On Wed, 29 May 2019 08:58:54 -0300
Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx> wrote:
> Em Wed, 29 May 2019 13:43:20 +0200
> Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
>
> > On 5/29/19 1:28 PM, Mauro Carvalho Chehab wrote:
> > > Em Tue, 28 May 2019 14:02:19 -0300
> > > Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> escreveu:
> > >
> > >> From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> > >>
> > >> Users can define custom sizeimage as long as they're big enough to
> > >> store the amount of pixels required for a specific width/height under a
> > >> specific format. Avoid overriding those fields in this case.
> > >>
> > >> We could possibly do the same for bytesperline, but it gets tricky when
> > >> dealing with !MPLANE definitions, so this case is omitted for now and
> > >> ->bytesperline is always overwritten with the value calculated in
> > >> fill_pixfmt().
> > >>
> > >> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> > >> ---
> > >> Changes from v5:
> > >> * Overwrite bytesperline with the value calculated in fill_pixfmt()
> > >>
> > >> Changes from v4:
> > >> * New patch
> > >>
> > >> drivers/media/v4l2-core/v4l2-common.c | 58 ++++++++++++++++++++-------
> > >> 1 file changed, 43 insertions(+), 15 deletions(-)
> > >>
> > >> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> > >> index b2d1e55d9561..fd286f6e17d7 100644
> > >> --- a/drivers/media/v4l2-core/v4l2-common.c
> > >> +++ b/drivers/media/v4l2-core/v4l2-common.c
> > >> @@ -585,9 +585,9 @@ int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
> > >> pixfmt->num_planes = info->mem_planes;
> > >>
> > >> if (info->mem_planes == 1) {
> > >> + u32 sizeimage = 0;
> > >> +
> > >> plane = &pixfmt->plane_fmt[0];
> > >> - plane->bytesperline = ALIGN(width, v4l2_format_block_width(info, 0)) * info->bpp[0];
> > >> - plane->sizeimage = 0;
> > >>
> > >> for (i = 0; i < info->comp_planes; i++) {
> > >> unsigned int hdiv = (i == 0) ? 1 : info->hdiv;
> > >> @@ -598,10 +598,21 @@ int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
> > >> aligned_width = ALIGN(width, v4l2_format_block_width(info, i));
> > >> aligned_height = ALIGN(height, v4l2_format_block_height(info, i));
> > >>
> > >> - plane->sizeimage += info->bpp[i] *
> > >> - DIV_ROUND_UP(aligned_width, hdiv) *
> > >> - DIV_ROUND_UP(aligned_height, vdiv);
> > >> + sizeimage += info->bpp[i] *
> > >> + DIV_ROUND_UP(aligned_width, hdiv) *
> > >> + DIV_ROUND_UP(aligned_height, vdiv);
> > >> }
> > >> +
> > >> + /* Custom bytesperline value is not supported yet. */
> > >> + plane->bytesperline = ALIGN(width,
> > >> + v4l2_format_block_width(info, 0)) *
> > >> + info->bpp[0];
> > >> +
> > >> + /*
> > >> + * The user might have specified a custom sizeimage, only
> > >> + * override it if it's not big enough.
> > >> + */
> > >> + plane->sizeimage = max(sizeimage, plane->sizeimage);
> > >
> > > No upper limit? That doesn't sound a good idea to me, specially since some
> > > (broken) app might not be memset the format to zero before filling the ioctl
> > > structure.
> > >
> > > Perhaps we could do something like:
> > >
> > > sizeimage = min (sizeimage, 2 * plane->sizeimage)
> > >
> > > or something similar that would be reasonable.
> >
> > I've no idea what's sane.
> >
> > Buffers can be really large. The largest video resolution defined by CTA-861-G
> > is 10240x4320, so at 4 bytes per pixel that's 0x0a8c0000. So perhaps we can
> > use min(sizeimage, 0x10000000)? Although we should probably use the clamp function
> > instead of min/max.
>
> Well, the max is driver-specific.
>
> For example, for a camera with a max resolution of 640x480 with 2 bytes
> per pixel as the max format can only be
>
> max_size = 640*480*2 (plus some alignment value if pertinent)
>
> It sounds to me that the best would be to have a callback function
> or value filled by the drivers that would support custom sizeimage.
>
> The core could actually calculate during init (by asking the driver
> to a very big resolution and getting the returned value), but
> it sounds better to let the drivers to explicitly calculate it.
If we want max_sizeimage to be driver specific I can add it as an extra
arg to the fill_pixfmt() funcs.
If that works for you, we'll send a new version of this patch alone
(unless you want us to send the whole series again).
