More bugs in ogg subtitle mixer

[primitive]

Through use of the subtitle mixer I have found a few more issues with that piece of software.

-If the delay between two lines is less than about 50ms, the second line will fail to display 100% of the time.
-If the srt file is missing one or several subtitles, the ogg subtitle filter will fail to display any subtitles about 50% of the time. (To be clear: the srt file contains subtitles that are sequentially numbered. If any of those lines are removed so that the file is no longer sequentially numbered, the subtitler will sometimes fail.)
-The subtitler will occasionally fail to display a line that should be displayed right after a scene change. (The 50ms bug again?)

[gabest]

You should note that it is impossible to display two different states of the subtitles within ONE frame. (25fps => 40 ms/frame)

[d_dave]

also, if the srt file contains the X and Y coordinates, oggmux will not complain when muxing but the subtitle file will not be present within the final muxed ogg.

anyone else having their subtitles stop after 3.5minutes of play?

[ppera2]

Originally posted by gabest
You should note that it is impossible to display two different states of the subtitles within ONE frame. (25fps => 40 ms/frame)

That's true, but it has nothing with bug. It should display subtitle regardless of that. Even if it will delay 40 ms :) .

And btw. on monitor refresh rate is much more than 25 fps....

[gabest]

Nah, you didn't understand me. An example:

1
00:00:00,000 --> 00:00:00,020
Line1

2
00:00:00,020 --> 00:00:00,040
Line2

After starting the playback, the subtitler filter gets its first frame lasting from 0ms to 40ms. Then it looks up which text to paint on the picture, it finds line no.1. Then the next frame comes in between 40ms and 80ms... As you can see line no.2 was missed already.

And if the srt was like this:

1
00:00:00,000 --> 00:00:00,020
Line1

2
00:00:00,020 --> 00:00:01,000
Line2

Then the first line would only show on the first frame. (I know the subtitler filter fails to display the second in this case. I have no idea why :P)

[ppera2]

It all depends how code is made. There is many way how realise displaying each line(s) in apropriate time.

[d_dave]

the problems w/ the subtitles being displayed only in the first 3 minutes relates to buile 486 of bsplayer. build 487 corrects this problem.

[primitive]

Originally posted by gabest
Nah, you didn't understand me. An example:

1
00:00:00,000 --> 00:00:00,020
Line1

2
00:00:00,020 --> 00:00:00,040
Line2

After starting the playback, the subtitler filter gets its first frame lasting from 0ms to 40ms. Then it looks up which text to paint on the picture, it finds line no.1. Then the next frame comes in between 40ms and 80ms... As you can see line no.2 was missed already.

And if the srt was like this:

1
00:00:00,000 --> 00:00:00,020
Line1

2
00:00:00,020 --> 00:00:01,000
Line2

Then the first line would only show on the first frame. (I know the subtitler filter fails to display the second in this case. I have no idea why :P)

Perhaps because the subtitle filter looks ahead for the next subtitle it can display? I think I read on Tobias' page that it was difficult to program the filter to render the fonts and subtitle in real-time; some sort of rudimentary look-ahead would make sense.

Or maybe it just has to do with the stream format of the subtitles; say it's a streaming ogm; if you miss your cue to draw the subtitles right at the first, you aren't going to be cued again for that same subtitle even if you have the ability to display it because the data you need has already streamed past. Perhaps a subtitle queue that "catches" all the subtitles that would otherwise be undisplayed?

-p