< selects which program to discard and which to feed to the caller
< behavior on wrap detection
< reference dts for wrap detection
All fields below this line are not part of the public API. They may not be used outside of libavformat and can be changed and removed at will. New public fields should be added right above. ****************************************************************
New fields can be added to the end with minor version bumps. Removal, reordering and changes to existing fields require a major version bump. sizeof(AVProgram) must not be used outside libav*.