hardware compression / encoding on-board

[kylep 0]

Is there a general knowledge method to identify a DVR board as having hardware encoding /compression on it (as opposed to software compression)?

 

In addition to the conexant fusion 878a chip, there must be a MPEG or H.264 encoding chip dedicated to do this, perhaps one per channel or MUX.

 

 

I'm in the amateur side of things, 4 to 8 channels, looking for solutions.

 

Please expand my brain.

[kylep 0]

I think what was confusion is somewhat clearer. It's about how some ebay specials get off saying they "hardware encode"

 

Lower priced cards had the rockwell bt878/879 (aka Conexant Fusion or Techwell ?? ) chip on it, and was marketed as "hardware encoding". From what i understand the analog signal is captured by this chip on the pci card and does some processing, adjusting size, contrast, etc, and then pixel by pixel by frame the video is written to memory. The CPU then handles the MPEG or h264 encoding

 

High end cards have hardware encoding as well, but also includes MPEG or h.264 or mjpeg /etc encoding there on the card, and would put that stream into memory via the pci bus. I wonder that the CPU must decode the MPEG /etc stream for motion detection or content analysis, or if that's done by the encoding chips on the pci card?

 

Now, some ultra low priced ebay specials would not have the BT878/879 chip, probably an Analog-2-Digital converter, writes this stream of signal values (not pixels) to memory, and relies on the CPU to interpret the values and create a pixel, then revisit it as it creates the encoded MPEg /etc stream.

 

comments?

[phred 0]

Is there a general knowledge method to identify a DVR board as having hardware encoding /compression on it (as opposed to software compression)?

 

In addition to the conexant fusion 878a chip, there must be a MPEG or H.264 encoding chip dedicated to do this, perhaps one per channel or MUX.

 

 

I'm in the amateur side of things, 4 to 8 channels, looking for solutions.

 

Please expand my brain.

 

Bt 878/879 chip is only an ADC so compression has to be done by something else - the cpu unless you have hardware compression chips.

 

Hardware compression cards use additional digital signal processing chips like TI DM64x to do compression. With something like H.264, motion detection is part of the algorithm.

 

From experience - the big benefit of using a hardware compression card is stability as the cpu is left with very little to do.

 

I have used Vguard RT4 cards with very good results - recording all four channels at 704 X576 25fps using H.264 compression uses only a few percent CPU

 

These cards are expensive in the US but much cheaper in Europe