[FFmpeg-user] qsv : do I really need to patch and build the kernel ?

Dennis Mungai dmngaie at gmail.com
Fri May 3 07:20:16 EEST 2019

On Fri, May 3, 2019, 03:35 sean darcy <seandarcy2 at gmail.com> wrote:

> I'm getting old watching libx265 run, so I was thinkng of experimenting
> with hevc_qsv. I configured ffmpeg with libmpfx. But now I read I need a
> plugin: hevc_hw. And to get that plugin I need to install the Intel
> Media SDK, which requires me to patch and install a 2-year old centos
> kernel ! Say it ain't so .
>  From the ffmpeg wiki:
> "Note that the kernel patches and modified system libraries are all
> required. It is recommended not to install this on any machine also used
> for other purposes, as it does not use normal distribution mechanisms
> and may break / be broken by other packages unexpectedly."
> It seems h264_qsv does not require the plugin, but hevc does. Am I
> reading this correctly ?
> sean

That only applies to the proprietary Intel Media SDK, downloaded and
licensed through Intel.
The open source Intel Media SDK has no such restrictions, and can be built
from source on any Linux variant if so desired. The same applies to the
media-driver , iHD, needed to utilize the resulting QSV encoders in FFmpeg.

With that said, you'd be better served by the VAAPI-based encoders, as the
QSV implementation in FFmpeg has a somewhat unreliable mapping to the MFX
libraries underneath, and the runtime can easily fail due to factors such
as unsupported pixel formats, etc, often with a vague error message not
pointing to the actual cause.

See this answer on superuser for more details


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