I am encouraged by your progress. I believe you will be successful with this. I gave
you this link above:
https://groups.google.com/g/video-downloadhelper-q-and-a/c/BzPLK2YyL-s
This is an important link that I want you to get in the habit of using frequently as a
resource. That is why I am not going to just give you the link to the tutorial. I want
you to get used to using that as a reference. Within that thread, I want you to get used
to searching for text strings. The text string "cannot download" is the one you want.
That will give you the link to the ffmpeg tutorial.
You should also use the text string "stealth quote" to search that thread. That will
give you another link that will tell you something important.
I also mentioned DRM as a string to search for in there. It appears that your content is
not protected by DRM, but DRM is an issue you should keep in the back of your mind.
The media manifest you gave looks good. Once you have done ffprobe on that, you will
agree. However, it is usually better to find the master manifest. Most often, that one
will have a name that includes the word master in its name. But not always. Usually,
whichever m3u8 file is listed first in the Network Monitor is the master manifest. That
is the one that you will find the most useful in most cases.
I was expecting that you would be working on a web site that required a user ID &
password since you mentioned something about college videos. But I was able to run
ffprobe on the manifest whose URL you posted. I see in there that there is timed_id3
data in the stream. This is a type of data that has been well-knonw to cause problems
for VDH. You can search this forum with the search key "timed_id3" to find a number of
threads in which it is mentioned. You won't really learn anything more than the fact
that timed_id3 data is a problem for VDH so I wouldn't spend a whole lot of time reading
those stories. But the presence of the timed_id3 data may be what is causing VDH to
report those crazy durations & perhaps not complete the downloads you have been
attempting. Once you figure out how to use ffmpeg, it becomes a trivial matter to simply
ignore the timed_id3 data. I have not been able to download such data & look at it.
Both ffprobe & ffmpeg simply ignore such data. They both report that they have no codec
for interpreting it. It seems to be the correct thing to do to just ignore it. All the
downloads I have done with ffmpeg when timed_id3 data has been present just ignore the
timed_id3 data, and the resulting downloaded video has played perfectly fine in VLC.
But since your web site is not protected by a user ID & password, you should share some
URLs of pages on which your videos reside. I would then be able to advise you if you are
having trouble with anything at a certain point. You will find as you read the tutorial
that I learned things along the way. You should read the entire thread before you
attempt to do any downloads. The things I explain earlier on in the tutorial are useful
to know, but they are less useful than I originally thought when it comes to actually
running ffmpeg. Still, you should read the whole thing. Once you've done that, don't be
afraid to experiment. You generally learn as much from mistakes as you do from
successes. That thread hides so many mistakes I made that I couldn't possibly count
them. So it's probably a good thing to make mistakes. Eventually, they will teach you
more.