How to troubleshoot intermittent video recording and frame loss

Confirm the phenomenon first

• There is a time period that is skipped directly during playback (The video is missing).
• The playback screen is not smooth and lags (Frame loss).
• The timeline is broken but plays (intermittent).

The causes of the three are different. First describe the phenomenon accurately and then investigate.

Common reasons for missing videos

1. Network outage without ANR: Most common. When the camera is disconnected from the Internet, there is no local storage, and the video is lost directly. Solution: Enable ANR + SD card, or improve the link.
2. Storage full: Under the cycle overwriting strategy, insufficient capacity will lead to early overwriting. Check the capacity and storage days settings.
3. Hard disk failure: Bad sectors or disk failure prevent writing during this period. Check the hard drive SMART and system logs.
4. Schedule configuration error: The recording schedule does not cover the entire day, or the template is not applied to all channels.
5. Device restart: There is no recording during the restart due to power outage, insufficient power supply, or firmware abnormality.

Common causes of frame loss

• The bitrate does not match the storage performance: Multiple high-bitrate writes exceed the disk IO capacity. Especially when using SMR drives or RAID degradation.
• Network packet loss: Switch port congestion, poor network cable quality, and unstable wireless links.
• NVR access bandwidth is full: The bandwidth limit is exceeded after adding points.
• Insufficient camera performance: High resolution + high frame rate + intelligent analysis exceeds processing capabilities when turned on at the same time.
• CPU/memory usage is too high: NVR is also responsible for tasks such as decoding and uploading to the wall, intelligent analysis, etc.

Troubleshooting steps

1. View the Recording Completeness Report (most NVRs have this feature) to locate specific missing time periods.
2. Check whether the missing periods are regular (such as fixed times every day, high temperature periods) → point to power supply or scheduled tasks.
3. Check the hard disk health status and remaining capacity.
4. Check the switch port's packet loss/error count.
5. Calculate whether the total bit rate exceeds the NVR access bandwidth and disk writing capacity.
6. Check whether the recording plan covers the entire day.

Improvement measures

• Enable ANR + high endurance SD card at key points.
• Use CMR surveillance-grade hard drives to avoid SMR.
• Divide VLANs into storage networks and business networks to avoid mutual influence.
• Set the capacity alarm threshold to 15%, and perform regular video integrity checks.
• Configure double backup or off-site storage for important projects.