Re-organized the forum to more cleanly delineate the development section, as the end user support side appears to have taken a life of its own!

Author Topic: Audio mod for the cheaper cam clones (eg the Foscam brand ones)  (Read 12966 times)

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February 27, 2011, 02:44:22 am
While my original camera's don't appear to have this issue, the Foscam branded OEM models appear to be affected.

If you have a Foscam, this would be appropriate.

Foscam - How to improve Audio Quality Modification: /files/Manuals/How%20to%20improve%20the%20audio%20quality.pdf

March 01, 2011, 09:44:50 am
hey admin,

i have a foscam clone, but since you claim foscam to be cheaper clones, i wonder what is your cam :) ?

anyhow, i have some audio issues with my foscam clone, and wondering if this and other hacks may help --

1. speaker produces a fairly feeble "crackling" sound for audio sent from PC to camera. this is from the inbuilt speaker. if i whistle a tune or play a musical instrument (e.g. piano), the tune/melody is right there, and recognizable, but speech is like a high-pitch clipped crackly audio, very hard to make any sense of.

2. sensitivity of the inbuilt mic is quite low. if i speak standing next to the cam, the pickup level is acceptable, from about 3-4 feet it is still audible if i maximize PC speaker vol., but from 6-7 feet, i can only hear a feeble murmer at max. volume. i've seen some audio surveillance gear (amateur) which actually do a fabulous audio pickup from as fast as 15-20feet. wondering if changing the mic to a high-sensitivity mic would help, or is it something else.

finally, has anyone figured out the codec/protocol/transport of audio that is sent from PC to the camera ? I know that the ActiveX component does it somehow... but not more. I know that the audio sent from camera to PC is 16-bit 8kHZ ADPCM in ASF container streamed over HTTP ?


April 28, 2011, 03:25:56 pm
hey, icarusa!
do you know exactly what's the address to get the audio stream?
have you figured out what codec/api is used to stream the audio back to the camera?
finally, is there any way to set up admin's password without a windows machine?

May 09, 2011, 02:00:35 pm
Well, what I know for sure is that it is a proprietary protocol, and definitely doesn't use RTP, and that the data is generated in some 10ms frames, though I haven't managed to reverse engineer the it. There some be some JFIF headers to look at to figure out the MJPEG content. That should mark the video feed. Remaining i guess would be audio and control, but hard to make out audio from control.

The port number I am 99% sure is same as the one used for HTTP service, as I see all these binary message exchanges with that port.

February 14, 2012, 02:54:34 pm
My clone's audio quality from the built-in mic leaves much to be desired.  The volume is low and it crackles frequently even when there's no ambient noise in the room.  I'd like to attempt this audio improvement but I have a few questions about the resistor to get.

1) should I get a 2k +- 5% ohm film resistor with an encapsulation of 0603 metric (which is 0201 imperial) or 0603 imperial (which is 1608 metric) ?

2) how many watts should the resistor be rated at? 50 mWatts, 62.5 mWatts, 100 mWatts or 200 mWatts?

3) how many volts should the resistor be rated at? 25v, 30v, 50v, 75v or 150v ?

I'm looking to order the resistor through Mouser.  Lawrence, I don't know if you can reach this page in China, but I'm comparing the ones available from here:

June 17, 2012, 09:06:59 pm

The encapsulation is simply the size.  Just look up the size of each option and see which one is closest to the distance between the solder pads on the circuit board.

All of those power and voltage ratings are at least 5x beyond what you need.  So go with the smallest and you'll be OK.