MKVToolNix (64-bit)

What's new in this version:

New features and enhancements:
- mkvmerge: MP4 reader: added support for Vorbis

Bug fixes:
- configure: the checks for libEBML and libMatroska have been fixed to require libEBML 1.3.5 and libMatroska 1.4.7 as intended
- mkvmerge: AAC reader: mkvmerge will now emit an error message for AAC files whose header fields imply a sampling frequency or number of channels of 0
- mkvmerge: AVC/h.264 ES parser: fixed the calculation of reference information for P and B frames. This also fixes some P frames being marked as B frames and vice versa
- mkvmerge: AVC/h.264 ES parser: only non-key frames that have the NALU header field `nal_ref_idc` set to 0 will be marked as "discardable" in SimpleBlock` elements
- mkvmerge: HEVC/h.265: the generation of the HEVCC structure stored in CodecPrivate` was wrong in two places: 1. the position of the number of sub-layers was swapped with reserved bits and 2. the VPS/SPS/PPS/SEI lists did not start with a reserved 1 bit
- mkvmerge: output: the `doc type version` will be set at least to 2 if certain elements are written (`CodecState`, `CueCodecState`, FlagInterlaced`)
- mkvmerge: output: the track header attributes `MinCache` and `MaxCache` will not be written anymore
- mkvmerge: Matroska reader: the "key" and "discardable" flags of SimpleBlock elements will be kept as they are
- mkvmerge: Matroska reader: if present in the file, the "white colour coordinate x" track header attribute was written to both "white colour coordinate x" and "white colour coordinate y" in the output file
- mkvmerge: Opus output: mkvmerge will now put all frames with discard padding into their own block group
- MKVToolNix GUI: header editor: removed the check for external modification when saving the file
- MKVToolNix GUI: job queue: fixed calculation of total progress when automatic removal of completed is enabled

Build system changes:
- libEBML v1.3.5 and libMatroska v1.4.8 are now required. In fact v15.0.0 already requires libEBML v1.3.5 and libMatroska v1.4.7 but did not include proper version checks for them (nor was there a NEWS.md entry for the new
- libMatroska requirement). New is the requirement for libMatroska v1.4.8 due to it fixing writing block groups for tracks with the track number 128 (see 2103)