Patent Publication Number: US-2022217377-A1

Title: Physical adapter, signal processing equipment, methods and computer programs

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/103,784, filed Aug. 14, 2018, which is a continuation of International Application No. PCT/GB2017/050405, filed Feb. 16, 2017, which claims priority to GB Application No. 1602820.1, filed Feb. 17, 2016, under 35 U.S.C. §119(a). Each of the above-referenced patent applications is incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a physical adapter, signal processing equipment, methods and computer programs. 
     2. Description of the Related Technology 
     There is an existing ecosystem of signal processing hardware that contains dedicated hardware chips configured to process certain types of signal. As new signal processing technologies are developed, new hardware chips may need to be developed to enable use of the new signal processing technologies. As a consequence, existing signal processing hardware with legacy hardware chips may be compatible with existing signal processing technologies but may not be compatible with the new signal processing technologies. 
     One known solution for facilitating adoption of new signal processing technologies is to replace the existing signal processing hardware with new signal processing hardware, the new signal processing hardware having new hardware chips that are compatible with the newer signal processing technology. 
     SUMMARY 
     According to a first aspect of the present invention, there is provided a physical adapter configured to: 
     receive at least one data stream comprising at least: 
     data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and 
     reconstruction data produced by processing a rendition of the signal at a second, higher level of quality in the tiered hierarchy and indicating how to reconstruct the rendition of the signal at the second level of quality using the rendition of the signal at the first level of quality; 
     reconstruct the rendition of the signal at the second, higher level of quality based at least on the rendition of the signal at the first level of quality and the reconstruction data; and 
     output at least the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal, 
     wherein the physical adapter is configured to be connectable to signal processing equipment and, when connected to the signal processing equipment, to enhance the functionality of the signal processing equipment with additional functionality provided by the physical adapter, the signal processing equipment being configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     According to a second aspect of the present invention, there is provided signal processing equipment configured to: 
     receive at least one data stream comprising at least: 
     data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and 
     reconstruction data produced by processing a rendition of the signal at a second, higher level of quality in the tiered hierarchy and indicating how to reconstruct the rendition of the signal at the second level of quality using the rendition of the signal at the first level of quality; 
     extract the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the at least one data stream; 
     output the data usable to derive the rendition of the signal at the first level of quality; and 
     output the reconstruction data, 
     wherein the signal processing equipment is configured to be connectable to a physical adapter, the physical adapter being configured to enhance, when connected to the signal processing equipment, the functionality of the signal processing equipment with additional functionality provided by the physical adapter, the signal processing equipment being configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     According to a third aspect of the present invention, there is provided a method comprising, at a physical adapter: 
     receiving at least one data stream comprising at least: 
     data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and 
     reconstruction data produced by processing a rendition of the signal at a second, higher level of quality in the tiered hierarchy and indicating how to reconstruct the rendition of the signal at the second level of quality using the rendition of the signal at the first level of quality; 
     reconstructing the rendition of the signal at the second, higher level of quality based at least on the rendition of the signal at the first level of quality and the reconstruction data; and 
     outputting at least the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal, 
     wherein the physical adapter is configured to be connectable to signal processing equipment and, when connected to the signal processing equipment, to enhance the functionality of the signal processing equipment with additional functionality provided by the physical adapter, the signal processing equipment being configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     According to a fourth aspect of the present invention, there is provided a method comprising, at signal processing equipment: 
     receiving at least one data stream comprising at least: 
     data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and 
     reconstruction data produced by processing a rendition of the signal at a second, higher level of quality in the tiered hierarchy and indicating how to reconstruct the rendition of the signal at the second level of quality using the rendition of the signal at the first level of quality; 
     extracting the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the at least one data stream; 
     outputting the data usable to derive the rendition of the signal at the first level of quality; and 
     outputting the reconstruction data, 
     wherein the signal processing equipment is configured to be connectable to a physical adapter, the physical adapter being configured to enhance, when connected to the signal processing equipment, the functionality of the signal processing equipment with additional functionality provided by the physical adapter, the signal processing equipment being configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     According to a fifth aspect of the present invention, there is provided a computer program comprising instructions which, when executed, cause a physical adapter to perform a method comprising: 
     receiving at least one data stream comprising at least: 
     data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and 
     reconstruction data produced by processing a rendition of the signal at a second, higher level of quality in the tiered hierarchy and indicating how to reconstruct the rendition of the signal at the second level of quality using the rendition of the signal at the first level of quality; 
     reconstructing the rendition of the signal at the second, higher level of quality based at least on the rendition of the signal at the first level of quality and the reconstruction data; and 
     outputting at least the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal, 
     wherein the physical adapter is configured to be connectable to signal processing equipment and, when connected to the signal processing equipment, to enhance the functionality of the signal processing equipment with additional functionality provided by the physical adapter, the signal processing equipment being configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     According to a sixth aspect of the present invention, there is provided a computer program comprising instructions which, when executed, cause signal processing equipment to perform a method comprising: 
     receiving at least one data stream comprising at least: 
     data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and 
     reconstruction data produced by processing a rendition of the signal at a second, higher level of quality in the tiered hierarchy and indicating how to reconstruct the rendition of the signal at the second level of quality using the rendition of the signal at the first level of quality; 
     extracting the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the at least one data stream; 
     outputting the data usable to derive the rendition of the signal at the first level of quality; and 
     outputting the reconstruction data, 
     wherein the signal processing equipment is configured to be connectable to a physical adapter, the physical adapter being configured to enhance, when connected to the signal processing equipment, the functionality of the signal processing equipment with additional functionality provided by the physical adapter, the signal processing equipment being configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     Further features and advantages will become apparent from the following description of embodiments, given by way of example only, which is made with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic block diagram of an example of a signal processing system; 
         FIG. 2  shows a schematic block diagram of an example of a signal processing system in accordance with an embodiment of the present invention; 
         FIG. 3  shows a schematic block diagram of an example of a physical adapter in accordance with an embodiment of the present invention; 
         FIG. 4  shows a schematic block diagram of an example of a signal processing system in accordance with an embodiment of the present invention; 
         FIG. 5  shows a schematic block diagram of an example of signal processing equipment in accordance with an embodiment of the present invention; 
         FIG. 6  shows a schematic block diagram of an example of a physical adapter in accordance with an embodiment of the present invention; 
         FIG. 7  shows a schematic block diagram of an example of further equipment in accordance with an embodiment of the present invention; and 
         FIG. 8  shows a schematic block diagram of an example of an apparatus in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS 
     Referring to  FIG. 1 , there is shown a schematic block diagram of an example of a signal processing system  100 . 
     The signal processing system  100  can be used to process data that can be represented as a tiered hierarchy including multiple different levels of quality. The reader is referred to WO-A1-2014/170819, which describes in detail how data can be processed in such a tiered hierarchy and is hereby incorporated by reference. 
     The signal processing system  100  includes an encoder  101  and a decoder  102 . The encoder  101  and decoder  102  may be embodied in hardware and/or software. 
     The encoder  101  receives a rendition of a signal at a relatively high level of quality  103  directly or indirectly from a source. The source could be, for example, an electronic apparatus which generates and/or records a signal using sensors. For example, in the case of a video signal, the electronic apparatus can be a video camera which records a scene at a specific relatively high level of quality (e.g., Ultra High Definition (UHD)) by using a number of sensors (e.g., charge-coupled devices (CCDs), complementary metal-oxide semiconductor (CMOS), etc.) to capture the information in the scene (for example, the intensity of the light at a particular position in the scene). In general, the level of quality at which the scene is recorded is proportional to the number of sensors used by the camera. The video signal could be further processed and/or stored (by the camera and/or different apparatuses) before being received by the encoder  101 . 
     For convenience and brevity, in this example, the signal  103  is in the form of a video signal, it being understood that the signal  103  may be of a different type. For example, the signal  103  may be a sound signal, multichannel sound signal, picture, two-dimensional image, multi-view video signal, 3D video signal, volumetric signal, volumetric video signal, medical imaging signal or a signal with more than four dimensions. 
     The signal processing system  100  provides renditions of the video signal at multiple different levels of quality. In this example, the signal processing system  100  provides renditions of the video signal at three different levels of quality, it being understood that renditions of the video signal at a different number of levels of quality could be provided. In this specific example, the signal processing system  100  provides renditions of the video signal at relatively high, medium and relatively low levels of quality. In this specific example, the relatively high level of quality corresponds to UHD, the medium level of quality corresponds to High Definition (HD) and the relatively low level of quality corresponds to Standard Definition (SD). It is important to note that other configurations are possible. For example, the signal processing system  100  may provide renditions of the video signal at only two levels of quality; a relatively high level of quality and a relatively low level of quality. In such a case, the relatively level of quality may correspond to HD when the relatively low level of quality is SD, or it can correspond to UHD when the relatively low level of quality is HD. Alternatively, the signal processing system  100  may provide renditions of the video signal at more than three levels of quality. The embodiments described below apply mutatis mutandis to all such possible configurations. 
     One measure of the level of quality of a rendition of a video signal is its resolution. A higher resolution corresponds to a higher quality. The resolution may be spatial and/or temporal. Another measure of a level of quality of a rendition of a video signal is whether the rendition of the video signal is progressive or interlaced, with progressive corresponding to a higher quality than interlaced. 
     As described in detail in WO-A1-2014/170819, the encoder  101  processes the rendition of the video signal received directly or indirectly from a source at the relatively high level of quality  103  (e.g. UHD) to produce a rendition of the video signal at a medium level of quality  104  (e.g. HD) and to produce reconstruction data  105 . The reconstruction data  105  indicates how to reconstruct the rendition of the video signal at the relatively high level of quality  103  (e.g. UHD) using the rendition of the video signal at the medium level of quality  104  (e.g. HD). Reconstruction of the video signal at the relatively high level of quality  103  (e.g. UHD) may involve using other data. For example, such reconstruction may involve using synchronisation data to synchronise the reconstruction data  105  with the rendition of the video signal at the medium level of quality  104  (e.g. HD). 
     Further, the encoder  101  may process the rendition of the video signal at the medium level of quality  104  (e.g. HD) to produce a rendition of the video signal at a relatively low level of quality  106  (e.g. SD) and to produce reconstruction data  107 . The reconstruction data  107  indicates how to reconstruct the rendition of the video signal at the medium level of quality  104  (e.g. HD) using the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). Reconstruction of the video signal at the medium level of quality  104  (e.g. HD) may involve using other data. For example, such reconstruction may involve using synchronisation data to synchronise the reconstruction data  107  with the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). The process can then continue to produce further renditions at levels of quality lower than that of the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and to produce corresponding reconstruction data, each indicating how to reconstruct a rendition of the video signal at a higher level of quality using the rendition of the video signal at a lower level of quality. 
     The encoder  101  generates data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). The data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) may for example comprise an encoded version of the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). 
     The encoder  101  transmits the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and the reconstruction data  105 ,  107  to the decoder  102 . The encoder may transmit the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and the reconstruction data  105 ,  107  to the decoder  102  in one or more data streams. 
     In this example, the encoder  101  combines the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and the reconstruction data  105 ,  107  into a multiplexed data stream. In another example, the encoder  101  may send the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and the reconstruction data  105 ,  107  in separate, non-multiplexed data streams. 
     In this specific example, the multiplexed data stream is a Moving Pictures Expert Group (MPEG) transport stream (MPEG-TS). 
     MPEG-TS is a container format for transmission and storage of data including video, audio and other data. MPEG-TS is used in broadcast systems, such as Digital Video Broadcasting (DVB), Advanced Television Systems Committee (ATSC) and Internet Protocol Television (IPTV). 
     An MPEG-TS comprises multiple sub-streams known as elementary streams (ES), which are packetized and multiplexed together. An elementary stream can contain video data, audio data, or other data. For example, a video data stream can be encoded into an MPEG-2 encoded elementary stream. The MPEG-2 encoded elementary stream is then packetized into a packetized elementary stream (PES). To create the transport stream, the PESs are again packetized into transport packets, which are then multiplexed into the MPEG-TS. 
     Each elementary stream has an associated identifier, known as a packet identifier (PID). The PID comprises 13 bits. Each PID is unique within a particular MPEG-TS. 
     A program is associated with one or more elementary streams. For example, a program may be associated with a video elementary stream, an audio elementary stream and a data elementary stream. Each program is described by a Program Map Table (PMT), which also has its own PID and is transmitted in the MPEG-TS. Each elementary stream associated with a program has its PID listed in the PMT associated with that program. 
     For example, an MPEG-TS used in digital television may comprise three programs, each representing a different television channel. To decode a particular television channel, the receiver decodes the payloads of the packets having PIDs matching the PIDs in the PMT associated with the program corresponding to that channel. The receiver can discard the content of packets having other PIDs. 
     An elementary stream may be associated with multiple programs, by having its PID included in the PMTs associated with the multiple programs. 
     In this example, the encoder  101  produces a first elementary stream comprising the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and one or more further elementary streams comprising the reconstruction data  105 ,  107 . 
     The decoder  102  uses the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). This may for example involve the decoder  102  decoding the received data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). 
     The decoder  102  uses the reconstruction data  107  and the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) to reconstruct the rendition of the video signal at the medium level of quality  104  (e.g. HD). As such the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) is used as a baseline for reconstructing the rendition of the video signal at the medium level of quality  104  (e.g. HD). Such reconstruction may involve using synchronisation data. 
     The decoder  102  uses the reconstruction data  105  and the rendition of the video signal at the medium level of quality  104  (e.g. HD) to reconstruct the rendition of the video signal at the relatively high level of quality  103  (e.g. UHD). As such the rendition of the video signal at the medium level of quality  104  (e.g. HD) is used as a baseline for reconstructing the rendition of the video signal at the relatively high level of quality  103  (e.g. UHD). Such reconstruction may involve using synchronisation data. 
     A first program may have a PMT listing the PID of the elementary stream comprising the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD), but not the at least one PID of the at least one elementary stream comprising the reconstruction data  105 ,  107 . In this example, the first program is associated with the relatively low level of quality only (e.g. SD only). The decoder  102  seeking to decode the channel associated with the first program would decode the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) but not the reconstruction data  105 ,  107 . The decoder  102  would therefore be able to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) but would not be able to reconstruct the renditions of the video signal at the relatively high (e.g. UHD) or medium (e.g. HD) levels of quality  103 ,  104 . This may allow for backwards compatibility with existing decoders, for example where the existing decoders are compatible with SD video data but are not compatible with HD or UHD video data. 
     A second program may have a PMT listing the PID of the elementary stream comprising the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and also at least one PID of at least one elementary stream comprising the reconstruction data  105 ,  107 . In this example, the second program is associated with at least one of the relatively high (e.g. UHD) and medium (e.g. HD) levels of quality. The decoder  102  seeking to decode the channel associated with the second program would use the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and the reconstruction data  105 ,  107 . The decoder  102  would therefore be able to reconstruct the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) and would be able to reconstruct the rendition of the video signal at the medium level of quality  104  (e.g. HD) and, if the decoder  102  receives the reconstruction data  107 , also at the relatively high level of quality  103  (e.g. UHD). 
     The encoder  101  may transmit some or all of the reconstruction data  105 ,  107  to the decoder  102 . If the decoder  102  is not able to process the reconstruction data  105 ,  107  it receives, the decoder  102  may ignore any of the reconstruction data  105 ,  107  that it cannot process. In such an example, the decoder  102  may be able to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD) from the data  108  usable to derive the rendition of the video signal at the relatively low level of quality  106  (e.g. SD), but may not be able to reconstruct the renditions of the video signal at the relatively high (e.g. UHD) and medium (e.g. HD) levels of quality  103 ,  104 . 
     The encoder  101  may transmit all of the reconstruction data  105 ,  107  to a plurality of decoders  102 . Those decoders  102  that are able to process the reconstruction data  105 ,  107  may do so, for example to reconstruct the renditions of the video signal at the relatively high (e.g. UHD) and medium (e.g. HD) levels of quality  103 ,  104 . Those decoders  102  that cannot process the reconstruction data  105 ,  107  may ignore the reconstruction data  105 ,  107  and derive only the rendition of the video signal at the relatively low level of quality  106  (e.g. SD). This, again, can provide backwards compatibility when newer signal processing technologies are developed. 
     Obtaining the reconstruction data by processing a rendition of a signal at a given level of quality can comprise processing (e.g. downsampling) the rendition of the signal at the given level of quality to obtain a rendition of the signal at a lower level of quality and processing (e.g. upsampling) the rendition of the signal at the lower level of quality to obtain a further rendition of the signal at the given level of quality, the reconstruction data being indicative of the difference between the rendition of the signal at the given level of quality and the further rendition of the signal at the given level of quality resulting from such processing (e.g. downsampling and upsampling). The reconstruction data may be used to reconstruct the rendition of the signal at the given level of quality by processing (e.g. upsampling) the rendition of the signal at the lower level of quality to obtain the further rendition of the signal at the given level quality and then combining the reconstruction data with the further rendition of the signal at the given level of quality to obtain the rendition of the signal at the given level of quality. 
     Referring to  FIG. 2 , there is shown a schematic block diagram of an example of a signal processing system  200 . 
     The signal processing system  200  comprises signal processing equipment  201  and a physical adapter  202 . 
     The physical adapter  202  has a relatively small form factor compared to that of the signal processing equipment  201 . The physical adapter  202  is designed to perform at least one specific function in cooperation with the signal processing equipment  201 . In this example, the signal processing equipment  201  is not able to perform the at least one specific function by itself. In other words, the signal processing equipment  201  can only perform the at least one specific function when it is communicatively coupled to the physical adapter  202 . 
     The signal processing equipment  201  is communicatively coupled to the physical adapter  202  via at least one connection  203 . As such, the physical adapter  202  is configured to be connectable to the signal processing equipment  203 , via the at least one connection  203 . 
     In an example, the physical adapter  202  is directly physically connected to the signal processing equipment  201 . In another example, the physical adapter  202  is indirectly physically connected to the signal processing equipment  201 . The physical adapter  202  may be indirectly physically connected to the signal processing equipment  201  via at least one cable. In another example, the physical adapter  202  is wirelessly connected to the signal processing equipment  201 . 
     The signal processing equipment  201  is configured to transmit at least one data stream to the physical adapter  202  via the at least one connection  203 . The physical adapter  202  is configured to receive the at least one data stream from the signal processing equipment  201  via the at least one connection  203 . 
     The at least one data stream comprises data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality. The at least one data stream also comprises reconstruction data. The reconstruction data indicates how to reconstruct a rendition of the signal at a second, higher level of quality in the tiered hierarchy. The at least one data stream may comprise other data. Examples of other data include, but are not limited to, audio data and/or synchronisation data. 
     The physical adapter  202  is configured to use the data usable to derive the rendition of the signal at the first level to derive the rendition of the signal at the first level of quality. 
     The physical adapter  202  is configured to reconstruct the rendition of the signal at the second, higher level of quality based on the rendition of the signal at the first level of quality and the reconstruction data. The physical adapter  202  may be configured to reconstruct the rendition of the signal at the second, higher level of quality based on additional data, such as synchronisation data. 
     The physical adapter  202  is configured to output the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal. The physical adapter  202  may be configured to output additional data, such as audio data. In an example, the physical adapter  202  is configured to output the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal to the signal processing equipment  201 . In another example, the physical adapter  202  is configured to output the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal to further equipment (not shown), where the further equipment is different from the signal processing equipment  201 . 
     As such, the signal processing equipment  201  is configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter  202  is configured to increase the quality of the rendition of the signal relative to that produced by the signal processing equipment  201 . 
     By communicatively coupling the physical adapter  202  to the signal processing equipment  201  in this way, the signal processing equipment  201  does not need to be replaced by entirely new signal processing equipment, but is enhanced via the physical adapter  202 . As result it may not be necessary to dispose of the signal processing equipment  201 . This can have environmental benefits by reducing the amount of electrical waste. Further, the cost of providing the physical adapter  202  may be lower than providing an entirely new signal processing equipment. For example, at least some of the functionality of the existing signal processing equipment may still be compatible with the new signal processing technology and therefore does not need to be replaced. 
     Use of the physical adapter  202  may therefore allow the signal processing system  200  to perform operations where the signal processing equipment  201  is not capable of supporting such operations itself. For example, the signal processing equipment  201  may not have sufficient internal bandwidth to support such operations itself. In another example, it may not be possible, for technical or other purposes, to modify software in the video driver of the signal processing equipment  201  to allow the signal processing equipment  201  to support such operations itself. In yet another example, the signal processing equipment  201  may not have an output interface that would support output of the rendition of the signal at the second, higher level of quality; the physical adapter  201  may be used instead of, for example, updating an HDMI 1.4 output interface of the signal processing equipment  201  to an HDMI 2.0 output interface to support a higher data rate. 
     Referring to  FIG. 3 , there is shown a schematic block diagram of an example of a physical adapter  300 . 
     For convenience and brevity, in this example the physical adapter  300  is a conditional-access module (CAM), it being understood that the physical adapter  300  may be of a different type. 
     A CAM is an electronic device that enables a host device to handle conditional access content. Conditional access concerns the protection of content by requiring certain conditions to be met before access to the content is allowed. Examples of host devices include, but are not limited to, televisions, for example integrated digital televisions, and set-top boxes (STBs). 
     A host device has at least one slot adapted to receive a CAM. A host device may have multiple slots to allow the host device to communicate with multiple CAMs. The one or more slots may be of a Personal Computer Memory Card International Association (PCMCIA) type. Where a CAM is connected to the host device, the host device passes a received signal to the CAM for processing and the CAM returns the processed signal to the host device. 
     A CAM may have a slot for a smart card and a smart card reader to read data from the smart card for authentication and decryption purposes. Authentication and decryption functionality may instead be embedded in memory in the CAM. The CAM is used to derive short-term decryption keys for the conditional access content. The smart card may, for example, allow access to pay-per-view content. 
     The host device is responsible for tuning to the appropriate channel or channels and demodulating the received signal. The CAM is used for descrambling the received signal. For example, the CAM may receive a scrambled transport stream, for example an MPEG-TS, from the host device via a Common Interface (CI), descramble the scrambled transport stream, and output the descrambled transport stream to the host device via the CI in a format that is usable by the host device. 
     The CAM  300  has a physical interface  301 . The CAM  300  may be communicatively coupled to signal processing equipment via the physical interface  301 . In this example, the physical interface  301  is a Digital Video Broadcast-Common Interface, DVB-CI. 
     The physical interface  301  has a receiving part  302  and a transmitting part  303 . Although the receiving part  302  and the transmitting part  303  are shown as separate parts of the physical interface  301 , it will be appreciated that the separation may be logical rather than physical. 
     The CAM  300  is configured to receive data  304  via the receiving part  302 . 
     In this example, the data  304  is a multiplexed data stream. The multiplexed data stream  304  comprises data usable to derive the rendition of the signal at the first level of quality and reconstruction data. In this specific example, the multiplexed data stream is an MPEG-TS as described above. 
     The CAM  300  is therefore configured to receive the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data via a common physical interface, physical interface  301 , of the CAM  300 . In other words, the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data are both received via the same interface of the CAM  300 , namely physical interface  301 . 
     In this example, the receiving part  302  is configured to output data  305  to a demultiplexer  306 . 
     In this example, the demultiplexer  306  is configured to extract three data streams from data  305 . It will be appreciated however that the demultiplexer  306  could be configured to extract a different number of data streams from data  305 . The demultiplexer  306  is configured to extract the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the data  305  received from the receiving part  302 . In the case of the MPEG-TS, the demultiplexer  306  may extract the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the data  305  by identifying packets in the received MPEG-TS having PIDs associated with the elementary streams comprising the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data. 
     The demultiplexer  306  is configured to output a first extracted data stream  307  to a first decoder  308 . The first extracted data stream  307  comprises the data usable to derive the rendition of the signal at the first level of quality. In this example, the first extracted data stream  307  comprises encoded video data, for example MPEG- 2  encoded video data. The demultiplexer  306  therefore receives and outputs the data usable to derive the rendition of the signal at the first level of quality in an encoded form. 
     The first decoder  308  is configured to decode the data usable to derive the rendition of the signal at the first level of quality and to output a first decoded data stream  309  to a second decoder  310 . For example, the first decoder  308  uses an MPEG-2 codec to decode MPEG-2 encoded video data. 
     The demultiplexer  306  is also configured to output a second extracted data stream  311  to the second decoder  310 . The second extracted data stream  311  comprises the reconstruction data. 
     The second decoder  310  is configured to process the first decoded data stream  309  and the second extracted data stream  311 . The second decoder  310  is configured to derive the rendition of the signal at the first level of quality using the data usable to derive the rendition of the signal at the first level of quality comprised in the first decoded data stream  309 . The second decoder  310  is also configured to use the derived rendition of the signal at the first level of quality and the reconstruction data to reconstruct the rendition of the signal at the second, higher level of quality. 
     The second decoder  310  is configured to output decoded data  312  to an encoder  313 . The decoded data  312  comprises at least the rendition of the signal at the second, higher level of quality. In this example, the decoded data  312  does not comprise the reconstruction data, the reconstruction data having already been used by the second decoder  310  to reconstruct the rendition of the signal at the second, higher level of quality. 
     The encoder  313  is configured to encode the decoded data  312  and to output encoded data  314  to a multiplexer  315 . As such the encoder  313  is configured to encode the rendition of the signal at the second, higher level of quality. The encoded data  314  is derived from the rendition of the signal at the second, higher level of quality. In this example, the encoder  313  is configured to encode data  312  using an MPEG-2 codec. In a specific example, the encoder  313  is configured to encode data  312  using MPEG-2 intra-frame coding only. In other words, in such a specific example, the encoder  313  does not use MPEG-2 inter-frame coding. 
     The demultiplexer  306  is also configured to extract and output a third extracted data stream  316  to the multiplexer  315 . The third extracted data stream  316  comprises additional data. The additional data may comprise audio data. The demultiplexer  306  may extract the additional data by identifying packets in the received MPEG-TS having the PID with a elementary stream comprising the audio data. 
     The multiplexer  315  is configured to multiplex the encoded data  314  with the third extracted data stream  316  (which, in this example, is audio data) and to output multiplexed data  317  to the transmitting part  303  of the physical interface  301 . The transmitting part  303  is configured to output data  318 . 
     The CAM  300  is therefore configured to output the data derived from the reconstructed rendition of the signal at the second, higher level of quality via the same (or ‘common’) physical interface via which the data  304  is received, namely the physical interface  301 . 
     In this example, the CAM  300  is configured to output the data derived from the reconstructed rendition of the signal at the second, higher level of quality to the same signal processing equipment from which the data  304  is received. However, a physical adapter  300  may be configured to output the data derived from the reconstructed rendition of the signal at the second, higher level of quality to a different signal processing equipment than the one from which the data  304  is received. 
     In this example, the CAM  300  is configured to be powered by signal processing equipment. The CAM  300  may be configured to be powered via the common physical interface  301 . 
     In this example, the CAM  300  performs the function of a transcoder plugin. 
     In an example, the CAM  300  receives an MPEG-2 encoded transport stream and outputs an MPEG-2 encoded data stream. The output MPEG-2 encoded data stream comprises video data at a higher level of quality than the video data in the received MPEG-2 encoded transport stream. The level of quality is increased using the reconstruction data. As such, the CAM  300  processes the received data, increases the quality of the video data within it and outputs data as if the higher quality video data had been in the initially received data. This reconstruction process is, in effect, transparent to the signal processing equipment with which the CAM  300  communicates. From the perspective of the signal processing equipment, it is as if the CAM  300  had initially received the higher quality video. 
     Referring to  FIG. 4 , there is shown a schematic block diagram of an example of a signal processing system  400 . 
     The signal processing system  400  is similar to the signal processing system  200  described above in that it includes signal processing equipment  401  and a physical adapter  402  configured to be connectable to the signal processing equipment  401 . In this example, the physical adapter  402  is communicatively coupled to the signal processing equipment  401  via a first connection  403  and a second connection  404 . The physical adapter  402  is communicatively coupled to further equipment  405  via a third connection  406 . 
     For convenience and brevity, in this example the signal processing equipment  401  is an HD STB, it being understood that the signal processing equipment  401  may be of a different type. For example, the signal processing equipment  401  may be a different type of STB or a different type of signal processing equipment  401  altogether. 
     In this example, the HD STB  401  is capable of deriving a rendition of a video signal at a first level of quality (e.g. HD), but is not capable itself of reconstructing a rendition of the video signal at the second, higher level of quality (e.g. UHD). The HD STB  401  is provided with additional (or ‘enhanced’) functionality by communicatively coupling the physical adapter  402  to it. The physical adapter  402  is configured to reconstruct the rendition of the video signal at the second, higher level of quality (e.g. UHD). 
     For convenience and brevity, in this example the physical adapter  402  is an HDMI dongle, it being understood that the physical adapter  402  may be of a different type. For example, the physical adapter  402  may be a different type of dongle (for example one that does not use HDMI) or a different type of physical adapter altogether. 
     A dongle is a device that is configured to be communicatively coupled to another device to provide that device with additional functionality. A dongle may have a relatively small form factor compared to the form factor of the device to which it is communicatively coupled. The device to which the dongle is attached only has the additional functionality when the dongle is communicatively coupled to it. The dongle may be communicatively coupled via a direct physical connection, an indirect physical connection and/or a wireless connection. 
     The HDMI dongle  402  is configured to increase the quality of the rendition of the video signal to a higher level of quality (e.g. UHD) than the level of quality the HD STB  401  is capable of deriving (e.g. HD). 
     In this example, the HD STB  401  is configured to derive the rendition of the video signal at the first level of quality (e.g. HD) using an HD base codec. The HD STB  401  is configured to provide the decoded rendition of the video signal at the first level of quality (e.g. HD) to the HDMI dongle  402  over the first connection  403 . In this example, the first connection  403  is an HDMI connection. In this specific example, the HDMI connection  403  is an HDMI 1.4 connection. In this example, the HDMI 1.4 connection has sufficient capacity to be able to support transmission of the decoded rendition of the video signal at the first level of quality (e.g. HD) to the HDMI dongle  402 . However, in this example, the HDMI 1.4 connection does not have sufficient capacity to be able to carry the rendition of the video signal at the second, higher level of quality (e.g. UHD) to the HDMI dongle  402 . 
     The HD STB  401  is configured to extract reconstruction data from the received data and to provide the reconstruction data to the HDMI dongle  402  over the second connection  404 . In this example, the second connection  404  is a USB connection. 
     The HDMI dongle  402  receives the decoded rendition of the video signal at the first level of quality (e.g. HD) over the HDMI connection  403  and receives the reconstruction data over the USB connection  404 . The HDMI dongle  402  synchronises the received rendition of the video signal at the first level of quality (e.g. HD) and the received reconstruction data and reconstructs the rendition of the video signal at the second, higher level of quality (e.g. UHD) using the rendition of the video signal at the first level of quality (e.g. HD) and the reconstruction data. 
     The HDMI dongle  402  outputs the rendition of the video signal at the second, higher level of quality (e.g. UHD) to the further equipment  405  over the third connection  406 . In this example, the further equipment  405  comprises a display device capable of displaying the rendition of the video signal at the second, higher level of quality (e.g. UHD). In this example, the third connection  406  is an HDMI connection. More specifically, in this example, the HDMI connection  406  is an HDMI 2.0 connection. In this example, the HDMI 2.0 has sufficient capacity to be able to support transmission of the rendition of the video signal at the second, higher level of quality (e.g. UHD) to the further equipment  405 . 
     The further equipment  405  then processes the rendition of the video signal at the second, higher level of quality (e.g. UHD) received over the third connection  406 . For example, the further equipment  405  may cause the rendition of the video signal at the second, higher level of quality (e.g. UHD) to be displayed. 
     It will be appreciated that although, in this example, the HD STB  401  is capable of decoding HD video data, it is not capable of decoding video data at a higher level of quality. The HDMI dongle  402  enhances the functionality of the HD STB  401  by allowing the HD STB  401  to provide video data at the higher level of quality, using the HDMI dongle  402 . 
     Referring to  FIG. 5 , there is shown a schematic block diagram of an example of signal processing equipment  500 . 
     For convenience and brevity, in this example the signal processing equipment  500  is an STB, it being understood that the signal processing equipment  500  may be of a different type. 
     The STB  500  is configured to receive data  501 . The data  501  comprises at least one data stream. The at least one data stream comprises data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality. The at least one data stream also comprises reconstruction data indicating how to reconstruct a rendition of the signal at a second, higher level of quality in the tiered hierarchy. 
     In this example, the signal processing equipment  500  is configured to receive the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data in a multiplexed data stream. The multiplexed data stream may be a broadcast multiplexed data stream. In this example, the multiplexed data stream is an MPEG-TS as described above. In this example, the first level of quality is HD and the reconstruction data is UHD reconstruction data to allow reconstruction of the rendition of the video signal at the second, higher UHD level of quality. 
     In this example, signal processing equipment  500  has a CAM  502  that receives and processes the data  501 . In this example, the CAM  502  is a conventional CAM that descrambles received data but does not increase the level of quality of the received data in the manner described above in relation to CAM  300 . The CAM  502  is configured to output data  503  to a demultiplexer  504 . The data  503  output by the CAM  502  comprises the data usable to derive the rendition of the signal at the first level of quality (e.g. HD) and also comprises the reconstruction data. 
     In this example, demultiplexer  504  is configured to extract three data streams from the data  503  received from the CAM  502 . 
     The demultiplexer  504  is configured to extract and output a first extracted data stream  505  to a security module  506  of the signal processing equipment  500 . The first extracted data stream  505  comprises the data usable to derive the rendition of the video signal at the first level of quality (e.g. HD). 
     The demultiplexer  504  is also configured to output a second extracted data stream  507  to the security module  506  of the signal processing equipment  500 . The second extracted data stream  507  comprises additional data associated with the video signal. In this example, the additional data is audio data. 
     The security module  506  is configured to process the first extracted data stream  505  and the second extracted data stream  507  and to output data  508  to a first physical interface  509  of the signal processing equipment  500 . 
     In this example, the first physical interface  509  is a High-Definition Multimedia Interface, HDMI. The security module  506  is configured to encrypt at least the data usable to derive the rendition of the signal at the first level of quality (e.g. HD). The output data  508  is therefore encrypted data. In this example, the security module  506  is configured to use High-bandwidth Digital Content Protection, HDCP, to encrypt at least the data usable to derive the rendition of the signal at the first level of quality (e.g. HD). 
     The first physical interface  509  is configured to output data  510 . 
     The demultiplexer  504  is configured to extract and output a third extracted data stream  511  to a second physical interface  512  of the signal processing equipment  500 . The third extracted data stream  511  comprises the reconstruction data. The second physical interface  512  is different from the first physical interface  509 . In this example, the second physical interface  512  is a Universal Serial Bus, USB, interface. 
     The second physical interface  512  is configured to output data  513 . 
     The signal processing equipment  500  is configured to output data  510  and data  513  to a physical adapter. The physical adapter may, for example, be in the form of a dongle. 
     As such, the signal processing equipment  500  is configured to be connectable to a physical adapter. The signal processing equipment  500  is configured to output the data usable to derive the rendition of the signal at the first level of quality (e.g. HD) and the physical adapter is configured to increase the quality of the rendition of the signal relative to the first level of quality (e.g. from HD to UHD). 
     In this example, the signal processing equipment  500  is configured to transmit synchronisation data via the first physical interface  509 . The synchronisation data is to be used by the physical adapter to reconstruct the rendition of the signal at the second, higher level of quality (e.g. UHD). 
     In an example, the synchronisation data is comprised in a presentation timestamp (PTS). PTS is a timestamp metadata field in an MPEG transport stream that is used to achieve synchronisation of the different elementary streams of a program. 
     In another example, the signal processing equipment  500  is configured to transmit the synchronisation data as PTS in blanking periods of HDMI frames. For example, the PTS may be transmitted as island packets in horizontal blanking periods of the HDMI transmission. 
     In another example, the signal processing equipment  500  is configured to transmit the synchronisation data as PTS in a private audio stream. 
     In another example, the signal processing equipment  500  is configured to transmit the synchronisation data as PTS by placing it in a Chroma plane. For example, the PTS may be placed in the top right corner of the Chroma plane so that it is unlikely to be noticed by the user. 
     The signal processing equipment  500  is configured to provide power to the physical adapter. In this example, the signal processing equipment  500  is configured to provide power to the physical adapter via the second physical interface  512 . 
     In an example, the signal processing equipment  500  is modified to be able to operate in the manner described above with reference to  FIG. 5 . For example, signal processing equipment may initially be configured to such that the reconstruction data would not be output via the second physical interface  512 . Such modification may be made via a software update to the signal processing equipment  500  in order to have the reconstruction data output via the second physical interface  512 . The software update may for example be made via an over-the-air (OTA) update. Alternatively the software may be updated manually, for example by a user downloading the updated software onto the signal processing equipment  500  (for example using a memory stick) and then installing the updated software. 
     Referring to  FIG. 6 , there is shown a schematic block diagram of an example of a physical adapter  600 . 
     For convenience and brevity, in this example the physical adapter  600  is an HDMI dongle, it being understood that the physical adapter  600  may be of a different type. 
     The HDMI dongle  600  has a first physical interface  601 . The HDMI dongle  600  may be communicatively coupled to signal processing equipment  401 ,  500  via the first physical interface  601 . The HDMI dongle  600  is configured to receive first data  602  via the first physical interface  601 . In this example, the first physical interface  601  is an HDMI. In this specific example, the first physical interface  601  is an HDMI 2.0. In this example, the first data  602  comprises data usable to derive the rendition of the signal at the first level of quality (e.g. HD). 
     In this example, the first data  602  also comprises synchronisation data. The synchronisation data is to be used by the HDMI dongle  600  to reconstruct the rendition of the signal at the second, higher level of quality (e.g. HD). As such, the HDMI dongle  600  is configured to receive the synchronisation data via the first physical interface  601 . In this example, the synchronisation data is received from the signal processing equipment  401 ,  500 . 
     The HDMI dongle  600  has a second physical interface  603 . The HDMI dongle  600  may be communicatively coupled to signal processing equipment  401 ,  500  via the second physical interface  603 . The HDMI dongle  600  is configured to receive second data  604  via the second physical interface  603 . In this example, the second physical interface is a USB interface. 
     As such, the HDMI dongle  600  is configured to receive the data usable to derive the rendition of the signal at the first level of quality (e.g. HD) via the first physical interface  601  and to receive the reconstruction data via the second, different physical interface  603 . 
     The first physical interface  601  is configured to output data  605  to a first security module  606 . In this example, the data  605  comprises the data usable to derive the rendition of the signal at the first level of quality (e.g. HD). 
     The first security module  606  is configured to process the data  605  received from the first physical interface  601 . In this example, processing of the data  605  by the first security module  606  comprises decrypting the data usable to derive the rendition of the signal at the first level of quality (e.g. HD). In this example, the first security module  606  is configured to use HDCP to decrypt the data usable to derive the rendition of the signal at the first level of quality (e.g. HD). 
     In this example, processing of the data  605  by the first security module  606  also includes extracting a plurality of data streams from the data  605 . 
     In this example, the first security module  606  is configured to extract and output a first extracted data stream  607  to a decoder  608 . 
     The first security module  606  is also configured to extract and output a second extracted data stream  609  to a first synchronisation module  610 . 
     The first synchronisation module  610  is configured to receive output data  611  from the second physical interface  603 . In this example, the data  611  received from the second physical interface  603  comprises the reconstruction data. 
     The first synchronisation module  610  is configured to process the second extracted data stream  609  received from the security module  606  and the output data  611  received from the second physical interface  603  and to output data  612  to the decoder  608 . 
     The decoder  608  is configured to process the first extracted data stream  607  received from the first security module  606  and the data  612  received from the first synchronisation module  610  and to output decoded data  613  to a second synchronisation module  614 . 
     The first security module  606  is also configured to extract and output a third extracted data stream  615  to the second synchronisation module  614 . The third extracted data stream  615  comprises additional data. In this example, the additional data comprises audio data. 
     The second synchronisation module  614  is configured to process the decoded data  613  received from the decoder  608  and the third extracted data stream  615  received from the first security module  606  and to output data  616  to a second security module  617 . 
     The second security module  617  is configured to process the data  616  received from the second synchronisation module  614  and to output data  618  to a third physical interface  619  of the HDMI dongle  600 . 
     In this example, the processing of the data  616  by the second security module  617  comprises encrypting the reconstructed rendition of the signal at the second, higher level of quality (e.g. UHD) and/or encrypting data derived from the reconstructed rendition of the signal at the second, higher level of quality (e.g. UHD). In this example, the second security module  617  is configured to use HDCP to encrypt the reconstructed rendition of the signal at the second, higher level of quality (e.g. UHD) and/or encrypt the data derived from the reconstructed rendition of the signal at the second, higher level of quality (e.g. UHD). 
     The third physical interface  619  of the HDMI dongle  600  is different from the first physical interface  601  of the HDMI dongle  600 . The third physical interface  619  of the physical adapter  600  is also different from the second physical interface  603  of the HDMI dongle  600 . In this example, the third physical interface  619  is a HDMI. More specifically, in this example, the third physical interface  619  is a HDMI 2.0. 
     The third physical interface  619  of the HDMI dongle  600  is configured to output data  620 . 
     As such, the HDMI dongle  600  is configured to output the reconstructed rendition of the signal at the second, higher level of quality (e.g. UHD) and/or the data derived from the reconstructed rendition of the signal at the second, higher level of quality (e.g. UHD) via the third physical interface  619 . 
     In this example, the third physical interface  619  is configured to output the data  620  to further equipment. In an example, the further equipment is a television. 
     In this example, the HDMI dongle  600  is configured to be powered by signal processing equipment  401 ,  500 . For example, the HDMI dongle  600  may be configured to be powered via the second physical interface  603 . In another example, the HDMI dongle  600  may be powered in a different way. For example, the HDMI dongle  600  may be powered by an internal battery. 
     Referring to  FIG. 7 , there is shown a schematic block diagram of an example of further equipment  700 . 
     For convenience and brevity, in this example the further equipment  700  is a television, it being understood that the further equipment  700  may be of a different type. 
     The television  700  has a first physical interface  701 . The television  700  may be communicatively coupled to a physical adapter, for example physical adapter  600 , via the first physical interface  701 . The television  700  is configured to receive first data  702  via the first physical interface  701 . The first physical interface  701  is configured to output data  703  to a security module  704 . 
     The security module  704  is configured to process the data  703  received from the first physical interface  701 . In this example, processing of the data  703  by the security module  704  comprises decrypting the data  703 . In this example, the security module  704  is configured to use HDCP to decrypt the data  703 . 
     The security module  704  is configured to output data  705  to at least one further module  706  in the television  700 . This may, for example, involve displaying the decrypted received data. 
     Referring to  FIG. 8 , there is shown a schematic block diagram of an example of an apparatus  800 . 
     In an example, the apparatus  800  is signal processing equipment. Examples of signal processing equipment include, but are not limited to, an STB or television. In another example, the apparatus  800  is a physical adapter. Examples of physical adapter include, but are not limited to, a CAM or a dongle. 
     Other examples of apparatus  800  include, but are not limited to, a mobile computer, a personal computer system, a wireless device, base station, phone device, desktop computer, laptop, notebook, netbook computer, mainframe computer system, handheld computer, workstation, network computer, application server, storage device, a consumer electronics device such as a camera, camcorder, mobile device, video game console, handheld video game device, a peripheral device such as a switch, modem, router, etc., or in general any type of computing or electronic device. 
     In this example, the apparatus  800  comprises one or more processors  801  configured to process information and/or instructions. The one or more processors  801  may comprise a central processing unit (CPU). The one or more processors  801  are coupled with a bus  802 . Operations performed by the one or more processors  801  may be carried out by hardware and/or software. The one or more processors  801  may comprise multiple co-located processors or multiple disparately located processors. 
     In this example, the apparatus  800  comprises computer-usable volatile memory  803  configured to store information and/or instructions for the one or more processors  801 . The computer-usable volatile memory  803  is coupled with the bus  802 . The computer-usable volatile memory  803  may comprise random access memory (RAM). 
     In this example, the apparatus  800  comprises computer-usable non-volatile memory  804  configured to store information and/or instructions for the one or more processors  801 . The computer-usable non-volatile memory  804  is coupled with the bus  802 . The computer-usable non-volatile memory  804  may comprise read-only memory (ROM). 
     In this example, the apparatus  800  comprises one or more data-storage units  805  configured to store information and/or instructions. The one or more data-storage units  805  are coupled with the bus  802 . The one or more data-storage units  805  may for example comprise a magnetic or optical disk and disk drive or a solid-state drive (SSD). 
     In this example, the apparatus  800  comprises one or more input/output (I/O) devices  806  configured to communicate information to and/or from the one or more processors  801 . The one or more I/O devices  806  are coupled with the bus  802 . The one or more I/O devices  806  may comprise at least one network interface. The at least one network interface may enable the apparatus  800  to communicate via one or more data communications networks. Examples of data communications networks include, but are not limited to, the Internet and a Local Area Network (LAN). The one or more I/O devices  806  may enable a user to provide input to the apparatus  800  via one or more input devices (not shown). The one or more input devices may include for example a remote control, one or more physical buttons etc. The one or more I/O devices  806  may enable information to be provided to a user via one or more output devices (not shown). The one or more output devices may for example include a display screen. 
     Various other entities are depicted for the apparatus  800 . For example, when present, an operating system  807 , signal processing module  808 , one or more further modules  809 , and data  810  are shown as residing in one, or a combination, of the computer-usable volatile memory  803 , computer-usable non-volatile memory  804  and the one or more data-storage units  805 . The signal processing module  808  may be implemented by way of computer program code stored in memory locations within the computer-usable non-volatile memory  804 , computer-readable storage media within the one or more data-storage units  805  and/or other tangible computer-readable storage media. Examples of tangible computer-readable storage media include, but are not limited to, an optical medium (e.g., CD-ROM, DVD-ROM or Blu-ray), flash memory card, floppy or hard disk or any other medium capable of storing computer-readable instructions such as firmware or microcode in at least one ROM or RAM or Programmable ROM (PROM) chips or as an Application Specific Integrated Circuit (ASIC). 
     The apparatus  800  may therefore comprise a signal processing module  808  which can be executed by the one or more processors  801 . The signal processing module  808  can be configured to include instructions to implement at least some of the operations described herein. During operation, the one or more processors  801  launch, run, execute, interpret or otherwise perform the instructions in the signal processing module  808 . 
     Although at least some aspects of the examples described herein with reference to the drawings comprise computer processes performed in processing systems or processors, examples described herein also extend to computer programs, for example computer programs on or in a carrier, adapted for putting the examples into practice. The carrier may be any entity or device capable of carrying the program. 
     It will be appreciated that the apparatus  800  may comprise more, fewer and/or different components from those depicted in  FIG. 8 . 
     The apparatus  800  may be located in a single location or may be distributed in multiple locations. Such locations may be local or remote. 
     The techniques described herein may be implemented in software or hardware, or may be implemented using a combination of software and hardware. They may include configuring an apparatus to carry out and/or support any or all of techniques described herein. 
     Various measures (for example, a physical adapter, a method and a computer program) are provided wherein a physical adapter receives at least one data stream comprising at least: data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and reconstruction data indicating how to reconstruct a rendition of the signal at a second, higher level of quality in the tiered hierarchy using the rendition of the signal at the first level of quality. The physical adapter reconstructs the rendition of the signal at the second, higher level of quality based at least on the rendition of the signal at the first level of quality and the reconstruction data. The physical adapter outputs at least the reconstructed rendition of the signal and/or data derived from the reconstructed rendition of the signal. The physical adapter is configured to be connectable to signal processing equipment. The signal processing equipment is configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     The physical adapter may be configured to receive the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data in a multiplexed data stream. 
     The multiplexed data stream may be a Moving Picture Experts Group, MPEG, transport stream. 
     The physical adapter may be configured to extract the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the multiplexed data stream based on identifying one or more packet identifiers, PIDs, associated with the data usable to derive the rendition of the signal at the first level of quality and one or more packet identifiers, PIDs, associated with the reconstruction data in the transport stream. 
     The physical adapter may be configured to receive the data usable to derive the rendition of the signal at the first level of quality in an encoded form. 
     The physical adapter may be configured to decode the data usable to derive the received rendition of the signal at the first level of quality. The physical adapter may be configured to derive the rendition of the signal at the first level of quality using the decoded data usable to derive the received rendition of the signal at the first level of quality. The physical adapter may be configured to use the derived rendition of the signal at the first level of quality and the reconstruction data to reconstruct the rendition of the signal at the second, higher level of quality. 
     The physical adapter may be configured to encode the reconstructed rendition of the signal at the second, higher level of quality prior to said output of said reconstructed rendition of the signal at the second, higher level of quality and/or the data derived from the reconstructed rendition of the signal at the second, higher level of quality. 
     The physical adapter may be configured to receive the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data via a common physical interface of the physical adapter. 
     The physical adapter may be configured to output the reconstructed rendition of the signal at the second, higher level of quality and/or the data derived from the reconstructed rendition of the signal at the second, higher level of quality via the common physical interface. 
     The common physical interface may be a Digital Video Broadcast-Common Interface, DVB-CI. 
     The physical adapter may be configured to output the at least the reconstructed rendition of the signal and/or the data derived from reconstructed rendition of the signal to the signal processing equipment. 
     The signal processing equipment may be a television. 
     The signal processing equipment may be a set-top box, STB. 
     The physical adapter may be in the form of a conditional-access module, CAM. 
     The physical adapter may be configured to receive the data usable to derive the rendition of the signal at the first level of quality via a first physical interface of the physical adapter and to receive the reconstruction data via a second, different physical interface of the physical adapter. 
     The first physical interface may be a High-Definition Multimedia Interface, HDMI. 
     The second physical interface may be a Universal Serial Bus, USB, interface. 
     The physical adapter may be configured to receive synchronisation data from the signal processing equipment, the synchronisation data being usable by the physical adapter to reconstruct the rendition of the signal at the second, higher level of quality. 
     The physical adapter may be configured to output said at least the reconstructed rendition of the signal at the second, higher level of quality and/or the data derived from the reconstructed rendition of the signal at the second, higher level of quality via a third physical interface of the physical adapter, the third physical interface being different from the first and the second physical interfaces. 
     The third physical interface may be a High-Definition Multimedia Interface, HDMI. 
     The physical adapter may be configured to decrypt the data usable to derive the rendition of the signal at the first level of quality. 
     The physical adapter may be configured to use High-bandwidth Digital Content Protection, HDCP, to decrypt the data usable to derive the rendition of the signal at the first level of quality. 
     The physical adapter may be configured to encrypt the reconstructed rendition of the signal and/or encrypt the data derived from the reconstructed rendition of the signal. 
     The physical adapter may be configured to use High-bandwidth Digital Content Protection, HDCP, to encrypt the reconstructed rendition of the signal and/or encrypt the data derived from the reconstructed rendition of the signal. 
     The signal processing equipment may be a set-top box, STB. 
     The physical adapter may be configured to output said at least the reconstructed rendition of the signal at the second, higher level of quality and/or the data derived from the reconstructed rendition of the signal at the second, higher level of quality to a television. 
     The physical adapter may be in the form of a dongle. 
     The physical adapter may be configured to be powered by the signal processing equipment. 
     The at least one data stream may comprise additional data associated with the signal. The physical adapter may be configured to: extract the additional data from the at least one data stream; and combine the additional data with the rendition of the signal at the second, higher level of quality and/or the data derived from the rendition of the signal at the second, higher level of quality prior to said outputting. 
     The additional data may comprise audio data. 
     The signal may comprise a video signal. 
     Various measures (for example, signal processing equipment, a method and a computer program) are provided wherein signal processing equipment receives at least one data stream comprising at least: data usable to derive a rendition of a signal at a first level of quality in a tiered hierarchy including multiple levels of quality; and reconstruction data indicating how to reconstruct a rendition of the signal at a second, higher level of quality in the tiered hierarchy using the rendition of the signal at the first level of quality. The signal processing equipment extracts the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data from the at least one data stream. The signal processing equipment outputs the data usable to derive the rendition of the signal at the first level of quality. The signal processing equipment outputs the reconstruction data. The signal processing equipment is configured to be connectable to a physical adapter. The signal processing equipment is configured to output the data usable to derive the rendition of the signal at the first level of quality and the physical adapter is configured to increase the quality of the rendition of the signal relative to the first level of quality. 
     The signal processing equipment may be configured to output the data usable to derive the rendition of the signal at the first level of quality via a first physical interface of the signal processing equipment and to output the reconstruction data via a second, different physical interface of the signal processing equipment. 
     The first physical interface may be a High-Definition Multimedia Interface, HDMI. 
     The second physical interface may be a Universal Serial Bus, USB, interface. 
     The signal processing equipment may be configured to output the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data via a common physical interface of the signal processing equipment. 
     The common physical interface may be a High-Definition Multimedia Interface, HDMI. 
     The signal processing equipment may be configured to receive the data usable to derive the rendition of the signal at the first level of quality and the reconstruction data in a multiplexed data stream. 
     The multiplexed data stream may be a Moving Picture Experts Group, MPEG, transport stream. 
     The signal processing equipment may be configured to output synchronisation data, the synchronisation data being usable to reconstruct the rendition of the signal at the second, higher level of quality. 
     The signal processing equipment may be configured to encrypt at least the data usable to derive the rendition of the signal at the first level of quality. 
     The signal processing equipment may be configured to use High-bandwidth Digital Content Protection, HDCP, to encrypt said at least the data usable to derive the rendition of the signal at the first level of quality. 
     The at least one data stream may comprise additional data associated with the signal. The signal processing equipment may be configured to: extract the additional data from the at least one data stream; and output the additional data. 
     The additional data may comprise audio data. 
     The signal processing equipment may be a set-top box, STB. 
     The physical adapter may be in the form of a dongle. 
     The signal processing equipment may be configured to provide power to the physical adapter. 
     The signal may comprise a video signal. 
     In an example, the further equipment (which may be signal processing equipment) is configured to receive at least a reconstructed rendition of a signal and/or data derived from the reconstructed rendition of the signal from a physical adapter, the reconstructed rendition of the signal having been reconstructed by the physical adapter based at least on a rendition of the signal at a first level of quality in a tiered hierarchy including multiple levels of quality and on reconstruction data indicating how to reconstruct a rendition of the signal at a second, higher level of quality in the tiered hierarchy, the reconstructed rendition of the signal being at the second, higher level of quality, the physical adapter is configured to be connectable to signal processing equipment, the signal processing equipment being configured to output data usable by the physical adapter to derive the rendition of the signal at the first level of quality and the physical adapter being configured to increase the quality of the rendition of the signal relative to the first level of quality. The further equipment is also configured to process the received at least the reconstructed rendition of the signal and/or the data derived from the reconstructed rendition of the signal. 
     The above embodiments are to be understood as illustrative examples. Further embodiments are envisaged. 
     For example, several examples above relate to receiving video data in a broadcast transport stream, such as an MPEG-TS. Video data may however be received in other ways. For example, data usable to derive a rendition of a video signal at a first level of quality may be stored on a Blu-ray disc according to a suitable Blu-ray video format. Reconstruction data may also be stored on the Blu-ray disc, for example as metadata. Signal processing equipment reading the data stored on the Blu-ray disc may be communicatively coupled to a physical adapter that can use the rendition of the video signal at the first level of quality (e.g. HD) and the reconstruction data to reconstruct a rendition of the video signal at a second, higher level of quality (e.g. UHD), using the rendition of the video signal at the first level of quality (e.g. HD) as a baseline for reconstructing the rendition of the video signal at a second, higher level of quality (e.g. UHD). 
     In an example described above, signal processing equipment (such as an STB) has an HDMI 1.4 connection to a physical adapter. As also described above, an HDMI 1.4 connection may not have sufficient capacity to support transmission of video data above a threshold quality. In another example, the signal processing equipment is modified to have a HDMI 2.0 connection, or other suitable connection, that has sufficient capacity to carry video data above the threshold quality. In such an example, the additional functionality provided to the signal processing equipment by the physical adapter could be incorporated into the signal processing equipment itself, without the need for the physical adapter. 
     An example is described above in which signal processing equipment, for example an STB, is configured (for example modified) to output video data over one physical connection (e.g. an HDMI connection) and reconstruction data over a different physical connection (e.g. a USB connection). In another example, the signal processing equipment is configured (for example modified) to output the video data and the reconstruction data over the same physical connection (e.g. the HDMI connection). This may require modification of the chipset. In such an example, the physical adapter would receive both the video data and the enhancement data over a single physical connection (e.g. the HDMI connection) and would reconstruct the higher-quality video in substantially the same manner as that described above. This may avoid the need to use multiple different physical connections between the signal processing equipment and the physical adapter (e.g. an HDMI connection and a USB connection). In such an example, the single physical connection may output both the video data and the reconstruction data. In such an example, the signal processing equipment may be able to output a rendition of a video signal at a first level of quality and the reconstruction data to the physical adapter over an HDMI 1.4 connection. The physical adapter then reconstructs a rendition of the video signal at a second, higher level of quality and outputs this data over an HDMI 2.0 connection. 
     Examples have been described above in which data usable to derive a rendition of a signal at a first level of quality and reconstruction data are received in a multiplexed data stream. For example, the multiplexed data stream may be an MPEG-TS. 
     In another example, the data usable to derive a rendition of a signal at a first level of quality and reconstruction data are received in separate, non-multiplexed streams. For example, data usable to derive a rendition of a signal at a first level of quality may be received in a broadcast transport stream and the reconstruction data may be received as over-the-top (OTT) content via the Internet. The data usable to derive a rendition of a signal at a first level of quality would be synchronised with the reconstruction data and the synchronised data would then be used to reconstruct the rendition of the signal at the second, higher level of quality. 
     It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with at least one features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.