GB2407465A - Copy control and monitoring of audio and audio-visual recordings - Google Patents

Abstract

A method of improving a security measure for limited issues of audio of audio visual work includes recording multiple copes from a master data carrier, processing to impart an audio watermark to the audio portion of the signal the audio watermark being different for each recording made. Additional copy protection measures may be applied to the recording, along with use of a datafile to correlating with watermarks in order to identify the particular recording or party to whom it is to be sent. The format of the recording may be CD or DVD.

Description

COPY CONTROL AND MONITORING OF

AUDIO AND AUDIO-VISUAL RECORDINGS

This invention relates to the control and monitoring of multiple copies of audio and audio visual recordings.

Over recent years, the industry devoted to the recording and distribution of audio and audio visual works has undergone a revolution. On the one hand, new technology has made possible the high quality reproduction of audio and audio visual works to a degree of fidelity not achieved previously, in particular by the use of digital sampling and recording techniques. On the other hand, with the rise of such technology came the easy availability of means for copying such audio and audio visual recordings, and of doing so in a way which, in the case of digital recordings, suffered no degradation whatever compared with the 1 5 original.

In recent years, the recording industry, both purely audio and audio visual, has sought to combat increasing sophistication among the copyists by a variety of means including various copy protection schemes and attacks on the distribution of software which can be used for copying. Separately, the business model of phased release of material has been progressively abandoned, particularly since, as soon as any recording is publicly released, it can be legitimately purchased and then illegitimately copied very rapidly.

Although simultaneous global release is becoming the norm, this does not affect the fact that, prior to release, copies of audio and audio visual works need to be distributed on a confidential or embargoed basis in order that the audio and audio visual publicity industries can be ready at launch time with informed criticism of the work in question. This necessary degree of "pre-release" brings with it particular problems of security, and substantial efforts are taken, - 2 particularly with audio or audio visual works likely to command substantial popularity in the marketplace, to ensure that none of the pre-circulated copies can be diverted to an illegitimate copying end. Despite such measures, however, it is clear that interception can take place prior to the delivery of a recording to, e.g. a critic or reviewer, or, once it has been reviewed, the critic or reviewer may not take adequate care to ensure that the recording is secure, and it may be misappropriated, not necessarily by theft, but, for example, by apparently legitimate loan.

In recent years, so-called watermarking techniques have been developed for enabling the differentiation between a legitimate recording and a copy or bootleg one. The digital data on a conventional audio compact disc recorded medium may be manipulated in such a way that embedded in the data is a certain pattern of information which can be recognised by appropriate reading equipment, but which, when the compact disc is inserted into a compact disc player, does not adversely affect the reproduction of the recorded work as heard by the listener. Such techniques are widely known and used to identify a particular recording during the pre-mastering stage so that, following the usual CD mastering and manufacturing processes, each of the commercially available CDs bears the same watermark and is accordingly identifiable as genuine using appropriate equipment.

According to the present invention, there is provided a method of improving security in connection with a limited issue of an audio or audio visual work which comprises making the limited issue by sequentially recording, from a master data carrier, a plurality of individual audio or audio visual recordings, wherein the signal is processed between the master and the recording mechanism to impart to the audio portion of the signal an audio watermark, the audio watermark being different for each of the plurality of individual audio or audio visual recordings made. - 3

In this way, a limited edition of an audio or audio visual work can be produced where the recording reproduces the audio or audio visual work normally, with no identification or the like being applied to the visual data, but where the audio data contain a watermark enabling each individual recording to be identified.

Thus if, for example, 100 pre-release copies are to be uniquely produced for distribution to the relevant persons, these can be produced in accordance with the invention as 100 recorded units, for example on audio compact disc or Digital Versatile Discs (DVDs), each of which is unique, though it differs from the others only insofar as the watermark differs between each copy.

In this way, so long as an appropriate record is kept of which specific copy is distributed to whom, if there is any subsequent evidence of improper copying, for example the very rapid appearance of pirate DVDs from offshore, then, by extracting the watermark from the pirate DVD, it can easily be determined from which of the pre-release DVDs the pirated DVD was derived, thus enabling efforts to find out how the counterfeit activity occurred being able to be focussed on the single recipient of the particular DVD rather than having to check through all recipients to try and determine how and where the mis-use occurred.

The method of the present invention can be carried out without difficulty using standard equipment controlled by a suitable computer programme. A particular advantage arises in the application of the present invention in terms of the speed with which multiple but individually identifiable copies can be made. The process may be broken down into four steps: 1. analysis of the digital file corresponding to the original audio or audio visual work; 2. creation of a modified file including metadata which provides details of where the watermark should be placed; - 4 3. insertion of the watermark into the intended location, and 4. creation of the final digital file and recording it on to the output medium such as a DVD.

Of these, the first two need only be carried out once, and then steps 3 and 4 are carried out as many times as there are individually identifiable copies needed.

By way of diagrammatic illustration, the method is illustrated in the accompanying drawing which is a block diagram showing how the method can be put into effect. As illustrated, the recorded medium of choice is a DVD, but it will be appreciated that the method of the present invention is applicable to any audio or audio visual recording where the audio data is in a format which can be watermarked in accordance with the known technology.

It should be noted that, if desired, as well as the unique watermarking applied to the audio or audio visual recording, known copy-protection technologies can also be incorporated in each of the limited issue, this further reducing the risk of mis-use of the recordings sent out.

Referring to the drawing, this appears to show a number of discrete elements, but it should be understood that most or all of them can in fact be incorporated in a single computer unit, either stand-alone or networked.

Referring to the drawing, the apparatus for putting the present invention into effect consists essentially of a DVD reader 1 which is connected to a computer mother board 2. Likewise connected to the mother board 2 is a DVD recording unit, or so-called DVD burner 3, and this may be arranged to be fed with a series of blank DVDs for recording by a suitable stack feeder mechanism.

Connected to the computer mother board 2 are a monitor 4, keyboard 5 and disc printer 6, and (not shown) one or more suitable hard discs containing application programmes which can be run using commands input e. g. via the keyboard 5.

One of the programmed stored on the hard disc(s) of the computer is a programme which can take an audio file and apply a digital watermark to it.

This programme is called up by an appropriate overall simple application control programme for carrying out the method of the present invention.

The programme is caused to be automatically activated if a master DVDis placed in the DVD reader 1. This presents the user, on a screen or monitor 4, a menu of options and text boxes which may be filled with appropriate data, either by the user from keyboard 5, or automatically derived from data on the master disc or other file supplied. The user input, however, will include how many physically numbered copies are required, unless this is automatically generated, for example from a "distribution list" file.

Once the user has checked that the feeder for the DVD burner 3 has adequate supplies of blank DVDs, the programme is then set to run. First of all, the relevant audio files are extracted from the master DVD and subjected to the application of a digital watermark thereto. The watermarked audio file is then recorded in DVD burner 3 on to a blank DVD together with the visual data from the master disc in DVD reader 1 and, at the end of the recording process, a recorded DVDis ejected from burner 3 into an appropriate outlet hopper. At the same time, the disc printer 6 which is provided with a feed of adhesive label stock, prints data e.g. data corresponding to fixed graphic material as well as the variable data fed to it from the motherboard 2 on to the disc, including a particular serial number, for example 001 for the first disc printed and 050 for the last of a set of 50. As an alternative to the disc printer 6, it is possible to use - 6 a standard printer with a supply of label stock suitable for application to the disc once printed.

Each time the computer causes a fresh blank DVD to be recorded, it incorporates a different digital watermark into the audio data. At the same time, it builds up a correlation between the number of the DVD recording (1 to 50) and the respective digital watermark associated with that number in each case.

If the watermark is one which, in a standard reader, produces an alphanumeric string corresponding to that watermark, then a standard printer may, following the manufacture of the last item in the series by the burner, be used to print out a correlation listing of the individual disc numbers 1 to 50, the alphanumeric character strings corresponding to each of the unique digital watermarks on the discs, and the details of the recipient to whom each individual disc is then to be despatched, and, if desired, a set of address labels for those recipients. The details may also be stored electronically in a suitable file format on a suitable storage medium, e.g. hard disk, floppy disc, recordable optical disc.

If, following the pre-release distribution of the 50 discs, a pirate or counterfeit DVD is made from one of them, then, by looking at the digital watermark in the audio file on that disc, it can be determined which of the 50 pre-release DVDs was used as the master from which the counterfeit copies were derived, so enabling rapid and effective prosecution to take place. The present invention thus provides a further much-needed weapon in the armoury needed by the legitimate audio and audio visual creative and distribution industries in their fight against copyright infringement, counterfeiting and privacy. - 7

Claims (8)

1. A method of improving security in connection with a limited issue of an audio or audio visual work which comprises making the limited issue by sequentially recording, from a master data carrier, a plurality of individual audio or audio visual recordings, wherein the signal is processed between the master and the recording mechanism to impart to the audio portion of the signal an audio watermark, the audio watermark being different for each of the plurality of individual audio or audio visual recordings made.

2. A method according to Claim 1 wherein, at the same time as each recording is made, anti-copying protection measures are applied to the recording.

3. A method according to Claim 1 or 2 wherein the recordings are produced as CDs DVDs.

4. A method according to any one of Claims 1 to 3 and including producing a data correlation between the audio watermark on each recording and a datafile identifying the particular recording or a party to whom it is to be sent.

5. Apparatus for carrying out the method according to any one of Claims 1 to 4, and comprising, connected together for interaction adapted to carry out the method, a computer, means for recording data from a master recording, means for selecting audio data therefrom, means for applying a watermark to the selected data, - 8 means for producing a recording faithful to the master recording and incorporating the watermark therein on an individual data carrier, (other than by the watermark) to distinguish it uniquely from other data carriers on to which the same master recording has been applied.

6. Apparatus according to Claim 5 wherein the means for producing a recording includes a DVD burner.

7. Apparatus according to Claim 5 or 6 and arranged to produce a datafile correlating the watermarks and the individual data carriers.

8. Apparatus according to Claim 5 and substantially as hereinbefore described with reference to the accompanying drawings.