4k* HEVC => Actual performance of Motion Estimation and OpenCL Motion Compensation.

After several tests and experiments I have made significant improvement in OpenCL code.

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One part of our HEVC encoder is Motion Estimation module.
This module used as generator of quarter-pel motion vectors for Motion Compensation testing.

Numbers below is actual performance of both modules.

Motion Estimation (executed on CPU, one core i5-3570K, 3.4 GHz)
   // copy and pad input image, some initializations, Scene Change Detection:
   vsshevc::VssPreAnalyzerImpl::PreparePicture [ 10]: 68.146 ms, (6.815 ms each)
   // perform Motion Estimation for one reference frame (fastest mode):
   vsshevc::VssPreAnalyzerImpl::DoMotionEstimation [ 9]: 80.901 ms, (8.989 ms each)

Motion Compensation (OpenCL, AMD Radeon HD 7750)
    HevcCL::FillMotionData [ 9]: 24.594 ms, (2.733 ms each) - copy motion vectors
    HevcCL::RunFilter [ 9]: 64.640 ms, (6.960 ms each) - filter itself with prolog/epilog

Totals:

• Motion estimation: ~ 60 FPS / 4k video.
• Motion compensation: ~ 145 FPS / 4k video.

Notes:

1. Motion compensation is done by 8x8 luma blocks. Each block requires about 16x8x8+8x8x8 multiplications = 24 multiplications/pixel. For real world video it's close to worst case.
2. Input frame copying, output frame copying and motion vector filling are necessary only for test. In real encoder or decoder these buffers will always be prepared.

*4k = 3840x2160, YUV420.