Why my playback quality is not as good as real-time?

[rentonrenton 0]

Hi all,

 

I just installed a security camera system at my house. I used a Dahua 4-ch HDCVI DVR and 4 1080p HDCVI mini dome cameras. I connected a screen to the DVI and I watch everything on the screen.

 

What I have noticed is that my real time video is so good and smooth. However, the video in the playback is not so good. It's a little choppy. After some research online, I found that it is because of the limitation of the DVR. Most "household" system cannot record all channels at 30fps@1080p at the same time. I can only set 15fps@1080p for all 4 cameras or do 30fps@1080p for 1 of them and 7fps@1080p for the rest.

 

So here is my real questions: No matter how high I setup for one of my cameras(30fps@1080p, 6044 bit-rate) and sacrifice the rest 3, the camera's playback is still not as good as the real time quality. I just don't understand. Isn't real-time also 30fps@1080p?

Edited June 12, 2017 by Guest

[thewireguys 3]

The live video from CVI cameras is a uncompressed real-time video. The recorded video is compressed so you will never see the recorded image as good as the live.

[ssmith10pn 0]

And why do you need 30fps?

Checking for cheating in a card game?

[rentonrenton 0]

Thank you for your reply guys.

The contractor who installed my security camera system first showed me the app on my smartphone. To ensure my iphone wirelessly connects to the live feed quickly, he had to set the live video quality to substream(D1), and the playback is just the normal 15fps quality, which gave me an impression that the playback quality is better than the live video quality.

 

It was not until hours later that I found out it is not the case on the DVR screen. Plus, the smartphone live video quality can be changed to mainstream, it will just take my iphone longer to connect. Anyway, main or sub-stream, 15fps or 30fps, the playback will never be as good as live. And the reason has already been explained in the previous reply.

 

So thank you, guys.