Finds the field corresponding to @fieldname, and returns the string
contained in the field's value. Caller is responsible for making
sure the field exists and has the correct type.
The string should not be modified, and remains valid until the next
call to a gst_structure_*() function with the given structure.
Finds the field corresponding to @fieldname, and returns the string contained in the field's value. Caller is responsible for making sure the field exists and has the correct type.
The string should not be modified, and remains valid until the next call to a gst_structure_*() function with the given structure.