subtitles

[shenanigans]

Maybe I'm just stupid but I can't get subtitles to display. I've been doing this sort of thing...

var vlc = wcjs_renderer.init (canvasElem);
vlc.play (localFilePath);
vlc.events.once ('FrameReady', function (frame) {
    vlc.subtitles.track = 1;
});

I've tried placing a div.wcp-subtitles in the page like the normal player app would want, no luck. My reading leads me to believe that in -renderer the subtitles are supposed to be rendered by VLC and appear in the normal frame data, is this correct? Is there a doc page I missed somewhere? The "Javascript API" I keep seeing doesn't seem to describe webchimera.js at all, specifying lots of methods that aren't there. Is my problem between my keyboard and chair?

This has all been with an x64 build from wcjs-prebuilt.

[jaruba]

what kind of subtitles are you trying to load? from a file? from inside video files (ie: internal, such as the ones in some mkv files)

[jaruba]

"Javascript API" I keep seeing doesn't seem to describe webchimera.js at all

We're in the process of changing the entire website wiki to reflect only on webchimera.js and wcjs-player APIs, the website wiki is currently only hosting the APIs for WebChimera NPAPI and WebChimera QML Player.

WebChimers.js API Docs: https://github.com/RSATom/WebChimera.js/wiki/JavaScript-API

[RSATom]

@shenanigans, could you please check if you have vlc.subtitles.count > 0 ?

[RSATom]

@jaruba. +1

[jaruba]

@RSATom: I believe there's a different issue here, even if vlc.subtitles.count is greater then 0, I still wouldn't expect it to work.

[RSATom]

@jaruba, do you mean subtitles are broken in wcjs?

[jaruba]

@RSATom not in wcjs, no.. I think their broken in the VLC prebuilts from Magics..

[RSATom]

hm... I'm always recommend prefer use vanilla builds...

[RSATom]

let's wait @shenanigans, we need more info...

[shenanigans]

I tested two scenarios - bundled subtitles in .mkv files and a .srt file that VLC was detecting automatically. And yeah, of course I checked that count > 0....

[RSATom]

@shenanigans, do you use vanilla libvlc or from wcjs-prebuilt ?

[jaruba]

Download DebugView, open it, play something with wcjs.

Tell me if you see core decoder errors like in this image:

[shenanigans]

@RSATom wcjs-prebuilt with manually copied binaries a-la the x64 workaround. @jaruba When and only when subtitles would be displayed, I'm seeing "core blend error: blending YUVA to I420 failed"

[jaruba]

@RSATom nope, not what I was expecting, this is your battle not mine :)

[RSATom]

"core blend error: blending YUVA to I420 failed"

It could be some internal libvlc restriction (but don't sure 100% yet). Did you try any .avi ?

[shenanigans]

Same result with .avi and an external .srt file.

[RSATom]

ok, I'll check. Did you try it with 32-bit libvlc?

[shenanigans]

Looks to work just fine in win32.

[RSATom]

then I'm afraid it's a bug in libvlc

[RSATom]

@shenanigans, btw, why exactly did you decide to use x64 version?

[shenanigans]

The application was originally image-focused and used lwip to do really fast and pretty thumbnails for the big-three image formats. I initially had a hard time figuring out how to build a 32-bit version of lwip and that got me thinking in terms of an x64 application with a 32-bit port. There's not actually a good reason to use x64 here and I'll probably stick with 32-bit going forward just to avoid this kind of issue.

[shenanigans]

....wait, can you explain how this could be a libvlc bug? It's just a copy of libvlc.dll from the 64-bit desktop VLC I have installed and it displays subtitles just fine.

[RSATom]

1) WebChimera.js uses vmem module to receive video frames. 2) VLC itself don't use this module to display frames (it uses other more effective output modules) 3) WebChimera.js use only I420 pixel format, so libvlc have to transcode all frames to this format before give it to vmem. 4) according to "core blend error: blending YUVA to I420 failed" libvlc x64 has some problem with this transcode 5) libvlc ia32 doesn't have any problem with playback

so I think it's a bug in x64 build of libvlc's pixel format transform module (or something near it)

[RSATom]

btw, another solution could be add other than I420 pixel formats support to WebChimera.js. Just to workaround bug in pixel format transform module...

[shenanigans]

cool, thanks for a thorough answer.

[sunabozu]

Have the same issue with 64-bit version. Switching to ia32 does solve the problem.