GB2059713A - Video information transfer system - Google Patents

Abstract

A system for transferring digital video information held on a digital recording medium (10) on to an analogue recording medium (16). The data is suitably formatted via buffer store (12) and serialiser (13) and passes (still in digital form) via processor (15) where analogue synchronising and possibly colour burst information is added prior to recording on the analogue recording medium. On play-back the analogue synchronising information is removed by separator (18) and following suitable signal shaping by converter (19) the digital data is made available after any required formatting via deserialiser (20) and buffer store (21). The digital recording medium can be a video disc (10) or a solid state store and the analogue storage medium can comprise a standard video tape recorder (16). Such a transfer system allows duplication or transportation of digital video information from one location to another. <IMAGE>

Description

SPECIFICATION Video information transfer system The invention relates to a transfer system for video information.

It is known to record video information in digital form onto a video disc for storage purposes. An example of such a system is disclosed in our co-pending patent application 7910113. Such systems may require that information stored on such discs be transferred for duplication purposes for example or for transportation purposes where transportation is difficult due to the disc being of the type permanently fixed within the drive unit which requires transportation of the entire drive unit from one location to another.

The present invention provides a system which allows data from such stores to be transferred to another recording medium to allow duplication or ease transportation problems for example.

According to the invention there is provided a video information transfer system for transferring digital video information held on a digital recording medium onto an analog recording medium comprising input means for receiving digital information in a format received from the digital storage medium and required to be transferred; and processing means for processing the video information from said input means into a format suitable for subsequent recording onto the analog recording medium by including analogue sync information to the desired format digital information.

Further according to the invention there is provided a method of transferring digital video information from a digital recording medium onto an analog recording medium comprising receiving and assembling digital information from said digital recording medium and processing the information by including analogue sync information prior to recording the digital information on the analog recording medium.

The system may include a playback arrangement including sync separator means and conversion means for providing data in the format suitable for the receiving digital recording medium.

Means may also be provided to accommodate information presented in a non-continuous format and conversion of data from parallel to serial format and vice versa.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows one embodiment of the video information system concerned with recording; Figure 2 shows an embodiment of the playback system, Figure 3 shows one embodiment for realising the buffer store of Fig. 1, and Figure 4 shows an alternative embodiment to the Fig. 1 arrangement using data received from a solid state frame store.

An embodiment of the video information transfer system concerned with recording is shown in Fig. 1. Video data in digital form is already present on disc 10 as a result of earlier recording by standard techniques and requires transferring without erasure from the disc. Typically during read out, the output data rate from such a disc (e.g. a Winchester disc) will be 1 Megawords/second, each word being in 8 bit parallel form. This data is received by buffer store 1 2 which holds this data which will typically appear as interrupted blocks with data gaps according to the normal read out pattern of such a standard disc. The buffer store 1 2 outputs the data as a continuous stream at a somewhat slower rate typically + Megaword/sec again in 8 bit parallel form.This data is received by serialiser 1 3 which converts the parallel data into serial form, thus providing a data output rate typically 4M bit/sec. This data stream is received by a process amplifier 1 5 in which syncs and colour burst are added so as to produce a digital data stream with analog sync and burst information. This allows the data to be recorded on a standard analogue VTR 1 6. The syncs and colour burst may be provided from a local generator in well known manner.

Thus the standard analog tape can be used for duplication and is easy to transport. The information from a number of discs can be stored on one standard tape.

In the replay system of Fig. 2, the recorded tape with the digital data stream and added syncs and burst thereon is replayed on VTR 1 6 and the output is received by sync separator 1 8 which separates the added signals from the data stream and allows the data to pass to the 1 bit analogue to digital converter 1 9 which provides signal shaping for the replayed digital data. The serial data stream from the ADC passes to the deserialiser 20 to be changed into 8 bit parallel format. Clocking of the ADC 1 9 and deserialiser 20 is provided by the sync separator clocks.The parallel data is received by buffer store 21 where it is packed into the format compatible with the disc 23 (as explained in relation with the buffer store 1 2 of Fig. 1 but in reverse).

A suitable arrangement for realising the buffer store 1 2 of Fig. 1 is shown in Fig. 3 and includes input switch 30 which is selectable to allow incoming data from disc unit 10 to be input to either shift register 32 or 33.

The data output from registers 32 and 33 passes via switch 34 to the serialiser 1 3 of Fig. 1. The buffer 1 2 handles the data at the different rates under the control of switches 37 which effectively are ganged with switches 30 and 34. The switch 37 allows one particu lar register to receive clocks from input generator 36 whilst the input data from the disc is arriving and the other register outputs its held data by means of the output clock generator 38. The input clock generator will receive control clocks from the disc drive unit 10 typically in interrupted blocks. The output clock generator 38 receives control clocks from an internal oscillator 39 at a steady rate to provide the necessary data outputting from the registers.This register configuration would be expanded as required to handle the incoming data format (typically 8 bit).

The buffer store 21 could be realised using the same approach although the handling requirements would be reversed.

The shift register function could be performed by RAMs.

Although disc units 10 and 23 are shown as separate arrangements these could be a shared unit and the transfer system would allow data to be recorded on tape and then replayed back onto the disc in edited form if desired.

Thus the system is capable of being used with a standard analog video tape recorder to provide duplication or transfer facilities from storage media such as discs.

Although in the embodiment described the system uses both horizontal with vertical syncs and colour burst information for recording purposes, the system could operate with sync pulses alone.

Although the data to be transferred is described as being received from a disc 10, other digital storage media could be used to provide data for transferring including a solid state frame store as shown in Fig. 4.

The digital data provided by store 40 can be received directly by serialiser 1 3 and then passed to process amplifier 1 5 prior to recording on the VTR 1 6 in digital form with added analogue syncs and colour burst. With certain types of store the serialiser may not be essential.

Claims (14)

1. A video information transfer system for transferring digital video information held on a digital recording medium onto an analog recording medium comprising: input means for receiving digital information in a format received from the digital storage medium and required to be transferred; and processing means for processing the video information from said input means into a format suitable for subsequent recording onto the analog recording medium by including analogue sync information, to the desired format digital information.

2. A system as claimed in claim 1, wherein the input means includes a data converter for converting the incoming digital information from parallel bit to serial form.

3. A system as claimed in claim 1 or 2, wherein the input means includes a buffer store for assembling the digital information prior to receipt by the processing means.

4. A system as claimed in claim 3, wherein the buffer store is adapted to operate as a plurality of shift registers.

5. A system as claimed in claim 3 or 4, wherein the buffer store is adapted to accommodate information presented in a non-continuous format.

6. A system as claimed in any one of claims 1 to 5, wherein the processing means is adapted to also add anlogue colour burst information to the digital information.

7. A system as claimed in any one of claims 1 to 6, wherein a recovery arrangement is provided including sync separator means and output means for providing the recovered video information in digital form in a format suitable for digital restorage.

8. A system as claimed in claim 7, wherein the output means includes a converter for converting the received serial information into parallel bit form.

9. A system as claimed in claim 7 or 8, wherein the output means includes a discriminator for defining the digital status of the information received from the sync separator means.

10. A system as claimed in claim 9, wherein the discriminator comprises a single bit analog to digital converter.

11. A method of transferring digital video information from a digital recording medium onto an analog recording medium comprising: receiving and assembling digital information from said digital recording medium and processing the information by including analogue sync information prior to recording the digital information on the analog recording medium.

12. A method as claimed in claim 11, including adding analogue colour burst information to the digital information prior to recording.

1 3. A method as claimed in claim 11 or 12, wherein the assembling step includes converting the digital video information from parallel bit to serial format prior to processing.

14. A method as claimed in claim 11, 1 2 or 13, including recovering the information from said analoge storage medium by separating the analog synchronising information from the digital video information.

1 5. A video information transfer system substantially as described herein and with reference to the accompanying drawings.

1 6. A method of transferring video information substantially as described herein.