MKVToolNix v28.0.0 发布了，这是首个支持 AV1 的稳定版本。mkvmerge 可从 Matroska/WebM, MP4, IVF 容器文件和原始 OBU 流中读取它。mkvextract 会将其解压到 IVF 文件。除此之外就是一些 bug 修复，以及对可用性进行了改进。
mkvmerge: AV1 parser: updated the code for the finalized AV1 bitstream
specification. Part of the implementation of #2261.
mkvmerge: AV1 packetizer: updated the code for the finalized AV1-in-Matroska
& WebM mapping specification. Part of the implementation of #2261.
mkvmerge: AV1 support: the
--engage enable_av1option has been removed
again. Part of the implementation of #2261.
mkvmerge: MP4 reader: added support for AV1. Part of the implementation of
mkvmerge: DTS: implemented dialog normalization gain removal for extension
substreams. Implements #2377.
mkvmerge, mkvextract: simple text subtitles: added a workaround for simple
text subtitle tracks that don’t contain a duration. Implements #2397.
mkvextract: added support for extracting AV1 to IVF. Part of the
implementation of #2261.
mkvextract: IVF extractor (AV1, VP8, VP9): precise values will be used for
the frame rate numerator & denominator header fields for certain well-known
values of the track’s default duration.
mkvmerge: VP9: mkvmerge will now create codec private data according to the
VP9 codec mapping described in the WebM specifications. Implements #2379.
MKVToolNix GUI: added a menu item ("Help" → "System information") for
displaying information about the system MKVToolNix is running on in order to
make debugging easier.
MKVToolNix GUI: multiplexer, header editor: the user can enter a list of
predefined track names in the preferences. She can later select from them in
"track name" combo box. Implements #2230.
mkvmerge: JSON identification: fixed a bug when removing invalid UTF-8 data
from strings before they’re output as JSON. Fixes #2398.
mkvmerge: MP4/QuickTime reader: fixed handling of PCM audio with FourCC
in24. Fixes #2391.
mkvmerge: MPEG transport stream reader, teletext subtitles: the decision
whether or not to keep frames around in order to potentially merge them with
the following frame is made sooner. That avoids problems if there are large
gaps between teletext subtitle frames which could lead to frames being
interleaved too late. Fixes #2393.
mkvextract: IVF extractor (AV1, VP8, VP8): the frame rate header fields
weren’t clamped to 16 bits properly causing wrong frame rates to be written
in certain situations.
mkvpropedit, MKVToolNix GUI’s header editor: fixed file corruption when a
one-byte space must be covered with a new EBML void element but all
surrounding elements have a "size length" field that’s eight bytes long
already. Fixes #2406.
MKVToolNix（又叫 Matroska toolkit）是一套功能强大的 mkv(Matroska) 格式制作和处理的工具，支持将多种视频、音频、字幕等格式封装成 mkv 格式。