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tim_beynart's avatar
tim_beynart
Channel Surfer
8 years ago

Multiple Embedded Caption Tracks

Hi! We are trying to test multiple language captions. We use embedded EIA-608 captions in HLS.
I do not understand how to get multiple captions to appear as options in the captions selector (pressing the * button during playback). Is there some configuration I am expected to do?

Here's a pseudo example of our code, it work for default English captions. 
videoContent = createObject("RoSGNode", "ContentNode")
videoContent.url = my_media_url
videoContent.streamformat = "hls"
videoContent.SubtitleConfig = {TrackName:"eia608/1"}
m.videoplayer.content = videoContent
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2 Replies

  • RokuCC's avatar
    RokuCC
    Binge Watcher
    8 years ago
    In general, instead of SubtitleConfig, use SubtitleTracks.
    eia608 is a special case though... it basically tells the firmware to search for the tracks. When it finds data it will add tracks for the ones it finds data for (like CC1, CC2, Service1 etc).
    So in your case it may not be able to find the data, or the data is encrypted. If part of the slice header is in the clear - it will use picture order counts from the H.264 stream to reorder the captions. If only the SEI headers are in the clear, it will use the PTSs to reorder the captions.