<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Hello everyone,</div>
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<div>i have the same ffmpeg binary and .mkv (with mpeg2 video stream) source file on two different computers. One computer has a i5-2500 cpu and the other has a i3-4XXX cpu. I would like to encode the mpeg2 stream to H.264 with the following command:</div>
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<div>>> ffmpeg.exe -i test.mkv -c:v libx264 -c:a copy -c:s copy -map 0 -preset slow -tune film -crf 19 test-encoded.mkv</div>
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<div>On the i5-2500 computer the resulting file size is: 1.283.574.741 bytes</div>
<div>On the i3-4XXX computer the resulting file size is: 1.283.575.076 bytes</div>
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<div>Comparing the output on both machines with ffmpeg's md5 filter</div>
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<div>>> ffmpeg.exe -i test-encoded.mkv -c copy -f md5 -loglevel warning -</div>
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<div>On the i5-2500: MD5=3db1e5139d01b40e73c13d4e531329f2</div>
<div>On the i3-4XXX: MD5=dcec58f562a25b7a403f9e0cd71991de</div>
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<div>The only difference in the ffmpeg/x264 output (see attachments) are in the used cpu instruction sets</div>
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<div>i5-2500: MMX2 SSE2Fast SSSE3 SSE4.2 AVX</div>
<div>i3-4XXX: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2</div>
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<div>Should new CPU abilities actually only improve the performance, but not the output?</div>
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<div>Used ffmpeg.exe: https://ffmpeg.zeranoe.com/builds/win64/static/ffmpeg-20170503-a75ef15-win64-static.zip</div>
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<div>Kind regards</div>
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<div>Kim</div></div></body></html>