[libcamera-devel] [RFC PATCH] utils: ipu3-process: Stream multiple frames using v4l2-ctl

[Laurent Pinchart]

Hi Umang,

Thank you for the patch.

On Mon, Jul 11, 2022 at 10:14:13PM +0530, Umang Jain via libcamera-devel wrote:
> Stream IMGU using v4l2-ctl as it provides more granular controls
> on the video nodes. The goal here is to stream a single input
> file containing multiple frames in 10-bit IPU3 packed bayer format.
> Such a input file can be created using the ipu3-pack utility.

s/a input/an input/

> This patch enables the IMGU's parameter node as well in
> configure_pipeline() without which, the input node won't stream

s/ without which,/, without which/

> successive input frames.
> 
> The viewfinder and output nodes will still stream using yavta, so
> no changes required there.

Would it be difficult to use v4l2-ctl everywhere ? It would be nice to
avoid depending on multiple tools.

> It's is quite tricky to stream input and parameters nodes synchronously
> with v4l2-ctl commands for each. The patch overcomes this short-coming
> by streaming both the nodes endlessly until both of them are killed.
> A sleep of 1 second is introduced to make sure $frame_count buffers
> are captured on the output and vf nodes.

What's the issue, can't we get v4l2-ctl to stream a given number of
frames ?

> Another short-coming of this patch is when specific parameter-buffer(s)
> (from a file) are needed to streamed on the parameters node, this might
> require some adjusting. For now, the parameters node streams with
> un-assigned buffers. It depends on the decision how this script is
> expanded further down the line.

Any proposal ? :-)

> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> ---
>  utils/ipu3/ipu3-process.sh | 29 ++++++++++++++++++++++++-----
>  1 file changed, 24 insertions(+), 5 deletions(-)
> 
> diff --git a/utils/ipu3/ipu3-process.sh b/utils/ipu3/ipu3-process.sh
> index bb4abbe8..48466d70 100755
> --- a/utils/ipu3/ipu3-process.sh
> +++ b/utils/ipu3/ipu3-process.sh
> @@ -37,11 +37,13 @@ configure_pipeline() {
>  	local enable_3a=1
>  	local enable_out=1
>  	local enable_vf=1
> +	local enable_param=1
>  	local mode=0
>  
>  	# Configure the links
>  	$mediactl -r
>  	$mediactl -l "\"$imgu_entity input\":0 -> \"$imgu_entity\":0[1]"
> +	$mediactl -l "\"$imgu_entity parameters\":0 -> \"$imgu_entity\":1[$enable_param]"
>  	$mediactl -l "\"$imgu_entity\":2 -> \"$imgu_entity output\":0[$enable_out]"
>  	$mediactl -l "\"$imgu_entity\":3 -> \"$imgu_entity viewfinder\":0[$enable_vf]"
>  	$mediactl -l "\"$imgu_entity\":4 -> \"$imgu_entity 3a stat\":0[$enable_3a]"
> @@ -76,9 +78,26 @@ process_frames() {
>  	$yavta $($mediactl -e "$imgu_entity 3a stat") &
>  	sleep 0.5
>  
> -	# Feed the IMGU input.
> -	$yavta -f $IMGU_IN_PIXELFORMAT -s $in_size "-F$in_file" \
> -		$($mediactl -e "$imgu_entity input")
> +	echo "Feeding IMGU $in_size"
> +	# Start stream parameters node first
> +	v4l2-ctl -d$($mediactl -e "$imgu_entity parameters") --stream-out-mmap &
> +	local param_streaming=$!
> +
> +	# Start streaming on input node
> +	local width=$(echo $in_size | awk -F 'x' '{print $1}')
> +	local height=$(echo $in_size | awk -F 'x' '{print $2}')
> +	v4l2-ctl -d $($mediactl -e "$imgu_entity input") \
> +                --set-fmt-video-out=width=$width,height=$height,pixelformat=$IMGU_IN_PIXELFORMAT \
> +                --stream-out-mmap --stream-from=$in_file --stream-loop &
> +	local input_streaming=$!
> +
> +	# Sleep for 1 second and then kill the IMGU streaming. By then $frame_count output and vf
> +	# buffers should have been captured.
> +	sleep 1
> +	kill $input_streaming
> +	kill $param_streaming
> +
> +	echo "IMGU FED"
>  }
>  
>  # Convert captured files to ppm
> @@ -98,7 +117,7 @@ convert_files() {
>  }
>  
>  run_test() {
> -	IMGU_IN_PIXELFORMAT=IPU3_SGRBG10
> +	IMGU_IN_PIXELFORMAT=ip3G
>  	IMGU_OUT_PIXELFORMAT=NV12
>  	IMGU_VF_PIXELFORMAT=NV12
>  
> @@ -193,6 +212,6 @@ mediactl="media-ctl -d $mdev"
>  echo "Using device $mdev"
>  
>  output_dir="/tmp"
> -frame_count=5
> +frame_count=10
>  nbufs=7
>  run_test

-- 
Regards,

Laurent Pinchart