[FFmpeg-devel] [PATCH v2 1/2] doc/ffmpeg: update the documentation about qsv device creation

[Stefano Sabatini]

On date Friday 2024-01-05 10:33:51 +0800, Xiang, Haihao wrote:
> From: Haihao Xiang <haihao.xiang at intel.com>
> 
> Signed-off-by: Haihao Xiang <haihao.xiang at intel.com>
> ---
>  doc/ffmpeg.texi | 26 ++++++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> index 7246a46d2f..f095f402bd 100644
> --- a/doc/ffmpeg.texi
> +++ b/doc/ffmpeg.texi
> @@ -1406,16 +1406,38 @@ If not specified, @samp{auto_any} is used.
>  platform-appropriate subdevice (@samp{dxva2} or @samp{d3d11va} or @samp{vaapi}) and then deriving a
>  QSV device from that.)
>  
> -Alternatively, @samp{child_device_type} helps to choose platform-appropriate subdevice type.
> -On Windows @samp{d3d11va} is used as default subdevice type.
> +The following options are recognized:
> + at table @option

> + at item child_device
> +Specify a DRM render node on Linux or DirectX adapter on Windows

missing dot at the end of complete sentence, here and below

> + at item child_device_type
> +Choose platform-appropriate subdevice type. On Windows @samp{d3d11va} is used
> +as default subdevice type.

Is this needed for non-Windows platforms?

> + at end table
>  
>  Examples:
>  @table @emph
> + at item -init_hw_device qsv:hw,child_device=/dev/dri/renderD129

> +Create a QSV device with @samp{MFX_IMPL_HARDWARE} on DRM render node /dev/dri/renderD129

You can quote the device with @file{/dev/dri/renderD129}.

> +
> + at item -init_hw_device qsv:hw,child_device=1
> +Create a QSV device with @samp{MFX_IMPL_HARDWARE} on DirectX adapter 1. The subdevice
> +type is @samp{d3d11va} if @code{--enable-libvpl} is specified at configuration time, the
> +subdevice type is @samp{dxva2} if @code{--enable-libmfx} is specified at configuration time.
> +
>  @item -init_hw_device qsv:hw,child_device_type=d3d11va
>  Choose the GPU subdevice with type @samp{d3d11va} and create QSV device with @samp{MFX_IMPL_HARDWARE}.
>  
>  @item -init_hw_device qsv:hw,child_device_type=dxva2
>  Choose the GPU subdevice with type @samp{dxva2} and create QSV device with @samp{MFX_IMPL_HARDWARE}.
> +
> + at item -init_hw_device qsv:hw,child_device=1,child_device_type=d3d11va
> +Create a QSV device with @samp{MFX_IMPL_HARDWARE} on DirectX adapter 1 with subdevice type @samp{d3d11va}
> +
> + at item -init_hw_device vaapi=va:/dev/dri/renderD129 -init_hw_device qsv=hw1 at va
> +Create a VAAPI device called @samp{va} on /dev/dri/renderD129, then derive a QSV device called @samp{hw1}
> +from device @samp{va}

Looks good otherwise.

BTW, do you know why all hwaccels are not documented in a dedicated
file (hwaccels.texi or something)?