[FFmpeg-user] Troubles segmenting WebVTT

[Stefano Sabatini]

On date Saturday 2015-02-07 22:15:58 -0700, Deron wrote:
> I'm trying to capture ATSC with a tuner card and stream it out via
> HLS. I've got it more or less working, and now I would like to try
> my hand and streaming out closed captioning in WebVTT utilizing the
> eia 608 demuxer.
> 
> First, I captured 10 minutes of video to my HD. Then I used:
> 
> ffmpeg -f lavfi -i "movie=WPEC.ts[out0+subcc]" -map s WPEC.vtt
> 
> which generated a good .vtt file and then
> 
> ffmpeg -i WPEC.vtt -f segment -segment_time 10 -segment_format
> webvtt -scodec copy WPEC-%05d.vtt
> 
> to generate segments 00000 to 00038 and it works just fine.
> 
> However,
> 
> ffmpeg -f lavfi -i "movie=WPEC.ts[out0+subcc]" -map s -f segment
> -segment_time 10 -segment_format webvtt WPEC-%05d.vtt
> 
> fails to generate segments. What it generates is just one segment
> named WPEC-00000.vtt.
> 
> What am I doing wrong?
> 
> Deron
> 
> Complete uncut output:
> 

> # ffmpeg -f lavfi -i "movie=WPEC.ts[out0+subcc]" -map s -f segment
> -segment_time 10 -segment_format webvtt WPEC-%05d.vtt

Use -loglevel debug, segment will generate log messages showing the
input PTSs. Also, are you sure you have many key-frames in your input
file?