GStreamer: Adjust the camera's manual color temperature through V4L2

GStreamer does not support setup of manual color temperature for the
camera. Now it is implemented through the V4L2 interface, where it is
works together with the GStreamer and covers the GStreamer's holes.

Change-Id: Icaeadeb4e21ec7865bcfa908bead318d4ead8ba5
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

1 files changed, 242 insertions, 0 deletions

diff --git a/src/plugins/gstreamer/camerabin/camerabinv4limageprocessing.cpp b/src/plugins/gstreamer/camerabin/camerabinv4limageprocessing.cpp
new file mode 100644
index 000000000..47522565c
--- /dev/null
+++ b/src/plugins/gstreamer/camerabin/camerabinv4limageprocessing.cpp
@@ -0,0 +1,242 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Denis Shienkov <denis.shienkov@gmail.com>
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "camerabinv4limageprocessing.h"
+#include "camerabinsession.h"
+
+#include <QDebug>
+
+#include <private/qcore_unix_p.h>
+#include <linux/videodev2.h>
+
+QT_BEGIN_NAMESPACE
+
+CameraBinV4LImageProcessing::CameraBinV4LImageProcessing(CameraBinSession *session)
+    : QCameraImageProcessingControl(session)
+    , m_session(session)
+{
+}
+
+CameraBinV4LImageProcessing::~CameraBinV4LImageProcessing()
+{
+}
+
+bool CameraBinV4LImageProcessing::isParameterSupported(
+        ProcessingParameter parameter) const
+{
+    return m_parametersInfo.contains(parameter);
+}
+
+bool CameraBinV4LImageProcessing::isParameterValueSupported(
+        ProcessingParameter parameter, const QVariant &value) const
+{
+    QMap<ProcessingParameter, SourceParameterValueInfo>::const_iterator sourceValueInfo =
+            m_parametersInfo.constFind(parameter);
+    if (sourceValueInfo == m_parametersInfo.constEnd())
+        return false;
+
+    switch (parameter) {
+
+    case QCameraImageProcessingControl::WhiteBalancePreset: {
+        const QCameraImageProcessing::WhiteBalanceMode checkedValue =
+                value.value<QCameraImageProcessing::WhiteBalanceMode>();
+        const QCameraImageProcessing::WhiteBalanceMode firstAllowedValue =
+                (*sourceValueInfo).minimumValue ? QCameraImageProcessing::WhiteBalanceAuto
+                                                : QCameraImageProcessing::WhiteBalanceManual;
+        const QCameraImageProcessing::WhiteBalanceMode secondAllowedValue =
+                (*sourceValueInfo).maximumValue ? QCameraImageProcessing::WhiteBalanceAuto
+                                                : QCameraImageProcessing::WhiteBalanceManual;
+        if (checkedValue != firstAllowedValue
+                && checkedValue != secondAllowedValue) {
+            return false;
+        }
+    }
+        break;
+
+    case QCameraImageProcessingControl::ColorTemperature: {
+        const qint32 checkedValue = value.toInt();
+        if (checkedValue < (*sourceValueInfo).minimumValue
+                || checkedValue > (*sourceValueInfo).maximumValue) {
+            return false;
+        }
+    }
+        break;
+
+    default:
+        return false;
+    }
+
+    return true;
+}
+
+QVariant CameraBinV4LImageProcessing::parameter(
+        ProcessingParameter parameter) const
+{
+    QMap<ProcessingParameter, SourceParameterValueInfo>::const_iterator sourceValueInfo =
+            m_parametersInfo.constFind(parameter);
+    if (sourceValueInfo == m_parametersInfo.constEnd()) {
+        qWarning() << "Unable to get the parameter value: the parameter is not supported.";
+        return QVariant();
+    }
+
+    const QString deviceName = m_session->device();
+    const int fd = qt_safe_open(deviceName.toLocal8Bit().constData(), O_RDONLY);
+    if (fd == -1) {
+        qWarning() << "Unable to open the camera" << deviceName
+                   << "for read to get the parameter value:" << qt_error_string(errno);
+        return QVariant();
+    }
+
+    struct v4l2_control control;
+    ::memset(&control, 0, sizeof(control));
+    control.id = (*sourceValueInfo).cid;
+
+    const bool ret = (::ioctl(fd, VIDIOC_G_CTRL, &control) == 0);
+
+    qt_safe_close(fd);
+
+    if (!ret) {
+        qWarning() << "Unable to get the parameter value:" << qt_error_string(errno);
+        return QVariant();
+    }
+
+    switch (parameter) {
+
+    case QCameraImageProcessingControl::WhiteBalancePreset:
+        return QVariant::fromValue<QCameraImageProcessing::WhiteBalanceMode>(
+                    control.value ? QCameraImageProcessing::WhiteBalanceAuto
+                                  : QCameraImageProcessing::WhiteBalanceManual);
+
+    case QCameraImageProcessingControl::ColorTemperature:
+        return QVariant::fromValue<qint32>(control.value);
+
+    default:
+        return QVariant();
+    }
+}
+
+void CameraBinV4LImageProcessing::setParameter(
+        ProcessingParameter parameter, const QVariant &value)
+{
+    QMap<ProcessingParameter, SourceParameterValueInfo>::const_iterator sourceValueInfo =
+            m_parametersInfo.constFind(parameter);
+    if (sourceValueInfo == m_parametersInfo.constEnd()) {
+        qWarning() << "Unable to set the parameter value: the parameter is not supported.";
+        return;
+    }
+
+    const QString deviceName = m_session->device();
+    const int fd = qt_safe_open(deviceName.toLocal8Bit().constData(), O_WRONLY);
+    if (fd == -1) {
+        qWarning() << "Unable to open the camera" << deviceName
+                   << "for write to set the parameter value:" << qt_error_string(errno);
+        return;
+    }
+
+    struct v4l2_control control;
+    ::memset(&control, 0, sizeof(control));
+    control.id = (*sourceValueInfo).cid;
+
+    switch (parameter) {
+
+    case QCameraImageProcessingControl::WhiteBalancePreset: {
+        const QCameraImageProcessing::WhiteBalanceMode m =
+                value.value<QCameraImageProcessing::WhiteBalanceMode>();
+        if (m != QCameraImageProcessing::WhiteBalanceAuto
+                && m != QCameraImageProcessing::WhiteBalanceManual)
+            return;
+
+        control.value = (m == QCameraImageProcessing::WhiteBalanceAuto) ? true : false;
+    }
+        break;
+
+    case QCameraImageProcessingControl::ColorTemperature:
+        control.value = value.toInt();
+        break;
+
+    default:
+        return;
+    }
+
+    if (::ioctl(fd, VIDIOC_S_CTRL, &control) != 0)
+        qWarning() << "Unable to set the parameter value:" << qt_error_string(errno);
+
+    qt_safe_close(fd);
+}
+
+void CameraBinV4LImageProcessing::updateParametersInfo(
+        QCamera::Status cameraStatus)
+{
+    if (cameraStatus == QCamera::UnloadedStatus)
+        m_parametersInfo.clear();
+    else if (cameraStatus == QCamera::LoadedStatus) {
+        const QString deviceName = m_session->device();
+        const int fd = qt_safe_open(deviceName.toLocal8Bit().constData(), O_RDONLY);
+        if (fd == -1) {
+            qWarning() << "Unable to open the camera" << deviceName
+                       << "for read to query the parameter info:" << qt_error_string(errno);
+            return;
+        }
+
+        static const struct SupportedParameterEntry {
+            quint32 cid;
+            QCameraImageProcessingControl::ProcessingParameter parameter;
+        } supportedParametersEntries[] = {
+            { V4L2_CID_AUTO_WHITE_BALANCE, QCameraImageProcessingControl::WhiteBalancePreset },
+            { V4L2_CID_WHITE_BALANCE_TEMPERATURE, QCameraImageProcessingControl::ColorTemperature }
+        };
+
+        for (int i = 0; i < int(sizeof(supportedParametersEntries) / sizeof(SupportedParameterEntry)); ++i) {
+            struct v4l2_queryctrl queryControl;
+            ::memset(&queryControl, 0, sizeof(queryControl));
+            queryControl.id = supportedParametersEntries[i].cid;
+
+            if (::ioctl(fd, VIDIOC_QUERYCTRL, &queryControl) != 0) {
+                qWarning() << "Unable to query the parameter info:" << qt_error_string(errno);
+                continue;
+            }
+
+            SourceParameterValueInfo sourceValueInfo;
+            sourceValueInfo.cid = queryControl.id;
+            sourceValueInfo.defaultValue = queryControl.default_value;
+            sourceValueInfo.maximumValue = queryControl.maximum;
+            sourceValueInfo.minimumValue = queryControl.minimum;
+
+            m_parametersInfo.insert(supportedParametersEntries[i].parameter, sourceValueInfo);
+        }
+
+        qt_safe_close(fd);
+    }
+}
+
+QT_END_NAMESPACE