spawn_first only works on new mpv instance

[Kanjo63]

Currently when spawn_first is set to true it only spawns the thumbnailer on the first file load. If you open a file within the same instance of mpv afterwards the thumbnailer will not load automatically leading to slower thumbnail generation time on every file that was not the first opened file. Would it be possible to change this behaviour to automatically spawn the thumbnailer for every file loaded in the same instance of mpv or perhaps add a different option that would allow us to do so?

[N-R-K]

If you open a file within the same instance of mpv afterwards the thumbnailer will not load automatically

Seems to be working fine for me. If I switch to a new file I can see another mpv subprocess being created with the new file in htop.

[Kanjo63]

I apologize, I've probably described the problem incorrectly and/or poorly then as I'm not very experienced with this unfortunately. I did try with a fresh install of mpv + thumbast + osc.lua just now and still notice the delay I was attempting to describe though.

While testing I noticed that thumbnails will be entirely white if the 2nd file opened in an instance gets deleted before hovering over the progress bar. However the thumbnail will have generated just fine if it is the first file opened and the file is deleted before hovering the progress bar. Hopefully that's an easy example to recreate.

[N-R-K]

While testing I noticed that thumbnails will be entirely white if the 2nd file opened in an instance gets deleted before hovering over the progress bar.

I still can't reproduce. I still get thumbnail on whether it's the first or second file.

I did try with a fresh install of mpv + thumbast + osc.lua just now

Did you make sure to use spawn_first as well?

If I use spawn_first=yes then I get thumbnails on both first and 2nd file even after being deleted before hover. And if I disable spawn_first then I get no thumbnails on either file.

still notice the delay I was attempting to describe though

How much delay are you noticing exactly? I don't get any noticeable delay on first or 2nd file with spawn_first=yes.

[Kanjo63]

I did try with a fresh install of mpv + thumbast + osc.lua just now

Did you make sure to use spawn_first as well?

If I use spawn_first=yes then I get thumbnails on both first and 2nd file even after being deleted before hover. And if I disable spawn_first then I get no thumbnails on either file.

Yes, I did make sure to set spawn_first=yes in thumbfast.conf and did not edit any other settings. Very weird that we have different outcomes when starting from the same base. I'm using Windows 11 are you on a different OS?

still notice the delay I was attempting to describe though

How much delay are you noticing exactly? I don't get any noticeable delay on first or 2nd file with spawn_first=yes.

It's minimal, only one second or less of a white box before I see the thumbnails appear. Though if the file is deleted it will never generate for the second file.

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Edit months later:

I found a hacky(?) workaround for my issue by modifying the thumbfast.lua. I'm guessing the cause was spawn_first was waiting for something to be resized due to this line of code
if not spawned and not disabled and options.spawn_first and resized then
The and resized is what I suspect is the culprit.

In my case I think I wasn't meeting this resize trigger so I added an alternative trigger that should always be active if spawn_first is set to yes in the thumbsfast.conf. This should hopefully not remove any functionality the code already had but ideally catch more edge cases like mine.

Added this to line 181
local spawn_first_pending = false

Modified the suspected issue code at line 841 to be the below
if not spawned and not disabled and options.spawn_first and (resized or spawn_first_pending) then spawn_first_pending = false

Added this to line 898
spawn_first_pending = options.spawn_first

I am very much a novice at this stuff so take what I say with a grain of salt but this bothered me enough that I spent time until I found a fix for myself. If anyone else has this issue and wants to give it a shot feel free to try.