libexplain  1.4.D001
libexplain/iocontrol/vidioc_enum_fmt.c
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00001 /*
00002  * libexplain - a library of system-call-specific strerror replacements
00003  * Copyright (C) 2011, 2013 Peter Miller
00004  * Written by Peter Miller <pmiller@opensource.org.au>
00005  *
00006  * This program is free software; you can redistribute it and/or modify it
00007  * under the terms of the GNU Lesser General Public License as published by
00008  * the Free Software Foundation; either version 3 of the License, or (at your
00009  * option) any later version.
00010  *
00011  * This program is distributed in the hope that it will be useful, but WITHOUT
00012  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
00013  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
00014  * License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public License
00017  * along with this program. If not, see <http://www.gnu.org/licenses/>.
00018  */
00019 
00020 #include <libexplain/ac/errno.h>
00021 #include <libexplain/ac/linux/videodev2.h>
00022 #include <libexplain/ac/sys/ioctl.h>
00023 
00024 #include <libexplain/buffer/einval.h>
00025 #include <libexplain/buffer/v4l2_fmtdesc.h>
00026 #include <libexplain/buffer/is_the_null_pointer.h>
00027 #include <libexplain/iocontrol/generic.h>
00028 #include <libexplain/iocontrol/vidioc_enum_fmt.h>
00029 #include <libexplain/is_efault.h>
00030 
00031 #ifdef VIDIOC_ENUM_FMT
00032 
00033 
00034 static void
00035 print_data(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00036     int errnum, int fildes, int request, const void *data)
00037 {
00038     (void)p;
00039     (void)errnum;
00040     (void)fildes;
00041     (void)request;
00042     explain_buffer_v4l2_fmtdesc(sb, data, 0);
00043 }
00044 
00045 
00046 static void
00047 print_explanation(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00048     int errnum, int fildes, int request, const void *data)
00049 {
00050     switch (errnum)
00051     {
00052     case EINVAL:
00053         if (!data)
00054         {
00055             explain_buffer_is_the_null_pointer(sb, "data");
00056             return;
00057         }
00058 
00059         {
00060             const struct v4l2_fmtdesc *arg;
00061             int             nformats;
00062 
00063             arg = data;
00064             if (explain_is_efault_pointer(arg, sizeof(*arg)))
00065                 goto generic;
00066 
00067             /*
00068              * Check the type.
00069              * Not all types are available for enumeration.
00070              */
00071             switch (arg->type)
00072             {
00073             case V4L2_BUF_TYPE_VIDEO_CAPTURE:
00074             case V4L2_BUF_TYPE_VIDEO_OVERLAY:
00075             case V4L2_BUF_TYPE_VIDEO_OUTPUT:
00076             case V4L2_BUF_TYPE_PRIVATE:
00077 #ifdef V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE
00078             case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
00079 #endif
00080 #ifdef V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE
00081             case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
00082 #endif
00083                 break;
00084 
00085             case V4L2_BUF_TYPE_VBI_CAPTURE:
00086             case V4L2_BUF_TYPE_VBI_OUTPUT:
00087             case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
00088             case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
00089             case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
00090             default:
00091                 explain_buffer_einval_vague(sb, "data->type");
00092                 return;
00093             }
00094 
00095             /*
00096              * Check the index.
00097              */
00098             nformats = explain_v4l2_fmtdesc_get_nformats(fildes, arg->type);
00099             if (nformats == 0)
00100             {
00101                 /* FIXME: i18n */
00102                 explain_string_buffer_puts
00103                 (
00104                     sb,
00105                     "no pixel formats of the specified type are available"
00106                 );
00107                 return;
00108             }
00109             if (nformats > 0 && arg->index >= (unsigned)nformats)
00110             {
00111                 explain_buffer_einval_out_of_range
00112                 (
00113                     sb,
00114                     "data->index",
00115                     0,
00116                     nformats - 1
00117                 );
00118                 return;
00119             }
00120             return;
00121         }
00122 
00123         /* no idea */
00124         goto generic;
00125 
00126     default:
00127         generic:
00128         explain_iocontrol_generic_print_explanation
00129         (
00130             p,
00131             sb,
00132             errnum,
00133             fildes,
00134             request,
00135             data
00136         );
00137         break;
00138     }
00139 }
00140 
00141 
00142 static void
00143 print_data_returned(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00144     int errnum, int fildes, int request, const void *data)
00145 {
00146     (void)p;
00147     (void)errnum;
00148     (void)fildes;
00149     (void)request;
00150     explain_buffer_v4l2_fmtdesc(sb, data, 1);
00151 }
00152 
00153 
00154 const explain_iocontrol_t explain_iocontrol_vidioc_enum_fmt =
00155 {
00156     "VIDIOC_ENUM_FMT", /* name */
00157     VIDIOC_ENUM_FMT, /* value */
00158     0, /* disambiguate */
00159     0, /* print_name */
00160     print_data,
00161     print_explanation,
00162     print_data_returned,
00163     sizeof(struct v4l2_fmtdesc), /* data_size */
00164     "struct v4l2_fmtdesc *", /* data_type */
00165     0, /* flags */
00166     __FILE__,
00167     __LINE__,
00168 };
00169 
00170 #else /* ndef VIDIOC_ENUM_FMT */
00171 
00172 const explain_iocontrol_t explain_iocontrol_vidioc_enum_fmt =
00173 {
00174     0, /* name */
00175     0, /* value */
00176     0, /* disambiguate */
00177     0, /* print_name */
00178     0, /* print_data */
00179     0, /* print_explanation */
00180     0, /* print_data_returned */
00181     0, /* data_size */
00182     0, /* data_type */
00183     0, /* flags */
00184     __FILE__,
00185     __LINE__,
00186 };
00187 
00188 #endif /* VIDIOC_ENUM_FMT */
00189 
00190 /* vim: set ts=8 sw=4 et : */