[PATCH] cx18: Fix VIDIOC_TRY_FMT to fill in sizeimage and bytesperline

[PATCH] cx18: Fix VIDIOC_TRY_FMT to fill in sizeimage and bytesperline

[Simon Farnsworth]

I was having trouble capturing raw video from GStreamer; turns out that I
now need VIDIOC_TRY_FMT to fill in sizeimage and bytesperline to make it work.

Signed-off-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
---

I'm leaving ONELAN on Friday, so this is a drive-by patch being sent for the
benefit of anyone else trying to use raw capture from a cx18 card. If it's
not suitable for applying as-is, please feel free to just leave it in the
archives so that someone else hitting the same problem can find my fix.

 drivers/media/pci/cx18/cx18-ioctl.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/media/pci/cx18/cx18-ioctl.c b/drivers/media/pci/cx18/cx18-ioctl.c
index 55525af..1c9924a 100644
--- a/drivers/media/pci/cx18/cx18-ioctl.c
+++ b/drivers/media/pci/cx18/cx18-ioctl.c
@@ -234,6 +234,13 @@ static int cx18_try_fmt_vid_cap(struct file *file, void *fh,
 
 	fmt->fmt.pix.width = w;
 	fmt->fmt.pix.height = h;
+	if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_HM12) {
+		fmt->fmt.pix.sizeimage = h * 720 * 3 / 2;
+		fmt->fmt.pix.bytesperline = 720; /* First plane */
+	} else {
+		fmt->fmt.pix.sizeimage = h * 720 * 2;
+		fmt->fmt.pix.bytesperline = 1440; /* Packed */
+	}
 	return 0;
 }
 
-- 
2.1.0

Re: [PATCH] cx18: Fix VIDIOC_TRY_FMT to fill in sizeimage and bytesperline

[Simon Farnsworth]

On Tuesday 24 November 2015 21:27:33 Jean-Michel Hautbois wrote:

> Hi, 
> Le 24 nov. 2015 19:46, "Simon Farnsworth" <simon.farnsworth@onelan.co.uk> a écrit :
> >
> > I was having trouble capturing raw video from GStreamer; turns out that I
> > now need VIDIOC_TRY_FMT to fill in sizeimage and bytesperline to make it work.
> 
> You could have used v4l2-compliance tool it would give you at least (I don't have the HW to test) this error. Would save your time :-) 

It only took me 2 minutes to find - I'd have spent longer getting
v4l2-compliance running :)

As I'm not going to have access to the hardware after Friday, I'll leave
getting a full v4l2-compliance pass to someone else.

> > Signed-off-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
> > ---
> >
> > I'm leaving ONELAN on Friday, so this is a drive-by patch being sent for the
> > benefit of anyone else trying to use raw capture from a cx18 card. If it's
> > not suitable for applying as-is, please feel free to just leave it in the
> > archives so that someone else hitting the same problem can find my fix.
> >
<snip>

-- 
Simon Farnsworth
Software Engineer
ONELAN Ltd
http://www.onelan.com

Re: [PATCH] cx18: Fix VIDIOC_TRY_FMT to fill in sizeimage and bytesperline

[Hans Verkuil]

On 11/24/2015 07:09 PM, Simon Farnsworth wrote:
> I was having trouble capturing raw video from GStreamer; turns out that I
> now need VIDIOC_TRY_FMT to fill in sizeimage and bytesperline to make it work.
> 
> Signed-off-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
> ---
> 
> I'm leaving ONELAN on Friday, so this is a drive-by patch being sent for the
> benefit of anyone else trying to use raw capture from a cx18 card. If it's
> not suitable for applying as-is, please feel free to just leave it in the
> archives so that someone else hitting the same problem can find my fix.
> 
>  drivers/media/pci/cx18/cx18-ioctl.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/media/pci/cx18/cx18-ioctl.c b/drivers/media/pci/cx18/cx18-ioctl.c
> index 55525af..1c9924a 100644
> --- a/drivers/media/pci/cx18/cx18-ioctl.c
> +++ b/drivers/media/pci/cx18/cx18-ioctl.c
> @@ -234,6 +234,13 @@ static int cx18_try_fmt_vid_cap(struct file *file, void *fh,
>  
>  	fmt->fmt.pix.width = w;
>  	fmt->fmt.pix.height = h;
> +	if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_HM12) {
> +		fmt->fmt.pix.sizeimage = h * 720 * 3 / 2;
> +		fmt->fmt.pix.bytesperline = 720; /* First plane */
> +	} else {
> +		fmt->fmt.pix.sizeimage = h * 720 * 2;
> +		fmt->fmt.pix.bytesperline = 1440; /* Packed */
> +	}

This isn't correct: for MPEG formats bytesperline should be 0 and sizeimage is fixed
at 128*1024.

I really have no time to make a proper patch, Andy is this something you can look at?

Hmm, ivtv does it a bit better but it will return the wrong sizeimage.

Regards,

	Hans

>  	return 0;
>  }
>  
>