Hi there,
I am using a Blackmagic Decklink card on which I have connected a baseband signal to one of its input pins. With GStreamer, I record one-minute videos continuously. However, that baseband signal already carries closed captions, which I would like to retain in the metadata of the recorded videos.
The command I am using to record videos (which, by the way, I also want to compress) without yet keeping the closed captions is the following:
gst-launch-1.0 decklinkvideosrc device-number=0 mode=1080i5994 ! video/x-raw,format=UYVY,width=1920,height=1080,framerate=30000/1001,interlace-mode=interleaved ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=0 ! videoconvert ! video/x-raw,format=I420,width=1920,height=1080,framerate=30000/1001 ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=0 ! x264enc key-int-max=10 bitrate=16000 speed-preset=veryfast tune=zerolatency ! h264parse ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=0 ! splitmuxsink name=mux location="video%02d.mp4" max-size-time=60000000000 decklinkaudiosrc device-number=0 ! audio/x-raw,format=S16LE,rate=48000,channels=2,layout=interleaved ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=0 ! voaacenc ! aacparse ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=0 ! mux.audio_0
I read the documentation and found elements like “ccextractor”, but I’m not sure if it would be useful for what I need to do. And if that were the case, how should I include it in the command.
It would be very helpful if you could tell me how I can get this, or if it is possible. For the moment, I only know that the baseband signal includes closed captions, nothing more. Should I know anything else? I am a bit rookie at this. Thank you.
I’m using GStreamer 1.24.2 on Ubuntu 24.04.2 LTS.