Add utils/print-fmt.py

Add print-fmt.py util to show information about a pixel format.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

utils/print-fmt.py

@@ -0,0 +1,62 @@
+#!/usr/bin/python3
+
+import argparse
+
+from pixutils.formats import PixelFormats, fourcc_to_str
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('format')
+    parser.add_argument('-a', action='store_true', help='align pixel size')
+    parser.add_argument('width', nargs='?', default=640, type=int)
+    parser.add_argument('height', nargs='?', default=480, type=int)
+    parser.add_argument('align', nargs='?', default=1, type=int, help='stride byte align')
+    args = parser.parse_args()
+
+    width = args.width
+    height = args.height
+    align = args.align
+
+    try:
+        fmt = PixelFormats.find_by_name(args.format)
+    except StopIteration:
+        print(f'Format "{args.format}" not found')
+        return -1
+
+    if fmt.drm_fourcc:
+        drm_fourcc = fourcc_to_str(fmt.drm_fourcc)
+    else:
+        drm_fourcc = '    '
+
+    if fmt.v4l2_fourcc:
+        v4l2_fourcc = fourcc_to_str(fmt.v4l2_fourcc)
+    else:
+        v4l2_fourcc = '    '
+
+    if args.a:
+        width,height = fmt.align_pixels(width, height)
+
+    print(f'{fmt.name}')
+    print(f'drm_fourcc="{drm_fourcc:4}" v4l2_fourcc="{v4l2_fourcc:4}"')
+    print(f'color={fmt.color.name} pixel_align={fmt.pixel_align}')
+
+    print(f'width={width} height={height} align={align}')
+
+    for pi,p in enumerate(fmt.planes):
+        stride = fmt.stride(width, pi, align)
+        psize = fmt.planesize(stride, height, pi)
+        dsize = fmt.dumb_size(width, height, pi, align)
+
+        assert psize == dsize[0] * dsize[1] * dsize[2] / 8
+
+        print(f'plane{pi} bytes_per_block={p.bytes_per_block} pixels_per_block={p.pixels_per_block} hsub={p.hsub} vsub={p.vsub}')
+        print(f'       stride={stride} plane_size={psize} dumb_size={dsize}')
+
+    print(f'framesize={fmt.framesize(width, height, align)}')
+
+    return 0
+
+
+if __name__ == '__main__':
+    main()