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Table of Contents
DVD Subtitles
Detect VobSub
The MPG will need to be probed deeper than normal to check for VobSub streams because they only are detected once they show up in the video.
An example:
ffprobe -probesize 67108864 -analyzeduration 60000000 dvd_video.mpg
Input #0, mpeg, from '1.665.2138.17690.TNTGO.mpg': Duration: 00:11:09.02, start: 0.045500, bitrate: 5708 kb/s Stream #0:0[0x1bf]: Data: dvd_nav_packet Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, progressive), 720x480 [SAR 32:27 DAR 16:9], 29.92 fps, 59.94 tbr, 90k tbn, 59.94 tbc Stream #0:2[0x82]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s Stream #0:3[0x81]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s Stream #0:4[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s Stream #0:5[0x21]: Subtitle: dvd_subtitle Stream #0:6[0x20]: Subtitle: dvd_subtitle Stream #0:7[0x23]: Subtitle: dvd_subtitle Stream #0:8[0x22]: Subtitle: dvd_subtitle
For DVDs, closed captioning streams are embedded in the video stream.
Detect CC
See if a DVD has closed captioning:
dvd_copy -o - | ffprobe -v 0 -show_streams -show_entries stream=start_pts -select_streams s -f lavfi -i movie=pipe\\\\:0[out+subcc]
See if a video has closed captioning:
ffprobe -v 0 -show_streams -show_entries stream=start_pts -select_streams s -f lavfi -i movie=dvd_copy.mpg[out+subcc]
When splitting the streams using lavfi
device, ffmpeg will “create” a subtitle stream, even if one is not present. To make sure one exists or not, a closer look at the stream itself is actually needed.
This one has a starting presentation timestamp (PTS) that's a positive value, so it's safe to say that one exists.
[STREAM] start_pts=25257 DISPOSITION:default=0 DISPOSITION:dub=0 DISPOSITION:original=0 DISPOSITION:comment=0 DISPOSITION:lyrics=0 DISPOSITION:karaoke=0 DISPOSITION:forced=0 DISPOSITION:hearing_impaired=0 DISPOSITION:visual_impaired=0 DISPOSITION:clean_effects=0 DISPOSITION:attached_pic=0 DISPOSITION:timed_thumbnails=0 [/STREAM]
Here's one without it present:
[STREAM] start_pts=N/A DISPOSITION:default=0 DISPOSITION:dub=0 DISPOSITION:original=0 DISPOSITION:comment=0 DISPOSITION:lyrics=0 DISPOSITION:karaoke=0 DISPOSITION:forced=0 DISPOSITION:hearing_impaired=0 DISPOSITION:visual_impaired=0 DISPOSITION:clean_effects=0 DISPOSITION:attached_pic=0 DISPOSITION:timed_thumbnails=0 [/STREAM]
Extract CC
Use ffmpeg to extract the closed captioning stream from a DVD using dvd_copy:
dvd_copy -o - | ffmpeg -f lavfi -i movie=pipe\\\\:0[out+subcc] -map 0:s subtitles.srt
Extract CC subtitles from an MPG:
dvd_copy -o dvd_copy.mpg ffmpeg -f lavfi -i move=dvd_copy.mpg[out+subcc] -map 0:s subtitles.srt
Since the closed captioning is embedded in the video stream, you can re-encode that at the same time. It won't see any other streams though (audio, vobsub).
ffmpeg -f lavfi -i move=dvd_copy.mpg[out+subcc] -map 0:v -map 0:s video.mkv