modules/audio_filter/audiobargraph_a.c

   1 /*****************************************************************************
   2  * audiobargraph_a.c : audiobargraph audio plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2002-2014 VLC authors and VideoLAN
   5  *
   6  * Authors: Clement CHESNIN <clement.chesnin@gmail.com>
   7  *          Philippe COENT <philippe.coent@tdf.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_aout.h>
  34 #include <vlc_filter.h>
  35
  36 #include <math.h>
  37
  38 #define BARGRAPH_TEXT N_("Defines if BarGraph information should be sent")
  39 #define BARGRAPH_LONGTEXT N_("Defines if BarGraph information should be sent. "\
  40                 "1 if the information should be sent, 0 otherwise (default 1)." )
  41 #define BARGRAPH_REPETITION_TEXT N_("Sends the barGraph information every n audio packets")
  42 #define BARGRAPH_REPETITION_LONGTEXT N_("Defines how often the barGraph information should be sent. "\
  43                 "Sends the barGraph information every n audio packets (default 4)." )
  44 #define SILENCE_TEXT N_("Defines if silence alarm information should be sent")
  45 #define SILENCE_LONGTEXT N_("Defines if silence alarm information should be sent. "\
  46                 "1 if the information should be sent, 0 otherwise (default 1)." )
  47 #define TIME_WINDOW_TEXT N_("Time window to use in ms")
  48 #define TIME_WINDOW_LONGTEXT N_("Time Window during when the audio level is measured in ms for silence detection. "\
  49                 "If the audio level is under the threshold during this time, "\
  50                 "an alarm is sent (default 5000)." )
  51 #define ALARM_THRESHOLD_TEXT N_("Minimum Audio level to raise the alarm")
  52 #define ALARM_THRESHOLD_LONGTEXT N_("Threshold to be attained to raise an alarm. "\
  53                 "If the audio level is under the threshold during this time, "\
  54                 "an alarm is sent (default 0.1)." )
  55 #define REPETITION_TIME_TEXT N_("Time between two alarm messages in ms" )
  56 #define REPETITION_TIME_LONGTEXT N_("Time between two alarm messages in ms. "\
  57                 "This value is used to avoid alarm saturation (default 2000)." )
  58
  59 #define CFG_PREFIX "audiobargraph_a-"
  60
  61 /*****************************************************************************
  62  * Module descriptor
  63  *****************************************************************************/
  64 static int  Open( vlc_object_t * );
  65 static void Close( filter_t * );
  66 static block_t *DoWork( filter_t *, block_t * );
  67
  68 vlc_module_begin ()
  69     set_description( N_("Audio part of the BarGraph function") )
  70     set_shortname( N_("Audiobar Graph") )
  71     set_capability( "audio filter", 0 )
  72     set_category( CAT_AUDIO )
  73     set_subcategory( SUBCAT_AUDIO_AFILTER )
  74
  75     add_obsolete_string( CFG_PREFIX "address" )
  76     add_obsolete_integer( CFG_PREFIX "port" )
  77     add_integer( CFG_PREFIX "bargraph", 1, BARGRAPH_TEXT, BARGRAPH_LONGTEXT, false ) // FIXME: this is a bool
  78     add_integer( CFG_PREFIX "bargraph_repetition", 4, BARGRAPH_REPETITION_TEXT, BARGRAPH_REPETITION_LONGTEXT, false )
  79     add_integer( CFG_PREFIX "silence", 1, SILENCE_TEXT, SILENCE_LONGTEXT, false ) // FIXME: this is a bool
  80     add_integer( CFG_PREFIX "time_window", 5000, TIME_WINDOW_TEXT, TIME_WINDOW_LONGTEXT, false )
  81     add_float( CFG_PREFIX "alarm_threshold", 0.02, ALARM_THRESHOLD_TEXT, ALARM_THRESHOLD_LONGTEXT, false )
  82     add_integer( CFG_PREFIX "repetition_time", 2000, REPETITION_TIME_TEXT, REPETITION_TIME_LONGTEXT, false )
  83     add_obsolete_integer( CFG_PREFIX "connection_reset" )
  84
  85     set_callback( Open )
  86 vlc_module_end ()
  87
  88 typedef struct ValueDate_t {
  89     float value;
  90     vlc_tick_t date;
  91     struct ValueDate_t* next;
  92 } ValueDate_t;
  93
  94 typedef struct
  95 {
  96     bool            bargraph;
  97     int             bargraph_repetition;
  98     bool            silence;
  99     vlc_tick_t      time_window;
 100     float           alarm_threshold;
 101     vlc_tick_t      repetition_time;
 102     int             counter;
 103     ValueDate_t*    first;
 104     ValueDate_t*    last;
 105     int             started;
 106     vlc_tick_t      lastAlarm;
 107 } filter_sys_t;
 108
 109 /*****************************************************************************
 110  * Open: open the visualizer
 111  *****************************************************************************/
 112 static int Open( vlc_object_t *p_this )
 113 {
 114     filter_t     *p_filter = (filter_t *)p_this;
 115     filter_sys_t *p_sys = p_filter->p_sys = malloc(sizeof(*p_sys));
 116     if (!p_sys)
 117         return VLC_ENOMEM;
 118
 119     static const char *const options[] = {
 120         "bargraph", "bargraph_repetition", "silence", "time_window",
 121         "alarm_threshold", "repetition_time", NULL
 122     };
 123     config_ChainParse(p_filter, CFG_PREFIX, options, p_filter->p_cfg);
 124
 125     p_sys->bargraph = !!var_CreateGetInteger(p_filter, CFG_PREFIX "bargraph");
 126     p_sys->bargraph_repetition = var_CreateGetInteger(p_filter, CFG_PREFIX "bargraph_repetition");
 127     p_sys->silence = !!var_CreateGetInteger(p_filter, CFG_PREFIX "silence");
 128     p_sys->time_window = VLC_TICK_FROM_MS( var_CreateGetInteger(p_filter, CFG_PREFIX "time_window") );
 129     p_sys->alarm_threshold = var_CreateGetFloat(p_filter, CFG_PREFIX "alarm_threshold");
 130     p_sys->repetition_time = VLC_TICK_FROM_MS( var_CreateGetInteger(p_filter, CFG_PREFIX "repetition_time") );
 131     p_sys->counter = 0;
 132     p_sys->first = NULL;
 133     p_sys->last = NULL;
 134     p_sys->started = 0;
 135     p_sys->lastAlarm = 0;
 136
 137     p_filter->fmt_in.audio.i_format = VLC_CODEC_FL32;
 138     aout_FormatPrepare(&p_filter->fmt_in.audio);
 139     p_filter->fmt_out.audio = p_filter->fmt_in.audio;
 140
 141     static const struct vlc_filter_operations filter_ops =
 142     {
 143         .filter_audio = DoWork, .close = Close,
 144     };
 145     p_filter->ops = &filter_ops;
 146
 147     vlc_object_t *vlc = VLC_OBJECT(vlc_object_instance(p_filter));
 148
 149     var_Create(vlc, "audiobargraph_v-alarm", VLC_VAR_BOOL);
 150     var_Create(vlc, "audiobargraph_v-i_values", VLC_VAR_STRING);
 151
 152     return VLC_SUCCESS;
 153 }
 154
 155 static void SendValues(filter_t *p_filter, float *value, int nbChannels)
 156 {
 157     char msg[256];
 158     size_t len = 0;
 159
 160     for (int i = 0; i < nbChannels; i++) {
 161         if (len >= sizeof (msg))
 162             break;
 163         len += snprintf(msg + len, sizeof (msg) - len, "%f:", value[i]);
 164     }
 165
 166     //msg_Dbg(p_filter, "values: %s", msg);
 167     var_SetString(vlc_object_instance(p_filter), "audiobargraph_v-i_values",
 168                   msg);
 169 }
 170
 171 /*****************************************************************************
 172  * DoWork: treat an audio buffer
 173  ****************************************************************************/
 174 static block_t *DoWork( filter_t *p_filter, block_t *p_in_buf )
 175 {
 176     filter_sys_t *p_sys = p_filter->p_sys;
 177     float *p_sample = (float *)p_in_buf->p_buffer;
 178     float i_value[AOUT_CHAN_MAX];
 179
 180     int nbChannels = aout_FormatNbChannels(&p_filter->fmt_in.audio);
 181
 182     for (int i = 0; i < nbChannels; i++)
 183         i_value[i] = 0.;
 184
 185     /* 1 - Compute the peak values */
 186     for (size_t i = 0; i < p_in_buf->i_nb_samples; i++)
 187         for (int j = 0; j<nbChannels; j++) {
 188             float ch = *p_sample++;
 189             if (ch > i_value[j])
 190                 i_value[j] = ch;
 191         }
 192
 193     if (p_sys->silence) {
 194         /* 2 - store the new value */
 195         ValueDate_t *new = xmalloc(sizeof(*new));
 196         new->value = 0.0;
 197         for (int j = 0; j<nbChannels; j++) {
 198             float ch = i_value[j];
 199             if (ch > new->value)
 200                 new->value = ch;
 201         }
 202         new->value *= new->value;
 203         new->date = p_in_buf->i_pts;
 204         new->next = NULL;
 205         if (p_sys->last != NULL)
 206             p_sys->last->next = new;
 207         p_sys->last = new;
 208         if (p_sys->first == NULL)
 209             p_sys->first = new;
 210
 211         /* 3 - delete too old values */
 212         while (p_sys->first->date < new->date - p_sys->time_window) {
 213             p_sys->started = 1; // we have enough values to compute a valid total
 214             ValueDate_t *current = p_sys->first;
 215             p_sys->first = p_sys->first->next;
 216             free(current);
 217         }
 218
 219         /* If last message was sent enough time ago */
 220         if (p_sys->started && p_in_buf->i_pts > p_sys->lastAlarm + p_sys->repetition_time) {
 221
 222             /* 4 - compute the RMS */
 223             ValueDate_t *current = p_sys->first;
 224             float sum = 0.0;
 225             int count = 0;
 226             while (current != NULL) {
 227                 sum += current->value;
 228                 count++;
 229                 current = current->next;
 230             }
 231             sum /= count;
 232             sum = sqrtf(sum);
 233
 234             /* 5 - compare it to the threshold */
 235             var_SetBool(vlc_object_instance(p_filter), "audiobargraph_v-alarm",
 236                         sum < p_sys->alarm_threshold);
 237
 238             p_sys->lastAlarm = p_in_buf->i_pts;
 239         }
 240     }
 241
 242     if (p_sys->bargraph && nbChannels > 0 && p_sys->counter++ > p_sys->bargraph_repetition) {
 243         SendValues(p_filter, i_value, nbChannels);
 244         p_sys->counter = 0;
 245     }
 246
 247     return p_in_buf;
 248 }
 249
 250 /*****************************************************************************
 251  * Close: close the plugin
 252  *****************************************************************************/
 253 static void Close( filter_t * p_filter )
 254 {
 255     filter_sys_t *p_sys = p_filter->p_sys;
 256     vlc_object_t *vlc = VLC_OBJECT(vlc_object_instance(p_filter));
 257
 258     var_Destroy(vlc, "audiobargraph_v-i_values");
 259     var_Destroy(vlc, "audiobargraph_v-alarm");
 260
 261     while (p_sys->first != NULL) {
 262         ValueDate_t *current = p_sys->first;
 263         p_sys->first = p_sys->first->next;
 264         free(current);
 265     }
 266     free(p_sys);
 267 }