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~~Ned Scott~~ · 2013-07-13, 12:07

It's certainly important, but we need this to happen first: http://forum.xbmc.org/showthread.php?tid...pid1359674

It's not practical for us to keep maintaining our own set of ffmpeg patches. For every release the team tries to reduce the number of XBMC-specific patches, so that we can just use "pure" ffmpeg. The impact that has on development is a higher priority than ATSC closed captions.

svet-am · 2013-07-13, 16:51

(2013-07-13, 12:07)Ned Scott Wrote: It's certainly important, but we need this to happen first: http://forum.xbmc.org/showthread.php?tid...pid1359674

It's not practical for us to keep maintaining our own set of ffmpeg patches. For every release the team tries to reduce the number of XBMC-specific patches, so that we can just use "pure" ffmpeg. The impact that has on development is a higher priority than ATSC closed captions.

Ned Scott,

Fair enough -- I totally understand the argument about "the needs of the many vs. the needs of the few" and I am the first to get on board with making XBMC code clean and portable.

What I would use to counter that argument is that if XBMC is not going to support ATSC captions properly, then XBMC (as a project) needs to stop claiming to have _proper_ PVR / LiveTV support as it does in the wiki (http://wiki.xbmc.org/index.php?title=PVR).

Per the FCC (http://www.fcc.gov/guides/closed-captioning), closed captions (and in some specific cases, subtitles can replace captions) support in _rendering_ devices 13" or larger is required by law in the United States. Since XBMC operates upstream from the TV in the rendering stream I would argue that XBMC becomes the rendering device covered by this law (much like a Comcast TV box does).

Again, I understand the development needs -- this then becomes a marketing/positioning issue.

~~Ned Scott~~ · (This post was last modified: 2013-07-13, 17:40 by Ned Scott.)

Those laws don't apply to XBMC.

The FCC requires certain hardware manufacturers to comply when accessing TV content from certain sources. It does not require that any and all software that is able to access TV tuners must also support closed captioning. The people who make computer tuners are required to provide software that does, but additional 3rd party software is not under that requirement.

If the 3rd party software was require to comply it still wouldn't matter, because XBMC is not a PVR application. XBMC simply accesses a PVR backend (software or hardware) as a video player and PVR controller.

Failing all of that, if such laws could be apply directly to XBMC, we can simply just say that XBMC's Live TV features can use subtitles with certain backends. This thread is about a specific type of closed caption data type and being able to play it directly in XBMC without the backend needing to convert it.

These laws simply make it so that people have reasonable access to closed captions. That's not the same as having closed captions in every conceivable situation. No one has to use XBMC to watch TV, but someone selling an FCC-approved tuner in the US does have to provide at least one way to watch TV with closed captioning.

~~Ned Scott~~ · (This post was last modified: 2013-07-13, 17:47 by Ned Scott.)

Team XBMC has limited resources, but we do desire to support such things. We have a lot deaf or partially deaf users, and laws or no laws, we want to make XBMC accessible to as many people as possible. XBMC's dependency on ffmpeg patches already lead us to being rejected on several official linux application repositories, such as Debian and Ubuntu. For some users this is even a security concern, because XBMC isn't able to update ffmpeg security patches as often (we currently only do it once per release, which is once per year or more). It's not just a minor issue or about making the code extra lean.

**Martijn** · (This post was last modified: 2013-07-13, 17:51 by Martijn.)

And even if it is a law in the US that has nothing to say outside it. They think are the world but in fact they are anything but.
Like said this has to be added upstream to limit needed resources on each release

~~Ned Scott~~ · 2013-07-13, 18:02

Well, I guess an argument could be made that XBMC would have to comply because of the US-based foundation, but technically speaking, it would only apply to distribution. In other words, we would just put a disclaimer on the website that said "don't download if you are in the US". Kind of like that whole DCMA thing and XBMC's ability to decrypt DVDs. Technically speaking, everyone in the US is supposed to compile their own version without DVD support, but the Foundation doesn't have to remove it themselves. Burden is on the user in that case.

davilla · 2013-07-13, 18:06

xbcm dev works like this; some one requests a feature, if that feature interests some xbmc dev, fine. it gets worked on and added. if not, then someone outside might dev on it and request a PR. If neither, and user starts demanding xbmc devs work on adding it, then feature gets ignored...

atpage · 2014-01-19, 19:08

If the mythtv ffmpeg patches are too hackish or mythtv-specific, what about the VLC/CCExtractor code that basteagow mentioned?

The TV/PVR experience in XBMC has improved by leaps and bounds, but closed captioning support really should have been one of the first leaps.

svet-am · 2014-01-20, 01:24

(2014-01-19, 19:08)atpage Wrote: If the mythtv ffmpeg patches are too hackish or mythtv-specific, what about the VLC/CCExtractor code that basteagow mentioned?

The TV/PVR experience in XBMC has improved by leaps and bounds, but closed captioning support really should have been one of the first leaps.

I don't know how much of this is totally based on FFMPEG (unlike what has been said before). I was searching through the Xine codebase (what the current XBMC cc_decode.h is based on) and it looks like they have preliminary ATSC CC decode without rev'ing FFMPEG.

I am currently working on porting their code to my XBMC code clone with the intent of seeing if I can get it working in XBMC.

atpage · (This post was last modified: 2014-01-20, 01:39 by atpage.)

(2014-01-20, 01:24)svet-am Wrote: I don't know how much of this is totally based on FFMPEG (unlike what has been said before). I was searching through the Xine codebase (what the current XBMC cc_decode.h is based on) and it looks like they have preliminary ATSC CC decode without rev'ing FFMPEG.

I am currently working on porting their code to my XBMC code clone with the intent of seeing if I can get it working in XBMC.

I was thinking about implementing something like this so captioning would at least work on pre-recorded shows. (i.e., have mythtv trigger that script when a recording completes.) Of course, that still doesn't solve the problem for live TV or for other backends.

eman7 · 2014-02-03, 19:33

Following up on this - does Gotham support ATSC closed captioning? I'm at the point where I'm willing to try Gotham. Right now I have WMC (for live tv / PVR) and everything else XBMC. I have XBMC menu item on WMC but the integration doesn't always work e.g. when I exit XBMC I get black screen rather going back to WMC. I'd prefer single UI for everything.

fiveisalive · (This post was last modified: 2014-02-04, 07:06 by fiveisalive.)

(2014-02-03, 19:33)eman7 Wrote: Following up on this - does Gotham support ATSC closed captioning? I'm at the point where I'm willing to try Gotham. Right now I have WMC (for live tv / PVR) and everything else XBMC. I have XBMC menu item on WMC but the integration doesn't always work e.g. when I exit XBMC I get black screen rather going back to WMC. I'd prefer single UI for everything.

I'm running pre-Gotham using the MythTV PVR add-on which connects to an ATSC tuner. Unfortunately it does not yet support the closed captions (CC) embedded in the video (either for Live TV or recordings). Reading this thread, it seems that there is code to support CC in MythTV's local copy of FFMPEG (since mythfrontend does support CC) but apparently it's kind of hacky and may not not fit for porting to XBMC. Presumably because the video playback and subtitle display is done in core XBMC and not in the PVR add-on specific code, any support added in XBMC for displaying CC from ATSC streams/files would make CC work on all PVR add-ons, not just MythTV.

(2014-01-20, 01:24)svet-am Wrote:
(2014-01-19, 19:08)atpage Wrote: If the mythtv ffmpeg patches are too hackish or mythtv-specific, what about the VLC/CCExtractor code that basteagow mentioned?

The TV/PVR experience in XBMC has improved by leaps and bounds, but closed captioning support really should have been one of the first leaps.

I don't know how much of this is totally based on FFMPEG (unlike what has been said before). I was searching through the Xine codebase (what the current XBMC cc_decode.h is based on) and it looks like they have preliminary ATSC CC decode without rev'ing FFMPEG.

I am currently working on porting their code to my XBMC code clone with the intent of seeing if I can get it working in XBMC.

That would be awesome, svet-am. Only to happy to test (I am building gotham out of mainline git, so presumably could easily test pull requests/patches from your repo).

User 98869 · 2014-03-04, 21:51

Was this feature finally included in Gotham's beta?

dvgeek · 2014-03-12, 22:01

(2014-03-04, 21:51)iJunaid Wrote: Was this feature finally included in Gotham's beta?

I just compiled yesterday's Gotham "nightlies" - and sadly no ATSC cc. Sad

svet-am · 2014-06-10, 20:03

(2014-02-04, 07:03)fiveisalive Wrote: That would be awesome, svet-am. Only to happy to test (I am building gotham out of mainline git, so presumably could easily test pull requests/patches from your repo).

Life happened this spring (selling a house, moving, etc.) and I never got to finish this work. I'm just about settled again and will be working on this again soon.