Em Mon, 17 Feb 2014 10:57:35 +0100 Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > Document the support for the new complex type controls. > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > --- > .../DocBook/media/v4l/vidioc-g-ext-ctrls.xml | 43 ++++++++++++++++++---- > 1 file changed, 35 insertions(+), 8 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml > index b3bb957..d946d6b 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml > @@ -72,23 +72,30 @@ initialize the <structfield>id</structfield>, > <structfield>size</structfield> and <structfield>reserved2</structfield> fields > of each &v4l2-ext-control; and call the > <constant>VIDIOC_G_EXT_CTRLS</constant> ioctl. String controls controls > -must also set the <structfield>string</structfield> field.</para> > +must also set the <structfield>string</structfield> field. Controls > +of complex types (<constant>V4L2_CTRL_FLAG_IS_PTR</constant> is set) > +must set the <structfield>p</structfield> field.</para> Same notes I did to the other patches apply here: - s/complex/compound/ - Let's not mix strings with compound types - etc > <para>If the <structfield>size</structfield> is too small to > receive the control result (only relevant for pointer-type controls > like strings), then the driver will set <structfield>size</structfield> > to a valid value and return an &ENOSPC;. You should re-allocate the > -string memory to this new size and try again. It is possible that the > -same issue occurs again if the string has grown in the meantime. It is > +memory to this new size and try again. For the string type it is possible that > +the same issue occurs again if the string has grown in the meantime. It is > recommended to call &VIDIOC-QUERYCTRL; first and use > <structfield>maximum</structfield>+1 as the new <structfield>size</structfield> > value. It is guaranteed that that is sufficient memory. > </para> > > + <para>Matrices are set and retrieved row-by-row. You cannot set a partial > +matrix, all elements have to be set or retrieved. The total size is calculated > +as <structfield>rows</structfield> * <structfield>cols</structfield> * <structfield>elem_size</structfield>. > +These values can be obtained by calling &VIDIOC-QUERY-EXT-CTRL;.</para> > + > <para>To change the value of a set of controls applications > initialize the <structfield>id</structfield>, <structfield>size</structfield>, > <structfield>reserved2</structfield> and > -<structfield>value/string</structfield> fields of each &v4l2-ext-control; and > +<structfield>value/value64/string/p</structfield> fields of each &v4l2-ext-control; and > call the <constant>VIDIOC_S_EXT_CTRLS</constant> ioctl. The controls > will only be set if <emphasis>all</emphasis> control values are > valid.</para> > @@ -96,11 +103,17 @@ valid.</para> > <para>To check if a set of controls have correct values applications > initialize the <structfield>id</structfield>, <structfield>size</structfield>, > <structfield>reserved2</structfield> and > -<structfield>value/string</structfield> fields of each &v4l2-ext-control; and > +<structfield>value/value64/string/p</structfield> fields of each &v4l2-ext-control; and > call the <constant>VIDIOC_TRY_EXT_CTRLS</constant> ioctl. It is up to > the driver whether wrong values are automatically adjusted to a valid > value or if an error is returned.</para> > > + <para>For matrices it is possible to only set or check only the first > +<constant>X</constant> elements by setting size to <constant>X * elem_size</constant>, > +where <structfield>elem_size</structfield> is obtained by calling &VIDIOC-QUERY-EXT-CTRL;. > +Matrix elements are set row-by-row. Matrix elements that are not explicitly > +set will be initialized to their default value.</para> > + That sounds confusing: what are the defaults? Also, what happens if the size is set to, let's say, 1,5 * elem_size? Will it fill one element, will it return an error (what error?) or will it fill two elements, the second one with some wrong value? > <para>When the <structfield>id</structfield> or > <structfield>ctrl_class</structfield> is invalid drivers return an > &EINVAL;. When the value is out of bounds drivers can choose to take > @@ -158,19 +171,33 @@ applications must set the array to zero.</entry> > <entry></entry> > <entry>__s32</entry> > <entry><structfield>value</structfield></entry> > - <entry>New value or current value.</entry> > + <entry>New value or current value. Valid if this control is not of > +type <constant>V4L2_CTRL_TYPE_INTEGER64</constant> and > +<constant>V4L2_CTRL_FLAG_IS_PTR</constant> is not set.</entry> > </row> > <row> > <entry></entry> > <entry>__s64</entry> > <entry><structfield>value64</structfield></entry> > - <entry>New value or current value.</entry> > + <entry>New value or current value. Valid if this control is of > +type <constant>V4L2_CTRL_TYPE_INTEGER64</constant> and > +<constant>V4L2_CTRL_FLAG_IS_PTR</constant> is not set.</entry> > </row> > <row> > <entry></entry> > <entry>char *</entry> > <entry><structfield>string</structfield></entry> > - <entry>A pointer to a string.</entry> > + <entry>A pointer to a string. Valid if this control is of > +type <constant>V4L2_CTRL_TYPE_STRING</constant>.</entry> > + </row> > + <row> > + <entry></entry> > + <entry>void *</entry> > + <entry><structfield>p</structfield></entry> > + <entry>A pointer to a complex type which can be a matrix and/or a > +complex type (the control's type is >= <constant>V4L2_CTRL_COMPLEX_TYPES</constant>). > +Valid if <constant>V4L2_CTRL_FLAG_IS_PTR</constant> is set for this control. > +</entry> > </row> > </tbody> > </tgroup> -- Regards, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
