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Altera_Forum's avatar
Altera_Forum
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15 years ago

Sending 60 video frames per second using Ethernet

Hello,

First of all happy new year.

We are designing an embedded system that is used to send video frames to another embedded system via Ethernet connection.

It is required to send 60 frames per second.

To store the video frames we used a modular sgdma in such a way that odd frames are stored in a dedicated location in SDRAM and even frames are stored in another one.

To send these frames via the Ethernet, NicheStack TCP/IP is used with uC/OS-II as an RTOS.

While measuring the performance of NIOS-II processor (using the performance counter) when sending the video frames, we have the following inquiries:

1- Although using the same code, sending the odd frames takes longer time (~ 1.6 sec!!); when sending the even frames it takes only about 0.10 sec.

In addition to, when measuring the performance at the beginning of the function , the CPU execution time is 0.01295. !!!!

2- After changing the execution order of the profiled section, the execution time differs (frame zero send part replaces frame 1 and vice versa).

3- We sent only 2 frames per 1.5 sec??

Can any one advise me on this issue?:cry::(

Sorry for being long.

Kind Regards

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    I miss any information about the involved data amount respectively video coding. Usually video over ethernet deals with MPEG4 or similar encoding.

    There's an Altera application note about ethernet througput with and without hardware acceleration, you should compare your results with the theoretical values. Apart from these principle limits, there may be problem in your way of accessing the SDRAM.
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    --- Quote Start ---

    I miss any information about the involved data amount respectively video coding. Usually video over ethernet deals with MPEG4 or similar encoding.

    There's an Altera application note about ethernet througput with and without hardware acceleration, you should compare your results with the theoretical values. Apart from these principle limits, there may be problem in your way of accessing the SDRAM.

    --- Quote End ---

    Hello,

    Thank you for your reply.

    Regarding the video I am displaying, it is my computer's desktop.

    I am sending what is displayed in certain position on the desktop computer.

    This video data is sent to Cyclone III reference design board via the DVI connector of the Graphics card.

    Kind Regards.
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    I don't think, that the data amount can be transmitted in real time without effective compression. A SVGA frame (24 Bit) is about 2.3MByte.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    --- Quote Start ---

    I don't think, that the data amount can be transmitted in real time without effective compression. A SVGA frame (24 Bit) is about 2.3MByte.

    --- Quote End ---

    But we are clipping the image into smaller one with resolution 192 x 128 and data is 96 KBytes.

    Thank you