DVB Subtitle support in mkv files ( S_DVBSUB )

DVB Subtitles are a common way of attaching subtitles in TV(DVB)-streams. VLC has long been able to play the subtitles properly with .ts -files along with the videostream. For long time preservation and future compatibility it is essential (at least for me) to be able to transcode the recordings to another format.

I have TVHeadend as PVR backend, and it can create both .ts files and .mkv -files. The .ts-files play fine with VLC but .mkv -files give an error that states that a codec could not be identified (referring to the S_DVBSUB stream).

Also, if I transcode the .ts -file with either MKVToolNix of FFMpeg to a .mkv file by simply copying all of the streams, VLC can not play the subtitles.

There are other software that can play the subtitles correctly (to mention some: Kodi, FFPlay, MPC-HC, SMPlayer, Plex). But I really do like VLC as a general purpose player, and I'd wish to see the DVB Subtitle support in .mkv-files to be added.

I've understood that S_DVBSUB has not been officially included in mkv specifications, but I did some searching and found this: https://github.com/Matroska-Org/matroska-specification/pull/77 , apparently the the S_DVBSUB codec specs have been included in mkv database since Jan 2017. Though I have no know if this is a relevant fact.

I'm more than happy to provide some short sample videos if needed, I'll do some short sample recordings.

added Component::Subtitles Severity::normal Type::bug Version::master git + 1 deleted label

changed milestone to %Features paradize

Here are some example videos for testing, if needed. They are three minute clips recorded from a free-to-view channel (DVB-C, SD-definition) with TVHeadend. The original program has one video stream (MPEG2), two audio streams (German and hearing impaired, both MP2), DVB Subtitles and the teletext stream. See explanations for each file below. The first and third files were recorded a couple of minutes apart.

1. DVB_subtitle_example_ts.zip https://drive.google.com/open?id=1zisGm3xWZM4UUeLVMJEx542v8zEdMgQM

2. DVB_subtitle_example_ts_converted2h264AAC.zip https://drive.google.com/open?id=10XXvygSZcK6qb5nFK5XzUZwyKc3wCQfp

3. DVB_subtitle_example_mkv.zip https://drive.google.com/open?id=1rIeMonIrcBk1XIPJmP5pmOeMzw3LELPk

4. DVB_subtitle_example_mkv_converted2h264AAC.zip https://drive.google.com/open?id=1npWsRSeG94TjnvLP14UrCW0UqwHqoTaW

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1. The first (.ts) file was recorded using the "pass" setting of TVHeadend. It includes all of the streams, including the teletext stream. This can be played with VLC, the subtitles work also correctly.

2. The second file is the first (.ts) file converted to .mkv with the command >ffmpeg.exe -i DVB_subtitle_example_ts.ts -map 0:v -map 0:a -map 0:3 -vf yadif=0 -codec:v libx264 -codec:a aac -codec:s copy DVB_subtitle_example_ts_converted2h264AAC.mkv . The teletext stream is not supported by ffmpeg so it is discarded with the stream mapping options here. VLC gives the error and fails to show the subtitles.

3. The third (.mkv) file was recorded with TVHeadend using the "Matroska" option. TVH discards the teletext stream automatically, otherwise the file includes all the streams and also the metadata of the program (which is why I prefer this recording format in the first place).

4. The fourth/last file is the result when the third file is converted to a more compact (20-35% of the original size usually) and compatible (h264+AAC) format with stream errors fixed using the command >ffmpeg.exe -i DVB_subtitle_example_mkv.mkv -map 0:v -map 0:a -map 0:s-vf yadif=0 -codec:v libx264 -codec:a aac -codec:s copy DVB_subtitle_example_mkv_converted2h264AAC.mkv . This file resembles the final format that I use for my recordings (the metadata is scraped to an xml(nfo) file from file 3) ).

Duplicate of #14577 (closed).

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Thank you for your lengthy and detailed ticket, but I have already added support for S_DVBSUB in mkvs.

= 4d22be6dcc =	demux: mkv: add support for S_DVBSUB

If you would like to try it out, please build VLC from source, or use a nightly build.

added Status::duplicate label

closed

Marvellous and unreal!!! :)

I just can't believe that I've tried to stay updated for this for the last four years and still the pending fix slipped through. I did not find the issue anymore since the ticket was (of course) closed.

The 4.0.0 nightly works like charm, and I can easily wait for the final version to be released now that I know it's fixed.

Thank you, and sorry for the duplicate ticket, case closed!

changed milestone to %3.0.x maintenance

marked this issue as a duplicate of #14577 (closed)

marked this issue as related to #14577 (closed)

changed milestone to %4.0

Backported for 3.0.17/18

changed milestone to %3.0.18