Log Message:
mkvtoolnix: updated to 34.0.0

Version 34.0.0 "Sight and Seen":
Bug fixes
* mkvmerge: all subtitle frames are now treated as key frames in order to fix
  wrong data in source files.
* mkvmerge: AV1: fixed frame timestamp calculation when reading bitstreams
  that lack timing information from IVF files.
* mkvmerge: Matroska reader: fixed an infinite loop that could happen with
  large video frames and applied timestamp files due to too much data being
  buffered at the wrong time.