A method of processing an MPEG-2 transport stream for carriage of multi-layer video data, the method comprising: obtaining, from a first HEVC_extension_descriptor for a program comprising one or more elementary streams, a plurality of profile, tier, level syntax element sets wherein each profile defines a set of coding tools for use by a video coder and each level defines a set of constraints of values associated with each syntax element set and each tier defines a category of constraints within each level, and wherein each respective profile, tier, level syntax element set of the plurality of profile, tier, level syntax element sets comprises syntax elements specifying respective profile, tier, level information; obtaining, from the first descriptor or a second HEVC_extension_descriptor for the program, a plurality of operation point syntax element sets wherein each operation point defines a set of NAL units associated with the MPEG-2 transport stream, wherein the first descriptor and the second descriptor are in a program map table of the MPEG-2 transport stream and each respective operation point syntax element set of the plurality of operation point syntax element sets specifies a respective operation point of a plurality of operation points; and for each respective operation point syntax element set of the plurality of operation point syntax element sets, determining, for each respective layer of the respective operation point specified by the respective operation point syntax element set, based on a respective syntax element for the respective layer determined from the first or second HEVC_extension_descriptor by examining data in the HEVC_extension descriptor comprising data defining a number of operation points associated with each operation point syntax element set and data defining a number of layers associated with each operation point and an index of each respective profile, tier, level that is assigned to each layer in each operation point and mapping the profile, tier, level information to each index of each respective profile, tier, level that is assigned to each layer within each operation point using the data defining the number of operation points associated with each operation point syntax element set and the data defining the number layers within each operation point, which of the profile, tier, level syntax element sets specifies the profile, tier, level information assigned to the respective layer of the respective operation point, the respective syntax element being in the respective operation point syntax element set, the respective operation point having a plurality of layers; and decoding the video data using the determined index of each respective profile, tier, level that is assigned to each layer in each operation point. obtaining, from a first HEVC_extension_descriptor for a program comprising one or more elementary streams, a plurality of profile, tier, level syntax element sets wherein each profile defines a set of coding tools for use by a video coder and each level defines a set of constraints of values associated with each syntax element set and each tier defines a category of constraints within each level, and wherein each respective profile, tier, level syntax element set of the plurality of profile, tier, level syntax element sets comprises syntax elements specifying respective profile, tier, level information; obtaining, from the first descriptor or a second HEVC_extension_descriptor for the program, a plurality of operation point syntax element sets wherein each operation point defines a set of NAL units associated with the MPEG-2 transport stream, wherein the first descriptor and the second descriptor are in a program map table of the MPEG-2 transport stream and each respective operation point syntax element set of the plurality of operation point syntax element sets specifies a respective operation point of a plurality of operation points; and for each respective operation point syntax element set of the plurality of operation point syntax element sets, determining, for each respective layer of the respective operation point specified by the respective operation point syntax element set, based on a respective syntax element for the respective layer determined from the first or second HEVC_extension_descriptor by examining data in the HEVC_extension descriptor comprising data defining a number of operation points associated with each operation point syntax element set and data defining a number of layers associated with each operation point and an index of each respective profile, tier, level that is assigned to each layer in each operation point and mapping the profile, tier, level information to each index of each respective profile, tier, level that is assigned to each layer within each operation point using the data defining the number of operation points associated with each operation point syntax element set and the data defining the number layers within each operation point, which of the profile, tier, level syntax element sets specifies the profile, tier, level information assigned to the respective layer of the respective operation point, the respective syntax element being in the respective operation point syntax element set, the respective operation point having a plurality of layers; and decoding the video data using the determined index of each respective profile, tier, level that is assigned to each layer in each operation point.