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  1. Hi guys, I 'm reordering my Plex library and i noticed that plex shows closed caption in the subtitle list as they were normal subtitles.
    I read that closed caption are part of the video stream, so with tools like mkvtoolnix you can't remove them. Is there a way to remove them from the video stream without re-encoding it? I also found out that restream allows to do this, but it's outdated and works only with MPEG-2 format.
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    Originally Posted by arktay View Post
    Hi guys, I 'm reordering my Plex library and i noticed that plex shows closed caption in the subtitle list as they were normal subtitles.
    I read that closed caption are part of the video stream, so with tools like mkvtoolnix you can't remove them. Is there a way to remove them from the video stream without re-encoding it? I also found out that restream allows to do this, but it's outdated and works only with MPEG-2 format.
    It may be possible to remove them using Hybrid. See https://forum.videohelp.com/threads/390217-Deleting-CEA-608-(EIA-608)-captions-from-a-...le#post2561602
    Ignore list: hello_hello, tried, TechLord, Snoopy329
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  3. I tried Hybrid following all the stpes but didn't work. Scrolling up i saw a simple ffmpeg line that actually worked!
    Also hybrid seems such a powerful tool for aything else.
    Thanks!
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  4. Member Cornucopia's Avatar
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    "Closed" captions mean they aren't visible until you turn them on. So turn them off.

    If they are "Open" captions, otoh, aka hard-subs, you are stuck with them unless you want to go to the trouble of blur filtering, overlaying, temporal smear, etc. None of which will fully remove them without also removing or adversely altering the picture.

    Scott
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    Originally Posted by Cornucopia View Post
    "Closed" captions mean they aren't visible until you turn them on. So turn them off.

    If they are "Open" captions, otoh, aka hard-subs, you are stuck with them unless you want to go to the trouble of blur filtering, overlaying, temporal smear, etc. None of which will fully remove them without also removing or adversely altering the picture.

    Scott
    That isn't what is going on. The problem is that both regular subtitles and closed captions are automatically detected by Plex and appear on the list of available subtitles presented by its media player but arktay only wants the regular subtitles to be shown on the list.
    Last edited by usually_quiet; 4th Apr 2020 at 16:54. Reason: clarity
    Ignore list: hello_hello, tried, TechLord, Snoopy329
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  6. Member netmask56's Avatar
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    Originally Posted by arktay View Post
    Hi guys, I 'm reordering my Plex library and i noticed that plex shows closed caption in the subtitle list as they were normal subtitles.
    I read that closed caption are part of the video stream, so with tools like mkvtoolnix you can't remove them. Is there a way to remove them from the video stream without re-encoding it? I also found out that restream allows to do this, but it's outdated and works only with MPEG-2 format.


    You wrote "I read that closed caption are part of the video stream, so with tools like mkvtoolnix you can't remove them." The operative word for me is "I read" have you actually tried? If not try remuxing in MKVToolNix and untick all subtitles. If you need subs then you can always extract the ones you need from the original file and use it as an external sub.
    BeyonWiz T3 PVR ~ Popcorn A-500 ~ Samsung ES8000 65" LED TV ~ Windows 7 64bit ~ Yamaha RX-A1070 ~ QnapTS851-4G
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  7. Originally Posted by arktay View Post
    I read that closed caption are part of the video stream, so with tools like mkvtoolnix you can't remove them.
    Broadcast analog TV embeded the closed caption signal at the top of the frame -- outside the visible part of the picture:

    Image
    [Attachment 52622 - Click to enlarge]


    The TV would then decode that signal and overlay CC text onto the visible part of the picture. Some capture cards capture enough of the frame to include the lines with the CC signal. Of course, if you're recording from a device that is overlaying CC text, that text is burned into the picture. Remuxing will not get rid of them.

    In modern digital broadcast closed captions are just another digital data stream muxed with the video and audio streams. This soft CC data can be removed with a remux.
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  8. Unticking all subtitles with mkvtoolnix does not remove closed caption

    Code:
    set str=ffmpeg -i "input" -bsf:v "filter_units=remove_types=6" -c copy "output"
    I think this line removes closed caption without altering the picture since it process the output very fast and the filesize is almost the same
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    There are two styles of digital closed captions present in N. American digital TV signals, CEA-708 and CEA-608. NTSC DVD closed captioning is similar to CEA-608. CEA-708 includes more character sets and positioning options but as I recall, every software player that I have used is only aware of CEA-608 closed captions, which are a replacement for the old analog closed captions.

    I want to keep CEA-608 closed captions if they are present in my recorded TV shows, so I had to figure out what preserves them and what strips them. (I use CCs when I turn the sound down to avoid disturbing others so that I can still follow the dialog.) In my recordings of both OTA broadcasts and digital cable TV, CEA-608 closed caption data is stored in the video stream's GOP user data. Demuxing or remuxing doesn't usually remove it. Re-encoding does remove it most of the time.(VideoReDo TV Suite is the only program that I have used that is able to re-encode video and still preserve the closed captions.)
    Last edited by usually_quiet; 6th Apr 2020 at 10:13. Reason: clarity
    Ignore list: hello_hello, tried, TechLord, Snoopy329
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  10. Originally Posted by usually_quiet View Post
    (VideoReDo TV Suite is the only program that I have used that is able to re-encode video and still preserve the closed captions.)
    FFmpeg preserves closed caption data if you're using the libx264 encoder with the -a53cc true option. (VideoReDo TV Suite uses FFmpeg IIRC)


    https://ffmpeg.org/ffmpeg-all.html#Options-29
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