Page 1 of 1

Rewinding makes subtitles disappear.

Posted: 21 Nov 2014 21:06
by barosky
Hello!

I'm sorry if this not a right board for this kind of post, but I've checked this on both OSX and Windows 8 and looks like it occurs on every platform.

I'm deaf and I have to watch movies with subtitles, unfortunately there's one thing that really makes my life much harder.

It's not the case in other playes I've been testing.

I'll use an example of subtitle line from one of my favorite tv shows (Sons of Anarchy):

80
00:05:20,958 --> 00:05:25,768
It's just, Jax... he doesn't have
an outer crust like most of us.


So basically these sentences are supposed to be displayed for 5 seconds. This is correct, but when I'm at 00:05:25 and I rewind back I will end up at 00:05:22. Now, the problem is - VLC won't render these sentences for me in that case. I have to rewind to a place before 00:05:20 so they will kick in.

Is there a way to fix it? I don't know whether it's a bug or I am doing something wrong? :)

Thanks a lot!

Re: Rewinding makes subtitles disappear.

Posted: 21 Nov 2014 22:33
by mederi
It has already been requested/reported @ https://trac.videolan.org/vlc/ticket/10638

Re: Rewinding makes subtitles disappear.

Posted: 07 Sep 2016 15:54
by StreamR
Some years have passed, however subtitles and rewinding are still conflicting.

It is a a real pity that the used bug tracker does not allow voting for bugs.
Also the source code of VLC is pretty hard to understand because it contains nearly no comment.

Re: Rewinding makes subtitles disappear.

Posted: 05 Oct 2016 11:24
by nonzyro
This problem is not germane to VLC Player. Nearly all players suffer this, including the might MPC-HC (with CCCP) and I have hypothesized a simple explanation. If you examine an srt file (subtitle file, one of many formats), you'll see how the time stamping works. Basically, the player sees something like this:
01:20:25 -> 01:20:55
Sign: NO ENTRY

Now if you're at 01:21:30 and skip back at land at 01:20:30, the player will miss the start mark at 01:20:25 because 01:20:25 < 01:20:30. I don't know why both times aren't compared, but I'm assuming it has something to do with performance. A lot of extra if-statements, unless you optimise by comparing the end timestamp to the current position every seek and then adjusting the position to match the subtitle's start timestamp, say:

Code: Select all

/* assuming we've played with all the getters and have all the info re the closest match subtitle line */ if (curPos < curSubLineEnd) setpos(curSubLineStart);
Of course this is not ideal as it will always align to the starting timestamp of each sub, but it would be better for performance and solve the problem.

Anyway, enough of my two cents. That's the hypothetical explanation.

Re: Rewinding makes subtitles disappear.

Posted: 08 Jan 2017 00:09
by staratel20
I very suffer from this problem too.

I want to tell as a programmer - we don't need to talk about performance when we talk about this problem. Why? Because when user press rewind button that doesn't matter for him - to wait 0.2 sec or 0.5 sec before play will continue. So I suspect, the solving is very simple - for man who knows the code well.