FIELD OF THE INVENTION

The invention relates to processing video data, comprising outputting digital video data and control messages according to a predetermined digital video transfer format on at least one digital output, at least one of: receiving analog video data from a source device at an analog input, and receiving digital video data at a digital input connecting a source device having a digital output that does not provide control messages according to the predetermined digital video transfer format, and furthermore coupling a selected input to the digital output for transferring video data from the selected input to the digital output. BACKGROUND OF THE INVENTION

Devices for sourcing digital video data are known, for example video players like DVD players or set top boxes. In this document video includes any type of audiovisual data. The source device is to be coupled to a display device like a TV set or monitor. Video data is transferred between the devices via a suitable interface system, preferably a high- speed digital interface like High Definition Multimedia Interface (HDMI, see Reference [1]). For transferring the video signals from various source devices to the display device a device for processing video data as defined above may be used. Such a processing device, for example a HDMI switchbox or an audio/video receiver, has multiple digital video inputs and is arranged to select one of the available digital video signals and transfer the selected video data from the selected input to the output, which is coupled to the output (display) device, which renders the video.

A HDMI switchbox is particularly useful in the following situations:

- when more source devices need to be connected than that there are inputs on the output device (e.g. the TV).

- for cable management, especially in case of hanging the output device on a wall. In this case all source devices are connected to the switchbox and there is only one HDMI cable from the switch to the output device.

Alternatively, the HDMI switch may be split in two physical boxes, which are connected by a wireless link. The transmitter part is placed together with all source devices, i.e. the source devices are connected to the inputs of the transmitter. The receiver part hangs behind the TV, receives a wireless signal from the transmitter part and provides HDMI output to the TV. The two parts together work in the same way as a HDMI switchbox with multiple inputs and a single output.

The processing device has a number of digital inputs for receiving digital video data, and one or more digital outputs for outputting digital video data and control messages according to a predetermined digital video transfer format, e.g. HDMI. It is noted that the HDMI standard (Reference [1]) includes a standard interface format for such control messages called the Consumer Electronic Control (CEC) protocol. The processing device has switching circuitry for coupling a selected digital input to the digital output for transferring the digital video data from the selected digital input to the digital output.

According to HDMI-CEC (see 8.7 in Reference [1]) a unique hierarchical address code (called a Physical Address) is assigned to each input which comprises a predetermined hierarchical code for identifying a digital input at a hierarchical level of the device itself with respect to a next hierarchical level. In this document the highest hierarchical level is considered to be the final destination of the video signal, e.g. the TV set or display. A lower or preceding hierarchical level includes all devices coupled to the digital inputs of the higher level. For example, a TV set is considered to be at the first, highest level (i.e. the destination), a switchbox or audio/video receiver connected to the input of the TV is at the second level, a DVD player connected to the receiver is on the third level, etc. The HDMI Physical Address has 4 digits, where the first digit corresponds to the predetermined hierarchical code for the highest level. The device at the highest level (TV) assigns the codes to its inputs. The value of the first digit identifies the respective input of the device at the highest level, while a value of zero identifies the TV itself (0.0.0.0). The control messages include messages having the hierarchical address code for identifying the selected digital input and the device coupled thereto to the next hierarchical level.

CEC provides an example of a processing device (called CEC switch, see section 11.1 in reference [5]) that selects between multiple HDMI inputs and assigns physical addresses to each digital input. If the display device, source devices and switch support relevant parts of [CEC], control is not problematic. Devices report their existence by means of a message <Report Physical Address>) and the display (sink) device (e.g. a TV) inquires for additional information by using messages such as <Give OSD name>, <Give Device Vendor ID>, <Give CEC version>, .... The display device uses this information to present a list of available devices on its screen. A user can select any device from this list. The TV sends an appropriate CEC message to activate the targeted device. The targeted device sends an <Active Source> message which makes the TV and any intermediate switches switch to enable a video path from the source device to the TV. From this moment, the Remote Control Passthrough feature may be used to control the device (see references [1] and [5] for details).

Also, source devices can autonomously send an < Active Source> message when they want to be displayed on the TV screen, e.g. when they are switched on by the user, when the user inserts a disc into a disc player, when the device wants to show an alert message, etc. Similarly to the process described above, the <Active Source> message causes the TV and any intermediate switches to switch to enable a video path from the source device to the TV. Again, from that moment on, Remote Control Passthrough may be used to control the device (see references [1] and [5] for details).

The processing device (switch) may also have other, non-HDMI, sources, such as a tuner or further inputs. In CEC, see section 13.2.2 in Reference [1], it is described how such a switch should act when switching to and from non-HDMI inputs. When a selected input is a non-HDMI input the switch should not send the protocol messages used when associated with switching to/between HDMI inputs, such as <Routing Information> or <Routing Change>. When switching to the internal source (tuner) the device indicates to be a source device itself instead of indicating a lower hierarchical address having a source connected.

When one or more of the source devices connected to the switch do not support CEC, it is not possible to select them from the screen of the TV. Furthermore, the source devices are not able to wakeup the TV and cause the TV and any intermediate switches to switch to the correct input for transferring video data from the source device to the TV. Therefore, the source device cannot be controlled with the TV remote control using the CEC Remote Control Passthrough feature. So, in this case, the user needs to manually wakeup the TV and select the correct TV input. Then, the user needs to use a dedicated control (e.g. a separate remote control) to select the correct input on switch. So, the user cannot use the TV remote control to control playback etc. of such a source device, which does not support CEC.

US 2009/0015723 Al discloses a partial solution to this problem. It describes a switch that emulates a CEC device for each of the non-CEC source devices that its user has configured to emulate a CEC device. These emulated CEC devices show up on the TV screen and the user can select them. However, the proposed solution suffers from several drawbacks and has unsolved problems. It requires the user to configure the switch for each of the connected non- CEC source devices. When a source device activates, wake-up of the TV is not performed and also the switching of the TV and any intermediate switch to the correct HDMI input is not performed. As a result thereof, the source device cannot be controlled with the TV remote control using the Remote Control Passthrough feature.

SUMMARY OF INVENTION

It is an object of the invention to provide a processing device and corresponding method of the above type that at least partially solves the above mentioned problems. A first aspect of the invention is defined by the independent claims 1 and 9. A second aspect of the invention is defined by the independent claims 10 and 24. Advantageous embodiments are defined in the dependent claims.

For this purpose, according to a first aspect of the invention, the invention as described in the opening paragraph further comprises detecting a trigger indicating that it is required to transfer video data other than according to the predetermined digital video transfer format from either the analog input or the digital input to the digital output, in case that the trigger is detected, providing a control message according to the predetermined digital video transfer format to the digital output, the control message causing an output device for rendering the video data and any intermediate devices connected between the digital output and the output device to switch to the correct input for enabling transfer of the video data to the output device. In case that the predetermined digital video transfer format is HDMI-CEC the control message is the standardized <Active Source> message.

The measures have the effect that, source devices, which do not provide control messages according to the predetermined digital video transfer format, such as non- CEC devices, are better integrated to a system working according to the predetermined digital video transfer format. It is not required for the user to configure the processing device for each of the connected non-compliant source devices. Furthermore, no manual switching is needed of the display device and any intermediate switches, to switch to the correct input for enabling rendering of the video data. Finally, in case of a CEC system, the remote control commands of the display device reach the video processing device (switch) using the CEC Remote Control Passthrough feature. As a result, in case that the processing device (switch) has an Infra Red blaster, it can control non-CEC source devices by translating CEC messages to appropriate IR messages. According to an embodiment, in case that the trigger is detected, a further control message is provided to the digital output according to the predetermined digital video transfer format, the further control message causing the output device and any intermediate devices connected between the digital output and the output device to wake up. In case that the predetermined digital video transfer format is HDMI-CEC the further control message is for example the standardized <Image View On> or <Text View On> message. As a result thereof, a manual wake-up by the user of these devices is not needed.

The trigger is for example:

an activity on the digital input;

an activity on the analog input;

a user interaction with the device to select an input thereof; and a power on sequence of the device selecting an input thereof.

In case of the trigger being an activity on the analog input, it may be detected by detecting a predetermined signal thereon, for example a predetermined voltage or sync pulse detection. Both are simple but reliable ways to detect activity on the analog input.

In case of the trigger being an activity on the digital input, it may be detected by detecting Transition Minimized Differential Signaling [TMDS] activity or e.g. + 5V activity provided by source devices.

According to a further embodiment, information is obtained regarding other devices enabled to work according to the predetermined digital video transfer format. This information is used to ignore triggers at an input, in case that a device enabled to work according to the predetermined digital video transfer format is connected thereto. As a result, the control message causing an output device for rendering the video data to switch to the correct input is only provided to the digital output of the processing device if a device is connected to the input that is not compliant with the predetermined digital video transfer format.

According to a still further embodiment, a control message according to the predetermined digital video transfer format is provided from a predetermined address and any control messages originated from the output device and directed to the predetermined address are forwarded to the (non-CEC compliant) source device of the video data. This enables the user to control the non-compliant source devices with the remote control of the display device in the same way as the source devices, which are compliant with the predetermined digital video transfer format. According to a second aspect, the invention as described in the opening paragraph further comprises presenting the device (switch) towards other devices as a single source device according to the predetermined digital video transfer format (e.g. playback device, recording device, tuner; but not as a CEC switch). It should be noted that this is not an emulation of a CEC device for one of the source devices as in the patent application US 2009/0015723 Al . In the system disclosed in that US patent application, the switch presents itself as a switch, and for each of configured inputs, it emulates one CEC source device. It should be noted that TV's do not show switches (and amplifiers) in "device list", but only source devices, so the switch is not shown in the device list on the screen.

With the present invention, this predetermined digital video transfer format device (switch) itself appears on the TV User Interface (UI). This is because of a feature implemented in most modern TV's, which is usually referred to as "device list". Accordingly, TV's perform a "bus scan" and find all CEC sources in the system and present those sources on the UI. Thus, in our case, when a switch presents itself as a source device, it will endup in device list of TV's that implement this CEC feature.

The user can select this device representation from the TV UI to see the video output of the switch and control the switch by means of the standardized CEC Remote Control Passthrough feature, i.e. with his TV remote control. After a user selects a source from the TV-UI, the TV performs a device selection by sending several CEC messages. The key message thereof is SetStreamPath, which wakes up the selected device, and which forces all intermediate switches and the TV itself to select an appropriate input. This feature is part of the CEC standard. According to the second aspect of the present invention, both CEC enabled source devices and non-CEC devices connected to the inputs of the switch can be controlled in this way. No configuration by the user is needed. Furthermore, there is less clutter on the TV UI, because only one entry (i.e. the entry of the switch) is shown instead of the long list of entries (possibly including entries for non-connected inputs) depicted on the TV screen according to the prior art discussed herein above.

According to an embodiment, the step of presenting is performed by reporting the existence of the processing device to the other devices by causing the transmission of a control message including the type of source device and an address of a first type. In case of HDMI-CEC the address of the first type is a physical address and the control message including the type of source device comprises a field with information regarding the source device, e.g. a DVD player, tuner etc. Alternatively or additionally, the step of presenting is performed by using an address of a second type corresponding to a type of source device. In case of HDMI-CEC the address of the second type is a logical address. The logical addresses 1-11 but excluding 5, which is reserved for an amplifier, are reserved for source devices (see reference [5], section 10.2 table 5 for details), so the address should be taken from this range. As logical addresses are a scarce resource, according to the CEC standard only 3 playback devices, 3 recorder device and 4 tuner devices are allowed, it is advantageous that only one CEC Logical Address is used. As a result, the chance is low that all logical addresses are in use and that 'normal' CEC source devices are not able to get a logical address. In such case the CEC devices need to limit or disable their CEC functionality.

According to a further embodiment, upon the processing device receiving a control message from the output device for transferring video, an appropriate input of the processing device is selected. The control message is preferably generated due to user selection of an entry in the User Interface on the TV. In case of HDMI-CEC the control message is either a <User Control Pressed> message or a < User Control Released> message (see reference [1] section 15, table 19 for details).

According to an implementation of the further embodiment, upon the processing device repeatedly receiving the control message for transferring video, inputs of the device are sequentially (e.g. cyclically) selected. As a result, the user will cycle through the available inputs of the processing device (switch) without the need to control the switch itself directly by means of a corresponding remote control or buttons on the switch.

According to a further implementation of the further embodiment, the step of sequentially selecting inputs of the processing device is performed by one or more of the following:

skipping inputs to which no source device is connected,

skipping inputs that are connected to a source device in standby, (i.e. there is no video available on such an input at this moment).

skipping inputs to which a source device is connected, which provides video data and control messages according to the predetermined digital video transfer format, (in case that the predetermined digital video transfer format is HDMI-CEC and the source device is a CEC device, this device is already represented in the TV User Interface). As a result, only the inputs that may receive video data other than according to the HDMI-CEC format are included in the sequential selection, thereby saving time. According to a still further implementation of the further embodiment, the processing device stays on the same input when the control message for transferring video is received multiple times within a certain time frame. In this way, undue switching due to erroneous repeated transmission of the control message is avoided.

According to a yet further implementation of the further embodiment, the processing device is configured for, when switching to an input to which a source device is connected, which provides video data and control messages according to the predetermined digital video transfer format, causing the transmission of a control message to the source device, the control message causing the source device to forward video. As a result, the inputs connected to source devices, which are compliant with the predetermined digital video transfer format (e.g. HDMI-CEC), are included in the switching cycle.

According to a yet further implementation of the further embodiment, the processing device is configured for, when switching to an input to which a source device is connected, which provides video data and control messages other than according to the predetermined digital video transfer format, causing the transmission of a control message to the output device, the control message causing the output device to enable passthrough of remote control commands, which it receives, to the processing device, wherein the processing device is further configured for forwarding the remote control commands to the source device. In this way, the user can control the switching by means of a TV Remote Control using a standardized feature of HDMI-CEC (Remote Control Passthrough) without the need of using any buttons on the processing device (switch) itself or a remote control thereof.

According to a further embodiment, upon the processing device receiving a control message from the output device for transferring video, the transmission of a control message to the output device is caused, the control message causing the output device to enable Passthrough of remote control commands, which it receives, to the device, wherein the device is further configured for forwarding the remote control commands to the source device. In case of the predetermined digital video format being HDMI-CEC, the message transmitted from the processing device to the display device (TV) is a standardized CEC- message <Active source> which makes the TV starts Remote Control Passthrough.

According to an implementation of the further embodiment, the processing device is configured for, upon the device receiving a remote control command linked to a particular input, to select the particular input. According to a further implementation of the further embodiment the processing device is configured for, upon the device receiving a remote control command selecting the inputs one by one in a cycle, to select the next input in the cycle.

According to a still further implementation of the further embodiment the processing device is configured for, upon the device receiving a remote control command to go back to a previously selected input, to select the previous selected input.

As a result, in all three implementations, generally available buttons on the TV Remote Control can be used for the selection of the inputs on the processing device (switch), such as numerical keys, P+/P-, up/down arrow, left/right arrow, back key, which is user friendly.

According to an alternative implementation of the further embodiment, the processing device is configured for, upon the device not receiving a remote control command for a certain time, to select a next input. In this way a cycle is created through inputs showing each for a certain time until user presses a particular button.

Preferably, the method according to the invention is implemented by means of a computer program loaded to the processing device (switch).

Further preferred embodiments of the device according to the invention are given in the appended claims, disclosure of which is incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which

Fig. 1 shows a system wherein a device for processing video data according to the present invention may be used,

Fig. 2 shows the state of the devices in the system according to figure 1, before video from a CEC-enabled device is rendered according to a prior art procedure;

Fig. 3 shows the state of the devices in the system according to figure 1, when video from a CEC-enabled device is rendered according to the prior art procedure;

Fig. 4 shows the state of the devices in the system according to figure 1, before video from a non CEC-enabled device is rendered according to a first embodiment of the invention; Fig. 5 shows the state of the devices in the system according to figure 1, when video from a non CEC-enabled device is rendered according to the first embodiment of the invention;

Fig. 6 shows the state of the devices in the system according to figure 1, before switching the source device from which video is rendered according to the second

embodiment of the invention; and

Fig. 7 shows the state of the devices in the system according to figure 1, after switching the source device from which video is rendered according to the second

embodiment of the invention;

Throughout the figures like reference numerals refer to like elements.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows a device 10 for processing video data, which will also be referred to in this text as switch or switchbox. The device has digital inputs 11,12 for receiving digital video data, and at least one digital output 16 for outputting digital video data and control messages according to the predetermined digital video transfer format, e.g. HDMI-CEC (see Reference [1]). Source devices are connected to the digital inputs of the switch, such as a DVD player 5 (DVD connected to HDMI2). The digital inputs may fully comply with the predetermined digital video transfer format. For the further description HDMI-CEC is used as an example of the predetermined digital video transfer format. It is to be noted that other audio/video interface formats which have similar requirements and addressing schemes can be used also.

The digital video data at the digital output 16 is rendered by a display device (sink device) 22, in this example a TV. Furthermore, the system of consumer electronic devices depicted in figure 1 comprises a Set Top Box (STB) 21, at the same hierarchical level as device 10.

The device has a processor 18 for coupling a selected digital input to the digital output for transferring the digital video data from the selected digital input to the digital output. In order to implement the functionality described herein after, the processor is loaded with a suitable computer program. The processor assigns a hierarchical address code 19 to each input, in the example a Physical Address according to HDMI. In Fig. 1 the output of the device 10 is assumed to be connected to a TV set at the second input thereof; hence the first digit in the hierarchical address code is 2. The hierarchical address code 19 has a predetermined hierarchical code 20 for identifying a digital input at the hierarchical level of the device with respect to the next hierarchical level (i.e. the TV set) coupled to the digital output 16. In Fig. 1 the device is at the second level and its output is connected to a TV, therefore the second digit in the example in Fig. 1 identifies the inputs of the device. The value of the second digit identifies the respective digital input and device connected thereto. For further description of the addressing in HDMI see Reference [1], in particular section 8.7. The physical address is required in order to obtain a logical address (see Reference [1], section CEC 10.2.1). CEC logical devices can supply an On Screen Display (OSD) name to the TV that can be used for user- friendly names during source selection purposes (see Reference [1], section CEC 13.11).

The processor 18 provides and processes control messages according to the predetermined digital video transfer format. It is to be noted that the control messages may be separate messages, such as CEC messages defined in HDMI, see Reference [1] section 8.6 and Supplement 1 on Consumer Electronics Control (CEC). The messages may also be included in the audio/video data stream, e.g. in a control field of a video frame.

The control messages may include the hierarchical address code for identifying the selected digital input. It is noted that the control messages are transferred at least to the next hierarchical level, but may also be distributed to other devices in the system, e.g. via a communication bus. The TV can select one of the inputs by sending a

SetStreamPath CEC message with the physical address that it wants to select. Other messages are available for devices to indicate that they have become active or not active and for manual changes of the switch position. Examples of the messages are the following CEC messages:

- <SetStreamPath> => select a particular device on an input via the hierarchical address; - <Report Physical Address> => a device announces its physical and logical address (and device type);

- <Device Vendor ID> => a device announces a code identifying its manufacturer (see Reference [1], section CEC 13.9);

- <Set OSD Name> => a device announces its name of device (for use in User Interface of TV) (see Reference [1], section CEC 13.11).

Existing CEC devices use the <ActiveSource> message to declare themselves as active (see Reference [1], section CEC 12.1). When an existing CEC switch makes transitions between non-HDMI inputs, then it shall not send <RoutingChange> messages (see Reference [1], section CEC 13.2.2). Hence the rest of the system cannot "see" the analog inputs. When a TV switches to an internal tuner or other non HDMI source then it shall broadcast <ActiveSource> [0.0.0.0] (see Reference [1], section CEC 13.2.2). No such statement is made about non HDMI sources on CEC switches, but in existing CEC switches the TV behavior may be copied. Non HDMI sources on the switchbox can be selected via the local controls of the switchbox. No information is available towards the TV regarding which input is selected. In the existing system the TV is not aware of any available inputs or the associated names.

The device further has analog inputs 13,14 for receiving analog video or audio data, and a convertor 17 for converting the analog video or audio data into converted digital input data. One or more analog input devices are connected, like a recorder REC 7 to input Analog3. It is noted that the number of analog and/or digital inputs can be any number.

The processor 18 is further arranged for coupling a selected analog input 13,14 to the digital output 16 for transferring the converted digital input data to the output. The control of the switching and internal data traffic by the processor is indicated schematically by dashed lines in Fig. 1. The analog input signal is first guided to the convertor 17, and subsequently, after conversion to a digital signal, coupled to the output. The convertor may include an analog to digital convertor and further video signal processing for converting an analog video signal into a digital video signal according to the HDMI format, and is known as such. The converter may further include an analog to digital convertor and further audio signal processing for converting an analog audio signal into a digital audio signal.

In an embodiment the device has one or more digital inputs for connecting devices according to different digital input formats. For example, input 11 may be arranged for connecting a HDMI device of a preceding generation having a digital output that does not provide said CEC control messages. The processor 18 is arranged for providing the control messages for identifying the selected digital input. For non HDMI digital inputs also a further hierarchical address code for a digital input is assigned.

The processor 18 further provides control messages for identifying the selected analog input by assigning a further hierarchical address code, for example for the input labeled Analog3. The new address includes the further predetermined hierarchical code 20, which according to HDMI designates the device connected to a digital input. In the device as shown the value of the hierarchical code 20 identifies the selected analog input Analog3 to the next hierarchical level, i.e. the TV connected to the output, and/or other devices in the system. Now with reference to figures 2 and 3 the conventional procedure is described in case of detecting activity from a CEC device connected to the switch 10, in this case DVD player 5. This description is helpful for understanding the functioning of the different embodiments of the present invention, in case of detecting activity at non-CEC inputs.

At the start of the procedure all devices are in standby as shown in figure 2.

The user inserts a disc in the DVD player and closes the tray. The DVD player 5 wakes up and starts disc playback because of disc insertion. The DVD player sends an <Image View On> message to the TV set 22 via switch 10. As a result, the TV-set wakes up. The DVD- player sends <Active Source> 2.1.0.0 to the switch and the TV. As a result, the switch 10 and the TV-set 22 switch to the correct input and the video is transferred from the DVD-player via the switch to the TV and the user sees the video from the DVD on the TV. This procedure is the normal "One Touch Play" procedure, as described in Reference [1].

According to a first embodiment if the device 10 (switch) detects a trigger that indicates the user may want to see the video from a non-CEC device connected to the switch on the TV screen, it will send a CEC message to the TV and other devices in the system to make them switch to their correct input.

For switching the TV and any intermediate switch devices, the <Active Source> message is typically used. As detailed in Reference [1], this also informs other CEC devices in the system that such other devices are no longer considered <Active Source>.The Physical Address parameter of this <Active Source> message needs to be compliant with the addressing schemes detailed in Reference [1], and depends on the Physical Address that the switch has been allocated from the downstream devices such as the TV (as read from downstream Extended Display Information Display EDID, which is transmitted by the downstream device to the switch according to standard HDMI functionality).

For example, a switch connected directly to a TV can have been allocated a

Physical Address of 2.0.0.0 if it is connected to HDMI input#2 of the TV. The switch may use Physical Address parameter 2.x.0.0 for a device connected to input #x, as shown in figures 1-3. However, address 2.0.0.0 would work equally well for this purpose. Also address 2.a.b.c (where a and x are not necessarily the same, and b and c are not necessarily 0) could be used. So the Physical Address used for the CEC devices is not necessarily the same as the Physical Address that the switch presents in the EDID for the input #x to the connected device. Now with reference to figures 4 and 5 the procedure according to an embodiment of the present invention is described in case of the DVD player 5 being non- CEC compliant and becoming active.

First, all devices are in standby as shown in figure 4. The user inserts a disc in the DVD player and closes the tray. The DVD player wakes up and start disc playback because of the disc insertion. The switch detects video/activity on one of its non-HDMI-CEC inputs and selects that input and sends an <Image View On> message to the TV. As a result, the TV wakes up. The switch sends an < Active Source> 2.1.0.0 message (or < Active

Source> 2.0.0.0). As a result, the TV switches to correct input, the video is transferred from the DVD-player via the switch to the TV and the user sees the video from the DVD on the TV.

The trigger that the user wishes to seen video from non-CEC device connected to the switch on the TV screen is for example:

Activity on a HDMI non-CEC input;

Activity on a non-HDMI input;

User interaction with the switch;

Power on sequence of the switch;

In case of the trigger being activity on a HDMI non-CEC input, the detection of the activity can be based on a number of techniques, e.g. detection of 5V signal from the source device, Transition Minimized Differential Signaling (TMDS) signal activity, or any other appropriate technique for detecting activity on a HDMI connection.

In case that the trigger is an activity on a non-HDMI input, e.g. an analog input of the switch, the switch can employ the same mechanism as described herein above for a HDMI non-CEC input, i.e. sending the <Active Source> message to make TV and other devices in the system switch to the signal from this non-HDMI device. This signal is converted into a HDMI signal by the convertor 17 of the switch.

The analog input 11,12 is arranged for detecting status information of the analog input. The processor 18 then converts the status information to corresponding control data and includes said converted data in the control messages. The status information may be detected in any suitable way from the respective analog input signal, or from control signals as defined for the respective analog input. The switch device informs the TV about type of signal. The type of signal is sent via an AVI InfoFrame and/or a CEC message (e.g. vendor specific command, or a standardized command). Also the switch device informs the TV about its configuration and status. This can be done whenever the switch device detects a hot plug signal appearing at its sink connector, analog input becomes active/inactive etc. A few examples of detecting a basic status (such as the connected device being active) are as follows.

Generally, a control signal that defines the status information of the analog input is translated into corresponding protocol messages, for example a signal indicating that an analog signal for validly rendering video or audio data is present.

A common analog interface standard for video signals is called SCART (see Reference [2], and further extensions). A specific voltage level on a control pin (pin 8 of the SCART connector) indicates that the connected device is active, and further indicates the aspect ratio (see Reference [2]; Table 1 on page 7, FUNCTION SWITCHING on contact number 8). SCART allows a connected device to indicate the need to switch it to (or away) the AV connector. A VCR or other playback device will optimally power on when a cassette is inserted, may power on the television set (or switch it to video mode) and then start playing immediately if the cassette's write protection tab is absent. SCART also supports automatic widescreen switching. This is an extension of the functionality of a pin which previously only indicated to the TV set that an external signal should be displayed. In the SCART example a predetermined signal on the analog input is a signal level or signal level change on a control pin of the connector.

The analog input of the current device detects the predetermined signal levels on the analog input indicating said control information. The level indicates that the analog device is de-activated or activated to render video or audio data. A change of the signal level indicates that the connected device becomes active, or that the activity is terminated. For example, the analog status (break in/out and/or (user) selection of analog inputs and/or internal sources) is mapped to <ActiveSource> and <InactiveSource> messages of CEC.

In an embodiment the video signal itself is analyzed and a selected property is detected, for example the presence of sync pulses in the analog video signal. Based on the presence of the sync, the presence of a valid input signal is detected. Hence the active signal is detected based on a predetermined signal property of an analog video input signal.

In a further embodiment messages included in the analog input signal according to a predetermined analog video transfer format are detected. For example, the presence of messages on an interface bus defined on the analog input, such as messages on pin 10 of SCART (see Reference [2]; Table 1 on page 9, Control Signal Line on contact number 10). The use of the data pins was not standardized in the original SCART

specification, resulting in the use of several different protocols, both proprietary protocols and semi-proprietary protocols based on standards such as D ² B. CENELEC EN 50157-1 (Reference [4]) introduced AV.link as a standardized protocol to carry advanced control information between devices. It is a single-wire serial data bus and allows carrying remote control information and to negotiate analog signal types (e.g. RGB). AV.link is also known as nexTViewLink or under different trade names such as SmartLink, Q-Link, EasyLink, etc.

A further example are messages included in the input video signal itself, e.g. in the blanking period of the sync signals. An example is described in Reference [3], which defines Wide Screen Signalling (WSS) for 625-line television. The WSS messages indicate, inter alia, the aspect ratio of the video signal. Hence the analog input and the processor are arranged for receiving and analyzing the analog video signal according to a predetermined analog video transfer format, which for example corresponds to the Wide Screen Signalling [WSS] video transfer format. See Reference [3], page 9: groupl = indicates the aspect ratio : 4:3 , 14:9 , 16:9 , >16:9. The message information from analog sources, like said

WSS/SCART aspect ratio indication, is mapped in the control messages such as said AVI Info frames or CEC messages.

In an embodiment detecting the status information of the analog input is further augmented by detecting one or more of the characteristic properties, either from the video signal or from respective control signals or messages transferred with the signal. For example, frame frequency, line frequency (i.e. number of video lines in a frame), or interlace type of the analog video input signal may be detected. A specific signal type or signal format of the analog input signal, such as a PAL, SECAM or NTSC format signal may be detected and the respective properties, such as the number of video lines, may be retrieved from a memory in the detector. Also, the presence, language or content of additional data transferred with the analog audio or video data can be detected, such as teletext, subtitles or data streams transferred in between video data or on a separate data bus. Corresponding control information can be mapped onto the AVI InfoFrame and/or CEC messages.

In an embodiment the analog control information is transferred as a packet in the digital data stream while identifying the respective input to which it relates. The packet may include further metadata or control data for adjusting the video processing. In a practical embodiment the metadata is inserted in packets within the HDMI Data Islands.

The trigger can also be a user interaction with the switch, e.g. pressing a control button on the switch to select a particular non-CEC input. As a result, not only the non-CEC input of the switch is selected but also the CEC message is sent to the TV and other devices in the system to make them switch to their correct input, as described herein above.

Furthermore, the trigger may be the power-on sequence of the switch. This does not only select an appropriate input of the switch, but also results in sending the above CEC message to the TV and other devices in the system to make them switch to their correct input.

Instead of using the wakeup messages <Image View On> or <Text View On> as detailed in reference [1], alternative methods can be used to wake-up the TV. An example is <User Control Pressed> with some power-related argument, i.e. codes that can also wake up the TV, such as UserControlPressed 0x40, 0x6B and 0x6D (from CEC table 30 User

Control codes, reference [5]). All of these wake-up messages can be used in conjunction with messages to determine the power state of the TV, such as <Give Device Power Status>.

The switch may keep track of other CEC devices in the system, in particularly those connected to one of its inputs. Alternatively or additionally it may actively scan the CEC bus for such and other devices. It uses this knowledge to ignore some of the above mentioned triggers in case a CEC enable source devices is connected to the input that is activated. As a result, the sending of messages as discussed above will be sent only if a non- CEC device is connected to the input where activity is detected. For example, if a CEC device connected to one of the inputs raises its "5V power" signal and sends an <Active Source> message, the switch does not send an <Active Source> message, because this could confuse the TV.

In a system with CEC sources and a CEC TV, the TV forwards relevant remote control key presses to the device which is being watched. In this way, the user can control all devices with a single remote control, the one "belonging" to the TV. This is usually based on and activated by the <Active Source> message sent by the CEC source.

In the case of the <Active Source> message sent by the switch as detailed above upon one of the triggers indicating that video from a non-CEC source device should be rendered at the TV, the TV performs the same steps, i.e. it forwards relevant remote control key presses to the Logical Address of the CEC entity that sent the <Active Source> message, i.e. the CEC entity in the HDMI switch. This CEC entity in the switch can then forward such key presses using an appropriate mechanism to the source device, e.g. IR blaster, RS232, or any other communication mechanism. This allows the user to control the non-CEC source device with the TV remote control in the same manner as controlling CEC source devices. The switch may have to send additional messages before/after the <Active Source> message as needed by the Remote Control Passthrough mechanism in the TV, like for example <Menu Status Activated>.

If the switch emulates a source, it has a Logical Address different than 15, which should be used for sending the messages of the switch. If not, the messages can be sent from either Logical Address 15 (Unregistered) or from a Logical Address in the range 1..14, see reference [1].

The switch can be a stand-alone device or be integrated in another device.

Examples are an amplifier with HDMI inputs, Home Theatre system with HDMI inputs and a wireless link with HDMI inputs.

Now a second embodiment of the invention will be described. The switch device operates as follows. When the switchbox is connected to the TV, it can send configuration data to the TV. This data describes the available inputs, their nature/type (e.g. supported video signals) and the labels (strings) printed on the housing of the switchbox (or changed by the user in the GUI of the switch, if such feature is implemented in the switch). The TV uses this data to extend the source selection menu. On the digital inputs of the switch the TV is able to discover the connected devices by means of the existing HDMI-CEC messages, if the connected devices are CEC capable.

It is noted that, according to the existing HDMI-CEC standard, a stand-alone switch has a logical address of 15. This is a predetermined address and shared with other such devices. Also, in CEC, there is no way to send messages to such a switch directly, since the logical address value of 15 as Destination address is used as a broadcast address indication (see section CEC 6.1.3 and 10.2 in [1]). This means that TV cannot directly address a switchbox.

According to the second embodiment of the invention, The HDMI switch presents itself as a (single) CEC source device, for example a playback device, a recording device, a tuner, and not as a CEC switch. There are two ways to implement such

presentation:

The first way to present is to use a Logical Address that according to the CEC standard is allocated to a CEC source device in all CEC control messages, which are sent by the switch. In practice this means that the following logical addresses are available for this purpose: 1-4, 6-11 (see reference [5], section 10.2 CEC table 5).

The second way to present is to insert a device type parameter corresponding to a CEC source device into the field for this purpose, which is sent together with the physical address in a <Report Physical Address Message>. The second way of presenting may be used alone or in combination with the first way.

As a result, the switch appears as a single CEC device on the TV user interface (UI). The user can select this device representation from TV UI to see the video output of the switch and control the switch. No configuration by the user is needed for this purpose.

Modern TV sets have a Graphical User Interface (GUI). The pages in the GUI are usually presented as a TV menu. The TV-sets of most manufacturers show a "device list" with the CEC sources of the system. Since, as discussed herein above, in the second embodiment of the present invention, the switch presents itself as a CEC source device it will be shown in the device list with all other CEC sources.

There are various ways to control the switch and the devices connected thereto:

According to a first implementation, when the user selects an entry in the TV UI, the TV sends a message <Set Stream Path> to the switch to wake it up and forward the video (see reference [5] Section 13.2 Routing Control,for details).

The switch uses this message as trigger to wake up and to select an appropriate input of the switch. So, when the user repeatedly accesses the entry in the TV UI, he will cycle through the available inputs of the switch - without a need to operate the switch itself by remote control of the switch itself or a button on the switch.

An example is shown in figures 6 and 7. Figure 6 shows the initial situation wherein the switch 10 forwards video from the DVD player 5 to the TV 22. The TV menu shows the device list of CEC devices connected thereto, as discussed herein above. It shows the entry "switch". When the user selects this entry by using the TV remote control, the TV sends a <Set Stream Path> 2.0.0.0 to the switch. This message results in the switch moving to the next input, i.e. the Recorder 7. The video originated from the Recorder 7 is then rendered by the TV as shown in figure 7.

By repeating this procedure, the user can cycle through all input devices connected to the switch, both the CEC-devices as well as the non CEC-devices.

The cycling through the inputs may be modified in any of the following ways. These options can be combined as needed:

- Inputs can be skipped that are not connected to a source, because no video is available on such input, any way.

- Likewise, inputs can be skipped that are connected to a source in standby, because no video is available on such an input at this time. - Furthermore, it is possible to skip the inputs that are connected to a CEC device. Since such devices are already represented on the TV UI, they can be selected directly by the user by selecting the corresponding representation on the TV UI.

- Of course also non-HDMI inputs can be included in the loop of available input.

- Furthermore, it is possible to cycle the inputs in a non-numeric order depending on switch configuration (e.g. 3-1-2-4).

- The switch may stay on same input if multiple selections (<set stream path>

messages) from TV UI are received within a certain timeframe. In this way, erroneous switching may be avoided.

Stay on same input if previously watched content is not from the switch. This

"mimics" typical TV behavior. For example on older TV-sets if channel 1 is watched, then DVD is watched and the user presses Channel Up: in this case the TV-set goes back to the TV-tuner but it does no go to channel 2, rather it stays at channel 1. The next Channel Up press by the user changes the program to channel 2. Here, a similar algorithm is used: when "switch" is selected for the first time switch, it just stays on the last used input, the next time "switch" is selected it goes to the next input.

When switching to an input where a CEC device is connected, the switch may send it one or more messages (<Set Stream Path>, but possibly additional messages could also be sent for example <Get Device Power Status>, <User control pressed with power codes>,...) to wake it up and forward video.

When switching to a non-CEC device, the switch may send an <Active Source> or other suitable message to the TV to make the TV start Remote Control

Passthrough. The TV forwards the key presses, which the switch receives and can then forward such key presses using an appropriate mechanism to the source device, e.g. IR blaster, RS232, or any other communication mechanism.

According to a second implementation, when the user selects the entry of the switch in the TV UI, the TV sends a message <Set Steam Path > to the switch to wake it up and forward the video (see reference [5] section 13.2 Routing Control for details). In reply thereto, the switch returns an < Active Source> message so that the TV starts Remote Control Passthrough. Figure 7 shows the initial situation wherein the switch 10 forwards video from the DVD player 5 to the TV 22. The TV menu shows the device list of CEC devices connected thereto, as discussed herein above. It shows the entry "switch". When the user selects this entry by using the TV remote control, the TV sends a <Set Stream Path> to the switch to send (forward) video (see [CEC] for details). The switch reacts with an <Active Source> (or other) message, such as <Menu Status Activated>) to the TV to make the TV start Remote Control Passthrough. Now the user can use the TV remote control buttons to control the switch and select which input to watch. The TV sends a User Control

Pressed/Released message with information regarding this key press to the switch and the switch uses the information to select the corresponding input. The TV can also send other CEC commands like Deck Control messages (Play, Stop, FF, REW,...).

The video from the source device connected to this input is then forwarded to the TV, as shown in figure 7.

There are several possibilities of the keys that may be used to select a certain input. A non-restrictive list of examples is now given:

- The user presses a key linked to a particular input to select that input (e.g.

color/numeric key, "1" selects input HDMI1, etc.).

- The user presses a key to select the inputs one by one in a loop (e.g. P+/P-, up/down arrow, left/right arrow, next/previous keys cycle through the available inputs).

- A key is pressed to select the previously selected input (e.g. back key).

Another input is automatically selected after some time, i.e. the system cycles through inputs showing each for a certain time until the user presses a particular button.

Optionally, the switch comprises a mechanism to start Remote Control Passthrough to a selected CEC-enabled device. This mechanism may be triggered by e.g. automatic timeout or pressing an "OK" button by user. As a result, an <active source> message comprising the physical address of the CEC-enabled device is sent by the switch to the TV. Consequently, Remote Control Passthrough to the selected CEC-enabled device is activated.

In case of switching to a non-CEC-enabled device (or non-HDMI device), a mechanism to start Remote Control Passthrough to that device may be triggered, for example automatically by a timeout, by the user pressing an "OK" button, etc. The TV will send information regarding the keypresses. The switch receives this information and can then forward such keypresses using an appropriate mechanism to the source device, e.g. IR blaster, RS232, or any other communication mechanism. It forwards the key to the source that is currently active (e.g. to the source on input 3 if it is currently passing video from input 3).

It is to be noted that the invention may be implemented in hardware and/or software, using programmable components. Methods for implementing the invention have the processing steps corresponding to the processing of video data in the device as shown and elucidated with reference to Fig. 1. The first and second embodiments explained with reference to figures 4-5 and figures 6-7, respectively may be implemented in combination. Although, the invention has been mainly explained by embodiments using HDMI digital interfaces, the invention is also suitable for any video processing environment that is compliant with an interface standard having only digital inputs defined. The invention may be applied in every video processing device, like a switchbox, a multimedia server, an audio video receiver or amplifier, a personal computer having an audio/video interface, etc.

Furthermore, the invention may be applied in any device having any combination of non- HDMI inputs and/or internal sources which are exposed as individual HDMI source devices on different physical addresses, e.g. an apparatus only having a number of internal content sources, and no further digital or analog inputs.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The word 'comprising' does not exclude the presence of other elements or steps than those listed, and the word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. Any reference signs do not limit the scope of the claims. The invention may be implemented by means of both hardware and software, and several elements may be represented by the same item of hardware or software, and a processor may fulfill the function of one or more elements, possibly in cooperation with hardware elements.

LIST OF REFERENCES:

Reference [1]: "High Definition Multimedia Interface; Specification Version 1.3a of Nov 10 2006" available at http://hdmi.org/manufacturer/specification.aspx

Reference [2]: "EN 50049-1 : 1997 Peritelevision connector" (also called SCART); European Standard from CENELEC.

Reference [3]: "EN 300 294 Vl .3.2 (1998-04) Television systems; 625 television Wide Screen Signalling (WSS)"; European Standard from ETSI.

Reference [4]: "EN 50157-1 Domestic and similar electronic equipment interconnection requirements: AV. link. General"; European Standard from CENELEC

Reference [5]: "High-Definition Multimedia Interface Specification Version

1.4"