#tb 0: 1/90000
#media_type 0: subtitle
#codec_id 0: webvtt
#tb 1: 1/90000
#media_type 1: subtitle
#codec_id 1: webvtt
#tb 2: 1/90000
#media_type 2: subtitle
#codec_id 2: webvtt
#tb 3: 1/90000
#media_type 3: subtitle
#codec_id 3: webvtt
#tb 4: 1/90000
#media_type 4: subtitle
#codec_id 4: webvtt
#tb 5: 1/1000
#media_type 5: subtitle
#codec_id 5: webvtt
2,      90000,      90000,    90000,        4, 0x044101bc
3,      90000,      90000,    90000,        4, 0x042401aa
4,      90000,      90000,    90000,        3, 0x02a30154
5,       1000,       1000,     1000,        3, 0x028e0142, S=1, WebVTT ID,       15, 0x226c0444
5,       3000,       3000,      500,        3, 0x02b9015a, S=1, WebVTT Settings,        6, 0x08210213
0,     990000,     990000,    90000,        3, 0x028e0142, S=1, WebVTT ID,       15, 0x226c0444
1,    1125000,    1125000,    45000,        5, 0x06690218
0,    1170000,    1170000,    45000,        3, 0x02b9015a, S=1, WebVTT Settings,        6, 0x08210213
