@@ -131,7 +131,8 @@ static int v_sync_from_aspect_ratio(int width, int height)
bool calc_cvt_modeline(int image_width, int image_height,
int refresh_rate, int reduced_blanking,
- bool interlaced, struct v4l2_bt_timings *cvt)
+ bool interlaced, bool reduced_fps,
+ struct v4l2_bt_timings *cvt)
{
int h_sync;
int v_sync;
@@ -295,6 +296,9 @@ bool calc_cvt_modeline(int image_width, int image_height,
pixel_clock = v_refresh * total_h_pixel *
(2 * total_v_lines + interlace) / 2;
+ if (reduced_fps && v_refresh % 6 == 0)
+ pixel_clock = ((long long)pixel_clock * 1000) / 1001;
+
pixel_clock -= pixel_clock % clk_gran;
}
@@ -241,7 +241,7 @@ static void get_cvt_gtf_timings(char *subopt, int standard,
if (standard == V4L2_DV_BT_STD_CVT) {
timings_valid = calc_cvt_modeline(width, height, fps, r_blank,
- interlaced == 1 ? true : false, bt);
+ interlaced == 1 ? true : false, false, bt);
} else {
timings_valid = calc_gtf_modeline(width, height, fps, r_blank,
interlaced == 1 ? true : false, bt);
@@ -351,7 +351,8 @@ void edid_get(int fd);
/* v4l2-ctl-modes.cpp */
bool calc_cvt_modeline(int image_width, int image_height,
int refresh_rate, int reduced_blanking,
- bool interlaced, struct v4l2_bt_timings *cvt);
+ bool interlaced, bool reduced_fps,
+ struct v4l2_bt_timings *cvt);
bool calc_gtf_modeline(int image_width, int image_height,
int refresh_rate, int reduced_blanking,
Added reduced fps option in cvt timings calculation. In this case, pixel clock is slowed down by a factor of 1000 / 1001 and all other timing parameters are unchanged. With reduced fps option one could generate timings for refresh rates like 29.97 or 59.94. Pixel clock in this case needs better precision, in the order of 0.001 Khz and hence reduced fps option can be supported only when reduced blanking V2 is enabled. Reduced fps is applicable only to nominal refresh rates which are integer multiple of 6, say 24, 30, 60 etc. Cc: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Prashant Laddha <prladdha@cisco.com> --- utils/v4l2-ctl/v4l2-ctl-modes.cpp | 6 +++++- utils/v4l2-ctl/v4l2-ctl-stds.cpp | 2 +- utils/v4l2-ctl/v4l2-ctl.h | 3 ++- 3 files changed, 8 insertions(+), 3 deletions(-)