D-Link Forums
The Graveyard - Products No Longer Supported => IP Cameras => DCS-932L => Topic started by: Jonas on March 29, 2012, 09:50:39 AM
-
I recently purchased a DCS-932L and after a short while of playing with it I have stumbled upon an issue I simply cannot fix:
It streams at nowhere near the FPS stated on the box, even at the best of circumstances.
I would like to resolve this issue, if possible, as quickly as I can, as I have about 10 days remaining during which I can return the product for a full refund under local law etc, and right now I'm quite frankly feeling that D-Link has lied to its customers with this product.
The figures:
| |Resolution| | |Jpeg Quality| | |Frame Size| | |Actual FPS| | |Stated FPS| |
| 160x120 | Very Low | 3.3kB | 15 | 30 |
| 160x120 | Medium | 5.8kB | 15 | 30 |
| 160x120 | Very High | 6.1kB | 15 | 30 |
|
| 320x240 | Very Low | 8.2kB | 15 | 30 |
| 320x240 | Medium | 15kB | 15 | 30 |
| 320x240 | Very High | 17kB | 15 | 30 |
|
| 640x480 | Very Low | 22kB | 12 | 20 |
| 640x480 | Medium | 43kB | 12 | 20 |
| 640x480 | High | 50kB | 10 | 20 |
| 640x480 | Very High | 55kB | 10 | 20 |
The test itself:
The camera is connected with a cable directly from the camera to a NIC at the back of my computer, so network speed should be a non-issue, and as we can see above network speed does not seem to have any real impact on the FPS provided. Nor does Jpeg Quality, except for at the very highest end of the spectrum, and even then its a tiny effect.
Sound is disabled, motion detection is disabled, day/night mode is set to always day. I am using the latest firmware available as I'm writing this post, v1.02b03. FPS is set to auto, but testing with the FPS set to the stated figure doesn't change the actual FPS, even for the lowest quality image at the lowest resolution.
To actually get these figures I'm using a small Java application I hacked up, the source code for which can be found here: http://pastebin.com/Yc5zDzLD (http://"http://pastebin.com/Yc5zDzLD")
The application itself simply opens the stream(which coincidentally is just a simple stream of individual Jpeg images one after another) found at http://cam_ip_here/MJPEG.CGI , receives the images as they come flowing, displaying them on screen while keeping track of how many images/second are delivered and how large they are.
-
I found related results - posted at http://forums.dlink.com/index.php?topic=41183.0
-
I found that too while searching, but the whole thread kind of confused me with straying into some product return issue almost immediately, and seems to be mainly about whether the stream is a series of Jpegs or not, not so much the actual FPS delivered. Thanks for pointing it out regardless, his results are the ones that lead me to the conclusion that it's probably a camera-thing and not just a my-setup kind of thing, so it's definitely related.
-
How are you networking the devices.
I have two devices each set to max at 5fps. They push about 80KB/s each at that setting. Pushing the number to 20fps puts me at about 350KB/s. (That's 640x480, Medium) If you're using wireless, depending on what else is connected to your AP, and degradation of signal due to being to close, or to far - and the number of devices in the area this could impede your throughput.
Of course, if your wired directly to the cam, I have no argument. Other then, why do you really need such a high frame rate anyway? ;D
-
If you're using wireless, depending on what else is connected to your AP, and degradation of signal due to being to close, or to far - and the number of devices in the area this could impede your throughput.
Like I wrote in the first post, the camera is connected directly to the network interface card at the back of my computer, and as I also pointed out in the first post, based on the bandwidth numbers also posted it's clearly not a bandwidth issue.
Other then, why do you really need such a high frame rate anyway?
This product is sold with the speeds stated in the first post being the ones advertised. Check the box, those FPS numbers I cite in my first post are literally on the back of the box, yet the product does not deliver anything close to them. This means that either D-Link is selling a broken product right now, or they are simply lying about its performance, neither which makes me happy about having bought this camera.