The video control class names are used as titles for the GUI-tabs.
The current code relies on the driver enumerating the control classes
properly when using V4L2_CTRL_FLAG_NEXT_CTRL.
But the UVC-driver (and likely others, too) don't do that, so we can end
up with an empty class name string.
Make sure we always have a control class title:
If the driver didn't enumrate a class along with the controls, call
VIDIOC_QUERYCTRL for the class explicitly.
If that fails, fall back to an internal string list.
Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx>
---
utils/qv4l2/ctrl-tab.cpp | 15 ++++++++++++++-
utils/qv4l2/v4l2-api.cpp | 25 +++++++++++++++++++++++++
utils/qv4l2/v4l2-api.h | 3 +++
3 files changed, 42 insertions(+), 1 deletions(-)
diff --git a/utils/qv4l2/ctrl-tab.cpp b/utils/qv4l2/ctrl-tab.cpp
index 5bafbbd..6a4b630 100644
--- a/utils/qv4l2/ctrl-tab.cpp
+++ b/utils/qv4l2/ctrl-tab.cpp
@@ -133,7 +133,20 @@ void ApplicationWindow::addTabs()
m_col = m_row = 0;
m_cols = 4;
- const v4l2_queryctrl &qctrl = m_ctrlMap[id];
+ v4l2_queryctrl &qctrl = m_ctrlMap[id];
+ /* No real control, it's just the control class description.
+ Verify that the driver did enumerate the class properly
+ and add the class name if missing */
+ if (!strlen((char *)qctrl.name))
+ {
+ /* Try to request control class name from API */
+ qctrl.id = id;
+ qctrl.type = V4L2_CTRL_TYPE_CTRL_CLASS;
+ if (!queryctrl(qctrl) || !strlen((char *)qctrl.name))
+ /* Fall back to a local string list */
+ strcpy((char *)qctrl.name, ctrl_class_name(ctrl_class).toAscii());
+ }
+
QWidget *t = new QWidget(m_tabs);
QVBoxLayout *vbox = new QVBoxLayout(t);
QWidget *w = new QWidget(t);
diff --git a/utils/qv4l2/v4l2-api.cpp b/utils/qv4l2/v4l2-api.cpp
index 86cf388..5811cd7 100644
--- a/utils/qv4l2/v4l2-api.cpp
+++ b/utils/qv4l2/v4l2-api.cpp
@@ -638,3 +638,28 @@ bool v4l2::get_interval(v4l2_fract &interval)
return false;
}
+
+QString v4l2::ctrl_class_name(__u32 ctrl_class)
+{
+ switch (ctrl_class) {
+ case V4L2_CTRL_CLASS_USER:
+ return "User Controls";
+ case V4L2_CTRL_CLASS_MPEG:
+ return "MPEG-compression Controls";
+ case V4L2_CTRL_CLASS_CAMERA:
+ return "Camera Controls";
+ case V4L2_CTRL_CLASS_FM_TX:
+ return "FM Transmitter Controls";
+ case V4L2_CTRL_CLASS_FLASH:
+ return "Flash Device Controls";
+ case V4L2_CTRL_CLASS_JPEG:
+ return "JPEG-compression Controls";
+ case V4L2_CTRL_CLASS_IMAGE_SOURCE:
+ return "Image Source Controls";
+ case V4L2_CTRL_CLASS_IMAGE_PROC:
+ return "Image Processing Controls";
+ case V4L2_CTRL_CLASS_DV:
+ return "Digital Video Controls";
+ }
+ return "Controls (unknown class)";
+}
diff --git a/utils/qv4l2/v4l2-api.h b/utils/qv4l2/v4l2-api.h
index 4c10466..74e69a8 100644
--- a/utils/qv4l2/v4l2-api.h
+++ b/utils/qv4l2/v4l2-api.h
@@ -163,6 +163,9 @@ public:
bool set_interval(v4l2_fract interval);
bool get_interval(v4l2_fract &interval);
+
+ QString ctrl_class_name(__u32 ctrl_class);
+
private:
void clear() { error(QString()); }
--
1.7.7
--
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