GB2361127A

GB2361127A - Audio/video reproduction via a communications network

Info

Publication number: GB2361127A
Application number: GB0008429A
Authority: GB
Inventors: Morgan William Amos David; Vincent Carl Harradine; Alan Turner; Michael Williams
Original assignee: Sony United Kingdom Ltd
Current assignee: Sony Europe BV United Kingdom Branch
Priority date: 2000-04-05
Filing date: 2000-04-05
Publication date: 2001-10-10
Also published as: GB0008429D0

Abstract

An audio/video reproducing apparatus connectable to a communications network (182) for selectively reproducing items of audio/video material from a recording medium in response to a request received via said communications network (182). The audio/video reproducing apparatus may comprise a control processor (178) which is arranged in use to receive data representing the request for the audio/video material item via the communications network (182), and a reproducing processor (204) coupled to the control processor and arranged in response to signals identifying said audio/video material items from the control processor (178) to reproduce the audio/video material items, which are communicated via the communications network (182). The first network interface may adapted to communicate in accordance with a data communications network standard such as Ethernet, RS 322 or RS 422 or the like. The second network interface (206) may be arranged accordance with the Serial Digital Interface (SDI) or the Serial Digital Transport Interface (SDTI). The data representing requests for audio/video material items includes metadata indicative of the audio/video material items. The metadata may be one of UMID, tape ID and time codes, and a Unique Material Reference Number identifying the material items.

Description

2361127 1 AUDIONIDEO REPRODUCING APPARATUS AND METHOD

Field of the Invention

The present invention relates to audio/video reproducing apparatus and methods of generating video signals. The present invention also relates to methods of aeneratinc, an audio/video product W ions. Background of the Invention

Generally audio/video productions such as films, television programs and radio programs are produced by combining items of audio/video material generated for this W z: purpose. However. typically many audio/video material items are generated in comparison to the audio/video material items which are used in the audio/video production. For example, a television program, such as a high quality drama, may be formed from a combination of takes of audio/video material iterns from a single camera. As such, in order to form the program, several takes are combined in order to form a flow required by the story of the drama. Furthermore several takes may generated for each scene but only a selected number of these takes are combined in order to form the scene.

In a post production process the items of audio/video material are selectively combined by the editor to form the audio/video production. However in order to select the required audio/video material items to form the production, the editor must review all the takes that have been generated. This is a time consuming and arduous task.

W C1 particularly when a linear recording medium, such as a video tape has been used to record the audio/video material items.

Summary of Invention

According to the present invention there is provided an audio/video reproducing apparatus connectable to a communications network for selectively reproducing items of audio/video material from a recording medium in response to a request received via said communications network.

By providing an audio/video reproducing apparatus which is connectable to a communications network an editing facility is provided for reproducing audio/video material items, in which the items may be remotely selected. A network connection provides a facility for the audio/video material items to be accessed separately by more than one editina terminal.

The content of video material generated by a camera is typically stored in a form which facilitates a high quality reproduction. In general the quality of the images represented by the video signal. to the extent that the images reflect an original image source falling within the field of view of the camera. is arranged to be as high as possible. This means that an amount of information that must be store to represent these imaQes is relatively high. This in turn requires that the video sional is stored in a format that does not readily allow access to the content of the video st- nals. This is particularly so, if the video signal is compressed in sonic way. For example, video cameras and camcorders are arranaed conventionally to record a video slanals W 1 Z:

representing moving images on to a video tape. Once the video signals have been W Z:1 Z.

recorded on to the video iape. a user cannot readily determine the content of the video tape without reviewing the entire tape. Alternatively. the contents of the recording medium may be ingested to provide substantially non-linear access to the audio/video material. However this is time consuming, particularly for example for a linear recordine, medium. Therefore by providing a facility for accessing the audio/video material items via a network, the items may be selectively accessed via the network, without being ingested and without having to review the entire of the tape.

In preferred embodiments the audio/video reproducing apparatus may comprise a control processor which is arranged in use to receive data representing requests for audio/video material item via said communications network. and a reproducing processor coupled to the control processor and arranged in response to signals identifying the audio/video material items from the control processor to reproduce' the audio/video material items, which are communicated via the communications network.

The task of naviaatinc, throuah the media to locate particular content items of video material is time consumina and labour intensive. As a result during an editing process in which selected items from the contents of the video tape are combined in an 3 order which may be different to that in which they were recorded, it may be necessary to review the entire contents of the video tape in order to identify the selected items.

Hence by identifying the audio/video material items required and reproducing only the n j items identified, an advantage is provided in respect of the time taken to edit an Z:1 audio/video production.

In order to receive commands identifying the audio/video material items and to communicate the aiidio/video material items, the audio/video reproducing apparatus may comprise a first network interface connectable to a first corn rn un i cations network for receivina the data representing the requests for aiLdto,,",.ideo material. and a second network interface connectable to a second communications network for communicating the items of audio/video material. By providing a first network interface adapted to receive data representative of request for audio/video data and a second interface for communicating the items of audio/video material. the first and second interfaces can be optimised for the different type of data being communicated. For the audio/video material items this is particularly important because the network connection must stream audio/video which requires a relatively high bandwidth. As such in preferred embodiments, the first network interface may be arranged to operate in accordance with a data communications network standard such as Ethernet. RS 3T? or RS 422 or the like. Furthermore, the second network interface may be arranged to operates in accordance with the Serial Digital Interface (SDI) or the Serial Dialital Transport Interface (SDTI).

A particular advantage is provided by identifying the content of the audio/video material items so that appropriate items may be selected and ingested via the network. Metadata is data which serves to describe either the content of audio/video material or parameters present or used to generate the audio/video material or any other information associated with the audio/video material. Metadata may be, for example. C semantic metadata" which provides contextual/descriptive information about the actual content of the audio/video material. Examples of semantic metadata are the start of periods of dialogue, changes in a scene, introduction of new faces or face positions within a scene or any other items associated with the source content of the audio/video material. The metadata may also be syntactic metadata which is associated with items of equipment or parameters which were used whilst generating the audio/video material such as, for example, an amount of zoom applied to a camera lens, an aperture and shutter speed setting of the lens, and a time and date when the audio/video material was generated.

4 In preferred embodiments, the data representing requests for audio/video material items includes metadata indicative of the audio/video material items. The metadata may be at least one of UMID, tape [D and time codes, and a Unique Material Reference Number.

Althou h the reproducing apparatus may be arramged to reproduce items of 9 audio/video material from a single recording medium, the reproducing processor may comprise a plurality of audio/video recording/reproducing apparatus each of which is coupled to said control processor via a local data bus. A further improvement is provided to the audio/video reproducing apparatus in accessing a plurality of recording media from the control process so that, for example the entire contents of a shoot from which the audio/video production is to be generated can be accessed via the network.

Access may also be arranged in parallel. The recording media may also be different, so that some of the plurality of audio/video recording/reproducing apparatus mav reproduce the audio/video items from tape and some from disc.

In order to access the audio/video material present on the recording media, i 1:1 in preferred embodiments, the local bus may include a control communications channel for communicatina control data to and/or from the control processor. and a video data communications channel for communicating the items of audio/video material from the plurality of audio/video recording/reproducing apparatus to the communications cl network.

To provide an indication of the contents of the audio/video material, the audio/video reproducing apparatus may have a display device which is arranged in operation to display images representative of the audio/video material items present on the recording medium. Furthermore to facilitate access to the audio/video material items, the display device may be a touch screen coupled to the control processor, and arrange in use to receive touch commands from a user for selectine, the items of audio/video material.

According to an aspect of the present invention there is provided a method of reproducing items of audio/video material from a recording medium according to 330

Claims

Claim 12 of the appended claims. Various further aspects and features of the present invention are defined in the appended claims. Brief Description of Drawings Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 1 -1 Figure 1 is a schematic block dia-ram of a video camera arranged in operative 1 -- -- association with a Personal Digital Assistant (PDA), Fiaure 2 is a schematic block diazram of parts of the video camera shown in ZY - 1 fia,ure 1, 1 Fiaure ') is a pictorial representation providing an example of the form of the PDA shown in flaure 1, Figure 4 is a schematic block diazram of a further example arrangement of parts of a video camera and some of the parts of the video camera associated with generating and processing metadata as a separate acquisition unit associated with a further example PDA, Figure 5 is a pictorial representation providing an example of the form of the acquisition unit shown in figure 4, Figure 6 is a part schematic part pictorial representation illustrating an example 1 Z:1 of the connection between the acquisition unit and the video camera of figure 4, Figure 7 is a part schematic block diagram of an ingestion processor coupled to C1 a network, part flow diagram illustrating the ingestion of metadata and audio/video 20 material items, Figure 8 is a pictorial representation of the ingestion processor shown in figure 7, Figure 9 is a part schematic block diagram part pictorial representation of the inaestion processor shown in figures 7 and 8 shown in more detail, W Figure 10 is a schematic block diagram showing the ingestion processor shown in operative association with the database of figure 7, Figure 11 is a schematic block diagram showing a further example of the operation of the ingestion processor shown flaure 7, Figure 12a is a schematic representation of the generation of picture stamps at 0 sample times of audio/video material, 6 Fi-ure 12b is a schematic representation of the (Yeneration of text samples with respect to time of the audio/video material. Figure 13 provides as illustrative representation of an example structure for oreranisinLY metadata, Flaure 14 is a schematic block clia-ram illustratin,-, the structure of a data c 1- - reduced UMID, and Flaure 15 is a schematic block diagram the striiCtLire of an extended UMID. Description of Preferred Embodirrients Acquisition Unit Embodiments of the present invention relate to audio and/or video generation apparatus which may be for example television cameras, video cameras or camcorders. An embodiment of the present invention will now be described with reference to filgUre 1 which provides a schematic block diagram of a video camera which is arranged to communicate to a personal digital assistant (PDA). A PDA is an example of a data processor which may be arranged in operation to generate metadata in accordance with a users requirements. The term personal digital assistant is known to those acquainted with the technical field of consumer electronics as a portable or hand held personal organiser or data processor which include an alpha numeric key pad and a hand writing interface. In figure 1 a video camera 10 1 is shown to comprise a camera body 102 which is arranged to receive light from an image source falling within a field of view of an imaging arrangement 104 which may include one or more imaging lenses (not shown). tn In The camera also includes a view finder 106 and an operating control unit 108 from which a user can control the recording of signals representative of the images formed within the field of view of the camera. The camera 101 also includes a microphone which may be a plurality of microphones arranged to record sound in stereo. Also shown in fiaure 1 is a hand-held PDA 112 which has a screen 114 and an alphanumeric key pad 116 which also includes a portion to allow the user to write characters recognised by the PDA. The PDA 112 is arranged to be connected to the video camera 10 1 via an interface 118. The interface 118 is arranged in accordance 7 with a predetermined standard format such as, for example an RS232 or the like. The interface 118 may also be effected using infra-red siGnals, whereb the interface 118 is y a wireless communications link-. The interface 118 provides a facility for communicatino, information with the video camera 101. The function and purpose of the PDA 112 will be explained in more detail shortly. However in general the PDA 112 provides a facility for sending and receiving metadata generated Using the PDA z: _n 112 and which can be recorded with the audio and video siúnals detected and captured by the video camera 1. A better understanding of the operation of the video camera 101 in combination with the PDA 112 may be gathered from figure 2 which shows a more detailed representation of the body 102 of the video camera which is shown in figure 1 and in which common parts have the same numerical designations. C1 C_ In fiaure 2 the camera body 102 is shown to comprise a tape drive 122 having read/write heads 124 operatively associated with a magnetic recording tape 126. Also shown in figure 2 the camera body includes a metadata generation processor 128 coupled to the tape drive 122 via a connecting channel 130. Also connected to the metadata generation processor 128 is a data store 132. a clock 136 and three sensors 1')8 140, 142. The interface unit 118 sends and receives data also shown in figure 2 via a wireless channel 119. Correspondingly two connecting channels for receiving and transmitting data respectively. connect the interface unit 118 to the metadata generation processor 128 via corresponding connecting channels 148 and 150. The metadata generation processor is also shown to receive via a connecting channel 151 the audio/video signals generated by the camera. The audio/video signals are also fed to the tape drive 122 to be recorded on to the tape 126. The video camera 110 shown in figure 1 operates to record visual information falling within the field of view of the lens arrangement 104 onto a recording medium. The visual information is converted by the camera into video sicynals. In combination, the visual imaces are recorded as video sianals with accompanying sound which is C1 W detected by the microphone 101 and arranged to be recorded as audio signals on the recording medium with the video signals. As shown in figure 2, the recording medium 330 g 1 is a ma netic tape 126 which is arranged to record the audio and video signals onto the recording tape 126 by the read/write heads 124. The arrangement by which the video 1 signals and the audio signals are recorded by the read/write heads 124 onto the 8 magnetic tape 126 is not shown in figure 2 and will not be further described as this 1 does not provide any greater illustration of the example embodiment of the present invention. However once a user has captured visual irna-es and recorded these Ima(ies using the magnetic tape 126 as with the accompanying audio signals, metadata C1 describing the content of the audio/video signals may be Input Using, the PDA 1121. As will be explained shortly this metadata can be information that identifies the audio/video signals in association with a pre-planned event. such as a take". As shown in figure 2 the interface Linit 118 provides a facility,'hereb, the metadata added by the user usino the PDA 112 may be received within the camera body 102. Data signals may be received via the wireless channel 119 at the interface unit 118. The interface unit 118 serves to convert these signals into a form in which they can be processed by the acquisition processor 128 which receives these data signals via the Z:1 connectM2 channels 148, 150. Metadata is -enerated automatically by the metadata (yeneration processor 128 in association with the audio/video sianals which are received via the connectinu channel 151. In the example embodiment illustrated in floure 2, the metadata (Yeneration processor 128 operates to generate time codes with reference to the clock 136, and to write these time codes on to the tape 126 in a linear recording track provided for this purpose. The time codes are formed by the metadata generation processor 128 from the clock 136. Furthermore, the metadata generation processor 128 forms other metadata automatically such as a UMID, which identifies uniquely the audio/video signals. The metadata generation processor may operate in combination with the tape driver 124, to write the UMID on to the tape with the audio/video signals. In an alternative embodiment, the UMID, as well as other metadata may be stored in the data store 132 and communicated separately from the tape 126. In this case, a tape ID is generated by the metadata generation processor 128 and written on to the tape 126, to identify the tape 126 from other tapes. In order to aenerate the UMID, and other metadata identifying the contents of d in operation 30 the audio/video signals, the metadata generation processor 128 is arrange to receive signals from other sensor 138, 140, 142, as well as the clock 136. The metadata generation processor therefore operates to co-ordinate these signals and 9 provides the metadata generation processor with metadata such as the aperture setting of the camera lens 104. the shutter speed and a signal rece'...ed via the control unit 108 to indicate that the visual images captured are a shot". These signals and data are (Yenerated bv the sensors 138, 140, 142 and received at the metadata generation processor 128. The metadata generation processor in the example embodiment is arranged to produce syntactic metadata which provides operating parameters which are used by the camera in generating the video signals. Furthermore the metadata generation processor 128 monitors the status of the camcorder 101, and in particular whether audio/video sicynals are bein. recorded by the tape drive 1,24. When RECORD START is detected the IN POINT time code is captured and a ULIVIII) is generated in correspondence with the IN POINT time code. Furthermore in some embodiments an extended UMID is aenerated, in which case the metadata (jeneration processor is arranged to receive spatial co-ordinates which are representative of the location at which the audio/video signals are acquired. The spatial co- ordinates may be generated by a receiver which operates in accordance with the Global Positioning System (GPS). The receiver may be external to the camera. or may be embodied within the camera body 102. When RECORD START is detected, the OUT POINT time code is captured by the metadata generation processor 128. As explained above, it is possible to generate a "good shot" marker. The "aood shot" marker is generated during the recording 0 Ity t> Z process, and detected by the metadata generation processor. The "good shot" marker is then either stored on the tape, or within the data store 1 3) 2. with the corresponding IN POINT and OUT POINT time codes. As already indicated above, the PDA 112 is used to facilitate identification of the audio/video material generated by the camera. To this end, the PDA is arranged to associate this audio/video material with pre-planned events such as scenes. shots or takes. The camera and PDA shown in figures 1 and 2 form part of an integrated system for planning, acquiring, editing an audio/video production. During a planning phase, the scenes which are required in order to produce an audio/video production are 3 0 identified. Furthermore for each scene a number of shots are identified which are required in order to establish the scene. Within each shot, a number of takes may be generated and from these takes a selected number may be used to form the shot for the i final edit. The planning information in this form is therefore identified at a planning stage. Data representing or identifying each of the planned scenes and shots is therefore loaded into the PDA 112 alone, with notes which will assist the director when the audio/video material is captured. An example of such data is shown in the table below. 1 A/V Production News story: BMW disposes of Rover Outside Loncybridge Scene ID: 900015689 Shot5000000199 LonQbridoe BMW Siorn Shot5000000200 Workers Leavino shift Shot5000000201 Workers in car park Scene ID: 900015690 BMW HQ Munich Shot 5000000202 Press conference Shot5000000203 Outside BMW building Scene ID: 900015691 Interview with minister Shot5000000204 1 Interview 1 1 1 In the first column of the table below the event which will be captured by the camera and for which audio/video material will be generated is shown. Each of the events which is defined in a hierarchy is provided with an identification number. Correspondingly,. in the second column notes are provided in order to direct or remind the director of the content of the planned shot or scene. For example, in the first row the audio/video production is identified as being a news story, reporting the disposal of Rover by BMW. In the extract of the planning information shown in the table below, there are three scenes, each of which is provided with a unique identification number. Each of these scenes are "Outside Long Bridge", "BMW HQ Munich" and "Interview with Minister". Correspondingly for each scene a number of shots are identified and these are shown below each of the scenes with a unique shot identification number. Notes cor-responding to the content of each of these shots are also entered in the second column. So, for example, for the first scene "Outside Long Bridge", three shots are identified which are "Long Bridge BMW", "Workers leaving shift" and "Workers in car park". With this information loaded onto the PDA, the director or indeed a single camera man may take the PDA out to the place where the new story is to be shot, so 11 that the planned audio/video material can be gathered. An illustration of the form of the PDA with the graphical user interface displaying this information is shown in fi C7ure t As indicated in figure 1. the PDA 112 is arranged to communicate data to the o camera 111. To this end the metadata generation processor 128 is arranced to communicate data with the PDA 112 via the interface 118. The interface 118 maybe for example an infra-red link 119 providing wireless communications in accordance with a known standard. The PDA and the parts of the camera associated with generatina metadata which are shown in fi,-iure 2 are shown in more detail in floure 4. In figure 4 the parts of the camera which are associated with generating metadata and communicatina with the PDA 112 are shown in a separate acquisition Z:1 unit 152. However it will be appreciated that the acquisition Unit 152 could also be embodied within the camera 102. The acquisition unit 1521 comprises the metadata generation processor 128, and the data store 1-32. The acquisition processor 152 also includes the clock 136 and the sensors 138, 140, 142 although for clarity these are not shown in floure 4. Alternatively, some or all of these features which are shown in flaure 2 will be embodied within the camera 102 and the signals which are required to define the metadata such as the time codes and the audio/video signals themselves may be communicated via a communications link 153 which is coupled to an interface port 154. The metadata generation processor 128 is therefore provided with access to the time codes and the audio/video material as well as other parameters used in generating the audio/video material. Signals representing the time codes end parameters as well as the audio/video signals are received from the interface port 154 via the interface channel 156. The acquisition unit 152 is also provided with a screen (not shown) which is driven by a screen driver 158. Also shown in figure 4 the acquisition unit is provided with a communications processor 160 which is coupled to the metadata generation processor 128 via a connecting channel 162. Communications is effected by the communications processor 160 via a radio frequency communications channel using, the antennae 164. A pictorial representation of the acquisition unit 152 is shown in figure 5. The PDA 112 is also shown in figure 4. The PDA 112 is correspondingly provided with an infra-red communications port 165 for communicating data to and 12 from the acquisition unit 152 via an infra-red link 119. A data processor 166 within the PDA 112 is arranged to communicate data to and from the infra-red port 165 via a connectin2 channel 166. The PDA 112 is also provided with a data store 167 and a screen driver 168 which are connected to the data processor 166. The pictorial representation of the PDA 112 shown in figure 3 and the acquisition unit shown in figure 5 provide an illustration of an example embodiment of the present invention. A schematic diagram illustrating the arrangement and connection of the PDA 112) and the acquisition unit 152 is shown in figure 6. In the example shown in figure 6 the acquisition unit 152 is mounted on the back of a camera 101 and coupled to the camera via a six pin remote connector and to a connecting channel conveying the external signal representative of the time code recorded onto the recording tape. Thus, the six pin remote connector and the time code indicated as arrow lines form the communications channel 153 shown in floure 4. The interface port 154 is shown in figure 6 to be a VA to DN I conversion comprising an RM P9/LTC to RS422 converter 154. RM-P9 is a camera remote control protocol. whereas LTC is Linear Time Code in the form of an analoeme si-nal. This is arranaed to communicate with a RS422 to RS232 converter 154" via a connectiniT channel which forms part of the interface port 154. The converter 154" then communicates with the metadata generation processor 128 via the connecting channel 156 which operates in accordance with the RS 232 standard. Returning to figure 4. the PDA 112 which has been loaded with the pre planned production information is arranged to communicate the current scene and shot for which audio/video material is to be generated by communicating the next shot ID number via the infra-red link 119. The pre-planned information may also have been communicated to the acquisition unit 152 and stored in the data store 132 via a separate link or via the infra-red communication link 119. However in effect the acquisition unit 152 is directed to generate metadata in association with the scene or shot ID number which is currently being taken. After receiving the information of the current shot the camera 102 is then operated to make a "take of the shot". The audio/video material of the take is recorded onto the recording tape 126 with corresponding time codes. These time codes are received along with the audio/video material via the interface port 154 at the metadata generation processor 128. The metadata generation processor 128 having. been informed of the current pre-planned shot now being taken logs the time codes for each take of the shot. The metadata generation processor therefore logs the IN and OUT time codes of each take and stores these in the data store 1 ')? The information generated and logged by the metadata generation processor 128 is shown in the table below. In the first column the scene and shot are identified with the corresponding ID numbers, and for each shot several takes are made by the camera operator which are indicated in a hierarchical fashion. Thus, having received information from the PDA 112 of the current shot. each take made by the camera operator is logged by the metadata generation processor 128 and the IN and OUT points for this take are shown in the second and third columns and stored in the data store 1 ')2. This information may also be displayed on the screen of the acquisition unit 152 as shown in figure 5. Furthermore, the metadata (Yeneration rocessor 128 as p already explained generates the UMID for each take for the audio/video material generated during the take. The UMID for each take forms the fourth Column of the C table. Additionally, in some embodiments, to provide a unique identification of the tape once which the material is recorded, a tape identification is generated and associated with the metadata. The tape identification may be written on to the tape, or stored on a random access memory chip which is embodied within the video tape cassette body. This random access memory chip is known as a TELEFILE (RTM) system which provides a facility for reading the tape ID number remotely. The tape ID is written onto the magnetic tape 126 to uniquely identify this tape. In preferred embodiments the TELEFILE (RTM) system is provided with a unique number which manufactured as part of the memory and so can be used as the tape ID number. In other embodiments the TELEFILE (RTM) system provides automatically the IN/OUT time codes of the recorded audio/video material items. In one embodiment the information shown in the table below is arranged to be recorded onto the magnetic tape in a separate recording channel. However, in other embodiments the metadata shown in the table is communicated separately from the tape 126 using either the communications processor 160 or the infra-red link 119. The metadata maybe received by the PDA 112 for analysis and may be further communicated by the PDA. 14 Scene ID: 900015689 Tape ID: 00001 UMID: Shot5000000199 Take 1 IN: 00:03:45:29 OUT: 00:04:21:05 060C23133)40 Take 2 IN: 00:04:21:20 OUT: 00:04:28:15 0 6 0 C2 ') B 3 4 0 Take IN: 00:04:28:20 OUT: 00:05:44:05 060C2313340 Shot5000000200 Take 1 IN: 00:05:44:10 OUT: 00:08:22:05 060C23-13-3)40-1 Take IN: 00:08:22: 10 OUT: 00:08:23:05 060C2313340 1 1 i 1 i The communications processor 160 mav be arranged in operati C 1 ion to transmit the metadata oenerated by the metadata generation processor 128 via a wireless communications link. The metadata maybe received via the wireless communications link by a remotely located studio which can then acquire the metadata and process this metadata ahead of the audio/video material recorded onto the magnetic tape 126. This ides an advantage in improving the rate at which the audlol,-,.,ldeo production ma provi n be -enerated during the post production phase in which the material is edited. A further advantageous feature provided by embodiments of the present invention is an arrancement in which a picture stamp is crenerated at certain temporal positions within the recorded audio/video signals. A picture stamp is known to those skilled in the art as being a digital representation of an image and in the present example embodiment is generated from the moving video material generated by the camera. The picture stamp may be of lower quality, in order to redLice an amoLint of data required to represent the image from the video signals. Therefore the picture stamp may be compression encoded which may result in a reduction in quality. However a picture stamp provides a visual indication of the content of the audio/video material and therefore is a valuable item of metadata. Thus, the picture stamp may for example be generated at the IN and OUT time codes of a particular take. Thus. the picture stamps may be associated with the metadata generated by the metadata generation processor 128 and stored in the data store 132. The picture stamps are therefore associated with items of metadata such as, for example, the time codes which identify the place on the tape where the image represented by the picture stamp is recorded. The picture stamps may be generated with the "Good Shof' markers. The picture stamps are generated by the metadata generation processor 128 from the audio/video signals received via the communications link 153). The metadata generation processor therefore operates to effect a data sampling and compression encoding process in order to produce the picture stamps. Once the picture stamps have been generated they can be used for several purposes. They may be stored in a data file and communicated separately from the tape 126, or they may be stored on the tape 126 in compressed form in a separate recording channel. Alternatively in preferred embodiments picture stamps may be communicated using the communicatiolls processor 160 to the remotely located studio where a producer may analysis the picture stamps. This provides the producer with an indication as to.'liether the audiolvideo material generated by the camera operator is in accordance with what is required. In a yet further embodiment, the picture stamps are communicated to the PDA 112 and displayed on the PDA screen. This may be effected via the infra-red port 119 or the PDA may be provided with a further wireless link which can communicate with the communications processor 160. In this way a director ha-,.,lncy the hand held PDA 112 is provided with an indication of the current audio/video content generated by the camera. This provides an immediate indication of the artist and aesthetic quality of the audio/video material currently being generated. As already explained the picture stamps are compression encoded so that they may be rapidly communicated to the PDA. A further advantacre of the acquisition unit 152 shown in figure 4 is that the editing process is made more efficient by providing the editor at a remotely located studio with an indication of the content of the audio/video material in advance of receiving that material. This is because the picture stamps are communication with the metadata via a wireless link so that the editor is provided with an indication of the content of the audio/video material in advance of receiving the audio/video material itself. In this way the bandwidth of the audio/video material can remain high with a correspondingly high quality whilst the metadata and picture stamps are at a relatively 3 0 low band width providing relatively low quality information. As a result of the low band width the metadata and picture stamps may be communicated via a wireless link 16 on a considerably lower band width channel. This facilitates rapid communication of the metadata describing content of the audio/video material. The picture stamps generated by the metadata generation processor 128 can be at any point during the recorded audio/video material. In one embodiment the picture stamps are generated at the IN and OUT points of each take. However in other embodiments of the present invention as an activity processor 170 is arranged to detect relative activity within the video material. This is effected by performing a process in which a histogram of the colour components of the images represented by the video signal is compiled and the rate of chan(ye of the colour components determined and chanaes in these colour components used to indicate activity within the image. C W Alternativelv or in addition, motion vectors within the image are used to indicate activity. The activity processor 176 then operates to generate a siornal indicative of the relative activity within the video material. The metadata -eneration processor 128 then operates in response to the activity signal to generate picture stamps such more picture stamps are generated for greater activity within the images represented by, the video signals. jM In an alternative embodiment of the present invention the activity processor is arranaed to receive the audio si-nals via the connecting channel 172 and to recognise speech within the audio signals. The activity processor 170 then generates content data representative of the content of this speech as text. The text data is then communicated to the data processor 12 8 which may be stored in the data store 1 ') 2 or communicated with other metadata via the communications processor 160 in a similar way to that already explained for the picture stamps. Figure 7 provides a schematic representation of a post production process in which the audio/video material is edited to produce an audio/video program. As shown in figure 7 the metadata, which may include picture stamps and/or the speech content information is communicated from the acquisition unit 152 via a separate route represented by a broken line 174, to a metadata database 176. The route 174 may be representative of a wireless communications link formed by for example UMTS, GSM or the like. The database 176 stores metadata to be associated with the audio/video material. The audio/video material in high quality form is recorded onto the tape 126. 17 Thus the tape 126 is transported back to the editincr suite where it is ingested by an inaestion processor 178. The tape identification (tape ID) recorded onto the tape 126 or other metadata providing an indication of the content of the aLidio/video material is used to associate the metadata stored in the data store 176 with the aLidio/",ldeo 5 material on the tape as indicated by the broken line 180. As will be appreciated although the example embodiment of the present invention uses a video tape as the recording medium for storing the audio/video siGnals. it will be understood that alternative recordin(2 niedILIM Such as magnetic disks and random access memories may also be used. Ingestion Processor -1 Figure 7 provides a schematic representation of a post production process in which the audio/video material is edited to produce an audio/video program. As shown in flaure 7 the metadata, which may include picture stamps and/or the speech content information is communicated from the acquisition unit 152 via a separate route represented by a broken line 174, to a metadata database 176. The route 174 may be representative of a wireless communications link formed by for example UN4TS, GSN/1 or the like. The database 176 stores metadata to be associated with the audio/video material. The audio/video material in high quality form is recorded onto the tape 126. Thus the tape 126 is transported back to the editing suite where it is ingested by an ine,estion processor 178. The tape identification (tape ID) recorded onto the tape 126 or other metadata providing an indication of the content of the audio/video material is used to associate the metadata stored in the data store 176 with the audiohadeo material on the tape as indicated by the broken line 180. The ingestion processor 178 is also shown in Figure 7 to be connected to a network formed from a communications channel represented by a connecting line 182. The connecting, line 182 represents a communications channel for communicating data to items of equipment, which form an inter- connected network. To this end, these items of equipment are provided with a network card which may operate in accordance with a known access technique such as Ethemet, RS422 and the like. Furthermore, as will be explained shortly, the communications network 182 may also provide data 18 communications in accordance with the Serial Digital Interface (SDI) or the Serial Digital Transport Interface (SDTI). Also shown connected to the communications network. 182 is the metadata database 176, and an audio/video server 190, into which the audio/video material is inerested. Furthermore, editin. terminals 184, 186 are also connected to the communications channel 182 along with a digital multi-effects processor 188. The communications network 1821 provides access to the aLidio/video material present on tapes. discs or other recording media which are loaded into the ingestion processor 178. The metadata database 176 is arranoed to receive metadata via the route 174 describing the content of the audio/video material recorded on to the recording media c t7 loaded into the ingestion processor 178. As will be appreciated although in the example embodiment a video tape has been used as the recordin(y medium for storinc, the audio/video siornals, it will be understood that alternative recordin. media such as maonetic disks and random access memories may also be used., and that video tape is provided as an illustrative example only. The editing terminals 184, 186 digital multi-effects processor 188 are provided with access to the audio/video material recorded on to the tapes loaded into the inaestion processor 178 and the metadata describing this audio/video material stored in In the metadata database 176 via the communications network 182. The operation of the ingestion processor with 178 in combination with the metadata database 176 will now be described in more detail. Figure 8 provides an example representation of the ingestion processor 178. In Figure 8 the ingestion processor 178 is shown to have a jog shuttle control 200 for nav 1 i_gat ng through the audio/video material recorded on the tapes loaded into video tape recorders/reproducers forming part of the ingestion processor 178. The inclestion processor 178 also includes a display screen 2202 which is arranged to display picture stamps which describe selected parts of the audio/video material. The display screen 202 also acts as a touch screen providing a user with the facility for selecting the audio/video material by touch.The inaestion processor 178 is also arranued to 19 display all types of metadata on the screen 202 which includes script, camera type, lens types and UMIDs. As shown in Fi-ure 9, the increstion processor 178 may include a plurality of video tape recorders/reproducers into which the video tapes onto which the audio/video material is recorded may be loaded in parallel. In the example shown in figure 9, the video tape recorders 204 are connected to the ingestion processor 178 via an RS422 link and an SDI IN/OUT link. The inoestion processor 178 therefore represents a data processor which can access any of the video tape recorders 204 in order to reproduce the audio/video material from the video tapes loaded into the video tape recorders. Furthermore, the ingestion processor 178 is provided with a network card in order to access the communications network 182. As will be appreciated from Fiaure 9 however, the communications channel 182 is comprised of a relatively low band width data communications channel 182' and a hi(yh band width SDI channel 18T' for use in streamin. video data. Correspondingly. therefore the Z:1 1 1011 processor 178 is connected to the video tape recorders 204 via an RS4,221 link in order communicate requests for corresponding items of audio/video material. Having requested these items of audio/video material, the audio/video material is communicated back to the ingestion processor 178 via an SDI communication link 206 for distribution via the SDI network. The requests may for example include the UMID which uniquely identifies the audio/video material item(s). The operation of the ingestion processor in association with the metadata database 176 will now be explained with reference to figure 10. In figure 10 the metadata database 176 is shown to include a number of items of metadata 210 associated with a particular tape ID 212. As shown by the broken line headed arrow 214, the tape ID 212 identifies a particular video tape 216, on which the audio/video material corresponding to the metadata 210 is recorded. In the example embodiment shown in Figure 10, the tape ID 212 is written onto the video tape 218 in the linear time code area 220. However it will be appreciated that in other embodiments. the tape ID could be written in other places such as the vertical blanking portion. The video tape 216 is loaded into one of the video tape recorders 204 forming part of the ingestion processor 178. In operation one of the editing terminals 184 is arranged to access the metadata database 176 via the low band width communications channel 182' the editing terminal 184 is therefore provided with access to the metadata 2 10 describing tile content of tile audio/video material recorded onto the tape 216. The metadata 210 may include such as the copyright owner "BSkyB". the resolution of the picture and the format in which the video material is encoded. the name of the program. which is in this case "Grandstand", and information such as the date, time and audience. Metadata may further include a note of the content of the audio/video material. Each of the items of audio/video material is associated with a UMID, idenifies the audio/video material. As such, the editinz terminal 184 can be Used to identify and select from the metadata 210 the items of aLidio/video material which are required in order to produce a program. This material may be identified by the UMID associated with the material. In order to access the audio/video material to produce the pro-ram, the editing terminal 184 communicates a request for this material via the low band width communications network 182. The request includes the UMID or the UMIDs identifying the audio/video material item(s). In response to the request for audio/video material received from the editinc, terminal 184, the in-estion processor 178 is arranged to reproduce selectively these audio/video material items identified by the UMID or UMIDs from the video tape recorder into which the video cassette 216 is loaded. This audio/video material is then streamed via the SDI network 181' back to the editing terminal 184 to be incorporated into the audio/video production being edited. The streamed audio/video material is ingested into the audio/video server 190 from where the audio/video can be stored and reproduced. Figure 11 provides an alternative arrangement in which the metadata 2 10 is recorded onto a suitable recordinc, medium with the audio/video material. For example the metadata 210 could be recorded in one of the audio tracks of the video tape 218'. Alternatively, the recording medium may be an optical disc or magnetic disc allowing random access and providing a greater capacity for storing data. In this case the metadata 2 10 may be stored with the audio/video material. In a yet further arrangement, some or all of the metadata may be recorded onto C the tape 216. This may be recorded, for example, into the linear recording track of the tape 218. Some metadata related to the metadata recorded onto the tape may be 21 conveyed separately and stored in the database 176. A further step is required in order to ingest the metadata and to this end the ingestion processor 178 is arran-ed to read the metadata from the recording medium 218' and convey the metadata via the communications network 182' to the metadata database 176. Therefore. it will be appreciated that the metadata associated with the audio/video material to be ingested by the ingestion processor 178 may be ingested into the database 176 via a separate medium or via the recordinLY medium on which the audio/video material is also recorded. The metadata associated with the audio/video material may also include picture stamps which represent low quality representations of the images at various points throughout the video material. These may be presented at the touch screen 202 on the ingestion processor 178. Furthermore these picture stamps may be conveyed via the network 182' to the editine, terminals 184, 186 or the effects processor 188 to provide an indication of the content of the audio/video material. The editor is therefore provided with a pictorial representation for the audio/video material and frorn this a selection of an audio/video material items may be made. Furthermore. the picture stamp may stored in the database 176 as part of the metadata 210. The editor may, therefore retreive a selected item for the corresponding picture stamp using the UMID which is associated with the picture stamp. In other embodiments of the invention, the recording medium may not have sufficient capacity to include picture stamps recorded with t he audio/video material. This is likely to be so if the recording medium is a video tape 216. It is particularly appropriate in this case, although not exclusively so, to generate picture stamps before or during ingestion of the audio/video material. Returning to figure 7, in other embodiments, the ingestion processor 178 may include a pre-processing unit. The pre-processing unit embodied within the ingestion processor 178 is arranged to receive the audio/video material recorded onto the recording medium which, in the present example is a video tape 126. To this end. the pre-processing unit may be provided with a separate video recorder/reproducer or may be combined with the video tape recorder/reproducer which forms part of the ingestion processor 178. The pre-processing unit generates picture stamps associated with the audio/video material. As explained above, the picture stamps are used to provide a pictorial representation of the content of the audio/video material items. However in accordance with a further embodiment of the present Invention the pre- processin-a- unit operates to process the audio/video material and generate an activity indicator representative of relative activity within the content of the audio/video material. This may be achieved for example using a processor which operates to generate an activity 1 Z:1 sianal in accordance with a histogram of colour components within the images W t represented by the video signal and to generate the activity signals in accordance with a rate of change of the colour histogram components. The pre-processing, unit then operates to generate a icture stamp at points throughout the video material where 1 p there are periods of activity indicated by the activity signal. This is represented in Figure 12. In Figure 12A picture stamps 224 are shown to be Clenerated along a line 22226 which is representing time within the video signal. As shown in figure 12A the picture stamps 224 are generated at times along the time line 226 where the activity C signal represented as arrows 228 indicates events of activity. This m',-, ht be for example someone walking into and out of the field of view of the camera where there is a great deal of motion represented by the video signal. To this end, the activity signal may also be generated using motion vectors which may be, for example, the motion vectors generated in accordance with the MPEG standard. In other embodiments of the invention, the pre-processor may generate textual - to speech present within the audio signal forming part of information correspondint,:n W the audio/video material items stored on the tape 126. The textual information may be generated instead of the picture stamps or in addition to the picture stamps. In this case, text may be generated for example for the first words of sentences and/or the first activity of a speaker. This is detected from the audio signals present on the tape recording or forming part of the audio/video material. The start points where text is to be generated is represented along the time line 226 as arrows 230. Alternatively the text could be generated at the end of sentences or indeed at other points of interest within the speech. At the detected start of the speech, a speech processor operates to --enerate a 330 1 textual representation of the content of the speech. To this end, the time line 226 shown in Figure 12B is shown to include the text 232 corresponding to the content of the speech at the start of activity periods of speech. 2 3) o 3 The picture stamps and textual representation of the speech activity generated W by the pre-processor Is COMMUnicated via the COII]n]Lincat'olis channel 18-1 to the metadata database 176 and stored. The picture stamps and text are stored in association with the UMID identifying the corresponding items of audio/video n t material from which the picture stamps 224 and the textual information 2321 were generated. This therefore provides a facility to an editor operating one of the editing terminals 184, 186 to analyse the content of the aiLdioi'-'ldeo material before it Is ingested using the ingestion processor 178. As such the video tape 126 is loaded into the ingestion processor 178 and thereafter the audio/video material can be accessed via the network communications channel 182. The editor is therefore provided with an indication, very rapidly, of the content of the audio/video material and so may ingest only those parts of the material, which are relevant to the particular material items required by the editor. This has a particular advantage in improving the efficiency with which the editor may produce an audio/video production. In an alternative embodiment, the pre-processor may be a separate unit and may be provided with a screen on which the picture stamps and/or text information are displayed, and a means such as, for example. a touch screen. to provide a facility for selecting the audio/video material items to be ingested. In a further embodiment of the invention, the ingestion processor 178 generates metadata items such as UMIDs whilst the audio/video material is being ingested. This may required because the acquisition unit in the camera 152 is not arranged to aenerate UMIDs, but does generate a Unique Material Reference Number (MURN). The MURN is generated for each material item, such as a take. The MURN is arranged to be considerably shorter than a UMID and can therefore be accommodated within the linear time code of a video tape, which is more difficult for UMIDs because these are larger. Alternatively the MURN may be written into a TELEFILE (RTM) label of the tape. The MURN provides a unique identification of the audio/video material items present on the tape. The MURINIs may be communicated separately to the database 176 as indicated by the line 174. At the ingestion processor 178, the MURN for the material items are recovered from the tape or the TELEFILE label. For each MURN, the ingestion processor 178 operates to generate a UMID corresponding to the MURN. The UMIDs are then 24 communicated with the MURN to the database 176, and are in-ested into the database in association with the MURNs. which may be already present within the database 176. Camera Metadata The following is provided. by way of example. to illustrate the possible types of metadata generated during the production of a programme. and one possible organisational approach to structurina that metadata. Fi-ure 13 illustrates an example structure for organising metadata. A number of tables each comprising a number of fields containing metadata are provided. The tables may be associated with each other by way of common fields within the respective tables, thereby providing. a relational structure. Also, the structure may comprise a number of instances of the same table to represent multiple instances of the object that the table may represent. The fields may be formatted in a predetermined manner. The size of the fields may also be predetermined. Example sizes include which represents 2 by-tes, Int" which represents 4 bytes and "Double" which represents 8 bytes. Alternatively, the size of the -fields may be defined with reference to the number of characters to be held within the field such as, for example, 8, 10, 16, 32, 128, and 255 characters. Turning to the structure in more detail, there is provided a Programme Table. The Programme Table comprises a number of fields including Programme ID (PID) Title, Working Title, Genre ID, Synopsis, Aspect Ratio, Director ID and Picturestam P. Associated with the Programme Table is a Genre Table, a Kevwords Table. a Scri 1 ipt Table, a People Table, a Schedule Table and a plurality of Media Object Tables. The Genre Table comprises a number of fields including Genre ID, which is associated with the Genre ID field of the Programme Table, and Genre Description. The Keywords Table comprises a number of fields including Programme ID, which is associated with the Programme ID field of the Programme Table, Keyword ID and Keyword. The Script Table comprises a number of fields including Script ID, Script 330 Name, Script Type, Document Format, Path, Creation Date, Original Author, Version, Last Modified, Modified By, PID associated with Programme ID and Notes. The People Table comprises a number of fields including Image. The People Table is associated with a number of Individual Tables and a number of Group Tables. Each Individual Table comprises a number of fields 5 including Image. Each Group Table comprises a number of fields including Image. 0 -- w Each Individual Table is associated with either a Production Staff Table or a Cast Table. The Production Staff Table comprises a number of fields including Production Staff ID. Surname. Firstname, Contract ID, Auent, A-ency ID, Email. Address. Phone Number, Role ID, Notes, Allergies. DOB, National Insurance Number and Bank ID and Picture Stamp. The Cast Table comprises a number of fields including Cast ID, Surname, Firstname. Character Name, Contract ID, Auent. Agency ID, Equity Number, E-mail, w C 1 1 Address, Phone Number. DOB and Bank ID and Picture Stamp. Associated with the Production Staff Table and Cast Table are a Bank Details Table and an Agency Table. The Bank Details Table comprises a number of fields including Bank ID, which is associated with the Bank ID field of the Production Staff Table and the BankID field of the Cast Table, Sort Code, Account Number and Account Name. The Agency Table comprises a number of fields including Agency 1D, which is associated with the Agency ID field of the Production Staff Table and the Agency ID field of the Cast Table, Name, Address, Phone Number, Web Site and E-mail and a Picture Stamp. Also associated with the Production Staff Table is a Role Table. The Role Table comprises a number of fields including Role ID. which is associated with the Role ID field of the Production Staff Table, Function and Notes and a Picture Stamp. Each Group Table is associated with an Organisation Table. The Organisation Table comprises a number fields including Organisation ID, Name, Type, Address, Contract ID, Contact Name, Contact Phone Number and Web Site and a Picture Stamp. Each Media Object Table comprises a number of fields including Media Object 3 0 ID, Name, Description, Picturestamp, PID, Format, schedule ID, script ID and Master ID. Associated with each Media Object Table is the People Table, a Master Table, a Schedule Table, a Storyboard Table, a script table and a number of Shot Tables. 26 The Master Table comprises a number of fields including Master ID, which is associated with the Master ID field of the Media Object Table, Title, Basic UNI1D, EDL ID. Tape ID and Duration and a Picture Stamp. The Schedule Table comprises a number of fields including Schedule ID, Schedule Name, Document Format, Path, Creation Date, Ori-inal Author. Start Date. End Date, Version, Last Modified. Modified BY and Notes and PID which Is associated with the programme ID. The contract table contains: a contract 11) which is associated with the contract ID of the Production staff. cast, and oreanisation tables, commencement date, rate, 'ob J title, expiry date and details. The Storyboard Table comprises a number of fields including Storyboard ID, which is associated with the Storyboard ID of the shot Table, Description, Author. Path and Media ID. Each Shot Table comprises a number of fields including Shot ID, PID, Media ID, Title, Location ID, Notes, Picturestamp, script [D, schedule ID, and description. Associated with each Shot Table is the People Table, the Schedule Table. script table. a Location Table and a number of Take Tables. The Location Table comprises a number of fields including Location ID, which is associated with the Location ID field of the Shot Table, GPS, Address. Description. Name, Cost Per Hour, Directions, Contact Name, Contact Address and Contact Phone Number and a Picture Stamp. Each Take Table comprises a number of fields including Basic UMID, Take Number, Shot ID, Media ID, Timecode IN, Timecode OUT, Sign Metadata, Tape ID, Camera ID, Head Hours, Videographer, IN Stamp, OUT Stamp. Lens ID, AUTOID ingest ID and Notes. Associated with each Take Table is a Tape Table. a Task Table, a Camera Table, a lens table., an ingest table and a number of Take Annotation Tables. The Ingest table contains an Ingest ID which is associated with the Ingest ld in the take table and a description. The Tape Table comprises a number of fields including Tape ID, which is 3M associated with the Tape ID field of the Take Table, PID, Format, Max Duration, First Usage, Max Erasures, Current Erasure, ETA ( estimated time of arrival) and Last Erasure Date and a Picture Stamp. 27 The Task Table comprises a number of fields including Task ID, PID, Media ID, Shot ID, which are associated with the Media ID and Shot ID fields respectively of the Take Table, Title. Task Notes. Distribution List and CC List. Associated with the Task Table is a Planned Shot Table. The Planned Shot Table comprises a number of fields including Planned Shot ID, PID, Media ID, Shot ID, which are associated with the PID, Media ID and Shot ID respectively of the Task Table, Director. Shot Title. Location, Notes, Description. Videographer, Due date, Programme title, media title Aspect Ratio and Format. The Camera Table comprises a number of fields Including Camera ID, which is associated with the Camera ID field of the Take Table. Manufacturer, Model, Format, Serial Number, Head Hours, Lens 1D. Notes, Contact Name, Contact Address and Contact Phone Number and a Picture Stamp. The Lens Table comprises a number of fields including Lens ID, which is associated with the Lens 1D field of the Take Table. Manufacturer. Model, Serial Number, Contact Name, Contact Address and Contact Phone Number and a Picture Stamp. Each Take Annotation Table comprises a number of fields including Take A, nnotation. ID, Basic UMID, Timecode, Shutter Speed, Iris, Zoom, Gamma. Shot Marker ID, Filter Wheel, Detail and Gain. Associated with each Take Annotation Table is a Shot Marker Table. The Shot Marker Table comprises a number of fields includint> Shot Marker ID, which is associated with the Shot Marker ID of the Take Annotation Table, and Description. UMID Description A UMID is described in SMPTE Journal March 2000 which provides details of the UMID standard. Referring to figures 14 and 15, a basic and an extended UMID t, are shown. It comprises a first set of 32 bytes of basic UMID and a second set of 32 bytes of signature metadata. The first set of 32 bytes is the basic UMID. The components are: 28 A 12-byte Universal Label to identify this as a SMPTE UMID. It defines the type of material which the UMID identifies and also defines the methods by which the globally unique Material and locally unique Instance numbers are created. A 1-byte length value to define the length of the remaining part of the UMID. A 3-byte Instance number which is used to distimwish between different instances' of material with the same Material number. A 16-byte Material number which is used to identify each clip. Each Material number is the same for related instances of the same material. The second set of 32 bytes of the signature metadata as a set of packed metadata items used to create an extended UMID. The extended UMID comprises the basic UMID followed immediately by signature metadata which comprises: An 8-byte, time/date code identifying the time and date of the Content Unit creation. Unit creation. codes A 12-byte value which defines the spatial co-ordinates at the time of Content 3 cj groups of 4-byte codes which register the country. organisation and user W W Each component of the basic and extended UMIDs will now be defined in turn. The 12-byte Universal Label The first 12 bytes of the UMID provide identification of the UMID by the registered string value defined in table 1. Byte No. Description Value (hex) 1 Object Identifier 06h Label size 0Ch Designation: ISO 213h 4 Designation: SMPTE 334h Registry: Dictionaries 01h 6 Registry: Metadata Dictionaries 01h 7 Standard: Dictionary Number 01h 8 Version number 01h 9 Class: Identification and location 01h Sub-class: Globally Unique Identifiers 01h 11 Type: UMID (Picture, Audio, Data. Group) 0 1, 02, 03), 04h 12 Type: Number creation method XXh Table 1: Specification of the UMID Universal Label The hex values in table 1 may be changed: the values given are examples. Also the bytes 1-12 may have designations other than those shown by way of example in the table. Referring to the Table 1, in the example shown byte 4 indicates that bytes 5-12 relate to a data format agreed by SMPTE. Byte5 indicates that bytes 6 to 10 relate to "dictionary" data. Byte 6 indicates that such data is "metadata" defined by bytes 7 to 10. Byte 7 indicates the part of the dictionary containing metadata defined by bytes 9 and 10. Byte 10 indicates the version of the dictionary. Byte 9 indicates the class of data and Byte 10 indicates a particular item in the class. In the present embodiment bytes 1 to 10 have fixed pre-assigned values. Byte 11 is variable. Thus referring to Figure 15, and to Table 1 above, it will be noted that the bytes 1 to 10 of the label of the UMID are fixed. Therefore they may be replaced by a 1 byte 'Type' code T representing the bytes 1 to 10. The type code T is followed by a length code L. That is followed by 2 bytes, one of which is byte 11 of Table 1 and the other of which is byte 12 of Table 1, an instance number (3) bytes) and a material number (16 bytes). Optionally the material number may be followed by the signature metadata of the extended UMID and/or other metadata. The UMID type (byte 11) has 4 separate values to identify each of 4 different data types as follows: 0 1 h' = UMID for Picture material 02h' = UMID for Audio material 0')h'= UMID for Data material 04h' = UMID for Group material (i.e. a combination of related essence). The last (12th) byte of the 12 byte label identifies the methods by which the material and instance numbers are created. This byte is divided into top and bottom nibbles where the top nibble defines the method of Material number creation and the bottom nibble defines the method of Instance number creation. Length The Length is a]-byte number with the value '13 h' for basic UMIDs and ")')h' for extended UMIDs. Instance Number The Instance number is a unique 3-byte number which is created by one of several means defined by the standard. It provides the link between a particular instance' of a clip and externally associated metadata. Without this instance number, all material could be linked to any instance of the material and its associated metadata. The creation of a new clip requires the creation of a new Material number together with a zero Instance number. Therefore, a non-zero Instance number indicates that the associated clip is not the source material. An Instance number is pi ily used to identify associated metadata related to any particular instance of a rimarl 1 1 clip. Material Number The 16-byte Material number is a non-zero number created by one of several means identified in the standard. The number is dependent on a 6-byte registered port ID number, time and a random number generator. Sianature Metadata Any component from the signature metadata may be null-filled where no meaningful value can be entered. Any null-filled component is wholly null- filled to clearly indicate a downstream decoder that the component is not valid. The Time-Date Format The date-time format is 8 bytes where the first 4 bytes are a UTC (Universal Time Code) based time component. The time is defined either by an AES-3) 32-bit audio sample clock or SMPTE 12M depending on the essence type. The second 4 bytes define the date based on the Modified Julian Data (MJD) as defined in SMPTE 309M. This counts up to 999,999 days after midnight on the 17th November 1858 and allows dates to the year 4597. The Spatial Co-ordinate Format The spatial co-ordinate value consists of three components defined as follows: Altitude: 8 decimal numbers specifying up to 99,999,999 metres. Longitude: 8 decimal numbers specifying East/West 180.00000 degrees (5 decimal places active).

1 1 j Latitude: 8 decimal numbers specifying, North/South 90.00000 decrees (_5 decimal places active).

The Altitude value is expressed as a value in metres from the centre of the earth thus allowing altitudes below the sea level.

It should be noted that although spatial co-ordinates are static for most clips. this is not true for all cases. Material captured from a moving source such as a camera mounted on a vehicle may show changing spatial coordinate values.

Country Code The Country code is an abbreviated 4-byte alplia-nLinieric string according to the set defined in ISO ') 166. Countries which are not re-alstered can obtain a registered alpha-numeric string from the SMPTE Registration Authority.

Organisation Code The Organisation code is an abbreviated 4-byte alpha-numeric string registered with SMPTE. Oroanisation codes have meanina onl, in relation to their re-istered c _n C Country code so that Orcanisation codes can have the same value in different countries.

User Code The User code is a 4-byte alpha-numeric string assigned locally by each or-anisation and is not globally registered. User codes are defined in relation to their registered Organisation and Country codes so that User codes may have the same value in different organisations and countries.

Freelance Operators Freelance operators may use their country of domicile for the country code and use the Organisation and User codes concatenated to e.g. an 8 byte code which can be registered with SMPTE. These freelance codes may start with the '-' symbol ( ISO 8859 character number 7Eh) and followed by a registered 7 digit alphanumeric string, As will be appreciated by those skilled in the art various modifications may be made to the embodiments herein before described without departing from the scope of the present invention. For example whilst embodiments have been described with recording audio/video onto magnetic tape, it will be appreciated that other recording media are possible.

32 CLAIMS An audio/video reproducing apparatus connectable to a communications network for selectively reproducino items of aLidio/video material from a recordino medium in response to a request received via said communications network.

2.

comprising t> An audio/video reproducing apparatus as claimed in Claim 1, - a control processor which is arranged in use to receive data representing said request for said audio/video material item via said communications network, and - a reproducing processor coupled to the control processor and arranged in W response to signals identifying said audio/video material items from said control processor to reproduce said audio/video material items, which are communicated via said communications network.

1

3. An audio/video reproducing apparatus as claimed in Claim 1 or 2, - a first network interface connectable to a first communications network for receiving said data representing said requests for said audio/video material items, and - a second network interface connectable to a second communications network for communicatin. said items of audio/video material.

0

4. An audio/video reproducing apparatus as claimed in any preceding Claim, wherein said first network interface is arranged to operate in accordance with a data communications network standard such as Ethemet, RS 322 or RS 422 or the like.

5. An audio/video reproducing apparatus as claimed in any of Claims 3 or 4, wherein said second network interface is arranged to operates in accordance with Z:1 the Serial Dialtal Interface (SDI) or the Serial Digital Transport Interface (SDTI).

C1 3 3

6. An audio/video reproducing apparatus as claimed in any precedina W Claim, wherein said data representing requests for audio/video material Items includes metadata indicative of the audio/video material items.

7. An audio/video reproducing, apparatus as claimed in any preceding Claim, wherein said metadata is at least one of UMID, tape 1D and time codes. and a Unique Material Reference Number, identifying the material items.

8. An audio/video reproducing apparatus as claimed in any of Claims 2 to 7, wherein said reproducing apparatus comprises a plurality of audio/video recording/reproducing apparatus each of which is coupled to said control processor via a local data bus.

9. An audio/video reproducing apparatus as claimed in Claim 8. wherein said local bus includes a control communications channel for cominunicatino control data to and/or from said control processor, and video data communications channel for communicating said items of audio/video material from said plurality of audio/video recording/reproducing apparatus to said communications network.

10. An audio/video reproducing apparatus as claimed in any preceding Claim. comprising a display device which is arranged in operation to display images representative of said audio/video material items present on said recording medium.

11. An audio/video reproducing apparatus as claimed in Claim 10, wherein said display device is a touch screen coupled to said control processor, and arrange in use to receive touch commands from a user for selectine, said items of audio/video material.

12. An audio/video reproducing apparatus as claimed in any of Claims 2 to 11, wherein said control processor is arranged to generate representing a material Z 3'4 identifier for each of said audio/video material items. from data recorded with said audio/video material items on said recording medium.

1 An audio/video reproducing apparatus as claimed in Claim 12, wherein said material identifier is a UMID or the like.

14. A method of reproducing items of iLidio,,'vldeo material from a recording medium, comprising the steps of - communicating an identification of a selected ltern of audio/video material 'ia a communications network, - receiving said identification at an audio/video reproducing apparatus in which s'd recordina medium is loaded, and al CY selectively reproducing said item of audio/video material from said recording medium in accordance with said identification.

15. A computer program providing computer executable instructions, which when loaded onto a data processor configures the data processor to operate as an audio/video reproducing apparatus as claimed in any of Claims 1 to 13.

16. A computer program providing computer executable instructions, 1P t which when loaded on to a data processor causes the data processor to perform the method according to Claim 14.

17. A computer program product having a computer readable medium recorded thereon information signals representative of the computer program claimed in any of Claims 15 or 16.

18. An audio/video reproducing apparatus as herein before described with reference to the accompanying drawings.

19. A method of reproducing items of audio/video material as herein before described with reference to the accompanying drawings.