Wednesday, May 23, 2007

Using an IP Cameras with Audio

An IP camera with IP software can be used to view and record video along with audio, but it may not be good for every application. IP cameras and software systems are designed for surveillance applications, so when used in a different application such as recording a presentation, may not be as good as using a standard camcorder. For example the audio and video may not be exactly synchronized. Slight differences can be seen on a web browser or when using IP video software (to record audio and video). There are also certain laws that relate to recording audio, and in most cases require people to be notified they are being recorded. With that said here are some things you can do.

Cameras with Audio
In almost all cases a camera that includes audio, supports MPEG4 compression. This form of compression includes data packets for audio transfer as well as video. For example, the Axis 210A includes two-way audio. It has audio input and audio output so you can attach a microphone and powered speaker. Other cameras with audio include Axis214PTZ and Axis211A, Vivotek IP6112, Panasonic WV-NS202 and WV-NP244.

Here is an example of a camera that can be used:

The AXIS 210A, indoor only camera with Computar 2.8-12mm manual focus, manual iris lens, delivers Motion JPEG images at up to 30 frames per second in all resolutions up to 640x480. With a built-in microphone and the ability to connect to external speaker or microphone, the AXIS 210A enables remote users to not only view, but also listen in on an area and communicate orders or requests to visitors or intruders. Includes built-in motion detection, and provides both full frame rate Motion JPEG and MPEG-4 video streams simultaneously. MPEG-4 compression mode is ideal for applications where available bandwidth is restricted and higher frame rates are required. Built-in Power over Ethernet allows the camera to receive both data and power over a single Ethernet cable.
The price is $570

Just like any application using audio, you have to consider how to pick up the sound. If you just use the microphone on the camera (some cameras have this included) you will pick up all the audio in the room, including noise you don’t want. If you want to listen to a person talking, the microphone should be as close as possible to the person. You can use many different kinds of microphones including handheld, wireless microphones and even directional room microphones. Just make sure the type of microphone matches input requirements of the camera. Many of the cameras take “line level” type mics. These are similar to those used with audio components such as CD and DVD players, TVs, audio amplifiers and other consumer equipment. Cameras usually accept the 3.5mm mono audio input. In some cases the microphone doesn’t have the right connector for the camera, but this can be corrected by using an adapter.

Wireless Microphone
The following wireless microphone can be used with IP cameras that have an audio input. The person can wear the lapel microphone or hold the microphone. The receiver connects to the audio input of the camera.

Azden Pro wireless VHF Mic system. Excellent sound quality at a range of over 250 feet. 2 switchable frequencies (169.445 and 170.245) to select the clearest sound. Receiver comes with belt clip, velcor and shoe mount. Includes one clip-on mic and one hand-held mic, either of which plugs into the mini transmitter. Clip-on mic transmitter attaches to belt or fits into pocket. Supplied with Leatherette carrying pouch and monitor ear phone. Both receiver and transmitter operate on 9V battery (not included)
The price is $235

Room Microphone
If instead you need to use a room mic, the Louroe omni-directional microphone can be used. This uses a very sensitive electret condenser omni-directional microphone with a pre-amp so it can be used with the camera. This is a good camera for small rooms. The police like this for interrogation rooms. Note that this also picks up all the noise in the room so it's not good if there are a lot of people talking.

The following kit includes everything you need to pick up sound in a room.

ASK-4 Kit300
Single zone audio monitoring system designed for direct connection to a camera. Omni-directional microphone can pick up normal sounds 15’ away or within a 30’ diameter circle. Provides three different audio outputs: RCA audio output to a DVR or VCR with RCA type audio input 3.5mm mono audio output to a DVR with 3.5mm mono audio input, 3.5mm stereo audio output to a camera or computer soundcard, or DVR with a stereo audio input. A connector cable for each type is included with. ASK-4 #300. Distance between the Verifact A. Microphone and Model IF-1 Interface Adapter may be up to 1,000 ft. using recommended wiring.
The price is $205

There are many other microphones that can be used. Contact me for some more recommendations.

How to hear the sound at a PC

A PC with a sound card allows you to view the video and hear the audio. Storing the audio and video requires special software and broadcasting to many people requires different software.

Viewing and hearing the audio
The simplest way to view an IP camera and listen to the audio is to use a web browser. Internet Explorer accepts the ActiveX component provided by the camera that allows you to see and hear the camera. Unfortunately many of the other browsers don't support the Active X. Also only a few people (up to 10) can view the video at the same time.

Storing the Audio with the Video
To store the video you need special IP software. OnSSI has a number of products that record audio as well as the video. ProSightSMB allows you to record the audio from only one camera. NetDVR allows you to record audio from all the cameras that have audio, but you can only hear the audio played back at the server and not hear it using the NetGuard Client software at other PCs on the network. NetDVMS records all the cameras and allows you to hear the audio at both the server and at various PCs on the network that are running NetGuard-EVS client software.

Here’s an example of the software that can be used:

4 Camera license - NetDVR provides access, viewing and control of surveillance cameras from any location on the network. Totally software based system which can be installed on a standard PC workstation. Instant Search on time date or activity alarm. Supports up to 30fps per camera. Secure time stamped and watermarked recordings. Fully adjustable Video Motion Detection. Can be expanded by trading in the software for the next level of license.
The price is $1195


You can talk through an IP camera that has audio output. Some cameras have built-in speakers, but in most cases you need an external powered speaker. The speaker needs to be powered because the camera doesn’t have enough amplification power. The cameras that support two-way audio have a 3.5mm mono audio output similar to the microphone input connection. I have seen some cameras with only one shared audio connection so be careful about this. In this case you need to use a splitter that allows both a microphone and speaker to be connected.

Almost any type of powered amplification system, like a PA system, can be connected. There are also some special powered speakers available that can be connected directly to the cameras. Here’s one example:

Speaker assembly for the cameras. The IPX-SA which is a 5” square, weather-resistant, black, metal, speaker box (2” depth) with a built-in amplifier. This unit can be wall-mounted outdoors but it is not designed to withstand direct moisture or harsh environments. The amp takes a 12VDC input which can be pulled from the 12VDC terminal inside the IPX-ED-24V enclosure
The price is $135

How to speak through the camera

At the moment, you can only speak through a PC (with sound card and microphone) using Internet Explorer. There is a microphone button that can be pushed to allow you to send audio through the camera to the speaker. Software companies are working on support for out bound audio.


Surveillance type software is not made to broadcast or web-cast to many people on the network. You need other software to create a web server that allows many people to connect to a real-time or stored video presentation that includes audio. There is no simple solution that we know of. It will require some programming or system work to get this done. One simple approach to create a web cast is to export the audio and video to an AVI type file. This can then be cached in a computer and used in a web server that allows many people to see it. NetDVR or NetDVMS software can provide this export data from the stored video and audio files.

If you need more information please contact me. I can be reached at 914-944-3425 or by contact form.


nokta said...

very good system That IP Kamera anyone else must haveKamera Sistemleri

Avcap DVR said...
This comment has been removed by the author.
Avcap DVR said...

yah this is a good article which you are post here, this is good information for all who is interested in security system and 4 Channel DVR and Stand Alone DVR

Rakesh said...

PA systems are often used in small venues such as school auditoriums, churches, and small bars. PA systems with a larger number of speakers are widely used in institutional and commercial buildings, to read announcements or declare states of emergency. The simplest PA systems consist of a microphone, a modestly-powered mixer amplifier and one or more loudspeakers.There are four Types of PA System: Small Systems, Telephone paging system,PA over IP,Long line PA.

Adam Scott said...

thanks for this information i also finding this information and u give me so thanks and i also find information about Security System.

Russell Reed said...

For this ASK-4 Kit300 we can fix 4 channel dvr?

Bowen Nelson said...

Thanks for explaining the IP cameras with audio in detail. Many people, nowadays, watch audio and video over IP. The innovative solution now enables them to synchronize the audio and video in a more efficient and easy way.

Guzzi sager said...

Your post really cool and interesting. Thanks very much.

Dell - 14" Latitude Notebook - 4 GB Memory - 320 GB Hard Drive

Dell - 15.6" Latitude Notebook - 8 GB Memory and 256 GB Solid State Drive

jowdjbrown said...

I'm discussing this purely in the historical context. virtual assistant program

Isabella moore said...

Buy IP speaker from best China IP audio brand name cmx audio, is the famous factory to produce IP speaker and IP amplifier in China. IP speaker

Security Product said...

Found your blog. Its really valuable for audio surveillance. I appreciate your article. Its important for get good informations on audio surveillance. So thanks for sharing all that important information.