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Recently I re-encoded a H264 video to HEVC using FFmpeg and Intel hevc_qsv hardware acceleration and libx265. hevc_qsv results in higher sized video and libx265 results in 50% lower sized video.

I Googled h265 vs HEVC it says they are same. If they are same why so much difference in the results?

These are the command lines I used:

ffmpeg -i "%%a" -c:v libx265 -vtag hvc1 "newfiles\%%~na.mp4

ffmpeg -i "%%a" -c:v hevc_qsv -vtag hvc1 "newfiles%%~na.mp4
Giacomo1968
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1 Answers1

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Are HEVC and H265 same?

Yes. They are two names for the same video format.

In ffmpeg they give different results why?

  • libx265 and hevc_qsv are two different encoders that both output the H.265/HEVC video format.
  • Just because they output the same format does not mean that the outputs will be identical.
  • libx265 is slow, but it can make a small file size and high quality.
  • hevc_qsv is less efficient than libx265, so it will never look as good as libx265 if you use the same bitrate. But it can use hardware acceleration to help encode and may be a better choice in some situations, such as if you need to reserve your CPU for some other tasks.
llogan
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