[FFmpeg-user] Guidance on converting images to video

Moritz Barsnick barsnick at gmx.net
Sun Oct 11 00:58:45 CEST 2015

On Sun, Oct 11, 2015 at 00:29:25 +0200, James Darnley wrote:
> And you wonder why it's slow.  You're on x86-64.  You at least have SSE2
> instructions.  Why are you not using them?  You have to explicitly
> disable assembly when building x264 to get "none".

Actually, in my experience, while ffmpeg configure fails when not
finding an appropriate assembler, x264 would just "silently" compile
without assembly. This was the case for me when my yasm was too old for
x264 to be used. But checking current x264's configure script, it
should actually error out. That said, not only is Joseph's ffmpeg quite
old, so is the x264 version that ffmpeg uses: core 138. So I'm guessing
that's what happened, but bad work of a repo to let that slip through!

The performance of my x264 build increased by about a factor of 5 (!)
as soon as I had built it with assembly. There you go, better than
buying a new server farm. :-)


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