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Video codec performance clarification

Eddie3909
Guru 10385 points

Hi

Does the CPU/DSP (MHz) column indicate the required DSP clock frequency to compute H264? For example, if it says 500 MHz and you have a 1 GHz DSP, the MIPs usage is 50%?

http://tiexpressdsp.com/index.php?title=Davinci_codec_performance_tables

Also, there is not any 720p or 1080p  data for the DM648 based video encoder. Anyone know where I can get this?

Thanks

  • 0
    TI__Guru*** 125430 points

    Yes, that's right.  Frequently algorithm performance is given as "MIPS".  However, "MIPS" can be a misleading term.  For example, the 64x+ can execute up to 8 instructions per clock cycle, so a 1 GHz device can be up to 8000 MIPS.  The actual amount of instructions executed will be application dependent though.  For these reasons in 64x+ it is more straight-forward to simply describe the performance in terms of "MHz".

    For DM648 video encoder I don't believe it's capable of 720p encode.  Some quick math shows that (1280*720)/(720*480) = 2.67.  The only codec that even stands a chance is the MPEG-4 encoder that was optimized for speed.  If we take the 282 MHz and multiply by our 2.67 factor that comes to 752 MHz.  So that one might potentially work, though it's hard to know if there will be any real-time issues related to DDR bandwidth, etc. when you get to that resolution.  The other codecs that are optimized for quality go over the 900 MHz number so those don't even look to be a possibility.

    If you're looking to do HD video encoding I recommend looking at DM6467 or DM365.  Those devices were designed to work at those resolutions.

  • 0 in reply to Brad Griffis
    Guru 10385 points

    Thanks Brad.