Here are some points to consider when purchasing a DVR Card. 

1. Do you know what the components SHOULD BE INSIDE the DVR?

This is CRITICAL. ANYONE who tells you that A DVR will run on an AMD processor isn't necessarily lying to you, they're just not telling you the whole truth. The FACT of the matter is, many of the cards WILL run on an AMD, BUT the performance will be sub-standard. Would you buy a car and have them put a lawn mower engine in it to save a few bucks? EVERY SINGLE DVR Card in the world was built FIRST AND FOREMOST to run on an INTEL Platform. As an afterthought, the software gets coded to "allow" it to run on other motherboards and cpu combinations. While it "works," it simply doesn't use the full potential of the card and software. Check with your vendor about the Motherboard Chipset and CPU. It makes a HUGE difference. Find out how much RAM is in the machine, what speed is the CPU, etc. RAM is a SUPER CRITICAL issue. If someone tells you that you only need 256 mb of RAM, expect the worst experience you've ever had in your life. A MINIMUM of 512 Mb and that is the ABSOLUTE MINIMUM....for best results, get a GB of RAM. These are the kinds of things that will turn your DVR into a horror story. We use ONLY Genuine Intel Chipsets and CPU's in our DVR Systems.

2. Frame Rate

Lots of people say their systems run in "real time." Make sure you understand this because it means different things to different people in different scenarios. First off, REAL TIME (as in watching Live TV) is 30 Frames per Second in NTSC mode and 25 Frames Per Second in PAL (European Standard). A card that features 30 frames per second and has four channels, is NOT delivering REAL TIME (unless you are running ONE camera ONLY AND the software allows you to change the Frame Rate on each camera, which MANY of the cards do NOT allow - HOWEVER, ALL of OUR cards DO allow this). A 30 FPS card with four cameras, will typically deliver 7.5 Frames Per Second per camera, or ONE QUARTER REAL TIME. To get REAL Time on 4 cameras, you need a 120 Frames Per Second Card. Now, you probably do NOT require real time performance, BUT you shouldn't pay for something and not get what you expect. You should KNOW whether the system you are buying is a Software Compression or Hardware Compression unit. There's nothing wrong with software compression systems BUT you will GIVE UP frame rate to get resolution...and that's a fact. Also, the Software Compression systems require bigger CPU's, Video Cards and RAM as they steal "clock cycles" from all three to accomplish their performance whereas the Hardware Compression systems have their own processors right on board. There is a significant difference in performance yet AMAZINGLY enough, in many cases, hardware compression is less expensive. This is a MAJOR deal as most companies that build software compression systems simply can't be price competitive.....Why? It's simple really, Software Compression is on it's way out, and older technology ALWAYS cost more than newer technology. It's a sign of the times.

3. There is a difference in Live View, Playback and Record Speeds.

On many DVR cards, the record and playback speeds will differ from the live view. Check the specs carefully, if you can't easily find the answer, be sure to ASK your sales rep. If the answers aren't forthcoming, find another vendor.

4. What does STACKABLE mean?

Many DVR cards are NOT stackable. When you purchase a four channel card that is NOT stackable, if you decide to upgrade to 8 cameras, you have to take the four channel out and buy an eight channel card. A Stackable card allows you to simply add another card, thus saving the old card and it's associated expense.

5. Get your questions answered - BEFORE you buy!

You can avoid a ton of problems by getting your questions answered before you make a purchase. Make sure your vendor TAKES the time to go over each aspect of a DVR with you. If you don't know what questions to ask, consider these:

Are you putting a DVR card in your computer? If you are, then you should find out what chipset your motherboard has, what make and model of CPU you have, how much ram you have, what kind of video card and what size hard drive. These are really critical factors and your vendor should ASK YOU these questions. If not, you may already be in trouble.

If you're buying a complete system, make sure you get all the specifications. Find out if you can Multi-task the system. How often is the software updated? Are the updates Free? Who will actually provide technical support for you? The Vendor? Is the service toll free? Do the people on the Tech Support line speak and understand English? Are they real technicians or just someone who has answer A for Question A, etc.

Be prepared to discuss the type of setting you're going to put the DVR in....is it home use? Commercial? Industrial? What kind of lighting conditions exist, are the cameras going indoors or outdoors? Are any of your indoor cameras looking through glass or into a rising or setting sun? Again, these are things you should discuss and get answers to, it will make your experience MUCH easier and more enjoyable. Keep in mind that you can turn a $20,000.00 DVR into a piece of junk with cheap cameras that are not designed for the conditions you are putting them in. If you're trying to catch a license plate number off a car - there are specialized cameras for that. Make sure you ask about this type of thing and you're out of the box experience will be a happy one.

Make sure someone explains FRAME RATE to you and that you understand it clearly. If you don't, KEEP ASKING until you do. If you don't get a clear answer, find someone else.

This is NOT rocket science, but any time you make a purchase, you should understand what you're getting, and get what you expect. We work hard to make sure your expectation level is proper and that we meet or exceed that expectation. NEVER be afraid to ask lots of questions. If the company is reputable, they'll work through the questions until you understand it all.

6. Make sure you're getting original boards and legitimate software.

There are a  TON of fake (copy) boards out there today. You'll find them on Ebay and many websites. You can always tell a copy board by it's price....usually 150.00 or less for boards that legitimate dealers sell for 500.00 plus. What's the difference? Software that actually works and has an actual license to be fully functional (most pirated software will operate in a limited demo mode), Real Tech Support, Continual FREE upgrades to the software, Manufacturer support, a REAL warranty and a REAL RETURN policy. Plus, the real thing actually WORKS the way it was supposed to. We get five or six calls a day from customers who have been taken to the cleaners after buying a 75.00 DVR card on Ebay or from some unscrupulous salesman. They are looking for answers and help. Unfortunately, there's not much ANYONE can do for them as the manufacturers will simply NOT provide support for either the hardware OR the software. It's very sad, but the old rule of thumb holds true....if it sounds to good to be true, it probably IS. We sell ONLY legitimate DVR Cards with LICENSED fully functional software. When you purchase a card from us, you can be ASSURED that it's the real deal, and that we will support it for as long as you own it. You also will get FREE UPGRADES for the life of the card. See what a difference it makes to buy legitimate product and support!

7. Why don't we sell DVR Cards and Accessories on our website with an online Store?

Actually, this is really simple. We believe that EVERY customer deserves to have all of their questions answered BEFORE they make a purchase. While we've tried to make our web site informative, some of the technical issues can get difficult to understand. If you're going to plunk down your hard earned money, we think we should take the time to make certain that you are getting EXACTLY what you need to do the job at hand. That's why our trained professionals are standing by the phones to assist you. Ask all the questions you want, we've got time for YOU.

8. Get PROFESSIONAL help

There is a HUGE proliferation of web sites today, all proclaiming to have this deal or that deal. Then when you try to call, you don't get answers or they don't have time to LISTEN to what you're asking for and solve your DVR questions. It's simple, if they don't have time for you BEFORE the sale, how much time will they spend with you AFTER they've got your money. We ask a lot of questions, we listen to your answers, we take the time to get you the RIGHT system. We're security professionals. It's what we do, and ONLY what we do. Give us a call and ask away, see what a difference there is in talking to someone who cares versus someone what just wants the deal. There IS a difference!

9. Ask About Technical Support AFTER the Sale

Is there a TOLL FREE number for technical support? If so, is it IN the United States or India or where? Do the people who man the support lines speak actual ENGLISH? Are they REALLY technicians who understand the technology or are they just reading a script? Are they employees of the company or are they subcontractors who really just want to get you off the phone? Make sure you have a support system, we're talking about a SECURITY product here, it could be your business or your life on the line.

10.  For MORE information, click HERE

• Fine-grained motion estimation. Temporal search seeks matching sub-macro blocks of variable size as small as 4x4, and finds the motion vector to _ pel resolution. Searches may also identify motion vectors associated with matching sub-macro blocks of 4x8, 8x4, 8x8, 8x16, 16x8, or the full 16x16. [In future, even finer 1/8 pel resolution will be supported.]

• Multiple reference frames. H.264 provides additional flexibility for frames to point to more than multiple frames – which may be any combination of past and future frames. This capability provides opportunities for more precise inter-prediction, but also improved robustness to lost picture data.

• Unrestricted motion search . Motion search allows for reference frames that may be partly outside the picture; missing data can be spatially predicted from boundary data. Users may choose to disable this feature by specifying a Restricted Motion search.

• Motion vector prediction. Where sufficient temporal correlation exists, motion vectors may be accurately predicted and only their residuals transmitted explicitly in the bitstream.

Such techniques not only provide for more accurate inter-prediction, but also help to partition and scale the bitstream with priority given to data that is more globally applicable. Thus, they not only improve compression but also resilience to errors and network instabilities.

Improved Intra Spatial Prediction and Transform

Because "intra prediction" is concerned with only one picture at a time, it relies upon spatial rather than temporal correlations. As the algorithm works through a picture's macro blocks in raster scan order, earlier results may be used to "predict" the downstream calculations. Then we need only transmit residuals as refinements to the predicted results.

H.264 performs intra prediction in the spatial domain (prior to the transform, and it is a key part of the approach. Even for an intra-picture, every block of data is predicted from its neighbors before being transformed and coefficients generated for inclusion in the bitstream.

• Coarse versus fine intra prediction. Intra prediction may be performed either on 4x4 blocks, or 16x16 macro blocks. The latter is more efficient for uniform areas of a picture.

• Direction Dependent Intra Modes. By doing intra prediction in the spatial domain (rather than in the transform domain), h.264 can employ prediction that is direction dependent, and thus can focus on the most highly correlated neighbors. For Intra 16x16 coding and Intra 4 x 4 coding, there are 9 and 4 directional modes, respectively.

• 4x4 transform of Residual Data. For initially supported profiles, residual data transforms are always performed for 4x4 blocks of data, and coefficients transmitted on this fine-grained basis.

• Variable block sizes for spatial transform*. Future profiles will allow transform of variable size blocks (4x8, 8x8, etc.) with the same level of flexibility as motion estimation blocks. This will provide more flexibility and further reduction of bitrate.

• Integer transforms. Efficiency in both computation and bitrate is gained by implementing the traditional Discrete Cosine Transform (DCT) as an integer transform that requires no multiplications, except for a single normalization. It can also be inverted exactly without mismatch.

• Deblocking filter. To eliminate fine structure blockiness that might be aggravated by the smaller transform blocks, a context-sensitive deblocking filter smoothes out the internal edges. Its filter strength depends upon the prediction modes and relationship between the neighboring blocks. In addition to increasing signal-to-noise ratio (S/N), this technique significantly improves the subjective quality of the image for a given S/N.

Improved Algorithms for Encoding

Two alternative methods improve efficiency of the entropy coding process by selecting variable length codes depending upon context of the data being encoded.

• Context-Adaptive Variable Length Coding (CAVLC) employs multiple variable length codeword tables to encode transform coefficients, which consume the bulk of bandwidth. Based upon a priori statistics of already processed data, the best table is selected adaptively. For non-coefficient data, a simpler scheme is used that relies upon only a single table.

• Context-Adaptive Binary Arithmetic Coding (CABAC*) provides an extremely efficient encoding scheme when it is known that certain symbols are much more likely than others. Such dominant symbols may be encoded with extremely small bit/symbol ratios. The CABAC method continually updates frequency statistics of the incoming data and adaptively adjusts the algorithm in real-time. This method is an advanced option available in profiles beyond the baseline profile.

Techniques for Mitigation of Errors, Packet Losses, and Network Variability

Error containment and scalability

H.264 includes several other features that are useful in containing the impact of errors, and in enabling the use of scalable or multiple bit streams:

• Slice coding. Each picture is subdivided into one or more slices. The slice is given increased importance in H.264 as the basic spatial segment that is independent from its neighbors. Thus, errors or missing data from one slice cannot propagate to any other slice within the picture. This also increases flexibility to extend picture types (I, P, B) down to the level of "slice types." Redundant slices are permitted.

• Data partitioning is supported to allow higher priority data (e.g., sequence headers) to be separated from lower priority data (e.g., B-picture transform coefficients).

• Flexible macro block ordering (FMO) can be used to scatter the bits associated with adjoining macro blocks more randomly throughout the bit stream. This reduces the chance that a packet loss will affect a large region and enables error concealment by ensuring that neighboring macro blocks will be available for prediction of a missing macro block.

• The Multiple Reference Frames that are used for improved motion estimation also allow for partial motion compensation for a P picture when one of its referenced frames is missing or corrupted.

SI and SP Pictures (or slices)*

MPEG-2 practice is to insert intra pictures (I) at regular intervals to contain errors that otherwise could propagate through the picture sequence indefinitely. In addition, intra-pictures provide a means for random access or fast-forward actions, because intra frames do not require any knowledge of other referenced frames. Similarly, regular I pictures would be necessary to switch promptly from between higher and lower bitrate streams – an important feature for accommodating the bandwidth variability in mobile networks. However, I pictures typically require far more bits than P pictures and thus are an inefficient means for addressing these two requirements.

H.264 introduces two new slice types , "Switching I Pictures" (SI) and "Switching P Pictures" (SP), which help address these needs with significantly reduced bit rate. Identical SP frames can be obtained even though different reference frames are used – thus, they can be substituted for I frames as temporal resynchronization points, but with significantly reduced bitrate. SP pictures rely upon the transformation and quantization of predicted inter blocks. Because SP pictures do not take full advantage of intra-prediction, at the cost of some bits they can be extended to SI pictures which do so.

Note that because slices are coded independently, switching slices (SI or SP) can be defined at that level.

Low Latency Feature

Arbitrary Slice Ordering (ASO) relaxes the constraint that all macro blocks must be sequenced in decoding order, and thus enhances flexibility for low-delay performance important in teleconferencing, surveillance and interactive Internet applications.

Simplified Profiles

H.264 is completely focused on efficient coding of natural video and does not directly address the object-oriented functionality, synthetic video, and other systems functionality in MPEG-4, which carries a very complex structure of over 50 profiles.

In contrast, H.264 is initially defined with only three profiles:

• Baseline Profile. A basic goal of H.264 was to provide a royalty-free baseline profile to encourage early application of the standard. The baseline profile consists most of the major features described above, with the exception of: B slices and weighted prediction; CABAC encoding; field coding; and SP & SI slices. Thus, the baseline profile is appropriate for many progressive scan applications such as video conferencing and video-over-IP, but not for interlaced television or multiple stream applications.

• Main Profile. Main profile contains all of the features in Baseline, except flexible macro block ordering (FMO), arbitrary slice order (ASO) and redundant slices. However, it adds field coding, B slices and weighted prediction, and CABAC entropy coding. This profile is appropriate for efficient coding of interlaced television applications where bit or packet error is not excessive, and where low latency is not a requirement.

• Extended Profile. This profile contains all features from the baseline profile and main profiles, except that CABAC is not supported. In addition, the Extended profile adds SP and SI for stream switching, and up to 8 slice groups. This profile is appropriate for server-based streaming applications where bit-rate scalability and error rate is very important. Security Applications and Mobile video services would be an example.

Where will H.264 have the biggest impact?

Any video application can benefit from a reduction in bandwidth requirements, but highest impact will involve applications where such reduction relieves a hard technical constraint, or which makes more cost-effective use of bandwidth as a limiting resource.

In addition, other h.264 features such error containment, error concealment, and efficient bitstream switching is especially useful for IP and wireless environments.

Squeeze More Services into a Broadcast Channel

Reduction in bandwidth requirements by factors of 2-3 provide cost savings for bandwidth-constrained services such as satellite and DVB-Terrestrial, or alternatively allow such providers to expand services at reduced incremental cost.

Facilitate High Quality Video Streaming over IP Networks
H.264 can produce very good quality, TV Quality streaming at less than 1Mbps (standard definition). This slips under 1 Mbps thresholds for xDSL and thus opens possibilities for new access methods for high quality, larger format video.

High Definition Transmission and Storage

Recall that MPEG-2 consumes 15-20 Mbps for High Definition video at suitable quality for broadcast or DVD. Use of h.264 will bring this down to about 8 Mbps, making it possible for bandwidth-strapped satellite service providers to fit 4 HD channels per QPSK channel.

Even more significant is that this reduction enables burning one HD movie onto a conventional DVD, thus avoiding the need for the industry to adapt a higher density ("blue laser") DVD format.

Mobile Video Applications

3G Mobile networks present an unusual array of technical challenges that have driven many features in h.264. Applications include video conferencing, streaming video on demand, multimedia-messaging services, and low resolution broadcast. Some key issues, and h.264 tools for dealing with them, include:

• Low bandwidth (50 – 300 kbps) is the key issue. The expected trend is for 3G deployment to start with h.263 and move up to h.264 as it matures. An industry analyst points out "… 3G networks are only likely to offer 57.6kbit/s initially. As those bit rates increase, mobiles and networks will move to the new H.264 codec, which offers twice the performance of H.263. This should result in the same picture quality being achieved at half the bit rate."

• Small devices with many formats ; variability of available bandwidth. For streaming applications, these two separate issues can be addressed by providing multiple streams with different formats and bandwidths, and selecting the appropriate stream at run-time. H.264's SP and SI pictures facilitate dynamic switching among multiple streams to accommodate bandwidth variability.

• High bit error rates, packet losses, and latenc y. For video applications, retransmissions are impractical for dropped or delayed packets, so h.264 provides several means (e.g., FMO, data partitioning, etc.) to contain error impacts and facilitate error concealment.

What is the relationship to MPEG-4 and MPEG-2?

Compared to MPEG-2

H.264 employs the same general approach as MPEG 1 & 2 as well as the h.261 and h.263 standards, but adds many incremental improvements to obtain coding efficiency improvement of about a factor-of-3.

MPEG-2 was optimized with specific focus on Standard and High Definition digital television services, which are delivered via circuit-switched head-end networks to dedicated satellite uplinks, cable infrastructure or terrestrial facilities. MPEG2's ability to cope is being strained as the range of delivery media expands to include heterogeneous mobile networks, packet-switched IP networks, and multiple storage formats, and as the variety of services grows to include multimedia messaging, increased use of HDTV, and others. Thus, a second goal for h.264 was to accommodate a wider variety of bandwidth requirements, picture formats, and unfriendly network environments that throw high jitter, packet loss, and bandwidth instability into the mix.

Compared to MPEG-4

During 2002, the h.264 Video Coding Experts Group combined forces with MPEG4 experts to form the Joint Video Team (JVT), so H.264 is being published as MPEG-4 Part 10 (Advanced Video Coding).

MPEG-4 is really a family of standards whose overall theme is object-oriented multimedia applications. It thus has much broader scope than H.264, which is strictly focused on more efficient and robust video coding. The comparable part of MPEG-4 is Part 2 Visual (sometimes called "Natural Video"). Other parts of MPEG address scene composition, object description and java representation of behavior, animation of human body and facial movements, audio and systems.