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[dejwi]

Hi,

I have an issue with HD recordings from set top box containing DVB Subtitles. They are displayed in wrong place and too small when played in JRiver. There is no problem when played in VLC or on set top box itself.

My wild guess is that dvb subtitles are pixel rendered the same way for SD and HD channels. And while set top box and vlc scale subtitles "display space" to movie "display space", the JRiver display them "pixel perfect".



Is there anything that I can do on my side to fix it? Or you can patch it in the application?

regards,
David

ps.: JRiver version 19.0.67

[dejwi]

Bump.

I've checked on the net that DVB subtitles are prerendered as a bitmap and included in Transport Stream (.TS) from DVB source. Now It would be nice if somebody from JRiver would check what method they use to got them aligned (centered & at the bottom) in the display window.

And probably corrected it?

red,
D>

[Hendrik]

Can you provide a small sample video that demonstrates the problem? That would make it so much easier for us!

[dejwi]

Here is a link to 16 MB sample:  https://app.box.com/s/8pkomxow5pmmsvf8nkua

I hope it's something simple

[dejwi]

bump.

[JimH]

Are you using 19.0.87?

[dejwi]

I was using 19.0.67 . I've just upgraded to 19.0.87, but the problem is still there.

[Hendrik]

Thanks for the sample, I'll look at it soon. Maybe Matt will also chime in, he wrote the original DVB Subtitle support, iirc.

[Matt]

Thanks for the sample, I'll look at it soon. Maybe Matt will also chime in, he wrote the original DVB Subtitle support, iirc.

I was just pulling it up in the debugger when I saw your post.  It's like you're in another country!

The first subtitle starts 505 pixels down, and is 720x46.

The video is 1920x1080, but the subtitles coordinates seem like they're for a much smaller size video.

Sometimes the header for subtitles will say "pretend the source video is this size" but I'm not aware of a way to do that with embedded DVB?

[Hendrik]

DVB subs have something called a "display definition segment", which defines the canvas size the subs were authored for.
They should probably be drawn on that size, and then scaled to video size.

I haven't actually checked if its contained in this particular video, though.

[Matt]

DVB subs have something called a "display definition segment", which defines the canvas size the subs were authored for.

I think that means that CSubtitleFormatDVB::RenderPage(...) just needs to set pItem->m_sizeSourceVideo with the "display definition segment".

So we just need to figure out where to get the "display definition segment" from.  Is it in each packet, or once at the start of the file?

[Hendrik]

It should be the thing called "DISPLAY" with the TODO block in the dvb parser....

[Matt]

It should be the thing called "DISPLAY" with the TODO block in the dvb parser....

Ah!

7.2.1:
http://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.03.01_60/en_300743v010301p.pdf

Care to take a crack at it?  I think you could just parse the stuff into m_Page, then use it in RenderPage like I mentioned above.

[Hendrik]

Yeah i'll take care of it, no problem. Hoping that there is actually such a segment in the stream, but if not i'll come up with other ideas!

[Hendrik]

In the next version:
Fixed: DVB Subtitles could render with an incorrect size and position

[dejwi]

I've downloaded the latest version of MC and it works great for most of the channels. While I was browsing through recorded movies I've found that movies from Canal+ still have the same issues. So whatever worked for HBO, doesn't work for C+.

Here is a link to fresh sample: https://app.box.com/s/z30qipoym4s3hao9v2vt
I am using 19.0.91

TIA

[Hendrik]

Leave it to the TV Networks to find new ways to screw with us. 

I'll have a look. Thanks for providing the sample!

[Hendrik]

In an upcoming version:
1. Fixed: DVB subtitles on certain TV channels could still render with incorrect size and position.

Turns out that the DVB spec has a implicit default subtitle size, if none is specifically designated in the subtitle stream, which was not applied to the subtitles, but that is now rectified.