[FFmpeg-trac] #6982(undetermined:new): Convert Subtitles or Respect PTS

FFmpeg trac at avcodec.org
Thu Jan 25 17:10:23 EET 2018

#6982: Convert Subtitles or Respect PTS
             Reporter:  fliston      |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:  subtitles,   |               Blocked By:
  dvb, pts                           |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |

 I'm trying to send a stream with subtitles. The input subtitles codec is
 dvb_subtitles, which is a bitmap based subtitle.
 Nowadays we are burning subtitles into the video, but we don't know how to
 follow pts, so they are not consistant with the audio or video.

 How we can acchive that?

 These are live ingest so we can't use different tools that increase delay.
 We would like to do it only with ffmpeg.

 ffmpeg -nostdin -loglevel verbose -hwaccel cuvid -deint 0 -c:v h264_cuvid
 -resize 1280x720 -y -re -i
 -filter_complex "[i:0x1e00]hwdownload,format=nv12[base];
 [i:0xc0]scale=1280:720[subtitle]; [base][subtitle]overlay[v];
 [v]hwupload_cuda[v]" -map "[v]" -map i:0x1020 -c:a libfdk_aac -ac 2 -b:a
 64k -map i:0x1021 -c:a libfdk_aac -ac 2 -b:a 64k -c:v hevc_nvenc -preset
 llhq -b:v 2000k -maxrate 2160k -bufsize 5000k -metadata service_name="HBO
 HD" -metadata:s:a:0 language=eng -metadata:s:a:0 title="English Audio"
 -metadata:s:a:1 language=spa -metadata:s:a:1 title="Spanish Audio" -f
 mpegts -mpegts_copyts 1 -pcr_period 40 udp://

 Output command is not relevant to my question.


Ticket URL: <https://trac.ffmpeg.org/ticket/6982>
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