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Swann NVR Night Recording

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Hi all,

 

Having an issue with the night recording on my Swann NVR-7300.

 

Playback using the software is perfectly fine and plays audio and video in sync at normal speed. However, when backing up/downloading either on the software on the PC or straight from the box via USB the recording plays at almost double the speed. It happens on all cameras (I have three in total).

 

A recording downloaded from during the day plays back perfectly. A recording downloaded from during the night plays back at almost double the speed and the audio is about 20 seconds behind. I have turned off the 3D noise reduction setting so will check again tonight however don't think it will make a difference.

 

Any ideas anyone? Many thanks in advance!!

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Hiya,

I've got the same issue...

I've got an open ticket with Swann on a different issue with regards to the WDR behaviour (there will be firmware coming out for the NHD 810,811,815 cameras soon to fix it).

but whilst there I asked about the frame rate issue and this was the response:

For the playback speed, this is due to the player assuming the frame rate rather than reading the header. The native player plays at normal speed. To improve the night vision quality the camera has a dynamic frame rate while in night mode to ensure the best image. You can turn this off and force full frames but it can result in reduced night image quality.

They sent me a link to the 'swannview player', which I can't get to run and isn't very practical, so I'll probably just find the setting to deactivate the variable framerate and suck up the quality.

 

Hope that helps

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Thanks, this helps - much appreciated!

 

I guess i'll just wait until the new firmware for the cameras comes out and then see what happens.

 

I had the same response in regards to the swanview player - I can't get it to run either (well, I can open the program but it crashes when loading a video). Failing that, it was Swann taking control of my computer to see what the problem is. I'm pretty decent with this sort of stuff so I declined the assistance from Swann and wasn't that convinced considering all I got was automated styles responses via email

 

The framerate issue you described makes perfect sense, I guess because the system is new to the market there are a couple of "teething" problems at the minute - After much fiddling around I did have half a mind to just return it but it looks like there is still hope!!

 

Thanks again

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I have the identical issue here. I have a NVR8-7400. Works fine during the day but as soon as it hits night vision it speeds up like crazy. The normal playback is fine but when put onto a USB and then to a computer its double the speed if not more. Did anyone find a fix yet? Swann is no help. If it is the Dynamic thing mentioned above, how can you force the option?

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Hi there. I too have been experiencing difficulties with the nighttime playback speed on my NVR8-7400 with the NHD-818 cameras. I'm guessing we're all still stuck on this one?

 

Has anyone successfully retimed any footage or discovered how to get third-party players to read the header speed?

 

I have tried converting my footage in vlc player and changing the fps but to no avail. I have also tried converting the file format to mp4 and this did nothing to the speed.

 

I think the problem of the variable night vision framerate is compounded by the H.264 format which, from what I have read on the web, seems a bit quirky in terms of the information it contains and shares with playback software (I think).

 

It's a shame as I have some footage I've captured that I need to share with the police. At present, it's like watching an episode of Benny Hill.

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Luckily all the information I had to share with Police was during the day time. I have spoken to Swann multiple times and they either do not know what is going on or say that it is because I convert it to AVI. But when I tell them that it is only the night footage and that it does it in the RAW file too they then refered me to a specialist who called me. He then went through a bunch of a settings and was not able to find an issue. He then said that he will refer me to the high tech team. 2 months later still no call or word from them. I just gave up. Im assuming it is a software issue rather than the hardware issue since we all have the same problem.

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Has anyone managed to find a solution yet? So far nothing from Swann, they had a tech call me and then refer the call to another tech. 6 months later still no word from Swann as if they do not even know about it. Has anyone managed to find a solution or even the cause for the issue?

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I've had this same problem with my NVR-7300. I had not realised that it only applies at night (which is when my wildlife footage happens). I guess either the cameras or the DVR cannot apply 'night' processing at the speed needed for 25fps. However, the files exported still have 25 in the header as the frame rate. This means that the quote from Swan that RacingSnake got in a post above is misleading:

 

For the playback speed, this is due to the player assuming the frame rate rather than reading the header. The native player plays at normal speed. To improve the night vision quality the camera has a dynamic frame rate while in night mode to ensure the best image. You can turn this off and force full frames but it can result in reduced night image quality.

 

Do we know what the "turn this off and force full frames" setting actually is, anybody?

 

The problem is that the files say FR=25 even when it is slower (around 12fps I usually find, although it seems to vary). So any playback software plays it at 25fps, which is then speeded up. It makes no difference if the files are exported raw (.264) or in AVI mode - thats just about the file wrapper.

 

Partial solution: I use the software ffmpeg (https://ffmpeg.org) to change the frame rate, using the command:

> ffmpeg -r 12 -i output_file.mp4

- where 12 is the guessed frame rate. I have to trial and error until the output file plays at the right speed.

But, this does not keep the audio. I think the only solution to that is to record off the audio output of the unit itself and then combine with the corrected video. Ugh! Any other ideas for audio?

 

I also tried Swannview Link on android, using playback and then the 'record video to phone' function. But those files were the same - they say 25fps but are lower.

 

One thing I need to try is to set the camera to run at (say) 10fps and see if that produces correct speed files. Will report...

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I finally managed to solve this (if anybody still interested) but it involved a bit of programming.

The problem is that the file header declares 25Hz (or whatever the unit is set to) but the actual frame rate is 8Hz, 13.5Hz or other random number, so it plays incorrectly.

If exported as AVI file, however, the audio is declared correctly, so the correct duration is known, and then dividing that by the number of frames gives the actual frame rate, which can then be overwritten back in the file. I wrote a bit of software to do this, but its for linux. Anyone who'd like to do a windows/mac version is welcome to the source code.

The output is a file that plays with correct frame rate (13.5Hz or whatever) and with the audio intact. I then use ffmpeg to resample the video to a standard rate like 30Hz, again preserving audio.

Has this problem been fixed on newer Swann units?

 

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