camera audio function, need better understanding

[serbokl 0]

Regarding a typical IP MP digital camera that has audio input and output RCA connectors, I'm trying to understand what is actually going on inside the camera. First off, is the audio in and out normally a line-level signal? Is an NVR camera tapping into the audio and recording it along with the video? If so, what the heck is the audio out RCA jack for? Please help me understand what is going on here.

[buellwinkle 0]

Every camera is different but in general, if the camera has mic in, then it means you can use a regular microphone. If it says audio in, you have to get an amplified mic. There's CCTV stores or online shops that sell mics for this purpose. They are usually pretty small and you can make it discrete or buy cameras like Mobotix D14 or M12 that have mic and speaker built in.

 

Audio out usually means you need an amplified speaker and in the case where I see this used it's box speaker mounted near the camera.

 

All this attaches to the camera in various ways depending on the manufacturer, but typically it's a terminal block that you wire into where there's audio in/out and alarm i/o.

 

As I've said for many, many years, RTFM.

[serbokl 0]

Thanks for your comments on audio function, too, buellwinkle. And by the way, I enjoyed reading your helpful information over at networkcameracritic.com!

 

With an eye toward figuring out how to use the audio function I read the manual for both the HFW3200CN IPC and the NVR3208 recorder and found virtually no truly helpful details. I will paste directly below what is said by Dahua regarding audio. Some of what is said sounds a little strange to me and my background is in electronics.

 

"2.3 Bidirectional talk

2.3.1 Device-end to PC-end

Device Connection Please connect the speaker or the pickup to the first audio input port in the device rear panel. Then connect the earphone or the sound box to the audio output port in the PC. Login the Web and then enable the corresponding channel real-time monitor. Please refer to the following interface to enable bidirectional talk. At the device end, speak via the speaker or the pickup, and then you can get the audio from the earphone or sound box at the pc-end.

 

2.3.2 PC-end to the device-end

Device Connection Connect the speaker or the pickup to the audio output port in the PC and then connect the earphone or the sound box to the first audio input port in the device rear panel. Login the Web and then enable the corresponding channel real-time monitor.

Please refer to the above interface (Figure 2-5) to enable bidirectional talk. Listening Operation At the PC-end, speak via the speaker or the pickup, and then you can get the audio from the earphone or sound box at the device-end."