1 /* GStreamer

     2  *

     3  * gstv4lcolorbalance.c: color balance interface implementation for V4L

     4  *

     5  * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>

     6  *

     7  * This library is free software; you can redistribute it and/or

     8  * modify it under the terms of the GNU Library General Public

     9  * License as published by the Free Software Foundation; either

    10  * version 2 of the License, or (at your option) any later version.

    11  *

    12  * This library is distributed in the hope that it will be useful,

    13  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    15  * Library General Public License for more details.

    16  *

    17  * You should have received a copy of the GNU Library General Public

    18  * License along with this library; if not, write to the

    19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    20  * Boston, MA 02111-1307, USA.

    21  */

    22 

    23 #ifdef HAVE_CONFIG_H

    24 #include "config.h"

    25 #endif

    26 

    27 #include <gst/gst.h>

    28 #include "gstv4lcolorbalance.h"

    29 #include "gstv4lelement.h"

    30 

    31 static void

    32 gst_v4l_color_balance_channel_class_init (GstV4lColorBalanceChannelClass *

    33     klass);

    34 static void gst_v4l_color_balance_channel_init (GstV4lColorBalanceChannel *

    35     channel);

    36 

    37 static const GList *gst_v4l_color_balance_list_channels (GstColorBalance *

    38     balance);

    39 static void gst_v4l_color_balance_set_value (GstColorBalance * balance,

    40     GstColorBalanceChannel * channel, gint value);

    41 static gint gst_v4l_color_balance_get_value (GstColorBalance * balance,

    42     GstColorBalanceChannel * channel);

    43 

    44 static GstColorBalanceChannelClass *parent_class = NULL;

    45 

    46 GType

    47 gst_v4l_color_balance_channel_get_type (void)

    48 {

    49   static GType gst_v4l_color_balance_channel_type = 0;

    50 

    51   if (!gst_v4l_color_balance_channel_type) {

    52     static const GTypeInfo v4l_tuner_channel_info = {

    53       sizeof (GstV4lColorBalanceChannelClass),

    54       NULL,

    55       NULL,

    56       (GClassInitFunc) gst_v4l_color_balance_channel_class_init,

    57       NULL,

    58       NULL,

    59       sizeof (GstV4lColorBalanceChannel),

    60       0,

    61       (GInstanceInitFunc) gst_v4l_color_balance_channel_init,

    62       NULL

    63     };

    64 

    65     gst_v4l_color_balance_channel_type =

    66         g_type_register_static (GST_TYPE_COLOR_BALANCE_CHANNEL,

    67         "GstV4lColorBalanceChannel", &v4l_tuner_channel_info, 0);

    68   }

    69 

    70   return gst_v4l_color_balance_channel_type;

    71 }

    72 

    73 static void

    74 gst_v4l_color_balance_channel_class_init (GstV4lColorBalanceChannelClass *

    75     klass)

    76 {

    77   parent_class = g_type_class_peek_parent (klass);

    78 }

    79 

    80 static void

    81 gst_v4l_color_balance_channel_init (GstV4lColorBalanceChannel * channel)

    82 {

    83   channel->index = 0;

    84 }

    85 

    86 void

    87 gst_v4l_color_balance_interface_init (GstColorBalanceClass * klass)

    88 {

    89   GST_COLOR_BALANCE_TYPE (klass) = GST_COLOR_BALANCE_HARDWARE;

    90 

    91   /* default virtual functions */

    92   klass->list_channels = gst_v4l_color_balance_list_channels;

    93   klass->set_value = gst_v4l_color_balance_set_value;

    94   klass->get_value = gst_v4l_color_balance_get_value;

    95 }

    96 

    97 static G_GNUC_UNUSED gboolean

    98 gst_v4l_color_balance_contains_channel (GstV4lElement * v4lelement,

    99     GstV4lColorBalanceChannel * v4lchannel)

   100 {

   101   const GList *item;

   102 

   103   for (item = v4lelement->colors; item != NULL; item = item->next)

   104     if (item->data == v4lchannel)

   105       return TRUE;

   106 

   107   return FALSE;

   108 }

   109 

   110 static const GList *

   111 gst_v4l_color_balance_list_channels (GstColorBalance * balance)

   112 {

   113   return GST_V4LELEMENT (balance)->colors;

   114 }

   115 

   116 static void

   117 gst_v4l_color_balance_set_value (GstColorBalance * balance,

   118     GstColorBalanceChannel * channel, gint value)

   119 {

   120   GstV4lElement *v4lelement = GST_V4LELEMENT (balance);

   121   GstV4lColorBalanceChannel *v4lchannel =

   122       GST_V4L_COLOR_BALANCE_CHANNEL (channel);

   123 

   124   /* assert that we're opened and that we're using a known item */

   125   g_return_if_fail (GST_V4L_IS_OPEN (v4lelement));

   126   g_return_if_fail (gst_v4l_color_balance_contains_channel (v4lelement,

   127           v4lchannel));

   128 

   129   gst_v4l_set_picture (v4lelement, v4lchannel->index, value);

   130 }

   131 

   132 static gint

   133 gst_v4l_color_balance_get_value (GstColorBalance * balance,

   134     GstColorBalanceChannel * channel)

   135 {

   136   GstV4lElement *v4lelement = GST_V4LELEMENT (balance);

   137   GstV4lColorBalanceChannel *v4lchannel =

   138       GST_V4L_COLOR_BALANCE_CHANNEL (channel);

   139   gint value;

   140 

   141   /* assert that we're opened and that we're using a known item */

   142   g_return_val_if_fail (GST_V4L_IS_OPEN (v4lelement), 0);

   143   g_return_val_if_fail (gst_v4l_color_balance_contains_channel (v4lelement,

   144           v4lchannel), 0);

   145 

   146   if (!gst_v4l_get_picture (v4lelement, v4lchannel->index, &value))

   147     return 0;

   148 

   149   return value;

   150 }