usbvision: disable scaling for Nogatech MicroCam

usbvision: disable scaling for Nogatech MicroCam

[Ondrej Zary]

Scaling causes bad artifacts (horizontal lines) with compression at least
with Nogatech MicroCam so disable it (for this HW).

This also fixes messed up image with some programs (Cheese with 160x120,
Adobe Flash). HW seems to support only image widths that are multiple of 64
but the driver does not account that in vidioc_try_fmt_vid_cap(). Cheese
calls try_fmt with 160x120, succeeds and then assumes that it really gets
data in that resolution - but it gets 128x120 instead. Don't know if this
affects other usbvision devices, it would be great if someone could test it.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>

diff -urp linux-2.6.39-rc2-/drivers/media/video/usbvision//usbvision-video.c linux-2.6.39-rc2/drivers/media/video/usbvision/usbvision-video.c
--- linux-2.6.39-rc2-/drivers/media/video/usbvision//usbvision-video.c	2011-07-16 16:42:35.000000000 +0200
+++ linux-2.6.39-rc2/drivers/media/video/usbvision/usbvision-video.c	2011-07-16 16:36:43.000000000 +0200
@@ -924,6 +924,11 @@ static int vidioc_try_fmt_vid_cap(struct
 	RESTRICT_TO_RANGE(vf->fmt.pix.width, MIN_FRAME_WIDTH, MAX_FRAME_WIDTH);
 	RESTRICT_TO_RANGE(vf->fmt.pix.height, MIN_FRAME_HEIGHT, MAX_FRAME_HEIGHT);
 
+	if (usbvision_device_data[usbvision->dev_model].codec == CODEC_WEBCAM) {
+		vf->fmt.pix.width = MAX_FRAME_WIDTH;
+		vf->fmt.pix.height = MAX_FRAME_HEIGHT;
+	}
+
 	vf->fmt.pix.bytesperline = vf->fmt.pix.width*
 		usbvision->palette.bytes_per_pixel;
 	vf->fmt.pix.sizeimage = vf->fmt.pix.bytesperline*vf->fmt.pix.height;
@@ -952,6 +957,11 @@ static int vidioc_s_fmt_vid_cap(struct f
 
 	usbvision->cur_frame = NULL;
 
+	if (usbvision_device_data[usbvision->dev_model].codec == CODEC_WEBCAM) {
+		vf->fmt.pix.width = MAX_FRAME_WIDTH;
+		vf->fmt.pix.height = MAX_FRAME_HEIGHT;
+	}
+
 	/* by now we are committed to the new data... */
 	usbvision_set_output(usbvision, vf->fmt.pix.width, vf->fmt.pix.height);
 

-- 
Ondrej Zary