edid-decode: show or calculate timings

Add new options to show all Established Timings, DMTs, VICs and
HDMI VICs.

Add new options to show the timings for specific Standard Timing codes,
or DMT, VIC and HDMI VIC codes.

Add new options to calculate GTF and CVT timings, fully implementing the
GTF and CVT standards, including interlaced, overscan, reduced blanking
and support for the GTF Secondary Curve.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

1 files changed, 8 insertions, 6 deletions

diff --git a/parse-vtb-ext-block.cpp b/parse-vtb-ext-block.cpp
index 4936f1e..05d54f4 100644
--- a/parse-vtb-ext-block.cpp
+++ b/parse-vtb-ext-block.cpp
@@ -29,12 +29,14 @@ void edid_state::parse_vtb_ext_block(const unsigned char *x)
 			detailed_cvt_descriptor("    ", x, false);
 	}
 	if (num_st) {
+		// Note: the VTB-EXT standard has a mistake in the example EDID
+		// that it provides: there the refresh rate (bits 5-0 of the
+		// second byte) is set to 60 for 60 Hz, but this should be 0
+		// since the actual refresh rate is the value + 60.
+		//
+		// The documentation itself is correct, though.
 		printf("  Standard Timings:\n");
-		for (unsigned i = 0; i < num_st; i++, x += 2) {
-			if ((x[1] & 0x3f) >= 60)
-				print_standard_timing("    ", x[0], x[1] - 60, true);
-			else
-				print_standard_timing("    ", x[0], x[1], true, 0);
-		}
+		for (unsigned i = 0; i < num_st; i++, x += 2)
+			print_standard_timing("    ", x[0], x[1], true);
 	}
 }