A utility that checks a file to see if it is a valid TTML document according to the specified profile. The code is written to be as forgiving as possible of input file errors, and continue, generating an output listing of all the checks made against the file, any assumptions made in order to continue, and the success or failure of each check. It's also written to look for errors that are hard to spot using traditional techniques.
For example, most simple XSD-based validators would stop on finding an error, even
though there may be many other errors or features that could be examined. This one will
try its best to continue. XSD-based validators cannot check some of the semantic
requirements of the format - this one will spot, for example, if a style attribute
contains a reference to an element that is not a <style> element, etc.
The profiles currently supported are:
The BBC Subtitle Guidelines - checks the parts of TTML, IMSC Text, external and EBU-TT-D, external that are supported by the guidelines.
The DAPT, external (Dubbing and Audio Description) profile of TTML2, external.
The output can be plain text, a CSV file or a JSON file. There's a utility for collating the results of multiple CSV results files, which can be helpful for analysing results across a large number of input documents.
