GB2343049A

GB2343049A - Digital audio or video playback arrangement and method of operation thereof

Info

Publication number: GB2343049A
Application number: GB9823050A
Authority: GB
Inventors: Martin John Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-10-21
Filing date: 1998-10-21
Publication date: 2000-04-26
Anticipated expiration: 2018-10-21
Also published as: GB0302439D0; GB2381371A; GB2381371B; GB9823050D0; GB2343049B

Abstract

A digital audio or video playback arrangement for a studio broadcast system is arranged to process a portion of a digital audio or video input stream (100), at a rate faster than real time, additionally to write into mass storage (20) said portion of said input stream whilst reading from mass storage, into eg one or more RAM buffers (401, 402) a previous portion of the digital audio or video input stream or a different digital audio or video input stream. The arrangement enables tracks (F and G) from CDs to be played from hard disk almost instantly with the flexibility and control provided by hard disk systems, but without the associated disadvantages of having to store all tracks in advance. One or more real time output streams (404, 405) can be generated simultaneously from the same CD. Furthermore, the arrangement includes at least one physical control panel and at least one virtual control panel represented on a touch-screen display.

Description

DiQital Audio/Video Playback Arrangement and Method of Operation thereof The present invention relates to a digital audio and/or video playback arrangement, particularly but not exclusively for broadcasting, and to a method of operation thereof. The invention is applicable both to audio and to video playback.

Ever since the introduction of the CD, digital recording has made a huge impact on the broadcast radio market. Few stations still play vinyl records and the NAB jingle cartridge has been replaced by digital floppy disk players and cheaper, maintenance free PC hard disk systems. Computer based music scheduling has become the norm at most stations and hard disk systems used for playing music have the avantages over CD's of instant access and the potential for automation.

In theory these developments should make systems easier to use, enabling audio material to be accessed quickly and making the disc jockey's life easier by increased automation.

In reality the situation is somewhat different.

The chief reason for this is that as components have evolved and replaced existing equipment the result is more computer keyboards, more screens to look at and more opportunities for mistakes to be made. The disc jockey can end up spending more time sorting out the sheer mechanics of the show than working on the show's content.

In the US, hard disk systems are becoming common for playing music but as stations are more specialised and play fewer tracks the disk storage requirements are not a problem.

In the UK market, stations tend to play a greater variety of music so the sheer amount of disk storage required to hold a radio station's CD collection makes the concept unworkable.

Throughout this transformation into the digital age, the mixing desk has remained largelyunchanged.

In particular, in one current CD-based studio, CDs are played from conventional CD players of which there are typically three. This allows one CD to play on-air, the next track to be standing by and a third player as a spare. Commercials and jingles are commonly played from a PC based hard disk system. This gives the disc jockey quick access to material and also allows logs of which items were played to be generated automatically. There are also various outside feeds such as Travel News, Newsroom and other studios in the station.

All the above sources are fed through a conventional analogue audio mixer for balancing of levels. This also allows remote start of the CD players and the ability to hear a source on prefade-i. e. to hear a mixer channel without it being broadcast on air.

The above system has the advantages of ease of use and being tried and trusted.

However it is relatively expensive, has limited automation potential and the disc jockey has to locate and load all CD's to play.

Conversely, in a hard disk-based studio, all music tracks are played from a PC based hard disk system, not directly from CD. Commercials and jingles are also played from the same hard disk system. There are various outside feeds such as Travel News, Newsroom and other studios in the station.

All the above sources are fed through a conventional analogue audio mixer for balancing of levels. This allows remote start of the hard disk players and the ability to hear a source on prefade though this can be limited as the hard disk system commonly only has two or three stereo outputs.

Such a hard disk system has the advantages that music tracks are instantly available, tracks from the same CD can be played back to back, automation is easier to implement and it can be fully integrated with a scheduling system.

It has the disadvantages that all music has to be loaded into the system in advance, it can be expensive, since more storage will need to be added as the station's library grows and it is inefficient because 40% of the tracks may only get played once every six months. Furthermore because such a system is inherently computer and mouse based, it can be less satisfying to use and the disk jockey can feel out of control.

The complexity of a television studio is even greater, placing even greater demands on the presenters and technicians.

An object of the present invention is to overcome or alleviate at least some of the above disadvantages.

In one aspect the invention provides a digital audio or video playback arrangement arranged to process a digital audio or video input stream and to write at least a portion of the processed digital input stream into mass storage at a rate faster than real. time, to read from mass storage at a rate faster than real time a previously written portion of the same or a different digital audio or video input stream and to read out via buffer means in real time said previously written portion.

In a related aspect the invention provides a digital audio or video playback arrangement arranged to write to mass storage, at a rate faster than real-time, a digital audio or video input stream from a removable data carrier, and simultaneously to output at least one audio or video output stream, said output stream being derived from the same or a different digital audio or video input stream previously written to the mass storage.

Preferably the arrangement is arranged to write successive portions of the digital audio or video input stream. to separate files, to read out said files from mass storage and to combine them into a real-time output stream.

In this manner a small portion (say the equivalent of 10 seconds to one minute in real time) of the audio or video can be recorded very quickly (in say half a second to 3 seconds if written at 20x) and then played back. ie in a time comparable to the delay before playback from a conventional CD player.

Preferably the files are processed individually before being combined into the output stream.

By processing (eg to detect the maximum level or to detect faults such as a scratch in a CD from which the input stream is read) and re-recording (at least temporarily) an audio or video input stream at a rate faster than it is played back, the ease of use of a CD-based arrangement can be combined with much of the versatility of a hard-disk based arrangement.

In particular, a disc jockey can listen to or view the audio or video before it is played back (e. g. by being broadcast) and can select different audio or video input streams from e. g. CD players in the same manner as in a CD-based studio arrangement.

Furthermore it has been found that recordings can be written into mass storage from a Cl layer at a rate faster than real time (e. g. 20x real time) and subsequently p ! ayed back successfully in rca ! time, even if the CD or other recording medium is damaged (e. g. scratched) and thereby rendered unplayable from some conventional players.

Preferahly the arrangement is arranged to analyse for faults in the audio or video portion being written into mass storage and to re-write any faulty portion whilst lowering the input stream rate.

Preferably the arrangement is arranged to re-write any faulty portion using an input stream rate slower than first-mentioned rate (but preferably still faster than realtime).

Preferably the arrangement is arranged to detect successive identical data stream samples indicative of a defect in a data carrier (eg a CD) from which the audio or video input stream is read.

In one embodiment CD tracks which are required for immediate playback are downloaded to several temporary files at a rate faster than real-time. Each file will contain an exact length of audio (for example 30 seconds). As each audio file is written to disk, the waveform is analyse for two things- i) moments when the stream has a run of identical samples (which indicates a scratched CD) ii) peak audio level within that section.

If the waveform analysis suggests a scratch is detected then that 30 second portion is downloaded to disk again at a lower rotational speed of the CD. Once the first 30 second portion has been successfully analysed and written to disk (which should take around 3 seconds or less) the first few seconds of that portion are written to the RAM buffer and can be played on Pre-Fade Listen (PFL) or on-air. The remaining 30 second portions are downloaded in an identical fashion as a background process. The numerous files get sent to the RAM buffer in bursts where they are reassembled into a continuous data stream, which plays out in real time.

The main advantage of downloading to separate temporary files is that playback can commence once the first file (i. e. the first 30 seconds of CD track) has been fully written to disk, thus giving only a few seconds'delay from inserting the CD to starting playback. The other advantage is that if there is a scratch on the CD at a given point (eg at time 4.05) then only the affected subsequent 30 second portion (eg between 4.00 and 4.30) has to be downloaded again rather than the whole track. This is especially important if that track has started playback on-air before having been fully downloaded.

In practice, CDs are sometimes only loaded in the player at the last possible moment before being played to air. The disc jockey cannot wait for the whole track to download-even ten seconds in a live situation is too long. This disadvantage is overcome by the above embodiment of the invention.

In the preferred embodiment the peak audio levels for each section are stored in RAM and when all sections have downloaded, the section with the highest peak audio level is used to decide whether extra gain should be introduced upon playback.

If playback on-air (as opposed to PFL) has commenced before all the sections have been downloaded then default gain will be used.

Preferably the input stream rate of the subsequent portion of the digital audio or video input stream or of the different digital audio or video input stream is faster than real time, e. g. 4x or greater. For example if the input stream rate is 20x, a complete song (typically about 4 minutes in real time) can be completely recorded in about 10 to 15 seconds with only a few seconds'delay before playback can begin.

It is not essential for the audio or video input stream being written during playback of the audio or video input stream previously written into memory to be the same as (ie from the same source as) the previously written audio or video input stream; the time gained by the high-speed writing can be used in various ways under manual control (eg of the disc jockey) or under the control of an automatic scheduling sequence.

Preferably the arrangement includes a display representing one or more virtual players on screen. When the audio file representing the track is ejected from the virtual player, the system preferably checks whether to keep or delete the track. If it is to be kept, then the separate temporary files are saved to disk as a single audio file, which also contains the peak audio level data.

The invention also provides a method of operating a digital audio or video playback arrangement, the method comprising the steps of processing a digital audio or video input stream and writing at least a portion of the processed digital input stream into mass storage at a rate faster than real time, reading from mass storage at a rate faster than real time a previously written portion of the same or a different digital audio or video input stream and reading out via buffer means in real time said previously written portion.

In a related aspect the invention provides a method of operating a digital audio or video playback arrangement, the method comprising the steps of writing to mass storage, at a rate faster than real-time, a digital audio or video input stream from a removable data carrier, and simultaneously outputting at least one audio or video output stream, wherein said output stream is derived from the same or a different digital audio or video input stream previously written to the mass storage.

In one embodiment in accordance with this aspect of the invention, tracks from a data carrier (eg a CD) which have previously been edited by the station can again be loaded from the original data carrier then played out with the desired edits reproduced from a data file storing edit information and produced during editing.

This file (herein called an EDL-Edit Decision List in the description of the preferred embodiment) typically functions as a template to reproduce all the edits at a future date, so when the CD track is again downloaded it is automatically modified according to the instructions set out in the EDL.

Preferably successive portions of the digital audio or video input stream are written to separate files, and said files are read out from mass storage and combined them into a real-time output stream.

Preferably the files are processed individually before being combined into said output stream.

Preferably the arrangement is arranged to analyse for faults in the audio or video portion being written into mass storage and to re-write any faulty portion whilst lowering the input stream rate.

Preferably any faulty portion is re-written at an input stream rate slower than said first-mentioned rate but still faster than real time.

Preferably there are detected any successive identical waveform samples indicative of a defect in a data carrier (e. g. a CD) from which the audio or video input stream is read.

It is envisaged that the invention will be applicable particularly to broadcast arrangements where ease of use and efficient use of time are of the essence, and not only to radio and television broadcast arrangements but also cable and satellite broadcast arrangements, particularly in view of their inherendy digital nature.

In accordance with another aspect of the invention, there is provided a digital audio or video playback arrangement which is arranged to write into mass storage, at a rate faster than real time, two or more tracks of a digital audio or video input stream read from a recording medium and to generate at least one real-time output stream in which the order of the tracks is different from the order of the tracks read from the recording medium or to generate two or more real-time output streams in which different tracks are playing simultaneously.

In this aspect the invention also provides method of operating a digital audio or video playback arrangement wherein two or more tracks of a digital audio or video input stream are read from a recording medium and written into mass storage at a rate faster than real time, and at least one real-time output stream is generated in which the order of the tracks is different from the order of the tracks read from the recording medium or two or more real-time output streams are generated in which different tracks are playing simultaneously.

In another aspect the invention provides a digital audio or video playback arrangement comprising at least one physical control panel which is aligned with and controls a virtual audio or video player represented on a display.

This has the advantage that the flexibility of a hard disk based system is retained in conjunction with the ease of use of a conventional hardware-based system.

Preferably successive portions of the digital audio or video input stream are written to separate files, said files are read out from mass storage and are combined into a real-time output stream.

Further preferred features of the invention are defined in the dependent claims.

A preferred embodiment of the invention is described below by way of example only with reference to Figures 1 to 10 of the accompanying drawings, wherein: Figure 1 is a schematic block diagram of a digital audio broadcasting arrangement in accordance with the invention; Figure 2 is a schematic block diagram of the processing, memory and storage arrangment of the arrangent of Figure 1 ; Figure 3A is a timing diagram showing the reading and writing of digital audio streams in the arrangement of Figure 2; Figure 3B is a timing diagram showing a variant of the reading and writing of the above digital streams in the arrangement of Figure 2 in response to the detection of a fault; Figure 4 is a view of the left hand touchscreen monitor and corresponding left hand portion of the mixer control surface of the arrangement of Figure 1; Figure 5 is a view of the right hand touchscreen monitor and corresponding right hand portion of the mixer control surface of the arrangement of Figure 1; Figure 6 is a screen shot of the left hand touchscreen monitor in"NORMAL" (default) mode; Figure 7 is a screen shot of the left hand touchscreen monitor in"LIBRARY"mode ; Figure 8 is a screen shot of the right hand touchscreen monitor in"STACKS"mode; Figure 9 is a screen shot of the right hand touchscreen monitor in"RECORD"mode, and Figure 10 is a screen shot of the left hand touchscreen monitor in"MASTER PFL" mode.

Referring to Figure 1, the arrangement comprises a personal computer (e. g. a Pentium II) (1) running a multi-tasking operating system such as Windows 98 or Windows NT with a keyboard (not shown), a trackball (not shown) and two touchscreen colour monitors 6 and 7 which provide a graphical user interface.

The computer has an audio hard disk recording card (not shown) connected to an external audio interface module 4 with multiple inputs and outputs. The inputs can include a news feed, a traffic information feed, and a telephone feed for example and can include both digital and analogue sources. In order to accommodate the latter, the interface module 4 is provided with an analogue to digital converter (not shown).

The computer 1 is provided with fast hard disk storage 20 for audio (either local disks or a networked storage), a fast (e. g. 20x) CD-ROM drive 3 and a network connection to other PCs in the building (not shown) for exchanging music scheduling and log information.

A digital mixing module 5 is coupled to the computer via a data link. It should be noted that no audio signal passes through the mixing module-it is used purely as a remote control surface. Additionally the computer 1 is coupled to a master digital control panel 8 located at the right hand side of mixer control panel 5. Control panel 8 is provided with a MASTER PREFADE button 90, and RECORD, LIBRARY and STACKS mode selection buttons 80, 81 and 82 and a group of four navigation buttons N for navigating honzontaHy and vertically through the tracks disp ! ayed on screen. The operation of control panel 8 will subsequently be described in detail.

Before describing the user interface aspect of the arrangement in more detail, the interna operation of the PC system I with its associated mass storage will be described with reference to Figures 2,3A and 3B.

As shown in Figure 2, the PC 1 is provided with a high capacity hard disk 20 and is arranged to read in a digital audio stream from CD-ROM drive 3 (Figure 1) at nX real time e. g. 15X real time as indicated by input stream 100, under the control of microprocessor 500 (which is suitably a Pentium II processor). The audio stream is fed into RAM 403 and checked for faults (e. g. a run of identical sample indicative of a-scratch in the CD) and for maximum level by a suitable program executed in processor 500. After checkino it is written sequentially to separate files F1, F2, F3, F4, F5, F6 (constituting one track F of the CD) and as a further sequence of files G 1.... G6 (constitutino another track G of the CD) only the first file G 1 having been written to disk at the stage shown in in Figure 2, each file comprising 30 seconds of audio. If a fault is detected in the audio stream before that particular 30 second portion of the audio stream has been fully written to disk, then the file is deleted and the process repeated at a lower speed (e. g. 4X) until all the separate files have been successfully written.

Once the first file Fi has been fully written to disk (i. e. has also been checked) then it will be possible to commence playback whilst the rest of the input stream from CD is still being processed and written to disk. Each separate stream of audio (whether for on-air playback or PFL) will require its own output buffer RAM memory region 401, 402, which will store approximately 5 seconds of audio. The output buffer memory regions 401, 402 may be separate memory modules (possibly located on the audio card) or may be discrete regions of a common memory e. g. the RAM associated with processor 500. to output buffer memory region 401 could already be playing back a different track which previously existed on disk. Small portions of the separate audio files Fl, F2, F3... are read at nX real time eg 15X or 20X real time to output buffer memory region 401 where they are reassembled into a continuous data stream 404 (TRACK F) which is played out in real time to external audio interface 4.

Similarly small portions of separate audio files G 1, G2, G3.... G6 which have been written to disk from another track G of the CD are read at nX real time to output buffer memory region 402 where they are reassembled into another data strream 405 which is similarly played out in real time as track G. The maximum level data (in respect of each track F and G) determined from the above processing is also fed to the audio card (not shown) of the PC and used to control the modulation levels of the respective digital signals in order to ensure optimum transmission.

Referring to Figure 3A, which tows th readrc and writirg operations of the CD (which generates the input stream 100), the hard disc 20, the RAM buffers 401 and 402 and the microprocessor RAM 403 at successive intervals between times t0 and tl8, the above process will be described in more detail. Where a reading or writing process is faster than real time (n times real time) this is indicated by (nX). All the other reading and writina processes not qualifie by" (nX)" are in real time.

As noted above, the CD is read at a rate of nX real time, eg 15 times faster than real time and this digital audio stream is read at the same rate to RAM 403 during period t0-tl. At the same time, RAM 403 is read and the resulting stream is written to hard disc 20 (after checking for data integrity and level) as an audio file F1 containing e. g.

30 seconds of audio.

In the second period tl-t2 an initial portion of audio file Fl is read from hard disk 20 to RAM buffer 401 where the resulting portions of the file reassembled and read out as real time audio stream 404. Thus playback of track F begins at tl, which may be only a few seconds after reading the input stream 100 from the CD. It should be noted that any combination of audio files (including files previously written) can be read from disk 20, distributed between the RAM buffers 401 and 402 and reassembled in any order under microprocessor control, so that, for example, tracks from the CD can be played simultaneously as separate output streams and can be played in a different order from that of the CD. During this period a further audio file F2 is written to disk 20 whilst Fl is being read. There may be a rapid alternation between reading and writing to disk during this period or the reading and writing can be truly simultaneous by virtue of the multi-tasking capability of the operating system.

In the third period (t2-t3) a similar process occurs, the only difference being that a new file F3 is written to disk whilst the RAM buffer 401 still has enough data left to continue reading out the initial portion of F1 in real-time. It is assumed for the sake of simplicity that there are only six 30 second files Fl to F6, which correspond to track F on the CD.

In the fourth period (t3-t4) the next portion of audio file F1 is read from hard disk 20 to RAM buffer 401. During this period a further audio file F4 is written to disk 20.

In the fifth period (t4-tS) a new file F5 is written to disk whilst the RAM buffer 401 still has enough data left to continue reading out the subsequent portion of F1 in realtime.

In the sixth period (t5-t6) the next portion of audio file Fl is read from hard disk 20 to RAM buffer 401 as real-time playback continues at output stream 404. During this period the final audio file F6 is also written to disk 20.

In the seventh period (tS-t7) all the separate files have been written to disk and realtime playback will continue via RAM buffer 40i.

In the eighth period (t7-t8) another track from a CD is written to disk as file G1.

Playback of file Fl continues as the next portion is read from disk and written to RAM buffer 401.

In the ninth period (t8-t9) the next portion of the CD track is written to disk as file G2. Playback of file Fl continues via RAM buffer 401 and the initial portion of file G 1 is written to RAM buffer 402 where it can be output in real-time. This playback of track C begins at time t9.

This process continues for the next few periods until tl3-tl4 when all files G1-G6 have been written to hard disk 20. It should be noted that due to the high speed transfer of data (assuming a transfer speed of 15 times real-time and a disk file duration of 30 seconds) it is not until period t15 - t16 that the initial portion of file F2 is read from disk and written to RAM buffer 401.

The sequence shown in Figure 3B is similar to that of Figure 3A except that it is assumed a scratch (correspond to a sequence of identical samples) is detected in the CD durit writing the F2 to hard disk 20 during the second period t1 - t2.

Accordingly this file is re-written at a lower speed (n'X) real time (#.g. 5X) in the third period t2 to t3. it should be noted that playback of file Fi had already commenced in the period tl-t2.

IL can be seen from comparing Figure 3A and 3B that as the defect was discovered in the second portion of the input stream (i.e. the file F2) playback of file F1 has not been affected at all and can still playback in real-time via RAM buffer 401. As mentioned before, it is not until period t15 - t16 that file F2 is read from disk and written to the RAM buffer, so there is sufficient time to download file F2 without defects as shown in Figure 3B.

The main advantage of downloading to separate temporary files F1, F2, F3... is that playback can commence once the first file (i.e. 30 second portion) has been fully written to disk thus giving only a few seconds' delay (eg about 1.5 seconds in this case) from inserting the CD to starting playback. The other advantage is if there is a scratch on the CD at 4.05 (for example) then only the affected 30 second portion (between 4.00 and 4.30) has to be downloaded again rather than the whole track. This is especially important if that track has started playback on-air before having been fully downloaded.

The peak audio levels for each file F1, F2, F3... are stored in RAM and when all sections have downloaded the section with the highest peak audio level is used to decide whether extra gain should be introduced upon playback. If playback on-air (as opposed to PFL) has commenced before all the sections have been downloaded then default gain will be used.

The concept of downloading all CDs to hard disk introduces another preferred innovative feature that conventional CD players will never be able to match. Because the desk's routing is effectively controlled by software, it will be possible to listen to the end of any track using the PFL (Pre Fade Listen) facility (provided by one of the buttons B shown in Figure 4) while the same track is currently playing out to air. The same will be true for commercial break stacks and jingles.

Downloading to disk whilst checking for sequences of identical samples as described above has another advantage: CDs will never skip on air. Testing has shown that even downloading at 8x real time has resulted in perfect rendition of tracks which are otherwise unplayable on some conventional CD players.

Because the system checks the peak level of the selected track, additional gain can be automatically added for quiet tracks upon playback. If the track starts to play onair before totally downloaded (and therefore before it is fully checked for peak level) then the default gain will be used but the peak level value will still be written to the audio file generated and will be used if the track is played in the future.

Several radio stations choose to edit tracks before broadcasting (either for removing bad language or to fit in with the station's style). When the track is first edited a data file is usually generated called an EDL (Edit Decision List). In accordance with a preferred feature of the invention the new edited version is automatically recreated when the original CD track is reloaded by using the EDL data. This effectively means that tracks which require editing before playback can be treated in the same way on the system as non-edited tracks.

In accordance with a further preferred feature, when a track is loaded in from CD, the present arrangement will automatically look up the programme schedule for the next four days (or other specified time) and check whether any track (s) from the same CD are scheduled. If they are to be played and currently have a MISSING status then they are also loaded to disk immediately after the original track has been downloaded.

For example, the breakfast show disc jockey scrolls down the schedule and sees that the next track to be played is Track 5. The status column displays MISSING so he puts the requested CD into the CD-ROM drive. Track 5 immediately starts to download to hard disk 20.

Meanwhile the program loaded in computer 1 finds that in three days time the late evening show is scheduled to play track 8 from the same CD, the status on this track ; also MISSING. So, once Track 5 has finished downloading, the arrangement automatically downloads Track 8 for future use. Because this process is so quick (around 15 seconds), the breakfast show dise jockey will probably be unaware that the extra download ever happened.

A couple of days pass, and the late show dise jockey is doing his show (maybe in a different studio, maybe even on the station's alternative output). He scrolls down the schedule, sees that Track 8 is scheduled. The status of the track is AVAILABLE. He hits the LOAD button on DISC 2 and instantly plays the track to air that the breakfast show dise jockey unwittingly loaded in for him.

Even though each extra track for future use will only take about 10-15 seconds to download there is of course the option to cancel the extra loading if the on-air disc jockey needs to get on with loading his own tracks. In this case the future event will sti ! ! show MISSING on the status line and will have to be loaded from CD during the show.

The preferred arrangement also features automatic track storage management. Once tv...,..i'...11...1.rl.., a track has been played out on-air, the automatic track storage facility will check the programme schedule for the following period e.g. four days and see whether that track is played again (even if it appears on the programme schedule for the station's alternative output). If it is to be played again within this specified time then the track is kept on the system and will be displayed as AVAILABLE on display arca D when the dise jockey comes to play it in the future. If it is not played again then the track is deleted from the hard disk automatically. So for instance, if it is played again in two weeks time the track will have to be loaded from CD. It makes little sense to have tracks sitting around on the system and using disk space if they are rarely played.

Playlisted tracks are the exception to this ; they will remain on the system until manually deleted by the system administrator.

This automatic and unique way of limiting the number of music tracks that need to be stored on the hard disk at any one time is a major advantage of the perferred embodiment. It essentially gives the station all the flexibility of a hard disk based system without the disadvantages of a member of staff required to load all the tracks onto the system and the ever increasing amount of disk storage required to hold the tracks.

It should he pointed out that the preferred embodiment allows tracks to be loaded in advance without loading into a virtual player. This can either he done on the same system or on a separate PC, which has a fast CDROM drive and is networked to the main hard disk storage. If tracks are loaded in advance in this way ; each track will be directly downloaded as one complete file rather than numerous temporary files.

Differently scheduled tracks from the same CD would be loaded at the same time.

Referrino now to Figures 4 and 5, the mixing module 5 is typically in the form of two mixing panels 51, and 5R (Figures 4 and 5 respectively) mounted in a desk (not shown) with space for scripts etc in the middle. The panels are e angled towards the disc jockey and are divided horizontally into channels Cl to CT and C8 to C 13 respectively as described above. Each channel has a standard fader F that is also motorise and also has illuminated pushbuttons R for LOAD, AUTO, CUE, PFL (Pre-Fade T isten) and START.

The channels are modular so different requirements can easily be accommodated.

The illuminated pushbuttons will differ according to the type of channel.

The channels (71 to (713 (Figures 4 and 5) are (from left to right) : C1 EFFECTS (internal effects output from audio card) C2 DISC 1 C3 DISC 2 C4 DISC 3 C5 MIC 3 C6 MIC2 C7 MIC 1 There is then a script space between two panels, followed by: C8 QUICKFIRE C9 AUX 1 C10 AUX 2 C11 CART 1 C 12 CART 2 C13 CART 3 The function of a mixer channel C2, C3 or C4 (Figure 4) or C11, C12 or C13 (Figure 5) will now be described. The CD track or cart can be started by pressing the START button B which will illuminate green when in playback mode. If the CUE button B is pressed then the track will stop playback and reset to the chosen start point (which is by default the start of audio but can be change) the CUE button will illuminate amber when reset and ready.

If a channel has its AUTO button B lit then its associated player will automatically start after the previous event finishes. Players will automatically start in order from left to right but if any carts have AUTO activated then they will take priority over discs.

For example if Disc 1 is playing and both Disc 2, Cart 1 and Cart 2 are loaded and have their AUTO buttons lit, when Disc 1 finishes, the players will automatically start in this order Cart 1, Cart 2 followed by Disc 2.

The QUICKFTRE fader will be described subsequently.

Behind mixing panel 5L is touchscreen colour monitor 6, which has three virtual CD players VP1, VP2 and VP3 at the bottom of its screen aligned with channels C2, C3 and C4 respectively. Similarly touchscreen monitor 7 has virtual cartridge players VP4, VP5 and VP6 which correspond to and are situated directly above the CART 1- 3 channels (C11, C12 and C13) on the right hand mixing panel SR. Uniquely, the disc jockey can see at a glance which player is operating and the state of its associated mixer channel.

Each on screen virtual player has a current status display L at the bottom (which shows READY/PLAY/PAUSE etc) and above that is a visual display D1 of the current position (time) within the audio file. Above display D1 is a representation V I of the disc being played by each virtual player with audio file details displayed such as track title and artist. Display D1 displays either an E (for tracks that end suddenly) or an F (for tracks that fade out). Intro countdowns are displayed with tenths of a second displayed after the"seconds"display. All the above timing information is either included as part of the music schedule data or is retrieved from the station's CD library database.

As shown in Figure 4 and more clearly in Figure 6, above the virtual disk players on the left hand screen 6 are six"soft"buttons SB I to SB6 (i. e. touch-sensitive regions of the screen) arranged horizontally across the screen. These allow control of the software and their functions will change depending on what mode the screen is in.

The following description relates to the default or"NORMAL"mode.

Above the soft buttons is the main programme schedule S (Figures 4 and 6) which can be scrolled up and down with the trackball (not shown). This central area is also where scripts which are to be read by the disc jockey will appear when required. The programme schedule area S contains information for each programme event such as source, status and title.

The status displayed for each event will be one of the following: i) ON AIR-the event (track/cart/commercial etc) is currently being broadcast on air. ii) READY-the relevant event has been loaded into a player and is ready to be played on-air. iii) AVAILABLE-the event already exists on the hard disk/s for loading into a player. iv) MISSING-only applies to tracks downloaded from CDs-the event is NOT currently on the hard disk/s and will need to be downloaded from CD.

If the LOAD NEXT soft button SB1 is pressed then the next AVAILABLE event, which is not either on-air or ready, is automatically loaded into the next available player of the correct type (whether disc or cart event). The event's status will change to READY and the disc/cart can be previewed on PFL (Pre-Fade Listen) or played out on air immediately. If the LOAD NEXT soft button SB 1 is pressed and the next event which is not either on-air or ready is shown as MISSING then the drawer of the CD-ROM player 3 will automatically open so the correct CD (as identified under the SOURCE column) can be inserted.

The system will check that the correct CD has been inserted (by reading the CD's serial number and/or index information) and will automatically start downloading the correct track in the manner described above with reference to Figures 2,3 and 3A. Within a few seconds the channel's CUE button will illuminate, the artist/title will be displayed on screen, relevant timings will be displayed (on Dl and D2) and when the downloading (including re-recording of any files with faults) has been completed satisfactorily the event's status will change to READY on both the programme schedule and the player's status display L.

The fact that the track title will be displayed on the player above the relevant channel greatly reduces the chance of the disk jockey starting the wrong player by accident.

If the disc jockey wants to play a track not on the programme schedule then he presses the LOAD button B (Figure 4) on the desired player and can choose to either insert a CD for downloading or select from the library of tracks already held on hard disk. Tracks/carts are ejected from the virtual players by holding the CUE and LOAD buttons B (Figure 4) at the same time.

Above the programme schedule area S is displayed the current time in written form (e. g. twenty-five minutes past four) and also digital form with seconds. There is also a countdown in minutes and seconds until the next top of the hour (eg minutes and seconds remaining until 4.00pm exactly).

Referring to Figures 5 and 8, the right hand portion 5R of the control panel and associated touch screen monitor 7, which are used for playing virtual cartridges, will now be described. Above the virtual cart players VP4, VP5 and VP6 (which function identically to the virtual disc players VP1 to VP3 apart from not displaying whether a track ends or fades) on the right hand screen 7 are displayed representations V2 of the vinuai cartridge being piayed by each virtual player with audio file details displayed such as track title and artist which are analogous to the representations VI of Figures 4 and 6. Above these are displayed three"next lots" V3 which simiiarly represent the next cart to be played after the current cart for each player when carts have been stacked up in sequence. Above the"next slots"is displayed a virtual cart library R.

There are provided: i) Virtual carts which are light blue in colour and as their name suggests, contain a single audio file, and ii) Virtual stacks, which are green in colour and contain a group of carts. These are ideal for commercial breaks so several carts can be grouped in advance onto a single stack.

Because each cart player is virtual it can have differently routed outputs according to requirements, so catering for split-frequency stations is no problem. For instance both AM and FM commercial stacks could be played from a single cart/stack, be controlled from the same fader whilst still going to the separate respective outputs.

Additionally, the system features a MASTER PFL mode, selected by button 90 on panel 8,} which allows the disc jockey to do a completely different mix on the prefade output without affecting what is going out on the main mixer output (i. e. on air). A screenshot of MASTER PFL mode is shown in FIGURE 10.

In the default mode, each channel's PFL button B (Figures 3 and 4) works in a conventional manner for previewing tracks and carts etc. However when the MASTER PFL mode is selected the faders F of any on air sources will physically close (all the faders are motorised for this purpose), and currently loaded players will empty. This allows the disc jockey to pre-record a telephone call, promotional script etc using any of his sources. He can even use the same players that are currently playing a track/cart to air on the main output.

In order to alert the disc jockey that MASTER PFL is on (so he does not mistakenly believe that what he is listening to is being broadcast) the layout of the schedule screen S will change. The event currently on-air will move to the top line 300 and the next three events will be displayed below. The fifth line 301 will change to a blue colour and display"Master Prefade On"which will move across the screen. This fifth line will also help separate the on-air events from every other event displayed below which can be scrolled up and down as described above.

Once the disc jockey has finished and switches MASTER PFL off, the faders return to their original position to display the on-air output.

MASTER PFL also provides the facility to record segues (in the manner of a script for controlling a program with a pre-recorded series of commands) which are further down the programme schedule. Everything that the disc jockey does will be remembered and recalled at the appropriate time when the arrangement is using the FULL AUTO facility.

In order to do this the disc jockey scrolls the schedule in region S of screen 6 (Figure 10) to a transition line TL (found between two events) and presses RX TRANS button SB5 on this screen. The desk will instantly switch into MASTER PFL mode and the players will automatically be loaded with the outgoing and incoming track plus any cart's specified in the transition.

The disc jockey will then press RECORD button 82 and the last 20 seconds or so of the outgoing track will start playing. In addition the clock displays will change to show what the time really would be at this point in the future. Thus"time checks"in the future are provided for. If the disc jockey just wants to do a straight music segue, the program will remember the point the next track was started and all the fader positions when it comes to the actual on-air time. If the disc jockey wants to do a link, then opening either mic fader F will automatically start recording the mic output which will be later replayed as a cart. If he is not happy with the result, he can keep recording the transition until satisfied.

The above process is completely transparent and allows the disc jockey to record some of his show in advance, including links if he wishes. It is believed that no other system currently offers this degree of flexibility and ease of use.

Additionally, a FULL AUTO function can be selected by toggling a full auto/manual button 180. The system will follow the schedule in column SC of region S of the left hand screen 6 (Figure 4), load tracks and carts and automatically transition between events. The background of the clock area T of the left hand screen will change to red when full auto mode is activated.

The right hand screen 7 operates in three basic modes: i) In LIBRARY mode as a cart library (selected by LIBRARY button 80 on the master control panel 8) to select which cart to load into the player. A screen shot of LIBRARY mode is shown in Figure 7. Each page holds 18 carts as shown in region R and pages are scrolled through using navigator buttons N. To load into a player, the LOAD button B is pressed on the desired player's channel and the required cart touched on the screen. It is also possible to load more than one cart into the same player at the same time. This is done by continuing to hold down the LOAD button B whilst the required cart is touched on the screen. If multiple carts are loaded into the same player this way, they will stack vertically (the next one to play now being visible in the"next slot"V3) and can be viewed and reordered by switching to STACKS mode as described below.

Carts can also be piayed out directly from the library on the QUICKFIRE fader channel C8 just by touching the title. More than one cart can be played simultaneously in this mode but all carts will appear on the QUICKFIRE fader. Once a cart has been started on the QUICKFIRE fader, the label will change to a countdown of remaining time. A second touch on the playing cart will fade it out.

Panel 8 features four navigation buttons N which are used to navigate horizontally and vertically through the cart library screens when in LIBRARY mode. ii) In STACKS mode (as shown in Figure 8) for viewing the progress of cart stacks (selected by STACKS button 81 on the master control panel 8). This will display the stack title ST at the top (only in the case of a pre-programmed stack having a title) and below that is a pile of the carts contained within the stack. There is also a CHAIN button CH which when touched ensures that each cart in the stack will automatically play in sequence after the previous cart finishes. The bottom cart in the stack will drop into the player and the stack will move down. Some stations like the ability to reorder the carts in a stack at anytime before playing to air, which is made possible in this mode by simply dragging the carts to a new position within the stack. iii) In RECORD mode (selected by button 82) for recording to hard disk. A screenshot of RECORD mode is shown in Figure 9. It is possible to select any number of sources for recording and there are provided controls 100,101,102,103, 104 and 105 for REWIND, STOP, PAUSE, PLAY, RECORD and FAST FORWARD respectively. It is also possible to provide an editing screen for editing the recorded audio by touching an EDIT button 106. The edit screen may be conventional and therefore is not shown. A SAVE button 107 is provided for saving the recording.

It should be noted that although an embodiment has been described in which a hard disk is used as the mass storage, any non-volatile memory of sufficent capacity for audio or video is suitable; other non-disk based memory types may become available in the future.

It should be noted that many of the preferred features of the described embodiment are novel and inventive in their own right and accordingly these features are not tied to the features of claim 1 or any other independent claim and are presented as independent inventions.

Claims

Claims 1. A digital audio or video playback arrangement arranged to process a digital audio or video input stream and to write at least a portion of the processed digital input stream into mass storage at a rate faster than real time, to read from mass storage at a rate faster than real time a previously written portion of the same or a different digital audio or video input stream and to read out via buffer means in real time said previously written portion.
2. A digital audio or video playback arrangement arranged to write to mass storage, at a rate faster than real-time, a digital audio or video input stream from a removable data carrier, and simultaneously to output at least one audio or video output stream, said output stream being derived from the same or a different digital audio or video input stream previously written to the mass storage.
3. A digital audio or video playback arrangement as claimed in claim 1 or claim 2 which is arranged to write successive portions of the digital audio or video input stream to separate files, to read out said files from mass storage and combine them into a real-time output stream.
4. A digital audio or video playback arrangement as claimed in claim 1 or claim 2 or claim 3 which is arranged to process said files individually before recombining them into a real-time output stream.
5 A digital audio or video playback arrangement as claimed in any preceding claim which is arranged to generate two or more simultaneous real-time output streams from the processed data.
6. A digital audio or video playback arrangement as claimed in any preceding claim wherein said processing includes the detection of data integrity.
7. A digital audio or video playback arrangement as claimed in claim 5 which is arranged to re-read any faulty portion of the input stream at a lower rate than said first-mentioned rate and to re-write it to mass storage.
8. A digital audio or video playback arrangement as claimed in claim 7 as dependent on claims 6 and 4 which is arranged to re-write any faulty file to mass storage.
9. A digital audio or video playback arrangement as claimed in any preceding claim wherein said processing includes the detection of peak level or dynamic range.
10. A digital audio or video playback arrangement as claimed in any preceding claim which is programmable to associate one or more playback parameters with a written portion of the digital audio or video input stream and arranged to play that written portion in accordance with its associated one or more playback parameters.
11. A digital audio or video playback arrangement which is arranged to write into mass storage, at a rate faster than real time, two or more tracks of a digital audio or video input stream read from a recording medium and to generate at least one realtime output stream in which the order of the tracks is different from the order of the tracks read from the recording medium or to generate two or more real-time output streams in which different tracks are playing simultaneously.
12. A digital audio or video playback arrangement as claimed in claim 11 which is arranged to write successive portions of the digital audio or video input stream to separate files, to read out said files from mass storage and recombine them into at least one real-time output stream.
13. A digital audio or video playback arrangement as claimed in claim 10 or claim 11 which is arranged to check data integrity of the input stream and to re-read the input stream at a different rate if necessary to achieve data integrity.
14. A digital audio or video playback arrangement as claimed in any of claims 10 to 12 which is arranged to detect peak level or dynamic range of the input stream and to utilise this data to process the output stream.
15. A digital audio or video playback arrangement comprising at least one physical control panel which is aligned with and controls a virtual audio or video player represented on a display.
16. A digital audio or video playback arrangement as claimed in claim 15 comprising two or more fader panels aligned with respective audio or video players represented on a common display.
17. A digital audio or video playback arrangement as claimed in claim 14 or claim 15 wherein one or more of the following items of information is arranged to be displayed in association with a virtual audio or video player on screen: operational status of the virtual player, title of track being played, timing information relating to such a track, and tracks available for playback.
18. A digital audio or video playback arrangement as claimed in any of claims 15 to 17 wherein the display is a touch-screen display having virtual buttons enabling the user to control each virtual audio or video player.
19. A digital audio or video playback arrangement as claimed in claim 18 wherein two or more modes of operation of the players are selectable by the user and the controls and/or information relating to an audio or video player displayed on screen change according to the mode selected.
20. A digital audio or video playback arrangement as claimed in any preceding claim which is controlled by a programme microprocessor arranged to play a userselectable sequence of audio or video tracks in at least one virtual audio or video player.
21. A digital audio or video playback arrangement as claimed in any of preceding claim which is arranged to write into mass storage, at a rate faster than real time, one or more tracks of a digital audio or video input stream read from a recording medium and to associate said one or more tracks with one or more virtual audio or video players which are arranged to control playback of at least one said track in real time.
22. A digital audio or video playback arrangement as claimed in claim 21 which is arranged to control playback of at least one said track in real time whilst writing into mass storage, at a rate faster than real time, further tracks of the digital audio or video input stream or a different digital audio or video input stream.
23. A playback arrangement as claimed in any preceding claim comprising a digital interface arranged to receive selectively at least one of a plurality of digital audio or video input streams.
24. A playback arrangement as claimed in claim 23 comprising at least one digital audio or video player arranged to provide at least one of said digital input streams.
25. A playback arrangement as claimed in any preceding claim wherein the mass storage comprises a magnetic or magneto-optic recording medium.
26. A playback arrangement as claimed in any preceding claim which is arranged to broadcast audio and/or video signals over an electronic broadcast medium.
27. A playback arrangement as claimed in any preceding claim comprising useroperable means for playing a first portion of audio and/or video from said digital input stream at one output port whilst playing a second portion of audio and/or video from said digital input stream at another output port.
28. A playback arrangement as claimed in claim 27 wherein the user-operable means comprises a pro-fade listen facility arranged to play said first portion of audio and/or video selectively to the user whilst broadcasting said second portion of audio and/or video.
29. A playback arrangement as claimed in any preceding claim comprising at least one display arranged to provide a graphical user interface for controlling the arrangement.
30. A playback arrangement as claimed in claim 29 wherein the display is arranged to display representations of controls and/or parameters of one or more sources of the digital input stream.
31. A playback arrangement as claimed in claim 30 wherein the representations on screen are grouped, each group relating to a respective selectable digital input stream, and the groups are aligned with respective physical control panels controlling the respective digital input streams.
32. A playback arrangement as claimed in any of claims 29 to 32 wherein the display is a touch-screen display.
33. A playback arrangement as claimed in any preceding claim, comprising means for displaying a schedule of audio and/or video tracks to be played and for indicating the status of the tracks.
34. A studio mixer comprising a digital audio or video playback arrangement as claimed in any preceding claim.
35. A method of operating a digital audio or video playback arrangement the method comprising the steps of processing a digital audio or video input stream and writing at least a portion of the processed digital input stream into mass storage at a rate faster than real time, reading from mass storage at a rate faster than real time a previously written portion of the same or a different digital audio or video input stream and reading out via buffer means in real time said previously written portion.
36. A method of operating a digital audio or video playback arrangement the method comprising the steps of writing to mass storage, at a rate faster than real-time, a digital audio or video input stream from a removable data carrier, and simultaneously outputting at least one audio or video output stream, wherein said output stream is derived from the same or a different digital audio or video input stream previously written to the mass storage.
37. A method as claimed in claim 35 or claim 36 wherein successive portions of the digital audio or video input stream are written to separate files, and said files are read out from mass storage and combined them into a real-time output stream.
38. A method as claimed in claim 37 wherein the files are processed individually before being combined into said output stream.
39. A method as claimed in any of claims 35 to 38 wherein two or more simultaneous real-time output streams are generated from the processed data.
40. A method of operating a digital audio or video playback arrangement wherein two or more tracks of a digital audio or video input stream are read from a recording medium and written into mass storage at a rate faster than real time, and at least one real-time output stream is generated in which the order of the tracks is different from the order of the tracks read from the recording medium or two or more real-time output streams are generated in which different tracks are playing simultaneously.
41. A method as claimed in claim 40 wherein successive portions of the digital audio or video input stream are written to separate files, said files are read out from mass storage and said files are combined into a real-time output stream.
42. A method as claimed in claim 40 or claim 41 wherein two or more simultaneous real-time output streams are generated from the processed data.
43. A method as claimed in any of claims 35 to 42 wherein the audio or video read out from mass storage is broadcast over an electronic broadcast medium.
44. An audio or video playback arrangement substantially as described hereinabove with reference to Figures 1 to 10 of the accompanying drawings.
45. An method of operating an audio or video playback arrangement, the method being substantially as described hereinabove with reference to Figures 1 to 10 of the accompanying drawings.