em28xx: Use v4l bounding/alignment function

From: Trent Piepho <xyzzy@speakeasy.org>

The v4l function has a better algorithm for aligning image size.

It appears that the em2800 can only scale by 50% or 100%, i.e. the only
heights supported might be 240 and 480.  In that case the old code would
set any height other than 240 to 480.  Request 240 get 240, but request 239
and then you get 480.  Change it to round to the nearest supported value.

Priority: normal

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>

1 files changed, 12 insertions, 26 deletions

diff --git a/linux/drivers/media/video/em28xx/em28xx-video.c b/linux/drivers/media/video/em28xx/em28xx-video.c
index 1614e5fc4..63d21698c 100644
--- a/linux/drivers/media/video/em28xx/em28xx-video.c
+++ b/linux/drivers/media/video/em28xx/em28xx-video.c
@@ -691,8 +691,8 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 {
 	struct em28xx_fh      *fh    = priv;
 	struct em28xx         *dev   = fh->dev;
-	int                   width  = f->fmt.pix.width;
-	int                   height = f->fmt.pix.height;
+	unsigned int          width  = f->fmt.pix.width;
+	unsigned int          height = f->fmt.pix.height;
 	unsigned int          maxw   = norm_maxw(dev);
 	unsigned int          maxh   = norm_maxh(dev);
 	unsigned int          hscale, vscale;
@@ -705,34 +705,20 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 		return -EINVAL;
 	}
 
-	/* width must even because of the YUYV format
-	   height must be even because of interlacing */
-	height &= 0xfffe;
-	width  &= 0xfffe;
-
-	if (unlikely(height < 32))
-		height = 32;
-	if (unlikely(height > maxh))
-		height = maxh;
-	if (unlikely(width < 48))
-		width = 48;
-	if (unlikely(width > maxw))
-		width = maxw;
-
 	if (dev->board.is_em2800) {
 		/* the em2800 can only scale down to 50% */
-		if (height % (maxh / 2))
-			height = maxh;
-		if (width % (maxw / 2))
-			width = maxw;
-		/* according to empiatech support */
-		/* the MaxPacketSize is to small to support */
-		/* framesizes larger than 640x480 @ 30 fps */
-		/* or 640x576 @ 25 fps. As this would cut */
-		/* of a part of the image we prefer */
-		/* 360x576 or 360x480 for now */
+		height = height > (3 * maxh / 4) ? maxh : maxh / 2;
+		width = width > (3 * maxw / 4) ? maxw : maxw / 2;
+		/* According to empiatech support the MaxPacketSize is too small
+		 * to support framesizes larger than 640x480 @ 30 fps or 640x576
+		 * @ 25 fps.  As this would cut of a part of the image we prefer
+		 * 360x576 or 360x480 for now */
 		if (width == maxw && height == maxh)
 			width /= 2;
+	} else {
+		/* width must even because of the YUYV format
+		   height must be even because of interlacing */
+		v4l_bound_align_image(&width, 48, maxw, 1, &height, 32, maxh, 1, 0);
 	}
 
 	get_scale(dev, width, height, &hscale, &vscale);