videodev2.h: go back to limited range Y'CbCr for SRGB and, ADOBERGB

commit 35879ee4769099905fa3bda0b21e73d434e2df6a upstream.

This reverts 'commit 7e0739cd9c40 ("[media] videodev2.h: fix
sYCC/AdobeYCC default quantization range").

The problem is that many drivers can convert R'G'B' content (often
from sensors) to Y'CbCr, but they all produce limited range Y'CbCr.

To stay backwards compatible the default quantization range for
sRGB and AdobeRGB Y'CbCr encoding should be limited range, not full
range, even though the corresponding standards specify full range.

Update the V4L2_MAP_QUANTIZATION_DEFAULT define accordingly and
also update the documentation.

Fixes: 7e0739cd9c40 ("[media] videodev2.h: fix sYCC/AdobeYCC default quantization range")
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 94f123f3e04e..7f34d3c67648 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -349,8 +349,8 @@ enum v4l2_quantization {
         /*
          * The default for R'G'B' quantization is always full range, except
          * for the BT2020 colorspace. For Y'CbCr the quantization is always
-         * limited range, except for COLORSPACE_JPEG, SRGB, ADOBERGB,
-         * XV601 or XV709: those are full range.
+         * limited range, except for COLORSPACE_JPEG, XV601 or XV709: those
+         * are full range.
          */
         V4L2_QUANTIZATION_DEFAULT     = 0,
         V4L2_QUANTIZATION_FULL_RANGE  = 1,
@@ -365,8 +365,7 @@ enum v4l2_quantization {
 #define V4L2_MAP_QUANTIZATION_DEFAULT(is_rgb, colsp, ycbcr_enc) \
         (((is_rgb) && (colsp) == V4L2_COLORSPACE_BT2020) ? V4L2_QUANTIZATION_LIM_RANGE : \
          (((is_rgb) || (ycbcr_enc) == V4L2_YCBCR_ENC_XV601 || \
-          (ycbcr_enc) == V4L2_YCBCR_ENC_XV709 || (colsp) == V4L2_COLORSPACE_JPEG) || \
-          (colsp) == V4L2_COLORSPACE_ADOBERGB || (colsp) == V4L2_COLORSPACE_SRGB ? \
+          (ycbcr_enc) == V4L2_YCBCR_ENC_XV709 || (colsp) == V4L2_COLORSPACE_JPEG) ? \
          V4L2_QUANTIZATION_FULL_RANGE : V4L2_QUANTIZATION_LIM_RANGE))
 
 enum v4l2_priority {