Subtitle Options


There are five places for subtitles, listed innermost layer first.
1. in VCL: Video Coding Layer, as part of the frame video, called hardsub. e.g. by ffmpeg drawtext.
2. in SEI as part of NAL in ES, Network Abstraction Layer, e.g. CEA-708. ffmpeg cannot generate this kind.
3. in track in a video file, e.g. mp4.
ffmpeg -i Party.mp4 -i cap.srt -c:v copy -c:a copy -c:s mov_text -metadata:s:s:0 language=eng PartyCap.mp4
Here is a sample video, playable with vlc, by clicking Menu – Subtitle – Sub Track:
[ http://riowing.net/local/subtitle/track/PartyCap.mp4 ]
4. WebVtt: subtitle in separate file, segmented VTT or not, for both VOD and live.
This sample page is segmented VTT: http://riowing.net/local/subtitle/caption.htm
5. Subtitle as a layer in web page outside video player. e.g. outside JW Player.
This is no longer video technology but HTML

 

PartyCap

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ffmpeg output thru http


ffmpeg can output to a remote host that runs web server, e.g nginx.
1. Configure nginx so that it can accept http PUT requests. three items:
Make sure nginx was built with –with-http_dav_module
nginx.conf: under location, add: dav_methods PUT;
Make sure nginx have write access to folder
2. Output to remote host
ffmpeg.exe -i SummerDance2016SC.mp4 -f hls -method PUT http://riowing.net/archive/put/SummerDance2016SC.m3u8

The other option to output to remote requires the remote host to run RTMP server.
The HLS URL generated for playing, of course, is:
http://riowing.net/archive/put/SummerDance2016SC.m3u8

SummerDance2016SC