libexplain  1.4.D001
libexplain/buffer/video_audio.c
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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/videodev.h>
00021 #include <libexplain/ac/string.h>
00022 #include <libexplain/ac/sys/ioctl.h>
00023 
00024 #include <libexplain/buffer/int.h>
00025 #include <libexplain/buffer/int16_t.h>
00026 #include <libexplain/buffer/video_audio.h>
00027 #include <libexplain/buffer/video_audio_flags.h>
00028 #include <libexplain/buffer/video_audio_mode.h>
00029 #include <libexplain/buffer/pointer.h>
00030 #include <libexplain/is_efault.h>
00031 
00032 
00033 #ifdef VIDIOCGAUDIO
00034 
00035 void
00036 explain_buffer_video_audio(explain_string_buffer_t *sb,
00037     const struct video_audio *data, int extra)
00038 {
00039     if (explain_is_efault_pointer(data, sizeof(*data)))
00040     {
00041         explain_buffer_pointer(sb, data);
00042         return;
00043     }
00044 
00045     explain_string_buffer_puts(sb, "{ audio = ");
00046     explain_buffer_int(sb, data->audio);
00047     if (extra)
00048     {
00049         if (data->flags & VIDEO_AUDIO_VOLUME)
00050         {
00051             explain_string_buffer_puts(sb, ", volume = ");
00052             explain_buffer_uint16_t(sb, data->volume);
00053         }
00054         if (data->flags & VIDEO_AUDIO_BASS)
00055         {
00056             explain_string_buffer_puts(sb, ", bass = ");
00057             explain_buffer_uint16_t(sb, data->bass);
00058         }
00059         if (data->flags & VIDEO_AUDIO_TREBLE)
00060         {
00061             explain_string_buffer_puts(sb, ", trebble = ");
00062             explain_buffer_uint16_t(sb, data->treble);
00063         }
00064         explain_string_buffer_puts(sb, ", flags = ");
00065         explain_buffer_video_audio_flags(sb, data->flags);
00066         explain_string_buffer_puts(sb, ", name = ");
00067         explain_string_buffer_puts_quoted_n(sb, data->name, sizeof(data->name));
00068         explain_string_buffer_puts(sb, ", mode = ");
00069         explain_buffer_video_audio_mode(sb, data->mode);
00070         if (data->flags & VIDEO_AUDIO_BALANCE)
00071         {
00072             explain_string_buffer_puts(sb, ", balance = ");
00073             explain_buffer_uint16_t(sb, data->balance);
00074         }
00075         if (data->flags & VIDEO_AUDIO_VOLUME)
00076         {
00077             explain_string_buffer_puts(sb, ", step = ");
00078             explain_buffer_uint16_t(sb, data->step);
00079         }
00080     }
00081     explain_string_buffer_puts(sb, " }");
00082 }
00083 
00084 
00085 int
00086 explain_video_audio_get_n(int fildes)
00087 {
00088     int lo = 0;
00089     int hi = 200;
00090     for (;;)
00091     {
00092         int mid = (lo + hi) / 2;
00093         struct video_audio qry;
00094         memset(&qry, 0, sizeof(qry));
00095         qry.audio = mid;
00096         if (ioctl(fildes, VIDIOCGAUDIO, &qry) >= 0)
00097         {
00098             if (hi <= 0 && lo <= 0)
00099                 return -1;
00100             /* mid < naudios */
00101             lo = mid + 1;
00102             if (lo > hi)
00103                 return lo;
00104         }
00105         else if (errno != EINVAL)
00106         {
00107             return -1;
00108         }
00109         else
00110         {
00111             if (hi <= 0 && lo <= 0)
00112                 return -1;
00113             /* mid >= naudios */
00114             hi = mid - 1;
00115             if (lo >= hi)
00116                 return lo;
00117         }
00118     }
00119 }
00120 
00121 #endif
00122 
00123 /* vim: set ts=8 sw=4 et : */