Frame rates, resolution and compression

[kenh 0]

I seen alot of questions about frame rates, resolution and compression

 

1) does anyone know of a card that will record at 30fps at hi res?

I know Chance i's hardware boards do. Does anyone else?

 

2) My older Chance i card mpg 12004 is pretty good but still is grainy on the record end. even at 702x480 but one i just installed is grainy even on the real time display?

 

3) What are the differences between mpeg-4 and H-264? Is the extra compression worth the loss of quality? as mpeg-4 is still not perfect. Is there anything out there the compares to a camera directly connected to a cctv monitor?

[Sherry_c 0]

In fact, there are many DVR Card can record at 30fps. But the software is as important as the hardware. If the software has poor database structure will slow down even the good quality hardware. And also the features of software can fully realize the combination with all the hardwares such as Cameras, DVR Card, Alarm Host, Matrix, Speed dome and so on.

 

Sherry

www.ortvision.com

[VST_Man 1]

I maybe wrong but a frame represents the final compressed product. any frame within the 30 frames is equal in terms of quality, bytes per frame, ect. If the 1st frame is grainy, adding 29 more will only add more grainy frames. more frames does not equal a better picture....only a more fluid in terms of motion. The quality of the overall "frame" is directly traceable to the compression type and hardware used. 30 fps cannot make a pic better in terms of quality.

 

Many video users out there think that 30fps is the "best".....and it is great to record at 30 fps IF you have a 30 fps requirement..ie, Vegas has a slight of hand requirement and therefore has a 30fps requirement. Catching a shoplifter only requires 7 - 10 fps in my opinion.

 

The overall quality of a recording system lies within the hardware and software, and also in cludes other things like the camera used, cable used, and monitor used. Any one of these items can cause a grainy pic, poor pic, ect. Just having a true 30fps is not an indicator of a GREAT pic......

 

we have a saying in the USMC com field; crap in crap out............this is the rated G version

[Security Consultant 0]

1. There are many cards support real-time recording for all the channels. As I know, most of hardware compression cards support it.

 

2. I agree with VST_Man that frame rate is not a determing factor for image quality. The factors affect image quality are such as software, compression algorithm, hardware, besdies camera, cable, and monitor. Among them, software design and compression algorithm may the mafor factor for image quality. Some software have many meansures to improve image quality, they can even dynamicall adjust algorithm to meet different transmission situation.

 

3. Technically, H.264 is the most advanced compression algorithm by now. In detail,

* Up to 40% higher image quality

* Over 60% savings on recording storage space

* Truly "Live" performance despite variations in network transmission conditions

 

But the meaning of "H.264" word is different from manufacturers. Few manufacturer can fulful real H.264 algorithm.

[kateoh_99 0]

Check out the AVerMedia NV6480Express line. We are currently testing the board and have been able to push the recording resolution to 30fps for each camera at 640x480 (480fps total for the 16 cameras). It's utilizing the PCI-X slot and running on an Intel Core 2 Duo 2.4GHz processor. Very Impressed thus far since CPU is hovering around 50-60% (Remember this is a software compression board).

[Thomas in BP 0]

3) What are the differences between mpeg-4 and H-264? Is the extra compression worth the loss of quality? as mpeg-4 is still not perfect. Is there anything out there the compares to a camera directly connected to a cctv monitor?

 

A dear child has many names, which is why MPEG-4 and H.264 are the same but different!

 

MPEG-4 is actually a 'family' of codecs, but often people refer to MPEG-4 as a misnomer for MPEG-4 Part 2 (ISO/IEC 14496-2). H.264 is a different 'generation' of the MPEG-4 codec, the MPEG-4 Part 10 (ISO/IEC 14496-10). To make the confusion complete, H.264, MPEG-4 AVC, and H.264/AVC are all used to describe MPEG-4 Part 10 depending on which partner in the standardization group talks about the codec. H.264 is the name used by ITU (the International Telecommunication Union) while MPEG-4 Part 10 is the name used by MPEG (the Moving Picture Experts Group) which is a working group established in a cooperation between the International Standardization Organization (ISO) and the International Electrotechnical Commission (IEC).

 

Some of the key improvements between the two generations are that Part 10 requires less processing power relative to higher compression rates than Part 2 and that features have been implemented to reduce the macro-blocking problem often seen when Part 2 is used at the limits of its compression capabilities. At the same file size Part 10 has better image quality than Part 2 and at the same image quality Part 10 has smaller file size than Part 2, so the main questions are whether there is justification for replacing an existing MPEG-4 Part 2 hardware compression card with a MPEG-4 Part 10 hardware compression card if the existing card is still working or how much it is worth paying extra to buy a card with MPEG-4 Part 10 rather than a card with MPEG-4 Part 2. These are two questions that can be hotly debated and I doubt there are any correct answers to them. It just depends!

 

The closest you get to images that directly compares to a camera connected to a CCTV monitor is if you use a lossless codec. Some MJPEG codecs as well as codecs based on JPEG2000 are lossless. However, at low to moderate compression rates for MPEG-4 I think most people would not be able to notice the difference in image quality between lossy MPEG-4 and lossless MJPEG/JPEG2000 compression.

 

I know that a lot of people are selling the H.264/MPEG-4 Part 10 as the answer from above and that they say it is much better than MJPEG/JPEG2000 and anything else in motion video compression ever invented, but I think that makes as much sense as saying that a screwdriver is much better than a hammer. If the most important feature is high compression for transmission over the Internet, then MPEG-4 Part 10 may be better, but if it is important to be able to pick out one individual image of high quality from an image stream, then MJPEG/JPEG2000 may be a better solution. Somewhere in between high compression and individual image quality, JPEG2000 my be the better option as it allows you to store the image stream in high resolution while you can pick out a lower resolution for Internet transmission without needing to recode the video stream. But, it just depends!

[rory 0]

Good analysis Thomas .. Ive noticed lower quality in H.264 though which is why Ive stuck with Mpeg4 for now, at least with the Geo cards. I still only use H.264 with the remote webcam application of Geo if the client has very low bandwidth, otherwise i need the higher quality, after all thats what DVRs are for.

[kangtree 0]

I seen alot of questions about frame rates, resolution and compression

 

1) does anyone know of a card that will record at 30fps at hi res?

I know Chance i's hardware boards do. Does anyone else?

--->there are many kinds of DVR cards from China market can do real time:120fps/4ch,240fps/8ch,480fps/16ch.such as KN40xx HCI series,KN15xx series,KAV4000/KAV8000...and so forth. and for hardware compression card,max do 64ch per system.

 

2) My older Chance i card mpg 12004 is pretty good but still is grainy on the record end. even at 702x480 but one i just installed is grainy even on the real time display?

--->abt resolutons:we have D1(704*576),CIF(352*288) optional

 

3) What are the differences between mpeg-4 and H-264? Is the extra compression worth the loss of quality? as mpeg-4 is still not perfect. Is there anything out there the compares to a camera directly connected to a cctv monitor?

--->H.264 is a standard of MPEG(part 10).and it gathered the advancement of H.263 and MPEG4.compare with MPEG4,it compresses more in rate.for a example,the same video record,only 70% capability for H.264.

[cctvexpert 0]

I think many people still miss the mark with these issues. Frame rate obviously has nothing to do with visual quality, rather it is a sequence of consecutive images. Further, 4CIF also does not indicate a standard of quality. The only thing that provides the image quality is the bitrate. So a 4CIF image with a low bit rate can provide lousy quality. There is actually a great DVR tutorial on the subject of video technology on the Aventura Technologies website. www.h264usa.com - it is very long winded but incredibly gets to the point.