Udemy preview videos
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mjs
May 25, 2022, 9:50:18 AM5/25/22
to Video DownloadHelper Q&A
I didn't know that there were video previews for courses on Udemy.
So if you look at this page it offers a simple mp4 video to download:
But on this page video downloadhelper does not detect anything:
It appears to be a hls stream in the developer tools / network and since there is nothing detected I tried in youtube-dl but results in a 403 forbidden. It doesn't matter if I use the page url or the manifest url. Whether actual course videos behave the same way I don't know, but those videos are being detected in vdh as small files based on a screenshot a Udemy user posted in this group. Is that because no aggregation info is found.
It would be of interest to find out more but someone would need to create a screen sharing session and to find out if downloading is possible or not.
Wild Willy
May 25, 2022, 12:39:00 PM5/25/22
to Video Download Helper Google Group
I can confirm that your first Udemy link does give something VDH can download. I can
also confirm that for your second link VDH doesn't show anything. However, I did get it
to show me 3 manifests, but they did not appear until after I clicked the play button on
the video & let it play for a couple of seconds. Once I did that, I picked the first
manifest & ignored the other 2. Running that first manifest through ffprobe showed up
Programs 0 through 7 encompassing streams 0:0 through 0:15. The programs were in
ascending order of video resolution. I decided upon the 1920x1080 variant, which was
video stream 0:14 & audio stream 0:15. I told ffmpeg to get that, which it did in just a
few seconds. I ended up with a video of duration 0:01:45 which VLC was quite happy to
play with both video & audio throughout the clip. I have found that sometimes, a
manifest will give the dreaded 403 error but if you reload the page & try again, you get
a new manifest that works fine. Sometimes. I have posted recently about the CBS Network
web site & that's one where I've hit 403 & a reload gave me a fresh manifest that worked
fine. But there's other sites where that doesn't help so it's not a guaranteed solution.
I'd be curious to know if a couple of retries don't clear the 403 for you. I'd also be
curious to know if youtube-dl continues to fail for you but ffmpeg works. The fact that
there's 8 choices of video resolution might trip up the other tool but ffmpeg can deal
with it better, especially when you help it out by coding -map instead of letting it find
a default.
also confirm that for your second link VDH doesn't show anything. However, I did get it
to show me 3 manifests, but they did not appear until after I clicked the play button on
the video & let it play for a couple of seconds. Once I did that, I picked the first
manifest & ignored the other 2. Running that first manifest through ffprobe showed up
Programs 0 through 7 encompassing streams 0:0 through 0:15. The programs were in
ascending order of video resolution. I decided upon the 1920x1080 variant, which was
video stream 0:14 & audio stream 0:15. I told ffmpeg to get that, which it did in just a
few seconds. I ended up with a video of duration 0:01:45 which VLC was quite happy to
play with both video & audio throughout the clip. I have found that sometimes, a
manifest will give the dreaded 403 error but if you reload the page & try again, you get
a new manifest that works fine. Sometimes. I have posted recently about the CBS Network
web site & that's one where I've hit 403 & a reload gave me a fresh manifest that worked
fine. But there's other sites where that doesn't help so it's not a guaranteed solution.
I'd be curious to know if a couple of retries don't clear the 403 for you. I'd also be
curious to know if youtube-dl continues to fail for you but ffmpeg works. The fact that
there's 8 choices of video resolution might trip up the other tool but ffmpeg can deal
with it better, especially when you help it out by coding -map instead of letting it find
a default.
mjs
May 25, 2022, 11:00:00 PM5/25/22
to Video DownloadHelper Q&A
The manifests are marked as x-mpegurl ,so if that's what you found then it still gives a 403 no matter which one I use in youtube-dl.
So looks like ffmpeg is able to succeed on this one.
Wild Willy
May 26, 2022, 12:13:12 AM5/26/22
to Video Download Helper Google Group
Manifests are always marked x-mpegurl. That's not really a significant thing. What is
significant it the first .m3u8 file in the Network Monitor. Never mind about the other
manifests. They appear to be subordinate stream manifests. The master manifest contains
references to those stream manifests. Pay attention to only the first manifest, which is
the master manifest. Have you run ffprobe on that one? If ffprobe throws up a 403,
reload the page & relaunch the video, letting it play for no more than a couple of
seconds, which will give you a new master manifest. You should eventually get a master
manifest that ffprobe will analyze. When you get one that doesn't 403 in ffprobe, try
using that one in youtube-dl. That's the case I'm curious about. I want to know if
reloading the page eventually gets you a master manifest that doesn't 403 on you.
But this may or may not be significant in eventually diagnosing whether we can get real
content, not just free samples, from Udemy (and Hotmart). We both know that web sites
are not necessarily consistent in the way they present their content. Web sites like to
change the way they operate, so older content may look one way but newer content may look
another way. Or they're just pathological, like a couple of sites we've encountered in
other threads here. Plus, like I say, the free samples may not be representative of the
paid content. So while this might be fun practice, it's not necessarily getting us
closer to solving the underlying problem that so many users have posted about & nobody
has yet followed up with us to pursue.
significant it the first .m3u8 file in the Network Monitor. Never mind about the other
manifests. They appear to be subordinate stream manifests. The master manifest contains
references to those stream manifests. Pay attention to only the first manifest, which is
the master manifest. Have you run ffprobe on that one? If ffprobe throws up a 403,
reload the page & relaunch the video, letting it play for no more than a couple of
seconds, which will give you a new master manifest. You should eventually get a master
manifest that ffprobe will analyze. When you get one that doesn't 403 in ffprobe, try
using that one in youtube-dl. That's the case I'm curious about. I want to know if
reloading the page eventually gets you a master manifest that doesn't 403 on you.
But this may or may not be significant in eventually diagnosing whether we can get real
content, not just free samples, from Udemy (and Hotmart). We both know that web sites
are not necessarily consistent in the way they present their content. Web sites like to
change the way they operate, so older content may look one way but newer content may look
another way. Or they're just pathological, like a couple of sites we've encountered in
other threads here. Plus, like I say, the free samples may not be representative of the
paid content. So while this might be fun practice, it's not necessarily getting us
closer to solving the underlying problem that so many users have posted about & nobody
has yet followed up with us to pursue.
mjs
May 26, 2022, 1:38:22 AM5/26/22
to Video DownloadHelper Q&A
I didn't get a 403 in ffprobe but it still won't work in youtube-dl. Anyway it was just a test.
I downloaded the photoshop video from a website.
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