Add support for hdr capture on amd/intel

Nvidia support will be added in the future.
Note that hdr metadata is missing from the output file as
amd and intel both have bugged drivers that dont add hdr metadata
to the output file.
Need to find a workaround for this (patching the video bitstream?).

Add -cr limited|full, to set color range

2 files changed, 42 insertions, 0 deletions

diff --git a/study/color_space_transform_matrix.png b/study/color_space_transform_matrix.png
new file mode 100644
index 0000000..2b7729e5
--- /dev/null
+++ b/study/color_space_transform_matrix.png
diff --git a/study/create_matrix.py b/study/create_matrix.py
new file mode 100755
index 0000000..96bfcd4
--- /dev/null
+++ b/study/create_matrix.py
@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+
+import sys
+
+def usage():
+    print("usage: Kr Kg Kb full|limited")
+    print("examples:")
+    print("  create_matrix.py 0.2126 0.7152 0.0722 full")
+    print("  create_matrix.py 0.2126 0.7152 0.0722 limited")
+    exit(1)
+
+def main(argv):
+    if len(argv) != 5:
+        usage()
+
+    Kr = float(sys.argv[1])
+    Kg = float(sys.argv[2])
+    Kb = float(sys.argv[3])
+    color_range = sys.argv[4]
+    luma_offset = 0.0
+    transform_range = 1.0
+
+    if color_range == "full":
+        pass
+    elif color_range == "limited":
+        transform_range = (235.0 - 16.0) / 255.0
+        luma_offset = 16.0 / 255.0
+
+    matrix = [
+        [Kr,                        Kg,                        Kb],
+        [-0.5 * (Kr / (1.0 - Kb)), -0.5 * (Kg / (1.0 - Kb)),  0.5],
+        [0.5,                      -0.5 * (Kg / (1.0 - Kr)), -0.5 * (Kb / (1.0 -Kr))],
+        [0.0,                       0.5,                      0.5]
+    ]
+
+    # Transform from row major to column major for glsl
+    print("%f, %f, %f, %f" % (matrix[0][0] * transform_range, matrix[1][0] * transform_range, matrix[2][0] * transform_range, 0.0))
+    print("%f, %f, %f, %f" % (matrix[0][1] * transform_range, matrix[1][1] * transform_range, matrix[2][1] * transform_range, 0.0))
+    print("%f, %f, %f, %f" % (matrix[0][2] * transform_range, matrix[1][2] * transform_range, matrix[2][2] * transform_range, 0.0))
+    print("%f, %f, %f, %f" % (matrix[3][0] + luma_offset,     matrix[3][1],                   matrix[3][2],                   1.0))
+
+main(sys.argv)