[FFmpeg-trac] #10505(undetermined:new): Closed Captions decode but stop on DeckLink SDI

[FFmpeg]

#10505: Closed Captions decode but stop on DeckLink SDI
-------------------------------------+-------------------------------------
             Reporter:  Brian        |                    Owner:  (none)
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  closed       |               Blocked By:
  caption decklink                   |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Description changed by Brian:

Old description:

> Summary of the bug: Closed Captions decode properly on Decklink SDI until
> the http/HLS stream provider drops captions during commercial breaks,
> after that happens, the captions never return back to working, unless you
> restart FFMPEG.  The same issue does not happen directly streaming in VLC
> or if I use FFMPEG to stream the HLS to a UDP player or directly to a
> file (like the one I am providing).
>
> I believe this issue is only related to the Decklink output. The Decklink
> output continues to display the idle caption bars on line 21/O even
> though the captions have returned in the stream.
>
> I have a recording sample that triggers this action on Google Drive:
> https://drive.google.com/file/d/1d8ts13PqRDp2mNR9E7W_cR9ztkBNzLUk/view?usp=drive_link
> How to reproduce:
> {{{
> ./ffmpeg -i AMGCCtoNoCCb.ts -filter:v fps=30000/1001 -f decklink -top 1
> -s 1920x1080 -r 30000/1001 -ar 48k -ac 2 -vcodec v210 "DeckLink SDI"
> ffmpeg version N-111626-g0ba719f726
> built with gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
> }}}

New description:

 Summary of the bug: Closed Captions decode properly on Decklink SDI until
 the http/HLS stream provider drops captions during commercial breaks,
 after that happens, the captions never return back to working, unless you
 restart FFMPEG.  The same issue does not happen directly streaming in VLC
 or if I use FFMPEG to stream the HLS to a UDP player or directly to a file
 (like the one I am providing).

 I believe this issue is only related to the Decklink output. The Decklink
 output continues to display the idle caption bars on line 21/O even though
 the captions have returned in the stream.

 I have a recording sample that triggers this action on Google Drive:
 https://drive.google.com/file/d/1d8ts13PqRDp2mNR9E7W_cR9ztkBNzLUk/view?usp=drive_link
 How to reproduce:
 {{{
 ./ffmpeg -i AMGCCtoNoCCb.ts -filter:v fps=30000/1001 -f decklink -top 1 -s
 1920x1080 -r 30000/1001 -ar 48k -ac 2 -vcodec v210 "DeckLink SDI"
 ffmpeg version N-111626-g0ba719f726
 built with gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
 configuration: --prefix=/root/ffmpeg_build --pkg-config-flags=--static
 --extra-libs='-lpthread -lm' --bindir=/root/bin --enable-gpl --enable-
 libzvbi --enable-libfdk-aac --enable-libass --enable-libfreetype --extra-
 ldflags=-L/root/ffmpeg_build/lib --enable-libopus --enable-libtheora
 --enable-libvorbis --enable-libvpx --enable-static --disable-opencl
 --enable-libx264 --enable-postproc --enable-openssl --enable-decklink
 --enable-small --enable-libklvanc --extra-
 cflags=-I/root/Decklink_SDK/Blackmagic_DeckLink_SDK_12.2.2/Linux/include
 --extra-
 ldflags=-L/root/Decklink_SDK/Blackmagic_DeckLink_SDK_12.2.2/Linux/include
 --enable-nonfree --disable-debug
 }}}

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Ticket URL: <https://trac.ffmpeg.org/ticket/10505#comment:1>
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