DVR CMS Remote Playback

[senator 0]

I have three DVRs at three different locations. Virtually all my interaction with these systems is done using the CMS client (PC) application that came with the DVR. The documentation for the CMS is woefully inadequate and technical support from the manufacturer is non-existent. The remote playback from one of the locations is extremely slow (~1/3 real-time) and I can’t figure out why because I am not experiencing this issue from the other two locations. The bandwidth is 60Mb/5Mb with a latency of 35ms. Live viewing is fine.

 

My general question is, does the remote playback using the CMS, use mainstream or sub-stream? There is no setting in the CMS application for remote viewing, only settings for mainstream & substream. Everything I’ve read indicates that sub-stream is only used for smartphones, but I’m not using a smartphone. I’m using the CMS application running on my PC. If the CMS uses mainstream, what settings do you recommend if I am experiencing very slow speed?

 

Many thanks.

[Magic of Philly 0]

I have three DVRs at three different locations. Virtually all my interaction with these systems is done using the CMS client (PC) application that came with the DVR. The documentation for the CMS is woefully inadequate and technical support from the manufacturer is non-existent. The remote playback from one of the locations is extremely slow (~1/3 real-time) and I can’t figure out why because I am not experiencing this issue from the other two locations. The bandwidth is 60Mb/5Mb with a latency of 35ms. Live viewing is fine.

 

My general question is, does the remote playback using the CMS, use mainstream or sub-stream? There is no setting in the CMS application for remote viewing, only settings for mainstream & substream. Everything I’ve read indicates that sub-stream is only used for smartphones, but I’m not using a smartphone. I’m using the CMS application running on my PC. If the CMS uses mainstream, what settings do you recommend if I am experiencing very slow speed?

 

Many thanks.

 

The bandwidth is 60Mb/5Mb with a latency of 35ms. Live viewing is fine.

 

The problem location has an internet connection whose DOWNSTREAM (download) speed is 60 mbps and UPSTREAM (Upload) speed is 5 mbps. Problem here is that when you are connecting remotely, say from your house, the DVR at that location is using the UPSTREAM speed to send the data to the Content Management Software (CMS), and in this case 5 mbps is too little, specially if the recording were done on a very high bitrate. Plus, some ISP doesn't deliver exactly what is promised so you might not be getting the full 5 mbps upload speed, but probably something like 3.5 to 4.x mbps which can further complicate the problem when attempting to view remote playbacks for high definition footage recorded at a bitrate higher than what your upload speed can accommodate.

 

Remote Playback is never sent through "substream", substream is something that is only used for LIVE remote viewing so that users with a much slower, say mobile 3G connection can be able to fluently and easily be able to watch the cameras in live, but at a much lower resolution and bitrate, a non issue specially if you are watching multiple cameras in your smartphone's screen, say 4, to 8 cameras at once.

 

Remote Playback basically streams the recordings off your DVR's hard drive at the exact quality they were recorded, so if you set your DVR to record at a very high bit-rate, then you will need a much faster upload speed to keep up with the demand.

 

Live viewing is fine.

 

Live viewing is fine because when you are viewing multiple LIVE cameras you are technically using "Substream" and sub Stream is almost always streamed at a lower resolution and lower bitrate, much lower that your 5 mbps upload speed is a non issue at all (possible substream resolution of 960x480 at a bitrate of 512 kbps, and some DVR's can even have a crappier max substream resolution of CIF which is 320x240 at a much lower bitrate or something in the middle of 704x480 D1, so that's why with remove LIVE viewing through substream, it will almost be alright with almost any consumer level internet speed package, including on a 1.544 mbps D. / 768 U. kbps DSL plan

 

Solution here: Either lower frame rate along with bitrate proportionally to compensate and get the same image quality for a lower frame rate or upgrade the upload internet speed of the site to a faster speed, say 10 mbps or greater. If the recordings on your DVR is set to a bit-rate of 4,96 kbps (4 mbps) then I would recommend an internet connection upload speed for the site at least 8 mbps or greater to compensate for the fact the ISP might not deliver you the full upload speed you pay for and want to have enough head room to ensure that 4 mbps can be uploaded whenever you decide to remote playback a recording - remotely.

 

Here's what I would do for a 1080P quality:

Main Stream: Set Frame Rate to 6 FPS and set bitrate to 3,072 kbps (3 mbps) or you can set frame rate to 4 FPS and a bitrate of 2048 kbps (2 mbps) add or substract 512 kbps for each frame you decide to add or elimiate to the equation to ensure the same exact picture quality.

 

If your DVR is a HiKVision DVR, try enabling, if your firmware supports it, H.264+ which retain the same exact image quality for half the bit-rate required.

To learn more about HiKVision's H.264+ codec you can read:

https://www.securitymagazine.com/ext/resources/whitepapers/Hikvision-H264-Encoding-Technology.pdf

 

If you DVR supports encoding at H.264+ you can decrease the bit-rate down from 3072 to 1536 kbps provided you set FPS to 6 FPS and the resulting video quality will be exactly the same if you were recording at 3072 kbps under regular H.264 (without the + at the end). So, with H.264+ you can set 4 FPS at a bit-rate of 1024 kbps (1 mbps) and add or remove 256 kbps per each frame rate you decide to add or remove to the equation, and with that change alone, to use H.264+ you may not even need to upgrade your site's upload internet speed.

 

WARNING:

=======

Beware of your site's potential "parasitic" applications hugging your limited upload bandwidth, such as leaving a computer on all the time while leaving a bit torrent client running with a bunch of files shared to the whole worlds. An employee of yours might have installed bit torrent and downloaded a few torrents, say the latest movie/tv show or even warez and those downloads, unless they are stopped/removed from the torrent client, are set to be shared (seeded), under such a configuration your upload speed will be used for anyone downloading such files directly off a computer at your site. So if you have multiple computers at your site you might want to monitor what bandwidths are being used to see if there is something you can optimize there.

[senator 0]

To Magic of Philly - Thanks very much for your excellent response. I’ve literally spent years corresponding with people about this issue and you are the first person who I feel actually understands what I’m talking about and isn’t trying to give a BS response.

 

A point of clarification, my DVR is older and pretty basic; no HiKVision or H.264.

 

I think I’m beginning to get the picture, but have a few questions:

- Does all remote viewing; on PC (CMS) and smartphone app, live viewing or playback, use substream?

- Is mainstream only for local recording & playback?

- What factors, other than HDD space are at play when selecting mainstream settings, given that I never view (live or playback) using the monitor directly attached to the DVR? The only time I use the directly connected monitor is to make setting changes. All viewing (live or playback) is done using the CMS or smartphone, mostly the CMS.

- I read somewhere that 7fps is considered “real time”, would you agree? If that is true, how does that factor into your recommended settings?

- Given what I have said, what settings would recommend for mainstream and substream?

 

Thanks again!

[Magic of Philly 0]

To Magic of Philly - Thanks very much for your excellent response. I’ve literally spent years corresponding with people about this issue and you are the first person who I feel actually understands what I’m talking about and isn’t trying to give a BS response.

 

A point of clarification, my DVR is older and pretty basic; no HiKVision or H.264.

 

I think I’m beginning to get the picture, but have a few questions:

- Does all remote viewing; on PC (CMS) and smartphone app, live viewing or playback, use substream?

- Is mainstream only for local recording & playback?

- What factors, other than HDD space are at play when selecting mainstream settings, given that I never view (live or playback) using the monitor directly attached to the DVR? The only time I use the directly connected monitor is to make setting changes. All viewing (live or playback) is done using the CMS or smartphone, mostly the CMS.

- I read somewhere that 7fps is considered “real time”, would you agree? If that is true, how does that factor into your recommended settings?

- Given what I have said, what settings would recommend for mainstream and substream?

 

Thanks again!

 

A point of clarification, my DVR is older and pretty basic; no HiKVision or H.264.

 

No H.264 support? Thats not good, depending on the current compression algorithm your DVR is using, it might not be hard drive space efficient, specially if its using Motion JPEG (MJPEG) among others that came before the invention of H.264 compression algorithm. So, upgrading your DVR will right of the bat give you H.264 capabilities which translates to being able to have a much broader margins of recorded days before the DVR starts deleting older footage in favor of newer footage when the hard drive rans out. And plus you will get the benefit of being able to use 1080P/3MP cameras if you go with a HiKVision TVI DVR, and wont have to replace your existing wiring, you can keep on using your existing coax setup.

 

- Does all remote viewing; on PC (CMS) and smartphone app, live viewing or playback, use substream?

 

Mainstream. Substream is exclusively used for remove live viewing, so you can pick a way much more lower bitrate as Substream as Substream is never used to record onto the hard drive, but a lower bit-rate for substream will help you see live streams even when you have low cellphone signal, like under a low bar 3G connection with a speed of about 512 kbps (that's why on my DVR install, I set substream to resolution: 960x480 at a bit-rate of 256 kbps since I take under consideration all these factors so that customers can be able to watch live streams anywhere they are, too much of a high sub-stream bandwidth and then live viewing all of a sudden becomes mobile phone unfriendly as it will only work reliably when either with a full 4G LTE bar or when connected over a WiFi.

 

* All remove viewing is doing is downloading recorded videos already saved on your DVR's hard drive and playing it back (streaming) to your CMS or your smartphone app, for this purpose neither "mainstream" or "substream" are being used, they are irrelevant as you cannot change the "quality" of the streamed videos once they are recorded and saved onto the DVR's hard drive(eg. you cannot adjust the quality of last week's videos, but you can adjust the quality through the Mainstream settings for videos that are to be recorded next minute and to the future), you can only change the quality for the videos to be recorded in the future so that in the future you can have a lighter bandwidth requirements when wanting to remote playback previously recorded footage (also known as bandwidth optimization - the recording of footage at a specific bit-rate that wont exceed your site's upload internet connection speed as to not cause "buffering" when playing them back remotely)

 

- Is mainstream only for local recording & playback?

 

Yes, whatever bitrate, FPS and Quality settings you have set on your "Mainstream" profile its used to record at that quality and save videos to your DVR. In turn when you are remotely located and open up the PC CMS software or the mobile app, it will be streaming videos that was already recorded and saved onto the DVR's hard drive utilizing your Mainstream bit-rate, quality and FPS settings. You cannot adjust the bit-rate, Quality and FPS to videos already recorded and store in the DVR's hard drive, but you can change these settings for videos that are to be recorded and stored onto the DVR's hard drive in the future (as soon as you press the Apply button and the new settings takes place then all further recordings are done using the new bit-rate, quality and FPS settings).

 

- What factors, other than HDD space are at play when selecting mainstream settings, given that I never view (live or playback) using the monitor directly attached to the DVR? The only time I use the directly connected monitor is to make setting changes. All viewing (live or playback) is done using the CMS or smartphone, mostly the CMS.

1. When adjusting your mainstream settings, the settings the DVR will base itself when recording and storing footage to its hard drive, you must take careful consideration your site's maximum available upload bandwidth because if you select a bitrate too high then when you want to playback a recording to see an "evidence" or an "incident" you will find yourself with lots of buffering/stuttering issues as the Site's upload internet connection speed cannot keep up with the demand.

2. You must also take under consideration your remote's location maximum DOWNLOAD bandwidth speed, this is almost a non-issue these days in year 2017 where most ISP are giving a very generous (25 mbps+) download speed so your house's download speed will almost be a non-issue and you wont have to worry about that, but your site's 5 mbps UPLOAD maximum speed yes, you do have to worry about that, its too little and its too easy to overboard that.

3. With all that said, you have to adjust your settings provided that your bit-rate is not too high in such a manner where your maximum 5 mbps upload speed wont be enough to stream your previously recorded videos without buffering/stopping here and there, and you also have to take care not to adjust the bit-rate way to low where the quality of the videos will be impaired and difficult the process of facially positively identifying a suspect, so dont set the bitrate too low for your desired frame rate, however if you lower your frame rate (FPS) way too low, then you can get away with a very little bit-rate. The rule of thumb is that the higher the FPS you desire, the higher the bit-rate has to be in order to ensure a good video quality where you have a good chance to have a positive facial identification.

 

- I read somewhere that 7fps is considered “real time”, would you agree? If that is true, how does that factor into your recommended settings?

Many people and installers have a varying definition on what they consider "real-time", but I was told by my large CCTV supplier where I have been buying CCTV equipment since over 30 years ago that in the CCTV world, "Real-time" is considered to be 15 fps. That is the definition that I have accepted and currently do accept, for me 15 fps is considered to be "real-time" as far as CCTV is concerned. of course, 30 FPS is the real "real-time" for many non-CCTV applications like consumer video taping, etc and now the newer "real-time" has morphed into 60 FPS, specially for those blockbuster bluerays in 1080P/4K quality. But as far as CCTV is concerned, its 15 FPS for "Real Time"

 

You can choose 7 FPS if you like, and a bit-rate of 512 kbps per frame (7 FPS * 512 KBPS = 3,584) Since you said your DVR is much older it is highly unlikely you are recording in High Definition and that your DVR is not one of those Analog High Definition ones such as HD-TVI, AHD, or CVI and your DVR most likely its a D1 only DVR, taking that under account you can further divide your bitrate by 4 since my calculation was for recording in 1080P Full HD, D1 is 1/4 of HD so you can do 512 KB / 4 = 128 KBPS, so my recommended bit-rate requirement for recording in D1 resolution would be 128 KBPS * 7 FPS = 896 KBPS way much better and under such bit-rate you shouldn't have any problems remote playing back under your site's limited 5 mbps upload internet connection.

 

- Given what I have said, what settings would recommend for mainstream and substream?

For mainstream, you can set it at 7 FPS and if the RESOLUTION is D1 (704x480) then you can set 128 KBPS per FPS, so 7 FPS * 128 KBPS = 896 KBPS per camera. If you DVR can only record in CIF resolutions (320x240) maximum, then you can further divide the bitrate by 4 since CIF is 1/4 of D1 so 128 KBPS D1 / 4 = 32 KBPS for CIF quality per frame rate, so 7 FPS * 32 KBPS = 224 kbps

 

For Substream, if your DVR allows you to set D1 quality, then set 7 FPS per camera and 256 KBPS per camera, if your DVR does not allow D1 for substream and its capped at CIF (many older DVR's only permits CIF for substream) then you can set 7 FPS, at a bit-rate of 128 KBPS.

 

To close, I would like to say, that if your DVR is a D1 only DVR or much worse a CIF only DVR that its time to upgrade to at least Analog High Definition TVI, you will get a much clearer picture on your recordings and the likelyhood of being able to positively identify a suspect at 1080P is much greater than at 704x480 and alot much greater than at 320x240. If you would like to keep on using your existing old DVR, then you can do so, but as soon as something critical fails, instead of replacing the failed component, such as the hard drive, just get a TVI DVR, you will even be able to continue to use your existing cameras and gradually upgrade cameras one by one to 1080P/3M ones. Your security is further improved the better and sharper your videos can look.

[senator 0]

I can’t thank you enough. I realize this took considerable time and thought.

 

It appears that I misspoke. I copied this from the user manual of my Dowson DVR “This product is a consumer-oriented 4/8/16-channels CIF/Half-D1/D1 real-time network DVR and adopt the industry's most advanced SOC technology and standard H.264 encoding method”. Sorry for the confusion.

 

I feel like I’m beginning to get the picture, but still have a couple of fundamental questions that I can’t seem to get past.

 

- Do remote (WAN) live viewing and remote playback both use sub stream? If so, why is remote playback quality so inferior to live viewing? Remote live viewing seems relatively smooth and real time; whereas remote playback runs about 1/3 real time and appears choppy.

- Is substream recorded as a separate track on the HDD or is it simply converted on the fly or down-sampled from the mainstream? If sub stream is recorded as a separate track and remote viewing and playback both use sub stream, then it would seem that mainstream settings have no bearing on remote viewing or playback.