Re: [PATCH 0/3] media: vim2m: add multiplanar API support

[Matthew Majewski <mattwmajewski@gmail.com>]

Hello Hans,

On Sun, 2025-04-27 at 11:45 +0200, Hans Verkuil wrote:
> Hi Matthew,
> 
> On 04/03/2025 20:16, Matthew Majewski wrote:
> > Hi everyone,
> > 
> > This patch series adds multiplane API support for the virtual M2M
> > driver, along with some minor driver refactoring/improvements.
> > 
> > I followed the lead of the vivid driver and made multiplanar
> > support
> > selectable with a module parameter, and the default is to use the
> > single planar api.
> > 
> > Although there are not yet any pixelformats in the driver that make
> > use of multiple memory planes, adding support for these should be
> > easier now with the API level changes taken care of.
> 
> Are you planning follow-up patches adding support for at least one
> multiplanar format? That would be really nice.
> 
> Regards,
> 
> 	Hans
> 

Yes, I currently have a WIP patch series to add support for all of the
formats that vivid currently supports to vim2m. It involves a huge
refactor though, so I split the groundwork for supporting the multi-
planar formats into a separate patch series first. 

Best,

	Matthew

> > 
> > v4l2-compliance reports the following with multiplane support
> > disabled:
> > 
> >   Total for vim2m device /dev/video0: 48, Succeeded: 48, Failed: 0,
> > Warnings: 0
> > 
> > and the same with multiplane support enabled:
> > 
> >   Total for vim2m device /dev/video0: 48, Succeeded: 48, Failed: 0,
> > Warnings: 0
> > 
> > Patches need to be applied in increasing numerical order (Patch
> > [3/3]
> > depends on [1/3] and [2/3]).
> > 
> > Since the multi-plane changes had to touch a lot of the driver, I
> > did
> > a basic regression test with the following script which generates a
> > test input image with vivid and an output image from vim2m for each
> > supported format. I confirmed all outputs visually and verified
> > they
> > were identical to the outputs before the change. Testing was done
> > on
> > an x86_64 qemu image.
> > 
> > #!/bin/sh
> > 
> > # tested with HDMI vivid emulation
> > # modprobe vivid num_inputs=1 input_types=3
> > 
> > vim2m=/dev/video0
> > vivid=/dev/video1
> > 
> > width=640
> > height=480
> > out_width=320
> > out_height=240
> > 
> > capture_formats=$(v4l2-ctl -d $vim2m --list-formats | awk '/\]:/
> > {print $2}' | sed "s/'//g")
> > output_formats=$(v4l2-ctl -d $vim2m --list-formats-out | awk '/\]:/
> > {print $2}' | sed "s/'//g")
> > 
> > # Turn off text mode so that images will be identical
> > v4l2-ctl -d $vivid -c osd_text_mode=2
> > 
> > for ofmt in ${output_formats}; do
> >     # generate input image
> >     inname="${width}x${height}.${ofmt}"
> >     v4l2-ctl -d $vivid -v
> > pixelformat=$ofmt,width=$width,height=$height,field=none \
> >              --stream-mmap --stream-count=1 --stream-to=$inname
> >     for cfmt in ${capture_formats}; do
> >         outname="${out_width}x${out_height}-out.${cfmt}"
> >         v4l2-ctl -d $vim2m -x
> > pixelformat=$ofmt,width=$width,height=$height \
> >                  -v
> > pixelformat=$cfmt,width=$out_width,height=$out_height \
> >                  --stream-from=$inname --stream-to=$outname --
> > stream-mmap --stream-out-mmap \
> >                  --stream-count=1
> >     done
> > done
> > 
> > Matthew Majewski (3):
> >   media: v4l2-common: Add RGBR format info
> >   media: vim2m: Simplify try_fmt
> >   media: vim2m: Add parametized support for multiplanar API
> > 
> >  drivers/media/test-drivers/vim2m.c    | 327 +++++++++++++++++++++-
> > ----
> >  drivers/media/v4l2-core/v4l2-common.c |   1 +
> >  2 files changed, 274 insertions(+), 54 deletions(-)
> > 
>