[x264-devel] multi-process encoding problem

[Jason Garrett-Glaser]

On Sun, Jan 29, 2012 at 2:57 AM, aviad rozenhek <aviadr1 at gmail.com> wrote:
> Dear Experts,
>
> we're using x264 CLI to transcode 1080p video to 240p, using default setting
> [--vf resize:432,240]
> we noticed that the transcode was slow, achieving only ~70fps on an 2-cpu,
> 8-core E5520 "Gainestown" machine, while utilizing only a very small portion
> of the available CPU.
> my analysis led me to think that the bottleneck is the down-scaling stage.

Transcode means to decode a video, then encode it.

Decoding 1080p video is vastly more processor-intensive than encoding
432x240 video.

You're probably going to be massively bottlenecked by the decoding
step, which x264 doesn't have anything to do with.

Jason