Video data encoding and decoding circuity applying constraint data

An apparatus comprising:

• video data encoder circuitry configured to encode an input video data stream to generate an output encoded video data stream, the video data encoder circuitry being responsive to configuration data defining a second decoding attribute comprising one or more of a bit depth and a chrominance subsampling format;
• and
• parameter encoder circuitry configured to encode the second decoding attribute to be associated with the output encoded video data stream in dependence upon the configuration data;
• in which the parameter encoder circuitry is configured to encode parameter data indicating a profile selected from a plurality of profiles, each profile defining a first decoding attribute, and constraint data defining a difference between the second decoding attribute defined by the configuration data and the first decoding attribute defined by the profile indicated by the parameter data, in which the constraint data is configured to indicate a zero difference of the first and second decoding attributes by a zero value of the constraint data.

A method comprising:

• decoding an input video data stream in response to parameter data associated with the input video data stream, the parameter data indicating a profile selected from a plurality of profiles, each profile defining a first decoding attribute comprising one or more of a bit depth and a chrominance subsampling format;
• detecting constraint data associated with the input video data stream, the constraint data defining a difference between a second decoding attribute applicable to the input video data stream and the first decoding attribute defined by the profile indicated by the parameter data, in which the constraint data is configured to indicate a zero difference of the first and second decoding attributes by a zero value of the constraint data;
• and
• controlling the decoding to generate a decoded video data stream having a third decoding attribute defined by the profile provided by the parameter data, as modified by the difference defined by the constraint data.