D-Link Forums
The Graveyard - Products No Longer Supported => IP Cameras => DCS-930L => Topic started by: acellier on September 14, 2011, 01:44:20 PM
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When accessing the camera on mydlink, or on a browser using http://x.x.x.x/mjpg.cgi, I would expect the net bit rate to be substantially less than for a sequence of jpg's, since true motion-jpg uses a lossy form of intraframe compression typically yielding a 20:1 data reduction (according to wikipedia). Indeed, I can readily see this reduction in mjpg clips made on my Canon S5is camera.
It's not clear whether that is happening with the d-link DCS-930L camera (640x480, quality "high", java). The mydlink app "Info" on the iPad2 (802.11n; no other apps running; no other streams to computer) shows these data rates (basically static scene, a few leaves moving):
1 fps ~ 605 kbps actual fps ~0.2 drops connection
5 fps ~350-1075 kbps initially went to ~3fps, then dropped to vary 1 to 2 fps
7 fps ~600-1600 kbps initially went to ~3fps, then dropped to vary 1 to 3 fps
15 fps ~68 kbps actual fps ~0.2 drops connection
My DCS-930L is not stable enough to perform these tests! – mydlink drops connection repeatedly, saying "Timed out" ??? or "check internet settings" ... grrr ... sigh ... product failure ...
I was trying to establish that the DCS-930L, unlike the DCS-932L, MAY be implementing true mjpg ...
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I have received and set up a replacement DCS-930L. So far, so good. This camera appears to perform similarly to the DCS-932L, with reasonable short ping times and frame rates in mydlink that appear to track the user settings (which the first unit did NOT). But today's weather is cool, low 70s.
I was able to perform the earlier aborted experiment on this DCS-930L camera (640x480, quality "high", java). The mydlink app "Info" on the iPad2 (802.11n; no other apps running; no other streams to computer) shows these data rates (basically static scene, a few leaves moving): [the first column is the setting of Video SetUp]
1 fps ~600 kbps
5 fps ~1900 kbps
7 fps ~2500 kbps
15 fps ~5000 kbps
20 fps ~5200bps actually ~15 fps
AUTO ~4900 fps actually ~15 fps
I conclude that the camera transmits a sequence of jpg images, not true mjpg.
Opening Live Video in a browser on the computer while viewing the fps on the iPad2 does not reveal any substantial change to the fps.
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Some more measurements of the mydlink app's reported data stream rate -
DCS-930L and DCS-932L (day mode) essentially the same -
A fairly static scene, video set to 640x480, 5 fps, java, varying the quality setting -
very low ~1200 kbps
low ~1550 kbps
medium ~1600 kbps
high ~2000 kbps
very high ~2000 kbps
setting audio OFF decreases all of these numbers by about 300 kbps (in the camera control panel, NOT in the mydlink live view sceen, that is just a local mute).
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...setting audio OFF decreases all of these numbers by about 300 kbps (in the camera control panel, NOT in the mydlink live view sceen, that is just a local mute).
Are you referring to a mute control on mydlink.com? I haven't seen any control on either IE or FF.
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Are you referring to a mute control on mydlink.com? I haven't seen any control on either IE or FF.
mydlink app on iPad2 ...
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mydlink app on iPad2 ...
Odd that there's a mute button for the iPad, no mute button for the mydlink website, and no audio at all for Android ???