[FFmpeg-user] Dynamic dvb subtitles

Felipe Mogollon fmogollon at vicomtech.org
Wed Feb 20 18:18:10 EET 2019


I am trying to generate a mpegts stream with live DVB subtitles.

I have managed to create DVB subtitles by doing some tricks with python +
spumux + ffmpeg and I can finally get a dvbsub file that contains subtitles.

If I mux dvbsubtitle file into a mpegts stream everything seems fine, just
a little bit out of sync.

ffmpeg  -re -f lavfi -i testsrc=size=1280x720:rate=30 -f mpegts -i
dvbsub.sub -vcodec h264_nvenc -g 10 -scodec dvbsub -f mpegts output.ts -y

My problem is when I try to generate live DVB subtitles:

I have tried to put dvbsub.sub input in loop mode:
ffmpeg  -re -f lavfi -i testsrc=size=1280x720:rate=30 -stream_loop -1 -i
dvbsub.sub  -vcodec h264_nvenc -g 10 -acodec aac -strict -2 -scodec dvbsub
-f mpegts output.ts -y

and generate new dvbsub.sub for each "chunk" of subtitles, but ffmpeg
doesn't seems to mux those new subtitles in the right way and "repeats" the
first ones in a "random" way.

Any suggestions about how to generate live subtitles and mux them in a live
way into de the mpegts stream?

Thanks in advance



Juan Felipe Mogollón Rodríguez
Researcher | Investigador
Digital Media
+[34] 943 30 92 30fmogollon at vicomtech.orgwww.vicomtech.org
Member of GraphicsMedia.net
Legal Notice - Privacy policy (http://www.vicomtech.org/en/proteccion-datos)

More information about the ffmpeg-user mailing list