Hello everyone !

This is my first post, even if I have been reading the forum for a while now... I'm a french user of vMix (so please excuse my mistakes in english :-) ).

vMix 15.0.0.74 (64 bits) is installed on a Windows 7 x64 SP1 machine (Core i5-4460, 8Gb RAM, Nvidia Quadro FX 580. Not a powerhouse, but works ok with USB cameras).
I encounter an issue with a Foscam IP Camera (FI9826W): I connect via RTSP (TCP or UDP: same issue), vMix displays the live stream, so OK... But every 5 seconds, the camera source freezes for 1 second in vMix (not in VLC, nor the webinterface of the camera), then works again for 5 seconds, and freezes for 1, etc... CPU usage is around 5%, render time 3ms, so everything looks fine on the machine itself.

I've also noted down the data in the statistics window after a few minutes of use:
Source Dropped: 1106 / Renderer Dropped: 27 / Resync: 31 / Queue: 5 / Video: 0 ms Buffers: V267ms. A 0ms 1,05x
(I'm not using Audio with this camera)

When the camera source freezes, vMix is still operational: I can switch sources etc... But the Queued images drop to 0, and a few frames are added to the "Resync" column. I've also tried increasing the buffer time to 750 / 1000ms. This extends a little the "smooth" period, but doesn't remove the freeze.

The camera ping over my wired gigabit network is less than 1ms, for every request, so the network works fine.

I did some experimentation with vMix and the Foscam FI9826W.
I've tested different settings combinations on the camera, to see if I can remove completely the stuttering issue. I've put something moving in front of the camera, and did the following tests (always with 720p, key frame interval at 30, and variable bitrate):

-512K, 10 fps : No stuttering
-512K, 15 fps : No stuttering
-512K, 20 fps : Stuttering (every 30 seconds)
-512K, 25 fps : Stuttering (every 10 seconds)
-512K, 30 fps : Stuttering (every 5 seconds)

-2M, 10 fps : No stuttering
-2M, 15 fps : No stuttering
-2M, 20 fps : No stuttering
-2M, 25 fps : Stuttering (every 6 seconds)
-2M, 30 fps : Stuttering (every 5 seconds)

-4M, 10 fps : No stuttering
-4M, 15 fps : No stuttering
-4M, 20 fps : No stuttering
-4M, 25 fps : Stuttering (every 5 seconds)
-4M, 30 fps : Stuttering (every 5 seconds)

Is anyone encountering the same issue with his IP cam via RTSP ?
I've also contacted Foscam's tech support, but as this is not happening under VLC (nor the embedded webinterface of the camera), I was thinking it may be an issue with vMix itself. So if someone knows a fix, or a workaround, it would be great !

Thanks a lot by advance.

New tests done here: I've installed vMix on another machine (Xeon W3520, 12 Gb RAM, GT 705), and still having the same issue with stuttering video every 5 seconds or so, when the camera sends a 720p, 4M, 30fps stream.

I've also tested the "buffer" settings in vMix, when I add the RTSP source: stuttering always happens, with every value (even high ones, like 2000ms, or 10000ms). But there is a variation: the higher the value, the less time it takes to "recover" from the freeze (for 10000ms, I simply see a "jump" in the video, whereas for 250ms, the video freezes for 1second). The buffering also has an impact on the timing between stutterings: at 10000ms, the "jump" occurs every 20 / 25 seconds (in comparision with every 5 seconds for 0ms).

Hope this can help understand what's wrong here.
Again, this works well in VLC. I've also tested directly via ffmpeg, and works perfectly too: video is smooth, no jumps or stutterings, even when I change manually the buffering to 150ms. Problems appear only in vMix.

Does anyone know a workaround, or fix to allow this cam to work ?
Thanks a lot by advance.

Thank you for your answer.
I'm using Gigabit Ethernet to connect the camera to the network.

Actually, the camera is connected to a Gigabit Ethernet switch, as the vMix machine (IP adresses are fixed on the machines themselves).
I don't plan to use Wifi with this setup.

I know this is an old thread, but I have had a problem with v 15.0.0.74 with using a usb web cam. Upgrading to 15.0.0.88 solved the problem. If you haven't upgraded to this level, you might try it. I found this thread because I am considering using a foscam in my application. Good luck.

I second the notion that this remains a problem with some IP cameras. I recently posted a new thread on this before I saw this thread, but it appears to be the same issue. I'd guess that the handshake across the RTSP/RTP link is not happening correctly with some set of cameras. As IP cameras are quickly becoming very important, I'd really like to see vMix investigate and fix this issue.

Again, this "stuttering" does not happen when viewing the same RTSP connection in VLC on the same machine on which vMix is running.

I understand that not all camera implementations of this protocol are the same but the common thread here is vMix where other programs are not seeing the problem (VLC and various other players).

How can we get this addressed?