tomcctv

At its most basic level, compression is performed when an input video stream is analyzed and information that is indiscernible to the viewer is discarded. Each event is then assigned a code - commonly occurring events are assigned few bits and rare events will have codes more bits. These steps are commonly called signal analysis, quantization and variable length encoding respectively. There are four methods for compression, discrete cosine transform (DCT), vector quantization (VQ), fractal compression, and discrete wavelet transform (DWT). Discrete cosine transform is a lossy compression algorithm that samples an image at regular intervals, analyzes the frequency components present in the sample, and discards those frequencies which do not affect the image as the human eye perceives it. DCT is the basis of standards such as JPEG, MPEG, H.261, and H.263. Vector quantization is a lossy compression that looks at an array of data, instead of individualvalues. It can then generalize what it sees, compressing redundant data, while at the same time retaining the desired object or data stream's original intent. Fractal compression is a form of VQ and is also a lossy compression. Compression is performed by locating self-similar sections of an image, then using a fractal algorithm to generate the sections. Like DCT, discrete wavelet transform mathematically transforms an image into frequency components. The process is performed on the entire image, which differs from the other methods (DCT), that work on smaller pieces of the desired data. The result is a hierarchical representation of an image, where each layer represents a frequency band. Compression Standards MPEG Stands for the Moving Picture Experts Group MPEG is an ISO/IEC working group, established in 1988 to develop standards for digital audio and video formats. There are five MPEG standards being used or in development. Each compression standard was designed with a specific application and bit rate in mind, although MPEG compression scales well with increased bit rates. They include: MPEG-1 Designed for up to 1.5 Mbit/sec Standard for the compression of moving pictures and audio. This was based on CD-ROM video applications, and is a popular standard for video on the Internet, transmitted as .mpg files. In addition, level 3 of MPEG-1 is the most popular standard for digital compression of audio--known as MP3. MPEG-1 is the standard of compression for VideoCD, the most popular video distribution format thoughout much of Asia . MPEG-2 Designed for between 1.5 and 15 Mbit/sec Standard on which Digital Television set top boxes and DVD compression is based. It is based on MPEG-1, but designed for the compression and transmission of digital broadcast television. The most significant enhancement from MPEG-1 is its ability to efficiently compress interlaced video. MPEG-2 scales well to HDTV resolution and bit rates, obviating the need for an MPEG-3. MPEG-4 Standard for multimedia and Web compression. MPEG-4 is based on object-based compression, similar in nature to the Virtual Reality Modeling Language. Individual objects within a scene are tracked separately and compressed together to create an MPEG4 file. This results in very efficient compression that is very scalable, from low bit rates to very high. It also allows developers to control objects independently in a scene, and therefore introduce interactivity. MPEG-7 This standard, currently under development, is also called the Multimedia Content Description Interface. When released, the group hopes the standard will provide a framework for multimedia content that will include information on content manipulation, filtering and personalization, as well as the integrity and security of the content. Contrary to the previous MPEG standards, which described actual content, MPEG-7 will represent information about the content. MPEG-21 Work on this standard, also called the Multimedia Framework, has just begun. MPEG-21 will attempt to describe the elements needed to build an infrastructure for the delivery and consumption of multimedia content, and how they will relate to each other. JPEG Stands for Joint Photographic Experts Group. It is also an ISO/IEC working group, but works to build standards for continuous tone image coding. JPEG is a lossy compression technique used for full-color or gray-scale images, by exploiting the fact that the human eye will not notice small color changes. JPEG 2000 An initiative that will provide an image coding system using compression techniques based on the use of wavelet technology. DV A high-resolution digital video format used with video cameras and camcorders. The standard uses DCT to compress the pixel data and is a form of lossy compression. The resulting video stream is transferred from the recording device via FireWire (IEEE 1394), a high-speed serial bus capable of transferring data up to 50 MB/sec. H.261 An ITU standard designed for two-way communication over ISDN lines (video conferencing) and supports data rates which are multiples of 64Kbit/s. The algorithm is based on DCT and can be implemented in hardware or software and uses intraframe and interframe compression. H.261 supports CIF and QCIF resolutions. H.263 Based on H.261 with enhancements that improve video quality over modems. It supportsCIF, QCIF, SQCIF, 4CIF and 16CIF resolutions. H.264 H.264, also known as MPEG-4 AVC (Advanced Video Coding), is a video compression standard that offers significantly greater compression than its predecessors. The standard offers up to twice the compression of the current MPEG-4 ASP (Advanced Simple Profile), in addition to improvements in perceptual quality. The H.264 standard can provide DVD-quality video at under 1 Mbps, and is optional for full-motion video over wireless, satellite, and ADSL Internet connections. DivX Compression DivX is a software application that uses the MPEG-4 standard to compress digital video, so it can be downloaded over a DSL/cable modem connection in a relatively short time with no reduced visual quality. The latest version of the codec, DivX 4.0, is being developed jointly by DivXNetworks and the open source community. DivX works on Windows 98, ME, 2000, CE, Mac and Linux. Terms Lossy compression - reduces a file by permanently eliminating certain redundant information, so that even when the file is uncompressed, only a part of the original information is still there. ISO/IEC International Organization for Standardization - a non-governmental organization that works to promote the development of standardization to facilitate the international exchange of goods and services and spur worldwide intellectual, scientific, technological and economic activity. International Electrotechnical Commission - international standards and assessment body for the fields of electrotechnology Codec - A video codec is software that can compress a video source (encoding) as well as play compressed video (decompress). CIF - Common Intermediate Format - a set of standard video formats used in videoconferencing, defined by their resolution. The original CIF is also known as Full CIF (FCIF). QCIF - Quarter CIF (resolution 176x144) SQCIF - Sub quarter CIF (resolution 128x96) 4CIF - 4 x CIF (resolution 704x576) 16CIF - 16 x CIF (resolution 1408x1152

mike no problem mate. my fault for not making my self clear.

also unistall your remove your viewer from pc and reinstall when you are on your active x set-up under network type click on 512k this will make your system alot faster. if you have installed all your web viewer and remote viewer from disks remove them because you dont need then.

Hi Braven. do you mean the eb1304 sata net ??? and can you tell us your ports you have set-up and type of router.

looked at spec cif is not h264. take a look at either avermedia or the avtech both are very good and do what it says on the box. there are cheap systems and budget systems ..................never use a cheap system

hi rory. the flash i have is master reset not full software flash. its 1am here so to late to do anything today for you but i can email the flash to you tomorrow. so dont do anything with your dvr till then. also there is another problem with the eb and sa dvrs the internet will no longer work on then the licence has ran out java/ active x they expirered on the 9/9/2009 so if you want to put it on the net just change the time and date on the pc you will be using to set it up to before 9/9/2009 but the good news all avermedias work on iphone 4-8-16-32 screen

Hi rory. i work for avermedia uk. if you have tried removing internal batt and that never sorted it then a quick firmware flash will sort it. is you system on the net ???

Hi Tom, Yes, I hope to be there. It's local to me so it'll be a shame to miss it. Would be nice to say hello. John. hi john. that is fine. then i can put some work your way. i have a few customrs in london but its a 410 mile round trip for me. you do know about the dvr offer ???

hi all in the uk it is known as the appolo. and it is well over priced. you can only back-up 1 camera at a time. h264 on cif. use d1 and it used to lockup. notice they never showed a demo of mobile (cellphone) working. that was also a problem. i would look at avermedia eb 1304 net or like guys on here have said take a look also at the AVtech. let them carry on selling paintballs . i dont think you will get back-up from ebay sales

Hi jonno. yes i am going along with avermedias uk tech manager. are you going ????

Hi Gordon. i think you are will find the spec on the dvr you posted is the same as most d1. mpeg 4 systems. take a look at the avermedia. you get full uk support. (not that you will need it) it is a very simple system to use. price wise well in your budget which means you can spend more on the cameras. take a look at this system below vga or tv output / sound/ 4 camera inputs/ internet viewer/mobile viewer. 30 days recording at 25fps they is a dealer not far from you in london. and if you would like to see a demo i can let you dial into mine at home. http://www.avermedia.com/AVerDiGi/Product/Detail.aspx?id=151

Hi dmmsta. they is also a licence problem with the eb/and sa dvrs. and this will stop you setting up remote viewing. you can pm me for the way past this problem.

Hi Jay. you need to give the guys here more info. internal/external voltage. do you need a controller. what system are you adding it too. and type of camera you are going to mount on the p/t if it is for external use. i would just buy a budget type ptz

hi rory. yes you are right port 80 or 81 is fine for IE but over smartphone nokia or others will not let you accsess port 80. vodafone usb works the same as smartphones so moving to high ports is best.

Hi Finch. like WRS-MARK i would also take a look at the avermedia. but ask your dealer to show you the new model 1304 mob/net/gsm/gps. i have one as a demo at the moment. but seems very good (only had it testing the last 10 days)

i know of 2 companys that use pc based dvrs/nvrs with auto ptz tracking. avermedia nv cards also have this as standard. the other company is adventura but a bit over price. see demo of 1 working below. http://www.aventuratechnologies.com/livedemo/

MOXA i have used for many years both for ptz and pos

hi. jonno. yes you need to change port forwarding on both the dvr and router. and yes it will work as normal though ie or the viewer software. just one thing on vista make sure you are in run as administrator. right click IE and select run as administrator

Hi rory. i come across this problem alot with customers. like jonno. going from pc to pc or pc to dvr with port 80 is fine. but mobile devices like smartphones or 3g data cards will not connect to anything with port 80 it just shuts ie down. by changing from port 80 on the dvr gets around this problem and going to ports around 5550 is ideal for mobile devices

what part of the US are you in ???

Hi jonno. with using vodafone i take it your in the uk ???? i use the vodafone dongle all the time to show people systems over the internet. but you need to change the port on the dvr from 80 to 5550 to be able to view from mobile devices. but when you look for the dvr in the remote software dont forget to add your port i.e yourip:5550

i would say your power supply 8 way 8 amp is only 1 amp per camera and over 500f that is not enough. you could install seperate power units. the camera you stated ECL-640 Eclipse will run 12v or 24v. i would go for 12v 5amp seperate power supplys

Cool! I didn't know something like that existed for CCTV! Where do you get it? None of my suppliers carry it. Biwave.com no workie either. When I was in broadcast we used similar technology that carried camera power, video, 2-way intercom, spot video, and audio all in one coax. The special triax cable was sure expensive though! Just one kink was enough to get you fired! in the uk it is £30 with power unit.....thats video/sound/power. if you have problems getting the unit i could ship some to a cctv company who is a friend of mine in westvirginia.

why not just keep it simple and use biwave connectors power/video/sound upto 500meters over coax http://www.secure.no/files/Biwave/BI-2100_2200.pdf

so what help do you need ..........has it failed..... or have you leased it from security max ??? or are you looking for another one. in which case look at my first post.....DONT.