Nebula TV - download fails

[Carl Fink]

Hi, When I try to download any video from Nebula.tv, it reaches 99% completion, then fails with the error:

MP2T - No data received

moz-extension://4b08d369-f44a-4687-9da8-b4043e8d2c65/background/main.js:1
value@moz-extension://4b08d369-f44a-4687-9da8-b4043e8d2c65/background/main.js:1:222222
value@moz-extension://4b08d369-f44a-4687-9da8-b4043e8d2c65/background/main.js:1:192586
value@moz-extension://4b08d369-f44a-4687-9da8-b4043e8d2c65/background/main.js:1:145203

e</value/t.endTimer<@moz-extension://4b08d369-f44a-4687-9da8-b4043e8d2c65/background/main.js:1:191728

Browser: Firefox 112.0.2

Extension version: 7.6.6

OS: Linux (Ubuntu kinetic)

CoApp version: 1.6.3

One page that will not download: https://nebula.tv/videos/tldrnewseu-why-slovakias-government-collapsed-and-why-its-bad-news-for-ukraine
(Note: Nebula requires a paid account.)

Thanks in advance for any help.

-Carl Fink

[Wild Willy]

Since you are dealing with a site whose content is behind a paywall, you are going to
have to do all the work here. Search this forum with "mp2t" as your search key. You
have a bunch of reading to do.

[Carl Fink]

I mean, I'm not averse to just buying the dev(s) a short-term membership for three bucks, but I'll try doing the reading assignment first. :-)

[Carl Fink]

I don't know how useful this might be to you, but I'm able to download the stream. First, locate two network streams named media.m3u8 in the browser developer console network tab. One represents the video and the other one, the audio. Then, download them both using VLC's Open Network Stream >> Convert action, and multiplex them using ffmpeg.

This is very annoying to do manually, but I'm pretty sure I can turn it into a script (since VLC has a command-line mode) or replace VLC with ffmpeg as well. Extracting the m3u8 URLs might be harder to automate.

Hmm ... I suspect that's not hard to do in a plugin, and I've never written a plugin. Might be an interesting first product.

(Why don't you multiplex using ffmpeg, by the way?)

[Carl Fink]

This is interesting. Turning on HLS as M2TS causes the plugin to say it succeeded in downloading, but not actually create a file at all.

[mjs]

Does the M2TS file have a file size and does it play ? If you ffprobe the file and it shows video information then just use ffmpeg to

repackage the file to MP4.

[Wild Willy]

Well, clearly you are an uber-geek. Which should be no surprise since you're using
Linux. I make no assumptions about your taxi driving abilities. If you found 2 media
manifests in the Network Monitor & used them to download the video & audio tracks with
VLC, your problem is solved. You can just play the 2 files back using VLC's synchronous
playback feature (Open Multiple Files, also on VLC's Media menu, where you found Open
Network Stream). However, it is weird that you didn't directly find a master manifest.
That could be because of this:

https://groups.google.com/g/video-downloadhelper-q-and-a/c/O_bRwxrfqS8

There, you will find a temporary workaround for the absence of a master manifest from the
Network Monitor. Actually, the workaround is described in Michel's Bugzilla report.
Maybe this will help your case. That seems to be a workaround that fixes some cases but
there's no guarantee.

In any case, if you are comfortable with ffmpeg, that is the way to go until (and if,
there is no guarantee on this) Michel gets around to fixing how VDH handles these MP2T
cases. Ffmpeg will get you a single file with both an audio track & a video track, & it
can do it in a single invocation. It's easier if you have a master manifest, but ffmpeg
can also do it if you feed it the two media manifests.

Another weird thing is that you say VDH successfully downloads something when HLS as M2TS
is enabled, but there's no resulting file. Whenever I've switched that setting on, I at
least get VDH to download something. It is a video file (sometimes audio file) whose
name has the extension .m2ts, & VLC is uniformly able to play such content. Perhaps it
got downloaded to a location you weren't expecting. Go into the VDH settings on the
Behavior tab & see what directory is named in the Default download directory setting.
That would be the location VDH most recently used to download something. Maybe your file
is there.

As for buying Michel a $3 subscription for a few days, I doubt he would take you up on
that offer. But I don't work for him & I am most definitely not his spokesman. I don't
think I'd be willing to take you up on it, either. But it sounds to me like you've got
this well in hand & there should be no need for this.

[Carl Fink]

I mean, having to manually extract the two m3u8 files from network monitoring is really awkward, especially when you want multiple files. I'd rather have a plugin just do it for me. Otherwise I'd just use screen capture.

[Carl Fink]

@mjs writes:

"Does the M2TS file have a file size and does it play ? If you ffprobe the file and it shows video information then just use ffmpeg to

repackage the file to MP4."

I never see the m2ts file. That's the problem.

[mjs]

There should be a folder called dwhelper , if you find it the file should be in there.

[Carl Fink]

@mjs: dwhelper is empty. Zero files.

This ffmpeg script works great, FWIW:
ffmpeg -i "first.m3u8" -i "second.m3u8" -codec copy TitleOfVideo.mp4

[Wild Willy]

Yeah, that's the ffmpeg invocation I was alluding to when I said you could download the
content by feeding the 2 media manifests to ffmpeg. You can probably get the manifest
URLs from VDH instead of the Network Monitor. Display the Hit Details on the 2 media
items. Or does VDH not recognize anything at all? Meanwhile, did you try the
circumvention from the Bugzilla report? That ought to get you the master manifest & then
you need only one -i parameter on ffmpeg.

I decided to click the link you gave. Turns out the site does offer one freebie. You
can see what I did in the attached images. I know you can include captions along with
the video & audio on a single invocation of ffmpeg. But I like to keep subtitles in a
separate file so I can correct them if I so choose. That's not so important here but I
usually find something I want to change when I'm dealing with an opera. So I just always
leave the captions in their own file & let VLC pick them up automatically.

My experiment here shows that the master manifest is there. See attached image #06. I
did that after the fact. That is the same master manifest that VDH detected. That means
you don't need the circumvention in the Bugzilla report after all. At least, not for
this freebie. I can only hope for your sake that this freebie is representative of what
you encounter when you get behind their paywall.

On a lark, I did verify what you are saying about the MP2T error. With HLS as M2TS
disabled, downloading both the video variant & the audio variant with VDH spends a few
moments downloading something, but then it errors out with the MP2T notification & all
you have it 2 small part files in your download directory, neither of which plays in VLC.
With HLS as M2TS enabled, the download of the video, which lasts about 1 second, indeed
does not create a result file, but it does generate an error about not being able to get
information for the media & the file being corrupt. The download of the audio takes a bit
longer & does result in a file of a little over 6M, but VDH generates the same error as
the video, & the file does not play in VLC. Maybe there is something you can do to
manipulate the file into something that can be played but I think it's a useless exercise
to try that. I mean, you obviously aren't getting the video via VDH, making the audio by
itself rather useless, while ffmpeg has no problem with it.

One reason VDH has trouble with this is that the audio track is shared by the various
resolutions of available video tracks. This is well-known to cause VDH to erroneously
detect this as separate video & audio. But the failure of the HLS as M2TS setting is
most curious, especially on the audio track.

Anyway, you seem to be successfully using ffmpeg to get this stuff so I imagine this
problem is solved.

[Wild Willy]

Hey Carl. Stop stealth quoting. Here's instructions. Go here:

https://groups.google.com/g/video-downloadhelper-q-and-a/c/BzPLK2YyL-s

String search for "stealth quote" within the text of that web page. Click the link,
learn what I'm talking about, & stop stealth quoting.

[Carl Fink]

@grampawildwilly, I don't ever expect to use Google Groups again after this conversation, because I hate it and it's dying and the VDH dev(?) doesn't actually participate here. But I destealthed just for you.

[Wild Willy]

Carl, not only are you an uber-geek, you are a scholar & a gentleman.

The dev's name is Michel Gutierrez. He posts here under the user name mig. He is on
here only occasionally, but he is on here. His right hand man is a guy named Jérôme. My
understanding is that Jérôme is not a programmer but he comes in here to help out,
especially with license issues. These guys are in France so you have to take the time
zone difference into account. Jérôme is usually visible early morning his time. For me
in the eastern US, that works out to some time between about 1:00 & 4:00 or 5:00 AM.
Jérôme is totally reliable. When something requires Michel's attention or when some
technical question can be answered only by Michel, Jérôme is very good about letting "the
boss" know. That usually gets a post from Michel. So folks shouldn't despair.

Google Groups is dying? That's news. Got a link? I wish they would improve it. I
think it was better before their last major change, which was about 3 or 4 years ago now.
I think. I haven't kept track. But in the absence of alternatives, I hope it sticks
around. I wouldn't mind if we just went to GITHub but I don't know how feasible that is.
It's not up to me.

[Carl Fink]

I don't have any inside info that Google will cancel Groups any time soon, but almost nobody seems to use it any more except by inertia, and sometimes a Google service will suddenly vanish or mutate without warning, e. g. Reader, Plus, Hangouts.

I always wonder how long Blogger and Groups will last before someone pulls the plug.

On Tuesday, May 16, 2023 at 11: