Video callbacks called even though no new image is available

This forum is about all development around libVLC.
badgeror
Blank Cone
Blank Cone
Posts: 22
Joined: 15 Oct 2014 15:31
Operating System: Windows
Location: Sophia-Antipolis - FRANCE

Video callbacks called even though no new image is available

Postby badgeror » 18 Feb 2016 14:31

Hi
I've just stumbled across this particular issue with the video callbacks using libVLC 2.2.1 on windows:
- I'm opening an RTSP stream on a network camera (Axis camera in this case with a required framerate at 8 fps)
- I'm setting the video callbacks using libvlc_video_set_callbacks
- In the unlock CB I check that new image buffer is actually different from the previous one (using memcmp)
=> every frame is received at least twice. Dumping media_player_get_time shows that when these duplicate frames are received player time is not incremented

My question is why is the media player calling the video callbacks when it's not receiving actual images? or maybe I forgot to set a flag in the initialization of the player?

Obviously I could check the player time but when used with HTTP based MJPG streams this time stays at 0. I could also check that image is not the same but I want to be able to detect that a video stream is actually frozen...

Thanks

Sebastien

badgeror
Blank Cone
Blank Cone
Posts: 22
Joined: 15 Oct 2014 15:31
Operating System: Windows
Location: Sophia-Antipolis - FRANCE

Re: Video callbacks called even though no new image is available

Postby badgeror » 07 Mar 2016 15:55

Hi
Am I the only one to have noticed that?

Sebastien

Rémi Denis-Courmont
Developer
Developer
Posts: 15265
Joined: 07 Jun 2004 16:01
VLC version: master
Operating System: Linux
Contact:

Re: Video callbacks called even though no new image is available

Postby Rémi Denis-Courmont » 07 Mar 2016 22:31

Rémi Denis-Courmont
https://www.remlab.net/
Private messages soliciting support will be systematically discarded

badgeror
Blank Cone
Blank Cone
Posts: 22
Joined: 15 Oct 2014 15:31
Operating System: Windows
Location: Sophia-Antipolis - FRANCE

Re: Video callbacks called even though no new image is available

Postby badgeror » 09 Mar 2016 11:54

Hmmmm
a ten year old bug to fix which impacts a LARGE part of the VLC code? sounds awfully promising.... :cry:

I'll try to find a way around then

Thanks for the reply though

Sebastien


Return to “Development around libVLC”

Who is online

Users browsing this forum: No registered users and 4 guests