Student video file submissions file size discrepancy

[kbarclay]

Student video file submissions are downloading as much smaller file sizes than shows up in Speedgrader. I attached a screenshot of a video file in Speedgrader that shows as 90.3 MB, but it downloads as only 3 MB. Does anyone know why? Is there a compression going on in the background to limit file sizes stored in Canvas Assignments? Also, they don't show up in Files, where do we find them?

[ProfessorBeyrer · Accepted solution]

Thank you for including the screenshot, @kbarclay. I did some testing and verified what you reported. I had students submit a video file in two different ways. One was submitting a media recording, which compressed a video by 90%. That's quite a compression ratio, and comparing the one the student uploaded and what the instructor downloaded shows the difference: The student uploaded with a 1920x1080 aspect ratio, but the file the instructor downloaded was 640x360. I then checked the student's Files area, where their uploaded media is stored, and I see the smaller file. So it looks like Canvas does the compression at the moment of upload.

The other option was to have the student submit the video as a file. In that case, the same thing happened. It went from a 33MB file on upload to a 3MB file on download. What's interesting, however, is that Canvas's pages indicate it's a 33MB file but its preview is the smaller aspect ratio. 

My guess is that the file compression is there to help Instructure save on storage.

[ColtonShanahan · Accepted solution]

Munson IT Tech here.  I may have found a solution to this issue.  

Our instructors were reporting the same thing when it came to downloading this Semesters Student Finals.  We found that anything over the 500mb limit was getting crunched down to a lower resolution, from 4k down to near 480p video.  

After some digging I found within Course > Settings > Quotas, that our user quota was only set at 500megabytes, and our Course Quota at 2500 megabytes.  We brought our user quota's up to 2500megabytes and Course quota to 25000megabytes to ensure enough headroom for the course storage, and click Update.

We tested uploading a 1.5 gig file, and downloaded it as intended and we were able to pull a 4k file this time.  Possibly a new feature or update to Canvas could have reset these values to a default setting.  This seems to have resolved our issue without having to Zip(compress) files.  Students did have to resubmit their work however.  

[ProfessorBeyrer · Accepted solution]

Thank you for including the screenshot, @kbarclay. I did some testing and verified what you reported. I had students submit a video file in two different ways. One was submitting a media recording, which compressed a video by 90%. That's quite a compression ratio, and comparing the one the student uploaded and what the instructor downloaded shows the difference: The student uploaded with a 1920x1080 aspect ratio, but the file the instructor downloaded was 640x360. I then checked the student's Files area, where their uploaded media is stored, and I see the smaller file. So it looks like Canvas does the compression at the moment of upload.

The other option was to have the student submit the video as a file. In that case, the same thing happened. It went from a 33MB file on upload to a 3MB file on download. What's interesting, however, is that Canvas's pages indicate it's a 33MB file but its preview is the smaller aspect ratio. 

My guess is that the file compression is there to help Instructure save on storage.

[kbarclay]

Hi Greg,

Thanks for testing it yourself (a couple of ways) and confirming my suspicions on this one. I think Canvas should put this info into their Canvas Guides support pages! - Cheers! Kent

[Chris_Hofer]

Good morning, @kbarclay ...

You can actually make suggestions to the Documentation Team at Instructure if you feel that any of their Guides here in the Community could use some improvements.  I know this particular Guide isn't really specific to your question, but I'm using it as an example:

How do I get to SpeedGrader from an assignment, qu... - Instructure Community (canvaslms.com)

If you scroll to the very bottom of this Guide, you'll see a blue "Leave Feedback" button.  By clicking on this button, a form will open up, and you can provide feedback directly to the Documentation Team for their review.  You can do this for any Guide in the Community.  Just visit the specific Guide you want to give feedback about, and then click the "Leave Feedback" button.

Hope this helps a bit!

[kbarclay]

Thanks Chris, that's a great idea. I'll definitely do that.

Cheers!
Kent

[AnthonyWarnick]

Thank you for this, but it is not a solution. This compression happens on file upload as well and when teaching multimedia editing I need to be able to download the full res files my students have made.

[Nancy_Webb_CCSF]

I just spoke with Canvas Support about a similar situation with audio files, and they say this compressed download problem has been fixed, probably within the last 24 hours.  It is only fixed for newly uploaded files, after fix was deployed.  Just checked with a file uploaded yesterday and it downloaded at full size.  Hope that will be true for all media files.

[PaulMcCormick]

This seems to be a new issue that started around the time of your post. I have had students uploading videos all semester and only files that have been uploaded since Weds/Thursday  have been over compressed.

[kbarclay]

That's not a very good way for Canvas to rollout a feature that has had the impact we're seeing without more of an announcement. We have our monthly meeting tomorrow with our CSM, I'll make sure to bring this up.

[jhenline]

Kindly let us know what you hear. Thank you!

[kbarclay]

I created a support ticket at the advice of our CSM. She indicated there was already an internal ticket to address this so it seems like it' a bug and not a feature. Here's the reply I got re: my ticket yesterday. Promising.

Hello Kent,

Looking into the internal ticket you provided it appears it is still being tested and worked on. The only update we currently have is they suspect that it may be downloading in a lower resolution that it was originally uploaded in which would explain why it is a much smaller file size. However they are still testing that theory and have not yet reached a conclusion or resolution at this time. 

Thank you for contacting Canvas Support! If you have any other questions or concerns please reply back to this email. 

Best regards,
Tai B.

L1 Canvas Support
support@instructure.com
community.canvaslms.com

[Darmilatron]

This has just caused a major issue on our course, is there somewhere to disable this undesirable functionality.

[AnthonyWarnick]

Same for me and i have not found any work around beyond having everyone resubmit and zipping their videos.

[jhenline]

We're also experiencing this issue. I've done some testing with various video and the results are not consistent. In some cases, the videos are being compressed and in others, they are not. It would be great if there was documentation explaining which videos, based on criteria such as file size, resolution, bit-rate, etc. would be compressed or re-sized after uploading.  

[kbarclay]

I totally agree. I'm going to follow @Chris_Hofer's advice and look for the closets documentation I can find and make the suggestion to include this with more of an explanation. Also, if there may be bugs in the new process, if it's inconsistent, it would appear so.

[PaulMcCormick]

In my tests yesterday I found that if you place the video in a zip file it wasn't compressed during the upload.

[kbarclay]

It seemed though that the files weren't compressed during upload as they were showing their original file size, it was happening in the download. At least that was my experience.

[Darmilatron]

We had to get all of our students to re-submit their work as zip files, this works for now without the files being transcoded.

[ColtonShanahan · Accepted solution]

Munson IT Tech here.  I may have found a solution to this issue.  

Our instructors were reporting the same thing when it came to downloading this Semesters Student Finals.  We found that anything over the 500mb limit was getting crunched down to a lower resolution, from 4k down to near 480p video.  

After some digging I found within Course > Settings > Quotas, that our user quota was only set at 500megabytes, and our Course Quota at 2500 megabytes.  We brought our user quota's up to 2500megabytes and Course quota to 25000megabytes to ensure enough headroom for the course storage, and click Update.

We tested uploading a 1.5 gig file, and downloaded it as intended and we were able to pull a 4k file this time.  Possibly a new feature or update to Canvas could have reset these values to a default setting.  This seems to have resolved our issue without having to Zip(compress) files.  Students did have to resubmit their work however.  

[kbarclay · Accepted solution]

That makes perfect sense, thanks Colton! I wonder why Canvas Support didn't figure that out? 😉

[ColtonShanahan]

We just found the issue today and it seemed to work out.  Hopefully it does the trick for everyone.