Bug 416466

Summary: GoPro footage thumbnails are just noise in Dolphin
Product: kdemultimedia Reporter: Isaac A. <isaac>
Component: ffmpegthumbsAssignee: Multimedia Developers <kde-multimedia>
Status: REPORTED ---    
Severity: normal CC: isaac, me
Priority: NOR    
Version: 22.04.0   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Attachments: Small patch deleting few lines

Description Isaac A. 2020-01-19 16:47:00 UTC
Whenever viewing footage from my GoPro Hero 8 with ffmpegthumbs enabled in Dolphin the thumbnails are just noise most of the time, may be related to #406981..

Occasionally some of the footage has a thumbnail, I'm not sure what causes it, but it's consistent on what footage does and does not. I can upload said footage if needed once I'm near a fast connection. It could also be related to file size somehow as I'm unable to find any files over around 150 MB that display thumbnails..

Picture of the issue: https://i.imgur.com/1wm2ITp.png
Comment 1 Christoph Feck 2020-02-05 14:03:31 UTC
The thumbnailer just uses FFMPEG libraries to extract the frame image.

Please try this command in Konsole (try with different time-stamps):

ffmpeg -ss 00:00:10 -i GXxxxxxx.MP4 -vframes 1 testoutput.jpg

If the testoutput.jpg shows the same errors, then the bug needs to be reported to FFMPEG developers.
Comment 2 Isaac A. 2020-02-05 16:51:25 UTC
(In reply to Christoph Feck from comment #1)
> Please try this command in Konsole (try with different time-stamps):
> 
> ffmpeg -ss 00:00:10 -i GXxxxxxx.MP4 -vframes 1 testoutput.jpg

When running this command with any timestamp on any of the footage that's corrupted I get a valid thumbnail from ffmpeg: https://i.imgur.com/LvAULtw.png
Comment 3 Christoph Feck 2020-02-05 21:31:14 UTC
Thanks for confirming. Is it possible you could add or upload a small test file for developers to test?
Comment 4 Christoph Feck 2020-03-03 21:07:28 UTC
If you can provide the information requested in comment 3, please add it.

You could also mail a test file to me privately.
Comment 5 Isaac A. 2020-04-19 18:28:04 UTC
Sorry, just now checked up on this issue. I'll upload a file shortly
Comment 6 Iyán Méndez Veiga 2020-05-21 11:24:55 UTC
I confirm that I have the same issue. Also, when trying the command suggested by Christoph I have no issues at all. I have also tried to disable the filmstrip effect, but same issue.

What is weird is that some videos have a thumbnail but others (most of them) not. Here I leave two files so you can compare and try to debug.

https://file.io/qY9Dr5lR (thumbnail not working)
https://file.io/dVpq7bha (thumbnail working)

Both videos are taken directly from the gopro and they are not edited.
Comment 7 Iyán Méndez Veiga 2020-05-21 11:33:01 UTC
Sorry, first time I tried that service but it looks like they deleted the videos a few minutes after uploading them. This links should work now.

https://cloudstore.uni-ulm.de/s/yRjjqCH5jAbZx34 (thumbnail not working)
https://cloudstore.uni-ulm.de/s/A9gw3eoPdqZax8Q (thumbnail working)

If you need any more information, please just let me know.
Comment 8 Iyán Méndez Veiga 2020-05-21 13:05:40 UTC
It looks like some problem with the swscaler. This is the output of running ffmpegthumbtest with the two files I provided before.

GX013708.MP4
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x55feeac5cd40] Using non-standard frame rate 29/1
[swscaler @ 0x55feeaf342c0] deprecated pixel format used, make sure you did set range correctly

GX013724.MP4
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x55e00ff9ed40] Using non-standard frame rate 29/1
[swscaler @ 0x55e0102a3c00] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 0x55e0102a3c00] bad src image pointers

If someone has the time to mentor me a little bit with the code (I know some C++) I could try to help with this bug.
Comment 9 Iyán Méndez Veiga 2020-05-21 14:27:18 UTC
Created attachment 128665 [details]
Small patch deleting few lines

The issue is solved for me with this patch, but I don't know if it's safe to delete those lines. Probably it is, but maybe someone can have a look?
Comment 10 Iyán Méndez Veiga 2020-05-21 14:52:39 UTC
Trying invent.kde.org for the first time. Here I leave the merge request, I guess is more convenient.

https://invent.kde.org/multimedia/ffmpegthumbs/-/merge_requests/1
Comment 11 Iyán Méndez Veiga 2020-05-21 23:34:33 UTC
Of course, the naive patch doesn't solve the real problem (and it breaks the thumbnails for good videos). While keep reading the code, ffmpeg docs, etc., I found these issues with GoPro videos that may be related.

https://github.com/opencv/opencv/issues/15352

So I closed the MR and I'm afraid I cannot help more without external help.
Comment 12 Iyán Méndez Veiga 2022-04-24 09:59:53 UTC
Despite latest changes in Dolphin, this is still true with latest version. Kdenlive creates thumbnails perfectly, but Dolphin doesn't.