V4L/DVB (12406): em28xx: fix: don't do image interlacing on webcams

Due to historical reasons, em28xx driver gets two consecutive frames and
fold them into an unique framing, doing interlacing. While this works
fine for TV images, this produces two bad effects with webcams:

1) webcam images are progressive. Merging two consecutive images produce
interlacing artifacts on the image;

2) since the driver needs to get two frames, it reduces the maximum
frame rate by two.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index c9e420e8a614de4b4aec3603136486e7a0c6b079..9011a498e5b3a99af48899f35e96084a3a2bf8ee 100644 (file)
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -2502,6 +2502,10 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev,
                if (em28xx_hint_sensor(dev) < 0)
                        dev->board.is_webcam = 0;
 
+       /* It makes no sense to use de-interlacing mode on webcams */
+       if (dev->board.is_webcam)
+               dev->progressive = 1;
+
        /* Do board specific init and eeprom reading */
        em28xx_card_setup(dev);
 

diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 5b78e199abd1ac9bbf433dba0012eafe02b0ab46..339fffdf6bcece10c383aa63c507d27d4c88d72d 100644 (file)
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -720,7 +720,10 @@ int em28xx_resolution_set(struct em28xx *dev)
 {
        int width, height;
        width = norm_maxw(dev);
-       height = norm_maxh(dev) >> 1;
+       height = norm_maxh(dev);
+
+       if (!dev->progressive)
+               height >>= norm_maxh(dev);
 
        em28xx_set_outfmt(dev);
 

diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 92ee9c6443287cb511b066ce9dfa6844443de2a4..ab079d9256c463a0c9889841ed3e0946969f1929 100644 (file)
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -194,15 +194,24 @@ static void em28xx_copy_video(struct em28xx *dev,
        startread = p;
        remain = len;
 
-       /* Interlaces frame */
-       if (buf->top_field)
+       if (dev->progressive)
                fieldstart = outp;
-       else
-               fieldstart = outp + bytesperline;
+       else {
+               /* Interlaces two half frames */
+               if (buf->top_field)
+                       fieldstart = outp;
+               else
+                       fieldstart = outp + bytesperline;
+       }
 
        linesdone = dma_q->pos / bytesperline;
        currlinedone = dma_q->pos % bytesperline;
-       offset = linesdone * bytesperline * 2 + currlinedone;
+
+       if (dev->progressive)
+               offset = linesdone * bytesperline + currlinedone;
+       else
+               offset = linesdone * bytesperline * 2 + currlinedone;
+
        startwrite = fieldstart + offset;
        lencopy = bytesperline - currlinedone;
        lencopy = lencopy > remain ? remain : lencopy;
@@ -376,7 +385,7 @@ static inline int em28xx_isoc_copy(struct em28xx *dev, struct urb *urb)
                        em28xx_isocdbg("Video frame %d, length=%i, %s\n", p[2],
                                       len, (p[2] & 1) ? "odd" : "even");
 
-                       if (!(p[2] & 1)) {
+                       if (dev->progressive || !(p[2] & 1)) {
                                if (buf != NULL)
                                        buffer_filled(dev, dma_q, buf);
                                get_next_buf(dma_q, &buf);
@@ -689,7 +698,10 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
        f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 
        /* FIXME: TOP? NONE? BOTTOM? ALTENATE? */
-       f->fmt.pix.field = dev->interlaced ?
+       if (dev->progressive)
+               f->fmt.pix.field = V4L2_FIELD_NONE;
+       else
+               f->fmt.pix.field = dev->interlaced ?
                           V4L2_FIELD_INTERLACED : V4L2_FIELD_TOP;
 
        mutex_unlock(&dev->lock);
@@ -753,7 +765,11 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
        f->fmt.pix.bytesperline = (dev->width * fmt->depth + 7) >> 3;
        f->fmt.pix.sizeimage = f->fmt.pix.bytesperline * height;
        f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-       f->fmt.pix.field = V4L2_FIELD_INTERLACED;
+       if (dev->progressive)
+               f->fmt.pix.field = V4L2_FIELD_NONE;
+       else
+               f->fmt.pix.field = dev->interlaced ?
+                          V4L2_FIELD_INTERLACED : V4L2_FIELD_TOP;
 
        return 0;
 }
@@ -1659,6 +1675,7 @@ static int em28xx_v4l2_open(struct file *filp)
        struct em28xx *dev;
        enum v4l2_buf_type fh_type;
        struct em28xx_fh *fh;
+       enum v4l2_field field;
 
        dev = em28xx_get_device(minor, &fh_type, &radio);
 
@@ -1700,8 +1717,13 @@ static int em28xx_v4l2_open(struct file *filp)
 
        dev->users++;
 
+       if (dev->progressive)
+               field = V4L2_FIELD_NONE;
+       else
+               field = V4L2_FIELD_INTERLACED;
+
        videobuf_queue_vmalloc_init(&fh->vb_vidq, &em28xx_video_qops,
-                       NULL, &dev->slock, fh->type, V4L2_FIELD_INTERLACED,
+                       NULL, &dev->slock, fh->type, field,
                        sizeof(struct em28xx_buffer), fh);
 
        mutex_unlock(&dev->lock);

diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 45bd513f62dcb8ed42bd9e37c58956f204f1d23f..8c2dc38bca9ffe8b9a02f7e7af5d5dcc17a9df61 100644 (file)
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -484,6 +484,9 @@ struct em28xx {
        int sensor_xres, sensor_yres;
        int sensor_xtal;
 
+       /* Allows progressive (e. g. non-interlaced) mode */
+       int progressive;
+
        /* Vinmode/Vinctl used at the driver */
        int vinmode, vinctl;