Using RAR'd .sub in Matroska

andy

I've searched around and haven't found anything on this topic.

Robot4Rip gives you the option to RAR up your video.sub file, reducing it to about 20% of it's size, because VobSub can read compressed info from it. However, when I try to add my video.idx file in mkMerge, I get an error, saying it couldn't find my .sub file. The sub file is contained in video.rar.

Is this just plain not possible?

mkvmerge offers the possibility to compress your vobsub files during muxing, but in contrary to RARing them the file will still be editable, because every single vobsub packet is compressed on its own, using Zlib.

Of course, the compression ratio will not be the same as when RARing the complete vobsub track, but you might be interested to learn that only when stripping the vobsub packets from their 'envelope' ( a MPEG container ) the size will shrink down to 60 - 70% of the original size already, even without any compression being used.

Zlib will then allow another 25 - 35% compression, so in the end your muxed and compressed vobsub packets will be about 50% of their original size. Still a very good result IMO, and the file is fully editable .....


Well don't I feel stupid, now I see it, zlib compression. Anyway, 50% sounds good enough for me, and thanks a lot for the quick reply!

Hehe I was about to post a similar topic right now, but I saw this. Thanks for the explanation Christian.

There has been a topic on extractingVobsub's subs from mkv.I don't remember if this was on this board but I would like to know if the subs can be extract from the mkv and if yes, in what format? Can we get the subs as they were before they were muxed?

Until now, I have always thougth that Vobsub subs were muxed without any modification in mkv.

Originally posted by JasonFly
There has been a topic on extractingVobsub's subs from mkv.I don't remember if this was on this board but I would like to know if the subs can be extract from the mkv

No.

Can we get the subs as they were before they were muxed?

No.

Until now, I have always thougth that Vobsub subs were muxed without any modification in mkv.

No. The VobSub format contains the SPU packets (the actual subs) embedded in a MPEG stream (dunno if it's program or transport or system... I have no idea about MPEG stream types). When muxing only the SPU packets are kept and assembled together. So an extractor would have to recreate the MPEG stream from the SPU packets. AFAIK there's no app that can do that.

Maybe vobsub's subtitles can be muxed in a mks container and be used in graphedit?Sorry my poor english?

Originally posted by jjseth
Maybe vobsub's subtitles can be muxed in a mks container and be used in graphedit?

I don't know. Why do you want/have to use graphedit?