output two separate original video signals at two corresponding output ports.

A uming Fig.2 has only two input signals, image output formats from the picture control selector 206 can at least be shown as the 5 feasible patterns of Figs. 3a-e, wherein Fig.3a and Fig.3b represent the output signals of two separate channels; Fig.3c shows the format for display of the complete images of Fig.3a and Fig.3b simultaneously in the same picture frame, the imageless portions therein being filled up with a predetermined background colour (e.g. blue); Fig.3d represents a "pic-in-pic" display format wherein the image in Fig.3a forms the secondary picture and the image in Fig.3b forms the primary; and Fig.3e represents another in-pic" display format when the image in Fig.3b forms the secondary picture and the image in Fig.3a the primar.It is seen that in an embodiment example with more than two TV signal inputs, the image output format selection will become complicated. Of course, it can be assumed to prefer some fixed output forrmats and to restrict the use of some other possible combination formats.

In regard to output formats, the picture control selector 206 is similarly controlled by the reproduction control logic signals for reproduction from the unshown control/select logic output circuits. After decoding, the control signals are sent to the internal CPU of the picture control selector 206, and the CPU immmediately invokes the control programs, to turn the picture control selector into a working condition dealig with a predetermined format, to correspondingly select, convert, store, read to reconvert, amplify, and process in other ways as necessary, the input video signals, and eventually to turn the video signals f #m the R/R unit into "new" TV signals corresponding to a selected format, and to output them via the output ports.All control programs, executed by the internal CPU and coressponding to various formats, are installed as firmware in the internal memory. It is natural that in the case of an embodiment example dealing with still more simultaneously input TV signals, this kind of programs will be still more complicated.

In the situation shown in Fig.2, the control logic code, issued by the unshown control/select logic output circuit for use in the reproduction portion is realised by a 3 bynary digit code. This 3-bit code represents at most 8 (= 2 to the power 3) states (or formats), five of which are selectable to represent the 5 different predetermined output formats shown as Figs. 3a-e. eslgning of these sets of combination logic circuits has been easy.

In Fig.2, the aural control selector 207 separately restores the input synthesised aural signal back to the two orralnal aural signals, and control the outputs in corresponding selected formats. When an output format like Fig.3a or Fig.3b is selected, the aural of the selected channel is output via an output port according to the instructions from internal CPU. When the output format is selected corresponding to Figs. 3c-e, the CPU can output an aural at the port only according to a predetermined corresponding format. For example, a "pic-in-pic" format is predetermined to output the aural of the primary imge.Like having been mentioned during the explanation of the picture control s ector 206, the reception, processing, selection, and switching, by the aural control selector 207, of the two aural signals coming from the R/R unit 205, are realised in the course of the CPU executing internal firmware control programs.

The image signals and aural signal from picture control selector 206, and from the aural control selector 207, simultaneously enter one output video signal synthesiser 208, wherein the output may be modulated on the carrier, and transmitted through transmitters or distributed in a cable Tv network.

Fig.4 snows the details of the embodiment example in Fig.2, wherein one R/R unit is applied in an analog recording mode.

In the embodiments of this invention, units 410-420 constitute a picture synthesiser, units 420-428 form a picture control selector, and modulator 430 performs the function of a video signal synthesiser.

Inthe present embodiment, the video signal through antenna TX into the video signal processors 410 and 411, wherein the tuner, IF amplifier and detector circuits all takes part to yield two video signals V1 and V2, and two aural siganls A1 and A2. Video signals V1 and V2 are separately amplitude-processed in the video processing units 411 and 413, and the chrominance sync and luminance sync signals are separated and sent to recording control and synchronisation unit 420. After being processed in the video p cessing units 412 and 418, the same video signals V1 and V2 are sent to respective A/D converting units 413 and 419 for conversions.The digital video signals thus obtained, are written into two areas at different addresses in memory 414, under the control of recording control and synchronisation unit 420, which, following the settings of the external commands (supplied by control/select logic output circuit) sends one or both digital video signals, that are stored in the memory 414, to the compression coding unit 415. When only one video signal is received or recorded, the recording control and synchronisation unit 420 controls the selected video signal to be sent from memory 414 via compression coding unit 415, to D/A conversion unit 416 without compression.When it is necessary to simultaneously receive and record two video signals, the recording control and synchronisation unit 20, working in the manner co rearing the stored video tat of two channels ever other lines ant every other points from memory 414, reads out the stored two video digital signals from memory 414, and forms in the compression coding unit 415, a quarter- screen sized, occupying upper-left and lower-right (or upper-right and lower left) of the screen, composite video signal inclusive of the two images, i.e., the screen displays in a format corresponding to Fig.3c.Meantime, the two imageless quarter-screen zones may be filled up w ' e- clr (e.g., blue). The said composite video signal is conver analog signal in the D/A conversion unit 416, and se processing in video processor 417, and the composite analog signal is output to R/R unit for recording on a magtape.

Said video signal processor 410 and 411 also separate two TV aural signals which are directly sent to the R/R unit 421.

The R/R unit 421, after the composite analog video signals from the video processor 417 being frequency-separated, modulates the luminance signal and lowers the frequency of the chrominance signal. Then the luminance and chrominance signals are synthesised to form a video signal recordable on magtapes. In this scheme of analog recording only two input TV signals, the R/R unit 421 records the aural signals from the video signal processors 410 and 411, on two respective magnetic tape sound tracks, like those in this embodiment example. At the time of reproducing, the R/R unit separates the reproduced analog video signals by means of a high-pass filter and a low-pass filter. After demodulation the luminance Y, and after frequency change the chrominance signal C, can be recovered. Then signals Y and C are synthesised to become a composite TV signal, and be sent to reproduction signal processing unit 422.

Reproduction signal processing unit 422 extracts the luminance sync and chrominance sync signals from the composite analog video signal, and sends the sync signals to reproduction control and synchronisation unit 428. After processing in the reproduction processing unit 422, the video signal is A/D converted in the A/D conversion unit, and then output the digital signal for writing into memory 424, under the control of the reproduction control and synchronIsation unit 428.

At the time of reproducing a magtape that records two TV programs, if external commands predetermine to play only one of the two programs, like in the formats given in Figs. a or b of Fig.3, the reproducing control and synchronisation unit 428 controls the memory, to send the digital corresponding image signal of a selected channel to the interpolate and output format storage unit 425. After being interpolated and enlarged to reconstruct a complete image signal for full screen display, the image is sent to D/A conversion unit 426 to be converted into analog video signal, and synchronised and amplified in the video output unit 427, before being sent -out.If the external commands select to screen two TV programs simultaneously and to display in a primary-secondary "pic-in-pic" format, (i.e., the format in Figs. d or e in Fig.3), the reproduction-control and synchronisation unit 428 controls the memory 424, to interpolate and enlarge in said manner the digital video signal that is selected to be the primary, to form the complete video signal for full screen display. However, video signal of another channel is compressed 2:1, and replaces the sample pixels in the corresponding screen locations of said primary image, to form the composite digital video signals in "pic-in-pic". Said composite digital video signals are converted into analog signals by D/A converter 426, and output after being synchronised and amplified by the video output unit 427.

The simplest reproduction format for the reproduction circuit portion, is a format completely identical to the recording format, like the one shown in Fig.3c. Using this format, reading out from the memory is done entirely in the manner of writting in coded digital video sIgnals. Hence the control method is the simplest.

The two aural signals from the R/R unit 421 reach the aural controller 429. The reproduction control and synchronizing unit 428 selects an aural signal corresponding to one of the images (either the primary image or any one sf the two complete images), amplifies it and output through the aural output port.

The video signal from the video output unit, and the aural signal from the aural controller 429, are sent simultaneously to modem 430, ant. modulated en an RF carrier for transmission, and or reception by TV receivers.

shows another circuit embodiment similar to Fig.2 but with more details The difference here is that digital s signals being recorded by the R/R unit.

In this embodiment of the invention, a picture synthesiser is formed b units 530-539, an aural synthesiser units 549-555, a picture controller by units 541-548, and an aural controller by units 556-560.

The Tv signals enter TV signal processors 510 and 520 through antenna. After tuning, I.F. am,plification, and detection, the video signals V1 and V2 rtespectively enter video processing units 530 and 534. Signal V1 goes through amplitude-processing in the v: eo processing unit 530, and has the luminance sync and chrominance sync signals separated. Said two sync signals are sent to recording control unit 536, which generates the required time base signals for video signal recording. Said video signal V1, after goes through further processing in the video processing unit 530, like amplification, synchronisation, luminance and chrominance signal isolations, is hen sent to the A/D converter for A/D conversion.The output digital image sampled data from A/D converter 531 are passed to a input interface unit 532, and written into memory 533 at the address specified by address generation unit 537, under the control of recording control unit 536.

The other video signal V2 from TV signal processor 520 undergoes the same processing as V1 does, i.e., enters input interrace unit 532 under the control of recording controller 536, and according to te address specified by the address generator 537, it is stored in another storage area n memory 533.The recording control unit 536 sends the two video digital signals of the memory, to synthesised signal processing unit 539 in time-divided and field bv field manner, according to the external commands (supplied by the control/ select logic output circuit).The signals input in parallel, including the luminance signal data, two colour difference signal data, are converted from parallel to series transmision, and compressed in time base, enhanced in amplitude, and processed for synchronisation, so as to output the synthesised digital signals or recording ifl the RIR unit 540.

Said TV signal processor 510 and 520 have the two channels of aural signal Al and A2 separated and output. These two aural signals are sent respectively to A/D converters 549 and 550 for conversion, and output via a input interface unit 551 and written into two difference areas in memory 552, under the control of recording control unit 555. Unit 555 outputs the two channels of aural signal, via a output interface unit 553 to a synthesis coder 554, under the control of the instructions from the control/select logic output circuits, for coding. The two coded digital aural signals are recorded onto carriers by means of the R/R unit 540, In coordination wth unit 539.

At the time of reproduction, the reproduced video signals are put through a composite video signal output @ port 53 3 of t unit 540, to an separating and decoding unit 541. In the unit, the coded data of different signal components are separated and written into different areas in memory 542, according to one address specified by the address generating unit 546. Reproduction controls unit 547 controls the address production or an undress generating nit 546, to realise the separation ant writing of said signal data.

As the external specifies to display picture on only one channel, the reproduction control unit 547 controls the address generation unit 546 and memory 542, to input the sampled data of TV signals on one selected channel, to feed the data into output format memory 543, and after processing in the D/A converter unit 544 and video processing unit 545, to obtain the TV signal of a complete composite picture (i.e., to realise the linear format in Figs. 3a and 3b). Under the control of an instructlon to realise the reproduction format shown in Fig.3c, address generator 546 outputs an address function, to select and transfer the two digital signals already stored, to form a complete TV signal displaying two images together, with the empty space on the screen filled with a single basic colour.Then the aforesaid contents stored in the output format memory, are sent to the D/A converter 544 and to video processor 545, to realise the formatted reproduction shown in Fig.3c. When the external command specifies to display TV images on two channels, reproducing a picture in a primary-secondary overlaying format like in Figs. 3d and 3e (i.e., compressed by the ratlo of 1:2), or, reproducing a picture in a primary-secondary overlaying formatlike in Figs. 3e' or 3d' (i.e., compressed by the ratio of 1::3), reproduction control unit 547 compresses the secondary picture data of a specified channel, to yield 1/4 or 1/9 of the original number of data, and at the same time specifies the primary digital picture data of a channel, to have the two sets or data combined in the output format memory 543, and sent to D/A conversion unit 544. The D/A conversion unit 544turns the digital signals into analog signals, and output them to video processing unt 5 , ror synchronisation processing according to the sync signals generated by the sync and clock unit 548.Lastly, the vicco processing nit 545 outputs analog signals or displaying on the T receivers.

By referencing to the method of processing image signals, the two aural signals may be processed in a similar manner. Of course, generally speaking, aural signal processing is much easier due to signal nature being different. R/R unit 540 outputs a composite aural signal, via port V54, to aural separation and decoding unit 556, which separates and yields digital aural signals on two channels. Select and switch unit 557, that executes the Instructions from reproduction control unit 560, selects one of the two digital aural signals corresponding to the formatted images on screen, and sends the aural to a D/A converter 558, which outputs analog aurals via output processing unit 558. The audio signal 15 then amplified and provided to TV receivers as aurals.

n this embodiment examples, said video signals output from the video processing unit 545, and the aurals output from the output processing unit 559, ae sent to modulation unit 551 to modulate on one F carrier as well for transmission. And, the transmitted signal will be received by TV receivers.

In oreder to give a comprehensive introduction of the processes of one stored, sampling, reading of data, and conceiving of formats, the folloWing is â description with reference to Figs. O and 7.

To make the explanation easy and in specific terms, an arbitrary TV system is chosen for the explanation, say, the NTSC system. It should be known that although the following descriptions and calculations are based on the related data taken from the NTSC system, the descriptions and calculation methods are similarly applicable to TV signals in the PAL or SECAM systems, provided the specific line and field data are replaced by corresponding ones.

Now in reference to Fig.6, the processes of TV signal sampling and storing in this invention are further explained. Fig.6 may be considered as a detailed block diagram expounding on units 531 through 540 of Fig.5.

In Fig.6, 601-606 are A/D converters, 607-612 buffer memorys, 613 writing distributor, 614 field memory for Y, 615 field memory or R-Y, 616 field memory for B-Y, 617 address multichannel switch, 618 writing address generator, 619 clock/timebase mean, 620 means for synthetic process/transfer/select, 621 R/R unit, and 622 recording control unit.

In order to facilitate processing of chrominance signals, generally speaking, the clock is phase-locked to sample the video signal at a frequency equal to the integral multiple of the freq-'ency fsc of the colour subcarrier. As far as NTSC system video signal is concerned, its colour subcarrier has a frequency of .A3 MHz. As seen in Fig.6, the embodiment example adopts a 4 so sampling frecuency for the video signals.Past experIence has demonstrated that video signal of this sampling density can be recostructed with excellent definition. Xeançhile, in order to have goot recording, the frequency of sampling on the two colour difference signals is also chosen to be 4fsc. The 4fsc (or 14.3 MHz) sampling frequency means a sampling period of 70 ns, and 910 coded sampled data, or 910 sampled pixels, in a NTSC line scan period of 63.5 us. Accordingly, in a field memory, each line storage unit has storage subunits of 910 words in length, each word being 8 bits long, corresponding to a line of samples. This storage requirement is constant for NTSC, wherein every line scan gives a line signal of exactly 227.5 colour subcarrier periods.Therefore, the A/D conversions at a sampling frequency of 4 times the colour subcarrier frequency (4 fsc = 14.3 MHz), are dealing with exactly 910 (= 4 x 227.5) pixels per line scan. As to the Y, R-Y, B-Y signals, they are coded in uniformly quantized PC'A, with each sample 8 bits long. The sampling scheme is that for repetition in lines, fields and frames, the positions of sampling points for R-y, are the same, and consistent with the positions of the Y points in each line.

Regardimg the selection of the memory device in the circuits, the first factor for consideration is the required capacity, the second factor is the accessing speed. In this embodiment example, the 6 signal components (luminance signals Yl, 2, colour difference signals R1-Y1, B1-Y1 and R2-Y2, B2-Y2) are fed to 6 respective A/D oon-:erters simultaneouly ant in parallel.Because the two TV signals are similarly processed, and each pair of corresponding signal components thereof are processed in the same way too, hence the following introduction is restricted to the sampling of the Y1, Y2 comonents and the storage of same into Y field memory, whereas t..tJ processing of B1-Y1, B2-Y2, and R1-Y1, R2-Y2 may make reference to the method of processing of Y1 and Y2.

The capacity of buffer memory connected to A/D converter in Fig.6, should be good enough if it can hold two complete lines of sampled signals. The Y field memory includes two separate independent components, each separate independent component being controlled by the same external clock, having the storage large enough for keeping the sampled signals of a complete frame. The whole Y field memory will contain the sampled data of luminance signals to cover a total of two frames (four fields).

When a line of sampled lumlnance signals output rom the A/D converter, are written into one of the two line memories in the buffer memory, signals of the previous line in the other line memory are being read out at a doubled sampling speed, and stored into a separate part of the Y field memory. Thus in a line period of A/D sampling, a multichannel switch in a writing distributor is working at a speed of 8 fsc to write a line of digital sampling codes of Y1, and another line of digital sampling codes of Y2, respectIvely into two consecut-ve addresses of the Y field memory.

In this manner, the two luminance signals Yl and Y2 coming from units 530 and 53 (See Fig.5) are written into a separate tart of the Y field memory within a field period. The space occupied by all data is a storage capacity of 910 x 625 words of 8 bits each.

When sampling of signals t the next field begins, the writing address generator and address multichannel switch jointly socre the signals from the multichannel switch into another separate part of the y field memory, meantime, also execute, according to the address generator and the time base signals, the input process of the stored data of luminance signals of the previous field into a synthetic process/transfer/select unit.

Talking about the time base, the process of writing sampled line signals from the buffer memory into the Y field memory through the multichannel switch of a writing distributor, is a time base compression process. And, every colour difference signal has z corresponding multichannel switch to similarly realise compression like the said luminance signal data, so that within a field period, sampled coded data of 77 signals of two channels are writted into three field memories via teh writing distributor.

The function of the synthetic process/transfer/select unit is to switch the sampled coded data input in parallel from three channels 2 means of the multichannel switch. On the one hand, as coordinated With the address multichannel switch, the sampled data of the original TV signals alternatively positioned in the field memory, are converted into the sampled data of TV signal of the same channel successively arranged within a field, on G recording medium, to reallse the filed alternate arrangements or tat - corresponding components of two TV signals, and at the same time, to realise the parallel-serial conversion of data from memory to R/R unit. It should be known that no matter the recording medium is magtape or optical disc, the data information on the media must be "serially" arranged with respect to the time axis, therefore this parallel-serial conversion is necessitated. On the other hand, the transfer/select function of said unit, may select the stored sampled signal data of one of the two channels, for example, barring sampled data of one of the two signals from entering the R/R unit.

The following is a more detailed explanation of the process of signal reproduction and format formation, using the Invented apparatus. (See Fig.7.) Fig.7 may be regarded as a detailed block diagram of the units 540-548 of the apparatus in Fig.5. During the explanation, emphasis is put upon the forming process of the reproduction format.

In Fig.7 701 is the .x/R unit, 702 the reading buffer, 703 a code distributive multichannel switch, 704 field memory, 705 (R-Y) field memory, 706 B- field memory, 708 output format memory, 709 output format (R-Y)' memory, 710 output format (E-Y) memory 711- 713 D/A converter, 714 video processing unit, 715 address multichannel switch, 716 read address generator, 717 clock/timebase means, and 718 reproduction control unit.

The reproduced digital coded data are passed through reat buffer, code distributive multichannel switch, and are written int field eories in coordination with read address generator ant wit actress multichannel switch. The operating principles in all portions are same as in the corresponding portions in Fig.6. The only difference exists in the serial-parallel conversion in the process of writing into the field memories (i.e., data changed from serial to parallel transmission), or the time base on the time axis is expanded.Besides, in any field memory, in order to facilitate processing, a certain component of the same field of the same TV signal (e.g., luminance signal Y), is stored in the memory at successive addresses. Thus it is possible to install bi-port automaitc cyclical address memory RAM (e.g. Hitachi HM53051P RAM, or a storage capacity of 262144 8-bit bytes), where by once the starting address is given, access becomes sequentially automatIc under the control of a clock, and its two ports may simultaneously perform writing and reading. Field memory providing tis kInd of functions makes formatted read control lot easier tat will be discussed later.

The formation of an output format is realised selectively reading the stored tat Information ant writing them Into an outpu format memory according to certain rules. As an example, iscuss how a luminance signal is selected so that a "pic-in-pic" display format with th a compression ratio of ;:3 is realised (i.e., the picture formats In Figs. 3d' and 3e'). omong all the format selections shown in Fig. 3, relatively speaking, these two overlaying display formats are the most complicated for two TV signals.

First, the amount of information contained in the secondary image, in a compression ratio 1:3, in these primary-secondary overlaying formats, will be considered.

In the NTSC system (525 lines/frame, i.e., 262.5 lines/field, TH=63.5 s) being sampled at a frequency 4 fsc (14.3 MHz) for PCM, 910 sampled data are obtained on every horizontal scan line. Among these 910 data, 760 are representative of image information (corresponding to a forward scan) and the other 150 = 910-760 sampled data are done during line blanking period and irrelevant to picture image. Similarly, in a field, 21 line scans occur during vertical blanking period of backward scanning.Therefore, for a complete TV picture field, 262.5 - 21 = 2ss1.5 scan lines are relevant to the contents of the picture image. is calculation shows a total of 241. 5 x 760 sampled data relevant to the contents of picture images, out or one PCM data of one rield of TV sIgnals sampled at 4 fsc frequency.If display of a 1:3 reduction "pic-in-cip" secondary image as in Figs. 3d' and 3e is to be realised, compression of the TV signal sampled data of the channel or the secondary image must be done correspondingly; and after compression, the number of sampled data for the secondary image should be (1/3 x 241.5) x (1/3 x 760) or 80 x 253, meaning that te compressed secondary image in a field of TV ticture takes 80 lines or about 235 sampled values per line.Selection or these sampled may a S2Y be accomplished z picking equidistantly 1 every 3 data, ant one line every three lines. Therefore, when writing the sampled digital data from field memory into output format memory, to realise the display formats of overlaying with an 1:3 compressed secondary image as in Figs. 3d' and 3e', the sampled data in the first 80 lines from line 1 to line 253, are the sampled secondary image data obtained by the said method of "pick 1 over every 3".

Sampled data in lines 254-760 are the corresponding sampled primary Image data. Provided the clock is accurate and control of the address is precise, it is entirely practicable to connect the first 80 lines in a field of TV picture signals. Lines 81-252.5 in the field may be realised by transferring and storing the sampled primary image data in the field memory, into format formation memory at the corresponding story address locations. It should also be noted that in order to realise the synchronisation of signals read out for two channels, te reading speed adopted for sampled secondary image tat is only 1/3 of that for the primary.

Obviously the same method can be applies to data processing of one two colour difference siganls. By means of this method, other output formats may be achieved. For example, to realise the formats for a 1:2 compresses secondary image as in Figs. 3d and e, slmliar methods may be applicable, except the sampling of the secondary image data is done on alternate points ant lines bass (i.e. "pick 1 over every 2").As to the display format shown in Fig.3c, for sampled data of TV signals of two channels, the data picking have to be executed simultasneously at alternate points and on alternative lines (i.e., a 1:2 data compression), whereas all imageless half-lines are filled a ceratin background colour.

It should be added that the aforesaid explanation of the principles in Figs. 6 and 7 is, theoretically, grossly workable. Adoption of superfast, high precision memory devices, and multichannel switches are practicable in engineering. Of course, this would certainly mean sophistication in control circuitry and expensiveness of the set-up. In order to use low-cost and mediocre components, the circuitry designs shown in drawings will have to be moderately altered when putting them into real application.

It is noted that with reference to Fig.6 and according to the aforesaid descriptions, as the sampled data from 3 field memories are transferred and recorded onto a medium, the parallel-serial conversion is simply a process of compressing the time base. To enable reading sampled data of 6 fields within a field period (two Y fields, two R-Y fields, and two B-Y fields), the speed of reading out these data in field memories should reach 6 x r so = 24 fsc.

This is to say, z reading time of only 10 ns or so is allowable for an 8-bit sampled data. This is an exacting requirement 0 ordinary RRl, and is hard to realise. Therefore, in the actual practice, a scheme may be devised to selectively read the data in field memory, namely, compressing before recording. For example, the store sampled data are picked on alternate lines ant alternate points basis ant are sent through synthetic processing/transfer/selecting it to reach the mean for recording. Thus, the RA set or field memory may have about 50 ns reading time for every bit, which is then practIcable for ordinary RUI.

Corresponding to the reading scheme in the last paragraph, in order to ensure good enough reproduction definition by the reproduction circuit shown in Fig.7, before the reproduced sampled data are stored into fIeld memory, the data has to be line-interpolated in order to recover the sampled data of all lost pixels. Contents of this concern are believed to be familiar to the person skilled in the art, hence further explanation is unnecessary. The ultimate goal of interpolation Is to make the amount of information contained in field memories shown in Fig.7, equal to the amount of information stored in the field memory shown in Fig.6.

Fig.8 partly shows the electric circuit of another embodiment of this invention. The embodiment deals with the situation of four simultaneous input TV signals. In the situation, the apparatus has the same hardware circuitry in the reproduction protion as that in Fig.5, and works on the same principles.Hence this portion is omitted. Apparently, because there are possibly tat sampled our channels, and output simultaneously from the RfR unit, one detailed concrete circuits, the external commands for one reproduction from the control/select logic output circuit, and t control programs executed by the reproduction controller, much more complicated than those in the embodiment shown in Fig.5.

In Fig.8, 801-804 is TV signal processor, 805-808 video signal processor, 813-816 A/D converter, 818 input interface unit, 819 memory, 820 address generator, 821 synthesised signal processor, 822 recording controller, 823 time base generator, 824 R/R unit, 825 memory, 826 output interface unit, 827 synthesis encoder, and 828 recording controller.

In the embodiment example corresponding to this block diagram, under the control of an external command, the TV signal processor selects to input and process the signals Va-Vd on channels 1-4, then sends the 4 Image signals to video signal processor 805-808 (a-d), and the aural signals to the respective A/D converter. The video signals, after being processed, are converted Into digital coded signals in the A/D converter, and under the control of a recording controller, the digital signals are stored in a memory area specified by the address generator.The time base and sync signals generated by the time base generator, are sent to a synthesised signal processor, wherein according to the Instructions from the recording controller, the sampled digital image data are read in a certain read format, and are synonesiset to form one synthesised image digital signals recordable on a records media.

Similarly, all aural signals are converted into digital aural signals by respective A/D converters. Under the control of a recording controller, all digital aural signals are stored in distributed area in the memory via an input port. In the synthesiset encoder, all digital aural signals rom one cuotut interface unit, arrive and are synthesised Into inl aural signals recordable in a specific format.

Although the embodiment deals with four simultaneous input signals, yet the methods used for signal processing on any channel are all identical to that in the embodiment shown in Fig.5. For the principles of data processing like sampling of signals on four channels and the storage, synthesis, and recording of these sampled coded data, the related explanatory sections regarding the embodiment, shown in Fig.5, may be referred.

Fig.9 shows yet another embodiment of this invention. In this figure, 940 is the R/R unit, 941 separation decoding means, 942 memory, 943 and 430 D/A converters, 944 video processor, 945 address generator, 946 reproduction controlling means, 947 synchronisation and clock means, 955 aural separation and decoding means, 956 selct/switch means, 957 A/D converter, 958 output processor, 960 and 961 modulators.

This embodiment is an improvement over the embodiment shown 1n Fig.5. The circuit block diagram in the recording portion or tis embodiment is completely identical to the actual circuitry In the embodiment shown in Fig.5, hence its description is omitted. On the basis of Fig.5, the present embodiment adds a second video signal D/A converter 430, a second aural D/A converter 570, a second video processor 440 and a second output processor 580. In addition, the output portion adds a second modulator 961.

Adoption of the circuitry of this embodiment may realise the output of two TV signals respectively from TV signal processors 410 and 411, for viewing on two display devices (e.g. TV respectivers) at the same time. Since in this embodiment emphasis has been attached to outputting two separate different TV signals, the output format memory 543 for display on a single screen has not been used as did in Fig.5.

On receipt of instructions from the control/select logic output circuit for outputting two separate different TV signals, the reproduction controller 946 transfers the sampled coded data of two different TV signals, stored in memory 942, respectively to D/A converters 943 and 430, and thenceforth the two analog signals respectively to video processors 90 and 440. In these video processors, the two signals, together with the sync signal supplied by the synchronisation and clock generator 947, are synthesised to produce video signals on two channels, and are seno to modulators 960 and 961.

Meanwhile, two digital aurals output from the select/switch unit 956, are sent respectively to two D/A converter 57 an 570, to generate aural signals for two channels. moreover, these two aural signals are sent to aural output processor 958 and 50, then onward to respective modulators 960 and 961. Finally, the modulators 960 and 961 simultaneously provide different TV signals on two channels for reception by two =; receivers.

Claims (9)

CLAIMS:

1. A recording/reproduction apparatus for simultaneously receiving and processing TV signals on a plurality of channels and for selecting one or more of the received TV signals for replaying, comprising: a plurality of V signal processors, each for processing a received TV signal and for outputting a video signal at a first output port of each individual processor and a corresponding audio signal at a second output port; picture synthesizer means for processing the video signals from the first output ports to form a synthetic picture signal for recording comprising selected ones of the video signals arranged in a predetermined format; audio synthesizer means for processing the audio signals from the second output port to form a synthetic simultaneously recordable audio signal; a recording/reproduction means for simultaneously recording the synthetic picture signal and the synthetic audio signal on a medium; picture control selector means for controlling, selecting and combining selected ones of the reproduced video signals comprising the synthetic picture signal into a format specified by input instruct ions to provide a specified video signal (on at least one channel); audio control selector means for selecting an audio signal in accordance with the input instructions; output video signal synthesizer means for combining the specified video signal and the selected audio signal into a composite video signal suitable for reproduction and viewing on a TV receiver; and control/select logic output circuit means or generating control signals to select a recording format and a reproduction format and for sending the control signals to the respective internal control circuit of the recording/reprcduction means to operate the recording/reprcauction means in accordance with predetermined control programs.

2. An apparatus according to claim 1, wherein the predetermined recording format and the specified reproduction format are both suitable for displaying selected ones of the video signals in sectional areas of a TV receiver screen.

3. An apparatus according to claim 1 or 2, wherein the recording format is different from the reproduction format.

4. An apparatus according to any preceding claim, wherein the recording or reproduction format comprises a single video signal.

5. An apparatus according to any one of claims 1 to 3, wherein the recording or reproduction format comprises a first video signal in one portion of a TV receiver screen and a second video signal in a second portion of a TV receiver screen.

6. An apparatus according to claim 5, wherein the portion occupied by the first video signal overlaps the portion occupied by the second video signal.

7. An apparatus according to claim 5 or 6, wherein the first video signal occupies a larger portion of the TV receiver screen than the second video signal.

8. A recording/reproduction apparatus substantially as described herein with reference t= and as shown in the accompanying drawings.

9. Any novel feature or combination of features disclosed herein.