我用MKVextractGUI抽取出的MKV字幕只有时间，没有字，这是什么原因啊？？？？
还可以有什么东东抽取MKV字幕呢？？
PS：有的可以，有的抽出来无字幕（如下）
[Script Info]
; This is an Advanced Sub Station Alpha v4+ script.
; For Sub Station Alpha info and downloads,
; go to
http://www.eswat.demon.co.uk/; or email
kotus@eswat.demon.co.uk;
; Advanced Sub Station Alpha script format developed by #Anime-Fansubs@EfNET
;
http://www.anime-fansubs.org;
; For additional info and downloads go to
http://vobsub.edensrising.com/; or email
gabest@freemail.hu;
; Note: This file was saved by Subresync.
;
ScriptType: v4.00+
Collisions: Normal
PlayResX: 800
PlayResY: 448
Timer: 100.0000
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: EDJP,VD-LogoMaru-Medium-G,24,&H00191919,&H00191919,&H00edcbcc,&H00ff8000,0,0,0,0,100,100,2,0.00,1,2,8,9,10,40,10,1
Style: OPJP,VD-LogoMaru-Medium-G,26,&H00ff8000,&H00191919,&H00ffffff,&H00ff8000,0,0,0,0,100,100,2,0.00,1,2,0,9,10,10,10,1
Style: Default,方正隶变简体,40,&H00ffffff,&H0000ffff,&H00808040,&H00000000,-1,0,0,0,100,100,0,0.00,1,1,0,2,0,0,6,1
Style: EDCN,方正准圆简体,26,&H86191919,&H86ff0000,&H00ffffff,&H80000808,-1,0,0,0,100,100,0,0.00,1,2,0,3,10,10,10,1
Style: Default1,方正隶变简体,26,&H00ffffff,&H0000ffff,&H00808040,&H00000000,-1,0,0,0,100,100,0,0.00,1,1,0,8,0,0,6,1
Style: OPCN,方正准圆简体,30,&H00ffffff,&H86ff0000,&H00ff8000,&H80000808,-1,0,0,0,100,100,0,0.00,1,2,0,9,10,10,40,1
Style: banner,方正准圆简体,28,&H00ff901e,&Hff000000,&H00ffffff,&H80000000,-1,0,0,0,100,100,0,0.00,1,2,0,8,10,10,8,1
Style: loge1,方正准圆简体,44,&H00bda339,&H0000ffff,&H00e3e1d7,&H00000000,0,-1,0,0,100,100,0,0.00,1,2,0,2,30,30,30,1
Style: 2,方正准圆简体,36,&H00fafafa,&H0000ffff,&H00c080ff,&H00000000,0,0,0,0,100,100,0,0.00,1,2,0,2,30,30,30,1
[Events]
Format: Layer, Start, End, Style, Actor, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:12.42,0:00:14.94,Default,,0,0,0,,
Dialogue: 0,0:00:16.75,0:00:17.44,Default,,0,0,0,,
Dialogue: 0,0:00:19.64,0:00:22.28,Default,,0,0,0,,
Dialogue: 0,0:00:23.49,0:00:24.99,Default,,0,0,0,,
Dialogue: 0,0:00:25.44,0:00:26.98,Default,,0,0,0,,
Dialogue: 0,0:00:27.24,0:00:30.55,Default,,0,0,0,,
Dialogue: 0,0:00:30.82,0:00:32.45,Default,,0,0,0,,
Dialogue: 0,0:00:35.31,0:00:38.91,Default,,0,0,0,,
Dialogue: 0,0:02:25.61,0:02:26.95,Default,,0,0,0,,
Dialogue: 0,0:02:35.03,0:02:37.21,Default,,0,0,0,,
Dialogue: 0,0:02:37.36,0:02:40.03,Default,,0,0,0,,
Dialogue: 0,0:02:40.08,0:02:41.27,Default,,0,0,0,,
Dialogue: 0,0:02:41.91,0:02:42.60,Default,,0,0,0,,
Dialogue: 0,0:02:43.76,0:02:44.61,Default,,0,0,0,,
Dialogue: 0,0:02:44.82,0:02:47.83,Default,,0,0,0,,
Dialogue: 0,0:02:48.49,0:02:51.09,Default,,0,0,0,,
Dialogue: 0,0:02:52.05,0:02:54.10,Default,,0,0,0,,
Dialogue: 0,0:02:58.00,0:02:59.07,Default,,0,0,0,,
Dialogue: 0,0:03:00.81,0:03:01.40,Default,,0,0,0,,
Dialogue: 0,0:03:05.57,0:03:07.17,Default,,0,0,0,,
Dialogue: 0,0:03:08.52,0:03:09.31,Default,,0,0,0,,
Dialogue: 0,0:03:16.55,0:03:18.38,Default,,0,0,0,,
Dialogue: 0,0:03:22.26,0:03:23.57,Default,,0,0,0,,
Dialogue: 0,0:03:23.78,0:03:24.53,Default,,0,0,0,,
Dialogue: 0,0:03:25.93,0:03:29.42,Default,,0,0,0,,
Dialogue: 0,0:03:31.10,0:03:33.35,Default,,0,0,0,,
Dialogue: 0,0:03:33.82,0:03:35.12,Default,,0,0,0,,
Dialogue: 0,0:03:35.48,0:03:37.12,Default,,0,0,0,,
Dialogue: 0,0:03:37.68,0:03:38.23,Default,,0,0,0,,
Dialogue: 0,0:03:38.64,0:03:42.90,Default,,0,0,0,,
Dialogue: 0,0:03:44.63,0:03:46.43,Default,,0,0,0,,
Dialogue: 0,0:03:47.07,0:03:48.44,Default,,0,0,0,,
Dialogue: 0,0:03:49.02,0:03:50.89,Default,,0,0,0,,
Dialogue: 0,0:03:51.19,0:03:53.43,Default,,0,0,0,,
Dialogue: 0,0:03:53.97,0:03:55.95,Default,,0,0,0,,
Dialogue: 0,0:03:56.27,0:03:57.71,Default,,0,0,0,,
Dialogue: 0,0:03:58.17,0:03:59.15,Default,,0,0,0,,
Dialogue: 0,0:04:00.28,0:04:02.51,Default,,0,0,0,,
Dialogue: 0,0:04:03.21,0:04:04.41,Default,,0,0,0,,
Dialogue: 0,0:04:04.90,0:04:07.02,Default,,0,0,0,,
Dialogue: 0,0:04:11.43,0:04:12.41,Default,,0,0,0,,
Dialogue: 0,0:04:14.71,0:04:19.27,2,,0,0,0,,
Dialogue: 0,0:04:30.91,0:04:33.51,Default,,0,0,0,,
Dialogue: 0,0:04:35.82,0:04:36.56,Default,,0,0,0,,
Dialogue: 0,0:04:36.71,0:04:37.12,Default,,0,0,0,,
Dialogue: 0,0:04:37.74,0:04:38.77,Default,,0,0,0,,
Dialogue: 0,0:04:39.18,0:04:41.27,Default,,0,0,0,,
Dialogue: 0,0:04:41.58,0:04:42.11,Default,,0,0,0,,
Dialogue: 0,0:04:42.45,0:04:44.34,Default,,0,0,0,,
Dialogue: 0,0:04:45.22,0:04:47.22,Default,,0,0,0,,
Dialogue: 0,0:04:47.97,0:04:53.03,Default,,0,0,0,,
Dialogue: 0,0:04:53.52,0:04:56.23,Default,,0,0,0,,
Dialogue: 0,0:04:56.48,0:04:57.49,Default,,0,0,0,,
Dialogue: 0,0:04:57.98,0:05:00.38,Default,,0,0,0,,
Dialogue: 0,0:05:00.84,0:05:01.34,Default,,0,0,0,,
Dialogue: 0,0:05:02.43,0:05:04.92,Default,,0,0,0,,
Dialogue: 0,0:05:05.39,0:05:07.55,Default,,0,0,0,,
Dialogue: 0,0:05:07.95,0:05:10.67,Default,,0,0,0,,
Dialogue: 0,0:05:12.04,0:05:15.58,Default,,0,0,0,,
Dialogue: 0,0:05:16.15,0:05:20.98,Default,,0,0,0,,
Dialogue: 0,0:05:22.22,0:05:23.51,Default,,0,0,0,,
Dialogue: 0,0:05:23.84,0:05:24.60,Default,,0,0,0,,
Dialogue: 0,0:05:25.02,0:05:28.01,Default,,0,0,0,,
Dialogue: 0,0:05:29.26,0:05:32.38,Default,,0,0,0,,
Dialogue: 0,0:05:35.46,0:05:36.74,Default,,0,0,0,,
Dialogue: 0,0:05:38.08,0:05:41.33,Default,,0,0,0,,
Dialogue:
