summaryrefslogtreecommitdiff
path: root/Documentation/DocBook
diff options
context:
space:
mode:
authorHans Verkuil <hverkuil@xs4all.nl>2015-02-19 10:49:40 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-03-03 10:11:48 -0300
commite6d72d20519c5d4941ed91d03edadd133d277e08 (patch)
tree2247b6baa61804fa963d37423e8ff2ae0314b365 /Documentation/DocBook
parent2438e78a48643d41defd4b90da19d17b9c3e65f3 (diff)
downloadkernel-e6d72d20519c5d4941ed91d03edadd133d277e08.tar.gz
[media] DocBook media: fix xvYCC601 documentation
The documentation of the xvYCC601 Y'CbCr encoding was part of the SMPTE 170M (SDTV) colorspace, but it should have been part of the Rec. 709 (HDTV) colorspace as per the xvYCC standard. This change only affects the documentation and not any code. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'Documentation/DocBook')
-rw-r--r--Documentation/DocBook/media/v4l/pixfmt.xml41
1 files changed, 17 insertions, 24 deletions
diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml
index 5e0352c50324..13540fad3b2f 100644
--- a/Documentation/DocBook/media/v4l/pixfmt.xml
+++ b/Documentation/DocBook/media/v4l/pixfmt.xml
@@ -666,8 +666,7 @@ as the SMPTE C set, so this colorspace is sometimes called SMPTE C as well.</par
<variablelist>
<varlistentry>
<term>The transfer function defined for SMPTE 170M is the same as the
-one defined in Rec. 709. Normally L is in the range [0&hellip;1], but for the extended
-gamut xvYCC encoding values outside that range are allowed.</term>
+one defined in Rec. 709.</term>
<listitem>
<para>L' = -1.099(-L)<superscript>0.45</superscript>&nbsp;+&nbsp;0.099&nbsp;for&nbsp;L&nbsp;&le;&nbsp;-0.018</para>
<para>L' = 4.5L&nbsp;for&nbsp;-0.018&nbsp;&lt;&nbsp;L&nbsp;&lt;&nbsp;0.018</para>
@@ -702,25 +701,6 @@ defined in the <xref linkend="itu601" /> standard and this colorspace is sometim
though BT.601 does not mention any color primaries.</para>
<para>The default quantization is limited range, but full range is possible although
rarely seen.</para>
- <para>The <constant>V4L2_YCBCR_ENC_601</constant> encoding as described above is the
-default for this colorspace, but it can be overridden with <constant>V4L2_YCBCR_ENC_709</constant>,
-in which case the Rec. 709 Y'CbCr encoding is used.</para>
- <variablelist>
- <varlistentry>
- <term>The xvYCC 601 encoding (<constant>V4L2_YCBCR_ENC_XV601</constant>, <xref linkend="xvycc" />) is similar
-to the BT.601 encoding, but it allows for R', G' and B' values that are outside the range
-[0&hellip;1]. The resulting Y', Cb and Cr values are scaled and offset:</term>
- <listitem>
- <para>Y'&nbsp;=&nbsp;(219&nbsp;/&nbsp;255)&nbsp;*&nbsp;(0.299R'&nbsp;+&nbsp;0.587G'&nbsp;+&nbsp;0.114B')&nbsp;+&nbsp;(16&nbsp;/&nbsp;255)</para>
- <para>Cb&nbsp;=&nbsp;(224&nbsp;/&nbsp;255)&nbsp;*&nbsp;(-0.169R'&nbsp;-&nbsp;0.331G'&nbsp;+&nbsp;0.5B')</para>
- <para>Cr&nbsp;=&nbsp;(224&nbsp;/&nbsp;255)&nbsp;*&nbsp;(0.5R'&nbsp;-&nbsp;0.419G'&nbsp;-&nbsp;0.081B')</para>
- </listitem>
- </varlistentry>
- </variablelist>
- <para>Y' is clamped to the range [0&hellip;1] and Cb and Cr are clamped
-to the range [-0.5&hellip;0.5]. The non-standard xvYCC 709 encoding can also be used by selecting
-<constant>V4L2_YCBCR_ENC_XV709</constant>. The xvYCC encodings always use full range
-quantization.</para>
</section>
<section>
@@ -803,6 +783,7 @@ rarely seen.</para>
<para>The <constant>V4L2_YCBCR_ENC_709</constant> encoding described above is the default
for this colorspace, but it can be overridden with <constant>V4L2_YCBCR_ENC_601</constant>, in which
case the BT.601 Y'CbCr encoding is used.</para>
+ <para>Two additional extended gamut Y'CbCr encodings are also possible with this colorspace:</para>
<variablelist>
<varlistentry>
<term>The xvYCC 709 encoding (<constant>V4L2_YCBCR_ENC_XV709</constant>, <xref linkend="xvycc" />)
@@ -815,10 +796,22 @@ is similar to the Rec. 709 encoding, but it allows for R', G' and B' values that
</listitem>
</varlistentry>
</variablelist>
+ <variablelist>
+ <varlistentry>
+ <term>The xvYCC 601 encoding (<constant>V4L2_YCBCR_ENC_XV601</constant>, <xref linkend="xvycc" />) is similar
+to the BT.601 encoding, but it allows for R', G' and B' values that are outside the range
+[0&hellip;1]. The resulting Y', Cb and Cr values are scaled and offset:</term>
+ <listitem>
+ <para>Y'&nbsp;=&nbsp;(219&nbsp;/&nbsp;255)&nbsp;*&nbsp;(0.299R'&nbsp;+&nbsp;0.587G'&nbsp;+&nbsp;0.114B')&nbsp;+&nbsp;(16&nbsp;/&nbsp;255)</para>
+ <para>Cb&nbsp;=&nbsp;(224&nbsp;/&nbsp;255)&nbsp;*&nbsp;(-0.169R'&nbsp;-&nbsp;0.331G'&nbsp;+&nbsp;0.5B')</para>
+ <para>Cr&nbsp;=&nbsp;(224&nbsp;/&nbsp;255)&nbsp;*&nbsp;(0.5R'&nbsp;-&nbsp;0.419G'&nbsp;-&nbsp;0.081B')</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
<para>Y' is clamped to the range [0&hellip;1] and Cb and Cr are clamped
-to the range [-0.5&hellip;0.5]. The non-standard xvYCC 601 encoding can also be used by
-selecting <constant>V4L2_YCBCR_ENC_XV601</constant>. The xvYCC encodings always use full
-range quantization.</para>
+to the range [-0.5&hellip;0.5]. The non-standard xvYCC 709 or xvYCC 601 encodings can be used by
+selecting <constant>V4L2_YCBCR_ENC_XV709</constant> or <constant>V4L2_YCBCR_ENC_XV601</constant>.
+The xvYCC encodings always use full range quantization.</para>
</section>
<section>