This commit implements frame decimation for stk1160, which allows
to support format changes instead of a static frame size.
The stk1160 supports independent row and column decimation, in two
different modes:
* set a number of rows/columns units to skip for each unit sent.
* set a number of rows/columns units to send for each unit skipped.
This effectively allows to achieve different frame scaling ratios.
The unit number can be set to either two row/columns sent/skipped,
or four row/columns sent/skipped. Since the video format (UYVY)
has 4-bytes, using a unit number of two row/columns results
in frame color 'shifting', so set to four row/columns sent/skipped.
Signed-off-by: Michael Stegemann <michael@xxxxxxxxxxxx>
Signed-off-by: Dale Hamel <dale.hamel@xxxxxxxxxx>
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
---
Changes from v2:
* Added div_round_integer to ensure the driver only
accepts width and height that results in integer
decimation factors. I. e., such that the modulo
of base width/height and target width/height is zero.
Changes from v1:
* Clamp width and height in stk1160_try_fmt, this guarantees
sane values are given to the driver.
drivers/media/usb/stk1160/stk1160-reg.h | 34 ++++++
drivers/media/usb/stk1160/stk1160-v4l.c | 201 +++++++++++++++++++++++++++-----
2 files changed, 207 insertions(+), 28 deletions(-)
diff --git a/drivers/media/usb/stk1160/stk1160-reg.h b/drivers/media/usb/stk1160/stk1160-reg.h
index 3e49da6..81ff3a1 100644
--- a/drivers/media/usb/stk1160/stk1160-reg.h
+++ b/drivers/media/usb/stk1160/stk1160-reg.h
@@ -33,6 +33,40 @@
*/
#define STK1160_DCTRL 0x100
+/*
+ * Decimation Control Register:
+ * Byte 104: Horizontal Decimation Line Unit Count
+ * Byte 105: Vertical Decimation Line Unit Count
+ * Byte 106: Decimation Control
+ * Bit 0 - Horizontal Decimation Control
+ * 0 Horizontal decimation is disabled.
+ * 1 Horizontal decimation is enabled.
+ * Bit 1 - Decimates Half or More Column
+ * 0 Decimates less than half from original column,
+ * send count unit (0x105) before each unit skipped.
+ * 1 Decimates half or more from original column,
+ * skip count unit (0x105) before each unit sent.
+ * Bit 2 - Vertical Decimation Control
+ * 0 Vertical decimation is disabled.
+ * 1 Vertical decimation is enabled.
+ * Bit 3 - Vertical Greater or Equal to Half
+ * 0 Decimates less than half from original row,
+ * send count unit (0x105) before each unit skipped.
+ * 1 Decimates half or more from original row,
+ * skip count unit (0x105) before each unit sent.
+ * Bit 4 - Decimation Unit
+ * 0 Decimation will work with 2 rows or columns per unit.
+ * 1 Decimation will work with 4 rows or columns per unit.
+ */
+#define STK1160_DMCTRL_H_UNITS 0x104
+#define STK1160_DMCTRL_V_UNITS 0x105
+#define STK1160_DMCTRL 0x106
+#define STK1160_H_DEC_EN BIT(0)
+#define STK1160_H_DEC_MODE BIT(1)
+#define STK1160_V_DEC_EN BIT(2)
+#define STK1160_V_DEC_MODE BIT(3)
+#define STK1160_DEC_UNIT_SIZE BIT(4)
+
/* Capture Frame Start Position */
#define STK116_CFSPO 0x110
#define STK116_CFSPO_STX_L 0x110
diff --git a/drivers/media/usb/stk1160/stk1160-v4l.c b/drivers/media/usb/stk1160/stk1160-v4l.c
index b4b737b..e12b103 100644
--- a/drivers/media/usb/stk1160/stk1160-v4l.c
+++ b/drivers/media/usb/stk1160/stk1160-v4l.c
@@ -42,6 +42,17 @@ static bool keep_buffers;
module_param(keep_buffers, bool, 0644);
MODULE_PARM_DESC(keep_buffers, "don't release buffers upon stop streaming");
+enum stk1160_decimate_mode {
+ STK1160_DECIMATE_MORE_THAN_HALF,
+ STK1160_DECIMATE_LESS_THAN_HALF,
+};
+
+struct stk1160_decimate_ctrl {
+ bool col_en, row_en;
+ enum stk1160_decimate_mode col_mode, row_mode;
+ unsigned int col_n, row_n;
+};
+
/* supported video standards */
static struct stk1160_fmt format[] = {
{
@@ -51,6 +62,19 @@ static struct stk1160_fmt format[] = {
}
};
+/*
+ * Helper to find the next divisor that results in modulo being zero.
+ * This is required to guarantee valid decimation unit counts.
+ */
+static unsigned int
+div_round_integer(unsigned int x, unsigned int y)
+{
+ for (;; y++) {
+ if (x % y == 0)
+ return x / y;
+ }
+}
+
static void stk1160_set_std(struct stk1160 *dev)
{
int i;
@@ -106,6 +130,41 @@ static void stk1160_set_std(struct stk1160 *dev)
}
+static void stk1160_set_fmt(struct stk1160 *dev,
+ struct stk1160_decimate_ctrl *ctrl)
+{
+ u32 val = 0;
+
+ if (ctrl) {
+ /*
+ * Since the format is UYVY, the device must skip or send
+ * a number of rows/columns multiple of four. This way, the
+ * colour format is preserved. The STK1160_DEC_UNIT_SIZE bit
+ * does exactly this.
+ */
+ val |= STK1160_DEC_UNIT_SIZE;
+ val |= ctrl->col_en ? STK1160_H_DEC_EN : 0;
+ val |= ctrl->row_en ? STK1160_V_DEC_EN : 0;
+ val |= ctrl->col_mode ==
+ STK1160_DECIMATE_MORE_THAN_HALF ?
+ STK1160_H_DEC_MODE : 0;
+ val |= ctrl->row_mode ==
+ STK1160_DECIMATE_MORE_THAN_HALF ?
+ STK1160_V_DEC_MODE : 0;
+
+ /* Horizontal count units */
+ stk1160_write_reg(dev, STK1160_DMCTRL_H_UNITS, ctrl->col_n);
+ /* Vertical count units */
+ stk1160_write_reg(dev, STK1160_DMCTRL_V_UNITS, ctrl->row_n);
+
+ stk1160_dbg("decimate 0x%x, column units %d, row units %d\n",
+ val, ctrl->col_n, ctrl->row_n);
+ }
+
+ /* Decimation control */
+ stk1160_write_reg(dev, STK1160_DMCTRL, val);
+}
+
/*
* Set a new alternate setting.
* Returns true is dev->max_pkt_size has changed, false otherwise.
@@ -323,41 +382,134 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
return 0;
}
-static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
- struct v4l2_format *f)
+static int stk1160_try_fmt(struct stk1160 *dev, struct v4l2_format *f,
+ struct stk1160_decimate_ctrl *ctrl)
{
- struct stk1160 *dev = video_drvdata(file);
+ unsigned int width, height;
+ unsigned int base_width, base_height;
+ unsigned int col_n, row_n;
+ enum stk1160_decimate_mode col_mode, row_mode;
+ bool col_en, row_en;
+
+ base_width = 720;
+ base_height = (dev->norm & V4L2_STD_525_60) ? 480 : 576;
+
+ /* Minimum width and height is 5% the frame size */
+ width = clamp_t(unsigned int, f->fmt.pix.width,
+ base_width / 20, base_width);
+ height = clamp_t(unsigned int, f->fmt.pix.height,
+ base_height / 20, base_height);
+
+ /* Let's set default no decimation values */
+ col_n = 0;
+ row_n = 0;
+ col_en = false;
+ row_en = false;
+ f->fmt.pix.width = base_width;
+ f->fmt.pix.height = base_height;
+ row_mode = STK1160_DECIMATE_LESS_THAN_HALF;
+ col_mode = STK1160_DECIMATE_LESS_THAN_HALF;
+
+ if (width < base_width && width > base_width / 2) {
+ /*
+ * The device will send count units for each
+ * unit skipped. This means count unit is:
+ *
+ * n = width / (frame width - width)
+ *
+ * And the width is:
+ *
+ * width = (n / n + 1) * frame width
+ */
+ col_n = div_round_integer(width, base_width - width);
+ if (col_n > 0 && col_n <= 255) {
+ col_en = true;
+ col_mode = STK1160_DECIMATE_LESS_THAN_HALF;
+ f->fmt.pix.width = (base_width * col_n) / (col_n + 1);
+ }
- /*
- * User can't choose size at his own will,
- * so we just return him the current size chosen
- * at standard selection.
- * TODO: Implement frame scaling?
- */
+ } else if (width <= base_width / 2) {
+
+ /*
+ * The device will skip count units for each
+ * unit sent. This means count is:
+ *
+ * n = (frame width / width) - 1
+ *
+ * And the width is:
+ *
+ * width = frame width / (n + 1)
+ */
+ col_n = div_round_integer(base_width, width) - 1;
+ if (col_n > 0 && col_n <= 255) {
+ col_en = true;
+ col_mode = STK1160_DECIMATE_MORE_THAN_HALF;
+ f->fmt.pix.width = base_width / (col_n + 1);
+ }
+ }
+
+ if (height < base_height && height > base_height / 2) {
+ row_n = div_round_integer(height, base_height - height);
+ if (row_n > 0 && row_n <= 255) {
+ row_en = true;
+ row_mode = STK1160_DECIMATE_LESS_THAN_HALF;
+ f->fmt.pix.height = (base_height * row_n) / (row_n + 1);
+ }
+
+ } else if (height <= base_height / 2) {
+ row_n = div_round_integer(base_height, height) - 1;
+ if (row_n > 0 && row_n <= 255) {
+ row_en = true;
+ row_mode = STK1160_DECIMATE_MORE_THAN_HALF;
+ f->fmt.pix.height = base_height / (row_n + 1);
+ }
+ }
f->fmt.pix.pixelformat = dev->fmt->fourcc;
- f->fmt.pix.width = dev->width;
- f->fmt.pix.height = dev->height;
f->fmt.pix.field = V4L2_FIELD_INTERLACED;
- f->fmt.pix.bytesperline = dev->width * 2;
- f->fmt.pix.sizeimage = dev->height * f->fmt.pix.bytesperline;
+ f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
+ f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
+ if (ctrl) {
+ ctrl->col_en = col_en;
+ ctrl->col_n = col_n;
+ ctrl->col_mode = col_mode;
+ ctrl->row_en = row_en;
+ ctrl->row_n = row_n;
+ ctrl->row_mode = row_mode;
+ }
+
+ stk1160_dbg("width %d, height %d\n",
+ f->fmt.pix.width, f->fmt.pix.height);
return 0;
}
+static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
+ struct v4l2_format *f)
+{
+ struct stk1160 *dev = video_drvdata(file);
+
+ return stk1160_try_fmt(dev, f, NULL);
+}
+
static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
struct v4l2_format *f)
{
struct stk1160 *dev = video_drvdata(file);
struct vb2_queue *q = &dev->vb_vidq;
+ struct stk1160_decimate_ctrl ctrl;
+ int rc;
if (vb2_is_busy(q))
return -EBUSY;
- vidioc_try_fmt_vid_cap(file, priv, f);
-
- /* We don't support any format changes */
+ rc = stk1160_try_fmt(dev, f, &ctrl);
+ if (rc < 0)
+ return rc;
+ dev->width = f->fmt.pix.width;
+ dev->height = f->fmt.pix.height;
+ stk1160_set_fmt(dev, &ctrl);
return 0;
}
@@ -393,22 +545,15 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id norm)
return -ENODEV;
/* We need to set this now, before we call stk1160_set_std */
+ dev->width = 720;
+ dev->height = (norm & V4L2_STD_525_60) ? 480 : 576;
dev->norm = norm;
- /* This is taken from saa7115 video decoder */
- if (dev->norm & V4L2_STD_525_60) {
- dev->width = 720;
- dev->height = 480;
- } else if (dev->norm & V4L2_STD_625_50) {
- dev->width = 720;
- dev->height = 576;
- } else {
- stk1160_err("invalid standard\n");
- return -EINVAL;
- }
-
stk1160_set_std(dev);
+ /* Calling with NULL disables frame decimation */
+ stk1160_set_fmt(dev, NULL);
+
v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_std,
dev->norm);
--
2.4.3
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