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MPEG Encoding

The Imagine stream programming model applies several kernels to an incoming video stream to generate MPEG-2 compressed video.  The kernels in the compressor are:

  • Color Conversion
  • Motion Estimation
  • Discrete Cosine Transform
  • Quantization
  • Run-length Encoding
  • Variable-length Coding
  • IDCTQ/Correlation for Reference Frame

Figure 1 shows how the MPEG-2 compression algorithm is mapped onto the Imagine.

Figure 1: Mapping MPEG-2 onto Imagine stream model



Cycle-accurate simulations of Imagine show the high performance that can be achieved on MPEG-2 compression.  

Raw speed measurements are:

  • For 360x288 images, 24-bit: 350 frames per second
  • For 720x480 images, 24-bit: 105 frames per second

Overall, the Imagine achieves 18.3 GOPS, with a power efficiency of 8.3 GOPS/W.