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<div>Hello,</div>
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<div>I have a question to x264. I already posted the question to the x264 developers but i got no answer yet, so I try it here.</div>
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<div>how is it possible that the diamond search achieves better compression than the Exhaustive Search (both ESA and TESA) for the same video.</div>
<div>Diamond search is faster and achieves a smaller average frame size.</div>
<div>This was tested for different search ranges.</div>
<div>I use fullpixel precision for both algorithms.</div>
<div>The PSNR of Diamond Search is about 34,85 and for TESA 34,96, visually I see no differences.</div>
<div>The test video is a high-motion video which is 355x288 resolution (showing a football match).</div>
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<div>As ratecontrol method I use CQP and I disabled adaptive quantization.</div>
<div>Furthermore I disable direct motion vector prediction.</div>
<div>As presets I use placebo and zerolatency with the profile high.</div>
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<div>My first idea was that TESA increases the header information for each frame, but i think this is not the case.</div>
<div>Or is it just a random occurence due to entropy coding (i use CABAC)?</div>
<div>I already read that the exhaustive search doesn't check all possible positions, so maybe the algorithm converges to a local minimum, which is suboptimal for my testvideo.</div>
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<div>But this is all very unlikely because i tested it for 3 other videos (one high-motion, two low-motion) with the same result.</div>
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<div>I am lost here and need help cause this is relevant for my master thesis.</div>
<div>In the annotations you find my plots for coding time and frame size.</div>
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<div>Best regards</div>
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<div>Felix Schillmaier</div>
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