Using a Dahua IP PTZ Camera as a Video Camera

R

RowRegatta

n3wb
Oct 31, 2017
4
1
I am still making up my mind as to which of the two 30x Optical Zoom Dahua cameras to get - either the SD50430U or the SD50230U. I have a few questions which your answers will hopefully make my decision easier.

I'll give you some background as to how I'll be using the camera. The camera will be providing a near-live (3 - 5 second delay) video stream of rowing regatta races to the attending crowd. Races take place over a 2km course, with "masters" races taking place over 1km. At the moment, only people with powerful binoculars can see the start of the 2km races. I intend to set the camera up at the finish line and, using the PTZ feature, zoom up on the start. I should get about 84m of coverage at a distance of 2km with a 2.4deg field of view, which is ideal. I would then control the camera, either through the SmartPSS (or similar) software or through bespoke software written against the Dahua SDK, and track the boats all the way down the course and across the finish line.

If there's an interest in this video stream, I plan to purchase another PTZ and place it at the start line and, using a radio link, broadcast this stream as well. I'd use OBS (Open Broadcaster Software | Home) to cut between the 2 video streams.

The reasons I've chosen to use "security cameras" and not broadcast spec PTZ cameras are :-
  1. The video from a broadcast camera would inevitably have be compressed and transmitted, and a "security camera" already does this with minimal latency.
  2. The image quality doesn't have to meet Sky Sports/BBC Sports broadcast specifications. The final stream will be scaled to a maximum resolution of 1280x720.
  3. Cost. "Security cameras" are cheaper.
My questions are :-
  • Which of the 2 models (SD50430U, SD50230U) will give me a crisper image at full zoom. I'm guessing the 4Mega Pixel model.
  • Is there a way to increase the video bit rate above the rates listed in the SmartPSS. Could this be done via the Dahua SDK/API? I need around 20Mbps at 4 Mega Pixels, as the ripples and waves on the water require a lot of data to "describe" these high contrast, high motion, organic objects. These randomly changing objects "steal" bandwidth from other, more important areas of the image, namely the boats and their crews.
  • Am I crazy for even thinking about doing it this way?!
Any input and guidance would be greatly appreciated.
 
RowRegatta said:
I am still making up my mind as to which of the two 30x Optical Zoom Dahua cameras to get - either the SD50430U or the SD50230U. I have a few questions which your answers will hopefully make my decision easier.

I'll give you some background as to how I'll be using the camera. The camera will be providing a near-live (3 - 5 second delay) video stream of rowing regatta races to the attending crowd. Races take place over a 2km course, with "masters" races taking place over 1km. At the moment, only people with powerful binoculars can see the start of the 2km races. I intend to set the camera up at the finish line and, using the PTZ feature, zoom up on the start. I should get about 84m of coverage at a distance of 2km with a 2.4deg field of view, which is ideal. I would then control the camera, either through the SmartPSS (or similar) software or through bespoke software written against the Dahua SDK, and track the boats all the way down the course and across the finish line.

If there's an interest in this video stream, I plan to purchase another PTZ and place it at the start line and, using a radio link, broadcast this stream as well. I'd use OBS (Open Broadcaster Software | Home) to cut between the 2 video streams.

The reasons I've chosen to use "security cameras" and not broadcast spec PTZ cameras are :-
  1. The video from a broadcast camera would inevitably have be compressed and transmitted, and a "security camera" already does this with minimal latency.
  2. The image quality doesn't have to meet Sky Sports/BBC Sports broadcast specifications. The final stream will be scaled to a maximum resolution of 1280x720.
  3. Cost. "Security cameras" are cheaper.
My questions are :-
  • Which of the 2 models (SD50430U, SD50230U) will give me a crisper image at full zoom. I'm guessing the 4Mega Pixel model.
  • Is there a way to increase the video bit rate above the rates listed in the SmartPSS. Could this be done via the Dahua SDK/API? I need around 20Mbps at 4 Mega Pixels, as the ripples and waves on the water require a lot of data to "describe" these high contrast, high motion, organic objects. These randomly changing objects "steal" bandwidth from other, more important areas of the image, namely the boats and their crews.
  • Am I crazy for even thinking about doing it this way?!
Any input and guidance would be greatly appreciated.
Click to expand...

Welcome RowRegatta,

I like the idea you have, it should work imho.

With regards to the bit rate, you can use lower compression - example H.264 instead of H.265

It's easy to get swamped with information here, so I wanted to share some notes with you

Please check out @giomania 's notes:
Dahua Starlight Varifocal Turret (IPC-HDW5231R-Z)

I have also made notes which are a summary of a lot of the reading I've been doing here,:
Looking for some advice and direction!

Have fun joining us here.
 
Hi mat200,

Thanks for the links - very informative with great insight into the various technologies used in Dahua products, sadly not too much info on PTZ cameras.

From my understanding H.265, compared to H.264, is a more efficient codec which produces a better quality image at identical bit rates. H.265 also goes by the name High Efficiency Video Coding (HEVC). Essentially both codecs would compress a video equally (the same compression ratio) given the same Constant Bit Rate (CBR) it's just that H.265 would produce better quality video (thus higher efficiency).

The issue I'm concerned with is bit rate depletion - running out of bits to describe the highly dynamic high detail within a video. The "highly dynamic high detail", in my case, are the waves on the lake/dam which have high contrast areas - areas reflecting the sun and darker areas which are constantly moving. High contrast areas normally draw bits away from "describing" areas of lower contrast, and since there are a lot waves this might lead to fewer bits being available to describe the subject of the video, namely the boats the their crews.

A higher bit rate, thus lower compression (as you pointed out), might improve the quality of lower contrast areas in my situation. I just need to find a way to increase the bit rate outside the bounds of what SmartPSS allows me to choose from.
 
RowRegatta said:
Hi mat200,

Thanks for the links - very informative with great insight into the various technologies used in Dahua products, sadly not too much info on PTZ cameras.

From my understanding H.265, compared to H.264, is a more efficient codec which produces a better quality image at identical bit rates. H.265 also goes by the name High Efficiency Video Coding (HEVC). Essentially both codecs would compress a video equally (the same compression ratio) given the same Constant Bit Rate (CBR) it's just that H.265 would produce better quality video (thus higher efficiency).

The issue I'm concerned with is bit rate depletion - running out of bits to describe the highly dynamic high detail within a video. The "highly dynamic high detail", in my case, are the waves on the lake/dam which have high contrast areas - areas reflecting the sun and darker areas which are constantly moving. High contrast areas normally draw bits away from "describing" areas of lower contrast, and since there are a lot waves this might lead to fewer bits being available to describe the subject of the video, namely the boats the their crews.

A higher bit rate, thus lower compression (as you pointed out), might improve the quality of lower contrast areas in my situation. I just need to find a way to increase the bit rate outside the bounds of what SmartPSS allows me to choose from.
Click to expand...

Hi RowRegatta,

I did not imagine having enough funds for a nice PTZ so my notes do not cover that much.

From what I can tell, there are very numerous options to tuning a camera which are available - and thus I would expect it to take some time to determine the best options for what you are looking for.
 
Hi mat200,

I've decided to go with the SD50430U-HNI. I'll try out both the H.264 and H.265 codecs and will endeavour to provide as much feedback as possible with my experience.

Thanks for your help and guidance so far. I'm sure I'll be back with more questions (after scouring the forum first!) once I've received the unit.
 
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RowRegatta said:
Hi mat200,

I've decided to go with the SD50430U-HNI. I'll try out both the H.264 and H.265 codecs and will endeavour to provide as much feedback as possible with my experience.

Thanks for your help and guidance so far. I'm sure I'll be back with more questions (after scouring the forum first!) once I've received the unit.
Click to expand...

RowRegatta - Did you receive the camera yet? Do you like it?
 
Hi Richtj99,

I will be picking the camera up on Dec 4th - I certainly took my time in purchasing it!

I will report back with my findings in the coming weeks.
 
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