[regression] animation wrong displayed in full screen without hardware acceleration

[ousia]

Describe the bug

In both Linux and Windows, when hardware acceleration isn’t available, the presentation contained in https://www.free-culture.tk/ is displayed in a totally wrong way:

Expected behavior

Compare it to the real page:

I cannot say when the regression was introduced, but this was displayed fine until recently (I think).

Affected platform

Browser's extension

Operating system

Linux

Browser

Firefox 103

[n0samu]

Can confirm this issue:

The screen appears blank most of the time because the text is somehow rendering mostly off-screen.

[n0samu]

Strangely, the issue does not occur on the Ruffle extension's internal player page. To figure out what the difference was, I tried disabling the CSS on your site, loading the extension copy of Ruffle into the page and removing the explicit width and height from your Flash embed. Yet the issue still occurs.

[ousia]

Strangely, the issue does not occur on the Ruffle extension's internal player page.

Many thanks for your help, @n0samu.

Do you mean https://ruffle.rs/demo/?

If I drag and drop https://www.free-culture.tk/lfc-presentation.swf over https://ruffle.rs/demo/, once I enable fullscreen mode (pressing f), fullscreen image is distorted.

This is not as distorted as in https://www.free-culture.tk/, because the original frame in this case is much smaller.

And again, this only happens with hardware acceleration disabled.

Or the distortion may occur when fullscreen is disabled again (if animation in fullscreen was displayed fine).

For some strange reason, image seems not to be recalculated again when changing fullscreen and normal modes.

I would be very surprised if this were the only animation that displays the issue.

Many thanks for your help again.

[n0samu]

Do you mean https://ruffle.rs/demo/?

No, I meant the Ruffle browser extension (I was using the Firefox extension). If you enable the browser extension and open the SWF URL directly, it will open in the extension's internal player page.

[ousia]

I think this regression may be a Firefox issue drawing the frames.

I’m not on Windows now, but Chrome seems not to have any issue displaying the presentation.

Thanks to https://sourceforge.net/projects/portableapps/files/Mozilla Firefox Developer Portable/, I was able to test https://www.free-culture.tk with Firefox 99 (beta 1) and with Firefox 104 (beta 1).

The issue arises when hardware acceleration is disabled (or not available):

1. Image is displayed perfectly fine with version 99.
2. Version 104 doesn’t seem to display image at all when in full-screen.

All this happened using the browser extension from the nightly build from today (2022-08-10).

So it is highly improbable that the regression was caused by Ruffle itself (I guess Firefox may be messing things here).

@n0samu, I updated the selfhosted build to the nightly from today.

Would you be so kind to check it with Chrome?

Many thanks for your help.

PS: I’m checking now with Firefox for Linux with hardware acceleration disabled (https://www.free-culture.tk/lfc-presentation.swf). I’m afraid that I have just realized get what was working fine for you, @n0samu (😅).

[ousia]

@n0samu,

playing directly https://www.free-culture.tk/lfc-presentation.swf, I get a first image such as:

It will be scaled perfectly fine to full screen (to the same image I already attached).

But going back to normal size distorts the image:

Again, I’m on Linux using Firefox with the nightly browser extension from 2022-08-10.

Clearer sample?

With a very similar presentation, https://www.improve-presentations.tk/Presentacion-presentation.swf:

The first image is fine:

Full screen is also fine:

But back to normal gets distorsion:

Just in case it helps.

[ousia]

After checking myself the presentation in Chrome (same computer as the original issue reported here), image is rasterized fine in both full and normal screen.

So the culprit seems to be Firefox rasterizing the images from frames.

BTW, this is what Firefox displays after setting the image to normal after full screen:

The animation is actually played in the bottom left corner, having the main image flickering but not advancing with the slides.

I think this may be be an upstream issue with Firefox, but I don’t know where to start or how to report this.

[ousia]

Just it case it might help, here you have the resource info:

1. Top left: Chrome in full screen.
2. Top right: Chrome in normal screen.
3. Bottom left: Firefox in full screen.
4. Bottom right: Firefox in normal screen.

The animation played was https://www.free-culture.tk.

Just in case it might help.

[ousia]

@Dinnerbonne,

sorry for bothering you here, but I’d avoid polluting the PR with comments that may not be related.

I guess that #7777 is not related to non-hardware accelerated graphics.

I wanted to know just to see if this could be improved in any way (or it could be a good test case for the PR).

Many thanks for your help.

[ousia]

This seems to be fixed in latest Firefox (106.0.1).

Closing the issue myself, although it would be great if @n0samu could confirm the fix too.

[n0samu]

Can confirm that this is fixed!