翻了一下changelog,看到如下内容
2009-04-08 Moritz Bunkus
* mkvmerge: By default mkvmerge keeps the aspect ratio information
in AVC/h.264 video bitstreams now (equivalent to specifying
"--engage keep_bitstream_ar_info" in earlier versions). A new
option "--engage remove_bitstream_ar_info" is available that
restores the previous behaviour.
默认这样了,以后不用在手动加参数保持码流内ar信息了,相对的增加了一个参数用来去除ar信息