ERROR: tvservice-client: Failed to connect to TV service: -1 pngview: pngview.c:177: main: Assertion `display != 0' failed.

[ozett]

hi, wonderful tool, this pngview. thanks.

if i run it first, i have no error.
i can than run omxplayer on top of my pngview-image. no error in omxplayer.

i got an error the other way round:

if i run my omxplayer first, an than pngview, i get this error from pngview:
root@raspberry2-www:/usr/src/pngview# ./pngview -l 5 Monsters30.png
tvservice-client: Failed to connect to TV service: -1
pngview: pngview.c:177: main: Assertion `display != 0' failed.
Abgebrochen
root@raspberry2-www:/usr/src/pngview#

i dont know if you can fix this?

[ozett]

sorry for putting this here in.
i investigated a little bit, because the image did not vanish, so i found a process still running, wich must have lead to this error. i found it with 'ps" and killed it. now it works normal....
BUT i can not start a pngview a second time, to put an image on an higher layer.
That woud be nice, to stack images over each other.

is pngview allowed only on one single instance?

i gave my first error-setting another try. same error again.
i have 3 omxplayer-streams displaying on layer 3,4,5. with alpha transparency and window-positions. everting is working fine. i cannot use pngview to put an image on top on layer 6. i can start another omxplayer, but not pngview. i have the error mentioned above.

[AttilaSVK]

It works for me both ways, however looks like pngview is either limited to 8 instances, since I can only display 8 images at the same time, on any layer. When I try to run the 9th instance, I get the same error message:
tvservice-client: Failed to connect to TV service: -1
s5: pngview.c:184: main: Assertion `display != 0' failed.
Aborted

[gev]

@AttilaSVK I've confirm. I have only 8 instances too. Also sometime after killing pngview I've empty black screen instead XServer, but application started in XServer continue to work as well

[nagualcode]

if you set dispmanx to offline to config.txt you will pas this limit, but things will slow down !

[SvenVD]

It works for me both ways, however looks like pngview is either limited to 8 instances, since I can only display 8 images at the same time, on any layer. When I try to run the 9th instance, I get the same error message:
tvservice-client: Failed to connect to TV service: -1
s5: pngview.c:184: main: Assertion `display != 0' failed.
Aborted

I have the same issue. Running on a raspberry pi 4 with 8G of ram with gpu_mem on 512. Is this a limit of the gpu? And why hasn't this limit changed with newer hardware, I can also run 8 pngviews on my raspberry pi 2. I had hoped newer hardware would have lifted this limit to a higher level. Or is this really a limitation on how pngview was written?

Thanks

[nagualcode]

There is not problem with this limit. You need to code your software. Raw tools like pngview are not suposed to be used as a desktop window manager.