Closed Captioning on Jetson TK1

Does NVIDIA Tegra K1 platform support Closedcaption readers for 608 and 708 standards?

That’s a question of kernel driver availability, rather than one of Tegra K1 abilities. If you have specific models of hardware you can check for linux kernel support; once you know of support, you can check if the modules are available on ARMv7. As an example, Jetson comes with the L4T linux operating system…basically a standard Ubuntu 14.04 LTS with a few extra files for hardware access. It’s impossible to research the question without knowing exact reader models.

Hi, I have met the same problem as well.

However, my question would be, is there any support(plug-in on gstreamer) to decode 608 closed caption? I have looked it up online and I have not yet found any plug-ins for closed captioning.

What I am trying to do is to demux a mpegts stream, add an timed overlay to the video, and then mux the audio, overlay-ed video, and closed captioning back to a mpegts stream. However the closed captioning (which can be seen in VLC) will not be visible in gstreamer. I have tried to save the stream in a mp4 file and use gst-discover-0.10 to inspect the file, and it shows only one video stream with two audio stream.

Here is the pipeline example:

gst-launch-0.10 udpsrc port=5050 ! ‘video/mpegts,systemstream=(boolean)true,packetsize=(int)188’ ! tsdemux name=demux demux.video_0200 ! ‘video/x-h264,width=(int)1920,height=(int)1080,framerate=30/1,format=(fourcc)I420’ ! queue ! nv_omx_h264dec ! timeoverlay halign=left valign=bottom text=“Stream time:” shaded-background=true ! nv_omx_h264 ! mux. demux.audio_0201 ! queue ! mux. demux.audio_0202 ! queue ! mux. mpegtsmux name=mux m2ts-mode=false pat-interval=3000 pmt-interval=3000 ! rtpmp2tpay pt=33 ! udpsink port=5005 host=127.0.0.1 sync=true enable-last-buffer=true -v

After processing, the stream can be seen, but with no closed caption in it. Maybe it is lost during the process of decoding/encoding. In addition, the stream is not as stable, so it may not work sometimes(jaggered, and plays for only like 3 frames per second… etc). If this happens, I just run it for a few more times, then it will run smoothly suddenly. It seems to be random, and I am not sure about the cause.

Thanks in advance.