Re: [PATCH] uvc: Fix bytesperline calculation for planar YUV

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Nicolas,

Thank you for the patch.

On Thursday 07 Jan 2016 15:43:48 Nicolas Dufresne wrote:
> The formula used to calculate bytesperline only works for packed format.
> So far, all planar format we support have their bytesperline equal to
> the image width (stride of the Y plane or a line of Y for M420).
> 
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> ---
>  drivers/media/usb/uvc/uvc_v4l2.c | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c
> b/drivers/media/usb/uvc/uvc_v4l2.c index d7723ce..ceb1d1b 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -142,6 +142,20 @@ static __u32 uvc_try_frame_interval(struct uvc_frame
> *frame, __u32 interval) return interval;
>  }
> 
> +static __u32 uvc_v4l2_get_bytesperline(struct uvc_format *format,
> +	struct uvc_frame *frame)

I'd make the two parameters const.

> +{
> +	switch (format->fcc) {
> +	case V4L2_PIX_FMT_NV12:
> +	case V4L2_PIX_FMT_YVU420:
> +	case V4L2_PIX_FMT_YUV420:
> +	case V4L2_PIX_FMT_M420:
> +		return frame->wWidth;
> +	default:
> +		return format->bpp * frame->wWidth / 8;
> +	}
> +}
> +
>  static int uvc_v4l2_try_format(struct uvc_streaming *stream,
>  	struct v4l2_format *fmt, struct uvc_streaming_control *probe,
>  	struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
> @@ -245,7 +259,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming
> *stream, fmt->fmt.pix.width = frame->wWidth;
>  	fmt->fmt.pix.height = frame->wHeight;
>  	fmt->fmt.pix.field = V4L2_FIELD_NONE;
> -	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
> +	fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(format, frame);
>  	fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
>  	fmt->fmt.pix.colorspace = format->colorspace;
>  	fmt->fmt.pix.priv = 0;
> @@ -282,7 +296,7 @@ static int uvc_v4l2_get_format(struct uvc_streaming
> *stream, fmt->fmt.pix.width = frame->wWidth;
>  	fmt->fmt.pix.height = frame->wHeight;
>  	fmt->fmt.pix.field = V4L2_FIELD_NONE;
> -	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
> +	fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(format, frame);
>  	fmt->fmt.pix.sizeimage = stream->ctrl.dwMaxVideoFrameSize;
>  	fmt->fmt.pix.colorspace = format->colorspace;
>  	fmt->fmt.pix.priv = 0;

This looks good to me otherwise.

If it's fine with you I can fix the above issue while applying.

-- 
Regards,

Laurent Pinchart