| John McCaskill 2007-11-29, 6:56 pm |
| On Nov 29, 8:42 am, "Denkedran Joe" <denkedran...@googlemail.com>
wrote:
> Hi all,
>
> I'm working on a hardware implementation (FPGA) of a lossless compression
> algorithm for a real-time application. The data will be fed in to the
> system, will then be compressed on-the-fly and then transmitted further.
>
> The average compression ratio is 3:1, so I'm gonna use some FIFOs of a
> certain size and start reading data out of the FIFO after a fixed
> startup-time. The readout rate will be 1/3 of the input data rate The size
> of the FIFOs is determined by the experimental variance of the mean
> compression ratio. Nonetheless there are possible circumstances in which no
> compression can be achieved. Since the overall system does not support
> variable bitrates a faster transmission is no solution here.
>
> So my idea was to put the question to all of you what to do in case of
> uncompressibility? Any ideas?
>
> Denkedran Joe
If the compression must be lossless, and you can not increase the bit
rate, you need to allow for the buffering of the input data to grow in
size to accommodate the worst case. If you can not build a big enough
FIFO inside the FPGA, add some external memory and use it as a FIFO.
Is the hardware already designed? What are your data rates, and do you
know what the worst case compression is?
Regards,
John McCaskill
www.fastertechnology.com
|