IIS是否支持CEA-608隐藏式字幕转换？

Question

我使用IIS Smooth Streaming（.isml）的东西通过IIS HLS重新编码“on fly”将视频流传送到Silverlight插件和IOS设备。此外，我发送“隐藏字幕”到实时流 - 它在Silverlight插件上工作正常，但HLS流不显示隐藏字幕。 IIS是否可能在源.isml流中忘记文本流？

播放列表示例

#EXTM3U
#EXT-X-VERSION:1
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=581120,RESOLUTION=276x208
QualityLevels(560000)/manifest(format=m3u8-aapl).m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=781432,RESOLUTION=364x272
QualityLevels(756000)/manifest(format=m3u8-aapl).m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1078834,RESOLUTION=480x360
QualityLevels(1047000)/manifest(format=m3u8-aapl).m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=167920
QualityLevels(160000)/manifest(format=m3u8-aapl).m3u8

#EXTM3U
#EXT-X-VERSION:1
#EXT-X-ALLOW-CACHE:NO
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:12,no-desc
Fragments(Video=0,format=m3u8-aapl).ts
#EXTINF:11,no-desc
Fragments(Video=100000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=200000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=300000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=400000000,format=m3u8-aapl).ts
#EXTINF:11,no-desc
Fragments(Video=600000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=700000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=800000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=900000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=1000000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=1200000000,format=m3u8-aapl).ts
#EXTINF:11,no-desc
Fragments(Video=1300000000,format=m3u8-aapl).ts
#EXTINF:12,no-desc
Fragments(Video=1400000000,format=m3u8-aapl).ts
#EXTINF:7,no-desc
Fragments(Video=1500000000,format=m3u8-aapl).ts
#EXT-X-ENDLIST

我认为现在的问题是“IIS是否支持CEA-608隐藏式字幕转换？”