Secure decoder and secure decoding methods

A secure memory configured to:

• receive, from a receiving module, via a secure channel, a decrypted encoded rendition of a base layer of a video signal;
• output, via a further secure channel, the decrypted encoded rendition of the base layer to a base decoding module;
• receive, via the further secure channel from the base decoding module, a decrypted decoded rendition of the base layer generated by the base decoding module;
• store the decrypted decoded rendition of the base layer;
• output, via an additional secure channel, to a module, the decrypted decoded rendition of the base layer of the video signal;
• receive, from the module via the additional secure channel, an output plane generated by the module;
• store the output plane;
• output the output plane to an output module for sending to a display.

A method, the method comprising reading, from a secure memory via a secure channel, a decrypted decoded rendition of a base layer of a video signal, wherein the decrypted decoded rendition of the base layer has a first resolution;

• reading, from an unsecure memory, a decoded rendition of an enhancement layer of the video signal, wherein decoded rendition of the enhancement layer has a second resolution, wherein the second resolution is higher than the first resolution;
• generating an upsampled decrypted decoded rendition of the base layer of the video signal by upsampling the decrypted decoded rendition of the base layer such that the upsampled decrypted decoded rendition of the base layer has the second resolution;
• applying the decoded rendition of the enhancement layer to the upsampled decrypted decoded rendition of the base layer to generate an output plane;
• outputting the output plane, via the secured channel, to the secure memory for storage in the secure memory, wherein the output plane is for use in outputting by an output module to a display.

A method comprising:

• receiving, from a receiving module, via a secure channel, a decrypted encoded rendition of a base layer of a video signal;
• outputting, via a further secure channel, the decrypted encoded rendition of the base layer to a base decoding module;
• receiving, via the further secure channel from the base decoding module, a decrypted decoded rendition of the base layer generated by the base decoding module;
• storing the decrypted decoded rendition of the base layer;
• outputting, via an additional secure channel, to a module, the decrypted decoded rendition of the base layer of the video signal;
• receiving, from the module via the additional secure channel, an output plane generated by the module;
• storing the output plane;
• outputting the output plane to an output module for sending to a display.

An output module having access to a secure memory and to an unsecure memory, wherein the output module is configured to:

• read, from the secure memory via a secured channel, a decrypted decoded rendition of a base layer of a video signal, the decrypted decoded rendition of the base layer having a first resolution;
• read, from the unsecure memory, a decoded rendition of an enhancement layer of the video signal, the decoded rendition of the enhancement layer having a second resolution, wherein the second resolution is higher than the first resolution;
• generate an upsampled decrypted decoded rendition of the base layer of the video signal by upsampling the decrypted decoded rendition of the base layer such that the upsampled decrypted decoded rendition of the base layer has the second resolution;
• apply the decoded rendition of the enhancement layer to the upsampled decrypted decoded rendition of the base layer to generate an output plane;
• output the output plane, via a further secured channel, to a protected display.