WO2005083977A1

WO2005083977A1 - Method and apparatus for reproducing a first data stream

Info

Publication number: WO2005083977A1
Application number: PCT/IB2005/050513
Authority: WO
Inventors: Willem Jonker; Jakobus Middeljans
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2004-02-19
Filing date: 2005-02-09
Publication date: 2005-09-09
Also published as: TW200603586A

Abstract

When zapping through channels, a user may encounter an interesting programme. It is annoying when this programme is already half-way. Therefore, it is advantageous to provide a user with the option to view this programme from the start. To this, the apparatus according to the invention comprises means for storing audio-visual data and a central processing unit, adapted for upon receiving a control command, controlling reproducing means like a video processor and a television set to reproduce the programme from the start.

Description

Method and apparatus for reproducing a first data stream

The invention relates to a method of reproducing a first data stream comprising audio-visual fragments. The invention further relates to an apparatus for reproducing a first data stream comprising audio- visual fragments. The invention also relates to a storage medium carrying computer executable code.

On a common television set, a user is enabled to zap from channel to channel at his own liking. Incentives for zapping are the end of a programme, the start of another programme and/ or the start of a commercial break. When zapping to a specific channel, this can be done intentionally, because a user knows that something that is of his interest is available, or at random. Usually in the latter case, but also in the first, a user may stumble across an interesting programme as well. However, the odds are high that the programme has already started for quite some time. This is annoying, since it might mean that the user misses the plot of- for example - a detective series. This problem not only turns up when switching from one programme to another. Also when the television set is switched on in the middle of a programme, the same problem occurs.

It is an object of the invention to provide a user with the possibility to view a programme from the start in case he switches to a channel and falls in the middle of a programme. To achieve this object, an aspect of the invention provides a method of reproducing a first data stream comprising audio-visual fragments, the method comprising the steps of: receiving the first stream; storing the first stream; reproducing a fragment of the first stream; and upon receiving a control command, reproducing the first stream from the start of the audio-visual fragment being reproduced at the moment the control command was received. This is advantageous when a user has a favourite channel, of which all content is always recorded. When a user switches to this channel, he has the possibility of switching to the start of the programme currently reproduced. An embodiment of the method according to the invention further comprises the steps of receiving a second stream wherein a multitude of streams of audio-visual data are multiplexed, the multitude comprising the first stream; de-multiplexing of the second stream; storing a groups of at least two of the multitude of streams, the group comprising the first stream. It will not always be predictable to which channel a user zapps and which channels provides the most interesting programmes. Therefore, it is advantageous to record multiple streams. This increases the odds that programmes interesting according to the user are stored. Another aspect of the invention provides apparatus for reproducing a first data stream comprising audio-visual fragments, comprising: a receiver for receiving the first stream; a storage device for storing the first stream; means for reproducing a fragment of the first stream; and a central processing unit, adapted for upon receiving a control command, controlling the reproducing means to reproduce the first stream from the start of the audiovisual fragment being reproduced at the moment the control command was received. Yet another aspect of the invention provides a storage medium carrying computer executable code enabling a processor to execute the method according to claim 1

These and other aspects of the invention will be elucidated by describing embodiments of the invention by means of Figures, wherein: Fig. 1 shows an embodiment of the apparatus according to the invention; Fig. 2 shows a stream of digital data comprising several streams of audiovisual data; and Fig. 3 shows a video server as an embodiment of the apparatus for storing a first data stream.

Fig. 1 shows a consumer electronics system 100 comprising a video recorder 110 as an embodiment of the apparatus according to the invention, a TV-set 150 and a control device 160. The video recorder 1 10 is arranged to record streams of audio-visual data and interactive applications associated with those streams of audio-visual data carried by a signal 170. To this, the video recorder 1 10 comprises a receiver 120 for receiving the signal 170, a de-multiplexer 122, a video processor 124 as a means for rendering the de- multiplexed video (and possibly also audio) data, a central processing unit like a microprocessor 126 for controlling components comprised by the video recorder 110, a storage device 128 such as a harddisk drive or an optical disk drive like a DVD or BluRay drive, a programme code memory 130, a user command receiver 132 for receiving signal from the control device 160 and a central bus 134 for connecting components comprised by the video recorder 1 10. The video recorder further comprises a network interface unit 140 for connecting to a network like the internet. The network interface unit 140 may be embodied as an analogue modem, an ISDN, DSL or cable modem or a UTP/ethernet network interface. The receiver 120 is arranged to tune in to a television channel and derive data of that television channel from the signal 170. The signal 170 can be received by any known method; cable, terrestrial; satellite, broadband network connection or any other method of distributing audio-visual data. The signal 170 can even be derived from the output of another consumer electronics apparatus. Data stored in the programme code memory 130 enables the micro processor 126 to execute the method according to the invention. The programme code memory 130 may be embodied as a Flash EEPROM, a ROM, an optical disk or any other type of data carrying medium. The storage device is adapted to store content that is received by either the receiver 120 or the network interface unit 140 for future reproduction on the TV-set 150 or for further dissemination via the network interface unit 140. The content may be processed prior to storage. In a preferred embodiment of the invention, the video recorder 1 10 receives a multiplexed digital stream 200, which is shown in Fig. 2, via the signal 170 in the receiver 120. The multiplexed digital stream 200 comprises a first stream of audio-visual data 210, a second stream of audio-visual data 220, a third stream of audio-visual data 230 and a fourth stream of audio- visual data 240. The streams of audio- visual data comprise fragments 232, 233 forming semantically related entities like television programmes, films, audio tracks like songs or orchestra concerts, or gaming sequences. These fragments may also be referred to as audio-visual fragments or multimedia objects. For the rest of the description the fragments will be referred to as television programmes or programmes and the individual streams will be referred to as channels (the first stream of audio-visual data 210 is the first channel, the second stream of audio-visual data 220 is the second channel, the third stream of audio-visual data 230 is the third channel and the fourth stream of audio-visual data 240 is the fourth channel). According to an embodiment of the invention, all channels in the multiplexed stream 200 received by the receiver 120 are de-multiplexed by the de-multiplexer 122 and stored by the storage device 128, which is a harddisk in this embodiment of the invention. Current harddisks can simultaneously store and retrieve up to 10 streams of audio-visual data. This means that when only one stream is retrieved for reproduction, up to 9 other streams can be stored. The third channel comprises a first programme 232, followed by a second programme 233, which is a commercial break. It is generally known that watching commercials is perceived as annoying by many consumers. So when a user has watched the first programme 232, reproduced by means of the TV-set 150, he switches to the second channel to avoid reproduction of the commercial break 233. When he switches to the second channel, a third programme 222 will be reproduced, starting in the middle. Since this might mean that the user misses the plot - say the programme 222 is a detective series and the murder is in the first two seconds - this is quite annoying. Therefore, it is advantageous to provide the user with an option to switch to the start of the programme 222. For this option, all incoming audio- visual data of all channels should be stored, since it is not known is advance from which channel to which channel a user will zapp and whether he would like to see a programme from the start or not. Advantageously, the control device 160 is equipped with a special button to go back to the start of the programme that is currently being reproduced by the TV-set 150. It will be apparent that only a limited length of the various streams has to be recorded. Usually, the preferred length is the length of a usual programme. Including films, this programme length will most probably not exceed four hours. This means that at most, only four hours of each channel have to be stored. This can be done in a circular buffer, i.e. the newest data overwriting old data, or in a FIFO buffer, i.e. writing new data and deleting old data (all exceeding the four hours). In an embodiment of the invention, a user is enabled to adjust the size of the channel buffer in the storage device 128. The borders between the various programmes can be identified using various known methods. Most commercial broadcasting stations provide commercial breaks between the various programmes. Commercial breaks can be identified as disclosed in document WO 02/093929. The borders between the various programmes can also be identified using an Electronic Programme Guide, EPG. Such EPGs are commercially available and can be obtained using the network interface unit 140. The invention and various embodiments thereof have been described for a digital scenario. However, the invention may also be applied in an analogue environment. To this, in a further embodiment of the apparatus according to the invention, the receiver comprises several tuners and analogue to digital converters to derive all channels from the incoming signal and to convert the analogue signals of the various channels to digital data for storage. In another embodiment of the invention, the reproduction is done on another location than the reception and storage of the audio-visual data. In this embodiment, reception and storage of the data is done at a server or provider site and the reproduction and control of the reproduction is done at a client location. Communication between the server and the video recorder 1 10 (Fig. 1) is established through the network interface unit 140 (Fig. 1). In this way, there is no need for a large amount of storage space. This embodiment will be further described by means of Fig. 1 and Fig. 3. Fig. 3 shows a video server 300, comprising a central processing unit 301, a programme memory 302 a receiver unit 303, a de-multiplexer 304, a harddisk drive 305 as storage device, a network interface unit 306 and a bus 307 for connecting the components of the video server 300. The receiver unit 303 is capable of receiving a signal 310, comprising multiple broadcast channels, multiplexed on an RF carrier. The receiver unit 303 transforms the RF signal to a baseband signal with multiplexed broadcast channels. The de-multiplexer 304 demultiplexes the various broadcast channels and offers them for storage to the harddisk drive 305. In this way, all the received broadcast channels are stored. The stored data is made available to users by means of the network interface unit 306. The operation of the video server 300 is controlled by the processing unit 301, sending control messages over the bus 307. The processing unit 310 is programmed to do so by computer code instructions stored in the programme memory 302. In this embodiment, when a user of the video recorder 100 zaps to a channel where a TV programme is ongoing and he wants to view the programme from the beginning, he indicates this by means of e.g. pressing a (preferably single) button on the control device 160. Upon reception by the micro processor 126 via the user command receiver 132 of a signal indicating the user action, the video recorder 100 sends a request for the programme to the video server 300. This is done by means of the network interface unit 140 of the video recorder 100. This request is addressed to the network interface unit 306 of the video server 300. Upon reception of the request, the video server looks up the requested programme on the harddisk drive 304 of the video server 300 and makes it available for sending to the video recorder 100 by means of the network interface unit 306 of the video server 300. The programme is preferably sent over a broadband network like DSL or cable internet, so the programme can be viewed while being received. Being received by the network interface unit 140, the received programme can be stored on the harddisk 128 upon reception for later viewing. It can also be directed via the multiplier 122 to the video processor 124 for immediate rendering and reproduction on the TV-set 150. In a further embodiment based on the embodiment that has just been described, the service is provided upon payment by the user of the service. The action of the user, i.e. the request for reception of a programme from the start, is registered by the video server. Upon registration, notification is made to a billing unit 320 and the user is accounted. Payment of the service can either be done instantaneously, by a micropayment, or by regular (monthly) billing. In the case of payment by micropayments, the user holds an account, either with the service provider or (electronically) in his video recorder 100 and with every request, money is withdrawn from this account and added to the account of the service provider, by the billing unit 320. It will be apparent that in the embodiment described directly above, the video recorder 100 and the video server 300 are located away from each other. The video server should at least be out of control for a user of the video recorder 100 other than ordering it to send the programme the user wants to watch from the beginning. It should be outside the personal environment of the user, so to say. Furthermore, in such an embodiment also another consumer electronics apparatus without mass storage means can take the place of the video recorder 100; it can also be embodied in a set-top box without a harddisk drive. The advantage of this embodiment is that it is a lot cheaper. Furthermore, a harddisk drive can be used more efficient. As mentioned, current harddisk drive can simultaneously store and retrieve up to 10 streams of audiovisual data like digitised analogue television channels. A general single user will probably not use this capacity. When this capacity is shared by multiple users, it is used more efficiently. In yet another embodiment of the invention, not all channels received can be stored by the storage device. Therefore, a user is enabled to select several favourite channels, of which audio-visual data is permanently stored. The length of programmes varies. Therefore, it is advantageous to vary the length of the amount of data that is stored. For example, when a user is most interested in films, the size of the stream stored may be longer than in case the user is interested in sitcoms, which usually do not last longer than an hour. Furthermore, the term "comprising" does not exclude other elements or steps, the terms "a" and "an" do not exclude a plurality and a single processor or other unit may fulfil the functions of several of the units or circuits recited in the claims. The invention may be summarised as follows: When zapping through channels, a user may encounter an interesting programme. It is annoying when this programme is already half-way. Therefore, it is advantageous to provide a user with the option to view this programme from the start. To this, the apparatus according to the invention comprises means for storing audio-visual data and a central processing unit, adapted for upon receiving a control command, controlling reproducing means like a video processor and a television set to reproduce the programme from the start.

Claims

CLAIMS:

1. Method of reproducing a first data stream comprising audio-visual fragments, the method comprising the steps of: (a) receiving the first stream; (b) storing the first stream; (c) reproducing a fragment of the first stream; and (d) upon receiving a control command, reproducing the stored first stream from the start of the audio-visual fragment being reproduced at the moment the control command was received.

2. Method according to claim 1, wherein the method further comprises the steps of: (a) receiving a second stream wherein a multitude of streams of audio-visual data are multiplexed, the multitude comprising the first stream; and (b) de-multiplexing of the second stream; (c) storing a groups of at least two of the multitude of streams, the group comprising the first stream.

3. Method according to claim 1, wherein the first stream is stored on a video server away from the location where the first stream is reproduced and the step d) method further comprises the substeps of: (a) transmitting the control command to the video server; (b) upon receiving the control command, retrieving the fragment from the video server; (c) transmitting the fragment to a reproducing apparatus; and (d) reproducing the fragment from the start.

4. Method according to claim 3, wherein the user pays for retrieval and reception of the fragment from the video server.

5. Apparatus for reproducing a first data stream comprising audio-visual fragments, comprising: (a) a receiver (120) for receiving the first stream; (b) a storage device (128) for storing the first stream; (c) means ( 134) for rendering a fragment of the first stream; and (d) a central processing unit (126), adapted for upon receiving a control command, controlling the rendering means to reproduce the first stream from the start of the audio-visual fragment being reproduced at the moment the control command was received.

6. Apparatus (300) for storing a first data stream comprising audio-visual fragments, the apparatus comprising: (a) a receiver (303) for receiving the first stream; (b) a storage device (305) for storing the first stream; (c) a unit for receiving control commands (306) to retrieve and transmit audio-visual fragments; and (d) means for transmitting (306) at least one fragment upon retrieving a control command requesting the apparatus to do so.

7. Apparatus (100) for reproducing a first data stream comprising audiovisual fragments, the apparatus comprising: (a) a receiver (120, 140) for receiving the first stream; (b) means for rendering (124) at least one fragment comprised by the first data stream; (c) a control unit (160, 132)) for receiving a control command indicating that the fragment being rendered at the moment the control command is received should be reproduced from the start of the fragment; (d) a transmitter (140) for transmitting the control command; and (e) a receiver (140, 120) for receiving the fragment for reproduction from the start of the fragment.

8. System for storage and reproduction of audiovisual data, comprising the apparatus as claimed in claim 6 and the apparatus as claimed in claim 7.

9. Storage medium carrying computer executable code enabling a processor to execute the method according to claim 1.