Validate JPEG 2000 codestreams

[palemieux]

Photon does not currently validates the contents of the JPEG 2000 codestreams themselves, instead relying on the information present in the Composition Playlist, which is extracted from MXF headers, which are themselves presumably generated from the contents of the JPEG 2000 codestreams.

This approach has two limitations:

• Photon does not confirm that the contents of the CPL match that of the JPEG 2000 codestreams
• several JPEG 2000 constraints cannot be verified from the CPL or MXF Header alone, e.g., presence of the TLM marker segment, number of tile-parts, absence of POC marker segments, etc.

Suggest considering validating the first codestream of each Image Track File included in an IMP.