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Altera_Forum's avatar
Altera_Forum
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17 years ago

Anyone have experience with using frame buffer to implement 3:2 pull-down?

We are looking for a fast and easy way to implement 3:2 pull-down utilizing the frame buffer. I have looked at the parameterization settings for the frame buffer and it seems that it is purely a storage device for frames agnostic of any selective frame rate control. If anyone knows about 3:2 pull-down using the frame buffer, I would surely appreciate the help to save some time.

Rick

3 Replies

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

    The frame buffer in the Altera VIP suite supports simple frame dropping and/or repeating. This allows for a simple form of frame rate conversion. For example, you could have a 24fps input and 60fps output.

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

    Kevin,

    How? I do not see this as being possible with the parameters presented. How does it know that the incoming is 24 fps and the outgoing is 60 fps? How do you tell it to do so? I want to know how to use it before I use it.

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

    You configure the frame buffer to allow frame dropping and repeating. The output frame rate should be driven by whatever is driving the output. So for example, if you are driving SDI video at 60Hz, it's going to pull frames out of the buffer at 60fps. The frame buffer will therefore automatically repeat frames. The only place you can get into trouble is if you put two frame buffers in the path that both allow frame dropping and repeating.

    Jake