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Video files are empty

Posted: Sat Mar 06, 2021 4:52 am
by nynx64
I have two outside cameras. They are identical models. I use motion detection on both.

The cameras are configured the exact same way 1080p @ 15fps.

The configuration on zoneminder's side is also the same for both cameras. Streams on both work fine but event playback only works on 1.

I did a test and forced an event on both cameras, then downloaded the mp4 on each.

The file sizes are very similar.

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When I open each in vlc, one of the files has 16 seconds of footage and the other shows 0:00/0:00. The video is basically empty except for the very first frame.

Also for some reason the one that doesn't work is sitting at an even 30.00 frames/sec with a much higher data rate then the one that works.

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I took a great deal of care to make sure that every setting on each camera is absolutely identical (both in ZM and out). What am I missing?

Re: Video files are empty

Posted: Sat Mar 06, 2021 5:22 am
by nynx64
Went through every setting again for a sanity check and noticed that the one that didn't work had h264 passthrough enabled on the storage tab.

The camera that works was using x264 encode. I set both to h264 passthrough and now they both have the same symptoms.

Why doesn't h264 pass through write video?

Re: Video files are empty

Posted: Sat Mar 06, 2021 7:15 am
by Magic919
The fact the files have a similar size says they are both writing video. An empty file or one with just one frame would be somewhat smaller.

Test the cameras using VLC or whatever without ZM. There is something about the camera output I suspect.

Re: Video files are empty

Posted: Sat Mar 06, 2021 4:04 pm
by Andyrh
Make sure the cameras are set to h264 also.

Re: Video files are empty

Posted: Sat Mar 06, 2021 6:45 pm
by nynx64
Here are the settings on each camera.

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Here is what VLC says about each RTSP Stream

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Last night I set both to encode x264 just so I could have working footage. It caught me taking the trash out this morning, a 12.88 second clip.

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Here's the same clip when playing it back. It sits on a single frame with a crazy long event duration. I tried downloading the mp4 and playing it with VLC and it plays through 12 seconds of the same image.

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Re: Video files are empty

Posted: Sat Mar 06, 2021 7:09 pm
by Magic919
They don’t seem to be honouring the frame rate or they don’t properly signal it. Would be worth restarting them after the change to see if it helps.

I presume the frame interval is for key frames. I’d drop that to match the frame rate (so one a second).

At least you know it’s not a ZM problem.

Re: Video files are empty

Posted: Mon Mar 08, 2021 1:03 am
by nynx64
Magic919 wrote: Sat Mar 06, 2021 7:09 pm They don’t seem to be honouring the frame rate or they don’t properly signal it. Would be worth restarting them after the change to see if it helps.

I presume the frame interval is for key frames. I’d drop that to match the frame rate (so one a second).

At least you know it’s not a ZM problem.

Yep I think that was it. I set the frame interval to the same as the FPS and played with the buffers tab a bit; then bounced both cameras. They are recording video files now.

Thank ya'll for the help.

Re: Video files are empty

Posted: Tue Mar 09, 2021 1:49 am
by river100
you might also want to try CBR instead of VBR, variable bit rate, with the i frame being default.