Shotcut won't render using nvidia h264_nvenc and hevc_nvenc

[Videomice]

In spring 2020, I could render a 1080p 50fps video of about 30 min length with shotcut. I am running Manjaro-Linux on my PC.
After a long pause, I now wanted to render a 720p 30 fps Video of 26 min length. There was no sophisticated cutting, filtering etc. as I only had to cut off the beginning and some frames from the end of that video.
The I tried to export it with the same format using the preset h264_baseline profile. After about 8 minutes of rendering time, I have got a video of 58 MB containing only the audio and perhaps a lot of video data which is shown as simply black.

When I tried to render with the linux / intel onboard-GPU, the rendering lasted about 38 minutes and the content was OK in audio and video. But of course, it is not funny to spend 38 minutes, when you can get the same within 8 minutes!

I have deinstalled and reinstalled shotcut, I have checked the nvidia drivers. My actual Linux Kernel is 5.8.16-2. Graphic card is Nvidia GeForce GTX 1650

Then I looked at the shotcut logfile and I wondered about the lot of warnings. I have attached the logfile at this posting. To make it easier to focus at the warnings and strange things, I have extracted the warnings here:

[Warning] mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltrubberband.so (librubberband.so.2: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden)
I have checked this and the file is there, where it should be!

[Warning] mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltrtaudio.so (librtaudio.so.6: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden)
I have checked this and the file is there, where it should be!

[Warning] mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltsox.so (libsox.so.3: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden)
I have checked this and the file is there, where it should be!

[Warning] mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltsdl.so (libSDL_image-1.2.so.0: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden)
I have checked this and the file is there, where it should be!

[Warning] [consumer 0x55c40c1f9330] The DeckLink drivers not installed.

[Warning] <> QSqlDatabasePrivate::database: requested database does not belong to the calling thread.

[Warning] <> file:///usr/share/shotcut/qml/views/timeline/TrackHead.qml:188:13: QML ToolButton: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.

[Warning] <> file:///usr/share/shotcut/qml/views/timeline/Track.qml:85:13: Unable to assign [undefined] to double
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/Track.qml:84:13: Unable to assign [undefined] to QString
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/Track.qml:83:13: Unable to assign [undefined] to int
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/Track.qml:82:13: Unable to assign [undefined] to int
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/Track.qml:86:13: Unable to assign [undefined] to QString
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/Track.qml:77:13: Unable to assign [undefined] to bool

[Warning] <> file:///usr/share/shotcut/qml/views/timeline/timeline.qml:333: TypeError: Cannot read property ‘height’ of undefined
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/timeline.qml:331: TypeError: Cannot read property ‘y’ of undefined
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/timeline.qml:330: TypeError: Cannot read property ‘x’ of undefined
[Warning] <> file:///usr/share/shotcut/qml/views/timeline/timeline.qml:329: TypeError: Cannot read property ‘y’ of undefined

20-10-20_failed-Shotcut.txt (45.7 KB)

At the end of October, I have to cut some videos and I should have solved this problem until then.

I want to know, whether there is a configuration problem or whether the problem can be found at the nvidia driver site (I do use the proprietary nvidia drivers) or if it is a bug in shotcut?

[shotcut]

Starting Shotcut version ARCH-20.09.13

We can only support the builds we provide, and this one is not provided by us. Maybe they did not build ffmpeg with support for nvenc. Also, it is not clear if you used the Detect button in the Shotcut hardware encoding configuration dialog.

[Videomice]

OK, I will try Shotcut using an appimage instead of the Arch edition. Additional info: When I click the DetectButton, the encoder switches to the Linux / Intel OnChip-GPU and then I get the video rendered.

I have tried this AppImage:
Shotcut-200927.glibc2.14-x86_64.AppImage
Now using the Detect Button the Nvidia-Encoder keeps activated. Further I see, that the Nvidia Graphic Card has about 25% load on graphics and up to 36% video load while CPU has nearly constant 74% load. (No other programs causing additional load.)
Rendering time was 7:26 minutes and the result was as expected.

But there are still some warnings and strange messages in the logfile. Therefore I will append this here. I think, it is strange, that in lines 125 til 130 as well on line 416 nvidia drivers are found, but in lines 423 til 442 it seems, that hevc_vaapi will be used instead of hevc_nvenc.
And there are some other things. Could you please have a look at this logfile?

Therefore we can conclude, that your assumption has been right:
The maintainer of the Arch Shotcut package must have built in some bugs.

Thank you answering, even in this case, where the problems were not caused by shotcut itself (41.4 KB)