libexplain  1.4.D001
libexplain/buffer/v4l2_input.c
Go to the documentation of this file.
00001 /*
00002  * libexplain - a library of system-call-specific strerror replacements
00003  * Copyright (C) 2011, 2013 Peter Miller
00004  *
00005  * This program is free software; you can redistribute it and/or modify
00006  * it under the terms of the GNU Lesser General Public License as
00007  * published by the Free Software Foundation; either version 3 of the
00008  * License, or (at your option) any later version.
00009  *
00010  * This program is distributed in the hope that it will be useful,
00011  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013  * Lesser General Public License for more details.
00014  *
00015  * You should have received a copy of the GNU Lesser General Public License
00016  * along with this program. If not, see <http://www.gnu.org/licenses/>.
00017  */
00018 
00019 #include <libexplain/ac/errno.h>
00020 #include <libexplain/ac/linux/videodev2.h>
00021 #include <libexplain/ac/string.h>
00022 #include <libexplain/ac/sys/ioctl.h>
00023 
00024 #include <libexplain/buffer/int32_t.h>
00025 #include <libexplain/buffer/pointer.h>
00026 #include <libexplain/buffer/v4l2_input.h>
00027 #include <libexplain/buffer/v4l2_input_capabilities.h>
00028 #include <libexplain/buffer/v4l2_input_status.h>
00029 #include <libexplain/buffer/v4l2_input_type.h>
00030 #include <libexplain/buffer/v4l2_std_id.h>
00031 #include <libexplain/is_efault.h>
00032 #include <libexplain/sizeof.h>
00033 
00034 
00035 #ifdef HAVE_LINUX_VIDEODEV2_H
00036 
00037 void
00038 explain_buffer_v4l2_input(explain_string_buffer_t *sb,
00039     const struct v4l2_input *data, int extra)
00040 {
00041     if (explain_is_efault_pointer(data, sizeof(*data)))
00042     {
00043         explain_buffer_pointer(sb, data);
00044         return;
00045     }
00046 
00047     explain_string_buffer_puts(sb, "{ index = ");
00048     explain_buffer_uint32_t(sb, data->index);
00049     if (extra)
00050     {
00051         explain_string_buffer_puts(sb, ", name = ");
00052         explain_string_buffer_putsu_quoted_n(sb, data->name,
00053             sizeof(data->name));
00054         explain_string_buffer_puts(sb, ", type = ");
00055         explain_buffer_v4l2_input_type(sb, data->type);
00056         explain_string_buffer_puts(sb, ", audioset = ");
00057         explain_buffer_uint32_t(sb, data->audioset); /* FIXME: bitfield */
00058         explain_string_buffer_puts(sb, ", tuner = ");
00059         explain_buffer_uint32_t(sb, data->tuner); /* name? */
00060         explain_string_buffer_puts(sb, ", std = ");
00061         explain_buffer_v4l2_std_id(sb, data->std);
00062         explain_string_buffer_puts(sb, ", status = ");
00063         explain_buffer_v4l2_input_status(sb, data->status);
00064 #ifdef V4L2_IN_CAP_PRESETS
00065         if (data->capabilities)
00066         {
00067             explain_string_buffer_puts(sb, ", capabilities = ");
00068             explain_buffer_v4l2_input_capabilities(sb, data->capabilities);
00069         }
00070 #endif
00071         if (!explain_uint32_array_all_zero(data->reserved,
00072             SIZEOF(data->reserved)))
00073         {
00074             explain_string_buffer_puts(sb, ", reserved = ");
00075             explain_buffer_uint32_array(sb, data->reserved,
00076                 SIZEOF(data->reserved));
00077         }
00078     }
00079     explain_string_buffer_puts(sb, " }");
00080 }
00081 
00082 
00083 void
00084 explain_buffer_v4l2_input_index(explain_string_buffer_t *sb, int value,
00085     int fildes)
00086 {
00087     struct v4l2_input in;
00088 
00089     explain_buffer_uint32_t(sb, value);
00090 
00091     memset(&in, 0, sizeof(in));
00092     in.index = value;
00093     if (ioctl(fildes, VIDIOC_ENUMINPUT, &in) >= 0)
00094     {
00095         explain_string_buffer_putc(sb, ' ');
00096         explain_string_buffer_putsu_quoted_n(sb, in.name, sizeof(in.name));
00097     }
00098 }
00099 
00100 
00101 void
00102 explain_buffer_v4l2_input_index_ptr(explain_string_buffer_t *sb,
00103     const int *data, int fildes)
00104 {
00105     if (explain_is_efault_pointer(data, sizeof(*data)))
00106     {
00107         explain_buffer_pointer(sb, data);
00108         return;
00109     }
00110 
00111     explain_string_buffer_puts(sb, "{ ");
00112     explain_buffer_v4l2_input_index(sb, *data, fildes);
00113     explain_string_buffer_puts(sb, " }");
00114 }
00115 
00116 
00117 int
00118 explain_v4l2_input_get_ninputs(int fildes)
00119 {
00120     int lo = 0;
00121     int hi = 200;
00122     for (;;)
00123     {
00124         int mid = (lo + hi) / 2;
00125         struct v4l2_input qry;
00126         memset(&qry, 0, sizeof(qry));
00127         qry.index = mid;
00128         if (ioctl(fildes, VIDIOC_ENUMINPUT, &qry) >= 0)
00129         {
00130             if (hi <= 0 && lo <= 0)
00131                 return -1;
00132             /* mid < ninputs */
00133             lo = mid + 1;
00134             if (lo > hi)
00135                 return lo;
00136         }
00137         else if (errno != EINVAL)
00138         {
00139             return -1;
00140         }
00141         else
00142         {
00143             if (hi <= 0 && lo <= 0)
00144                 return -1;
00145             /* mid >= ninputs */
00146             hi = mid - 1;
00147             if (lo >= hi)
00148                 return lo;
00149         }
00150     }
00151 }
00152 
00153 #endif
00154 
00155 /* vim: set ts=8 sw=4 et : */