modules/audio_filter/audiobargraph_a.c

   1 /*****************************************************************************
   2  * audiobargraph_a.c : audiobargraph audio plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2002-2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Clement CHESNIN <clement.chesnin@gmail.com>
   8  *          Philippe COENT <philippe.coent@tdf.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_aout.h>
  35 #include <vlc_filter.h>
  36
  37 #include <math.h>
  38
  39 #define BARGRAPH_TEXT N_("Defines if BarGraph information should be sent")
  40 #define BARGRAPH_LONGTEXT N_("Defines if BarGraph information should be sent. "\
  41                 "1 if the information should be sent, 0 otherwise (default 1)." )
  42 #define BARGRAPH_REPETITION_TEXT N_("Sends the barGraph information every n audio packets")
  43 #define BARGRAPH_REPETITION_LONGTEXT N_("Defines how often the barGraph information should be sent. "\
  44                 "Sends the barGraph information every n audio packets (default 4)." )
  45 #define SILENCE_TEXT N_("Defines if silence alarm information should be sent")
  46 #define SILENCE_LONGTEXT N_("Defines if silence alarm information should be sent. "\
  47                 "1 if the information should be sent, 0 otherwise (default 1)." )
  48 #define TIME_WINDOW_TEXT N_("Time window to use in ms")
  49 #define TIME_WINDOW_LONGTEXT N_("Time Window during when the audio level is measured in ms for silence detection. "\
  50                 "If the audio level is under the threshold during this time, "\
  51                 "an alarm is sent (default 5000)." )
  52 #define ALARM_THRESHOLD_TEXT N_("Minimum Audio level to raise the alarm")
  53 #define ALARM_THRESHOLD_LONGTEXT N_("Threshold to be attained to raise an alarm. "\
  54                 "If the audio level is under the threshold during this time, "\
  55                 "an alarm is sent (default 0.1)." )
  56 #define REPETITION_TIME_TEXT N_("Time between two alarm messages in ms" )
  57 #define REPETITION_TIME_LONGTEXT N_("Time between two alarm messages in ms. "\
  58                 "This value is used to avoid alarm saturation (default 2000)." )
  59
  60 #define CFG_PREFIX "audiobargraph_a-"
  61
  62 /*****************************************************************************
  63  * Module descriptor
  64  *****************************************************************************/
  65 static int  Open( vlc_object_t * );
  66 static void Close( vlc_object_t * );
  67 static block_t *DoWork( filter_t *, block_t * );
  68
  69 vlc_module_begin ()
  70     set_description( N_("Audio part of the BarGraph function") )
  71     set_shortname( N_("Audiobar Graph") )
  72     set_capability( "audio filter", 0 )
  73     set_category( CAT_AUDIO )
  74     set_subcategory( SUBCAT_AUDIO_AFILTER )
  75
  76     add_obsolete_string( CFG_PREFIX "address" )
  77     add_obsolete_integer( CFG_PREFIX "port" )
  78     add_integer( CFG_PREFIX "bargraph", 1, BARGRAPH_TEXT, BARGRAPH_LONGTEXT, false ) // FIXME: this is a bool
  79     add_integer( CFG_PREFIX "bargraph_repetition", 4, BARGRAPH_REPETITION_TEXT, BARGRAPH_REPETITION_LONGTEXT, false )
  80     add_integer( CFG_PREFIX "silence", 1, SILENCE_TEXT, SILENCE_LONGTEXT, false ) // FIXME: this is a bool
  81     add_integer( CFG_PREFIX "time_window", 5000, TIME_WINDOW_TEXT, TIME_WINDOW_LONGTEXT, false )
  82     add_float( CFG_PREFIX "alarm_threshold", 0.1, ALARM_THRESHOLD_TEXT, ALARM_THRESHOLD_LONGTEXT, false )
  83     add_integer( CFG_PREFIX "repetition_time", 2000, REPETITION_TIME_TEXT, REPETITION_TIME_LONGTEXT, false )
  84     add_obsolete_integer( CFG_PREFIX "connection_reset" )
  85
  86     set_callbacks( Open, Close )
  87 vlc_module_end ()
  88
  89 typedef struct ValueDate_t {
  90     float value;
  91     mtime_t date;
  92     struct ValueDate_t* next;
  93 } ValueDate_t;
  94
  95 struct filter_sys_t
  96 {
  97     bool            bargraph;
  98     int             bargraph_repetition;
  99     bool            silence;
 100     int64_t         time_window;
 101     float           alarm_threshold;
 102     int64_t         repetition_time;
 103     int             counter;
 104     ValueDate_t*    first;
 105     ValueDate_t*    last;
 106     int             started;
 107     mtime_t         lastAlarm;
 108 };
 109
 110 /*****************************************************************************
 111  * Open: open the visualizer
 112  *****************************************************************************/
 113 static int Open( vlc_object_t *p_this )
 114 {
 115     filter_t     *p_filter = (filter_t *)p_this;
 116     filter_sys_t *p_sys = p_filter->p_sys = malloc( sizeof( *p_sys ) );
 117     if( !p_sys )
 118         return VLC_ENOMEM;
 119
 120     p_sys->bargraph = !!var_CreateGetInteger( p_filter, CFG_PREFIX "bargraph" );
 121     p_sys->bargraph_repetition = var_CreateGetInteger( p_filter, CFG_PREFIX "bargraph_repetition" );
 122     p_sys->silence = !!var_CreateGetInteger( p_filter, CFG_PREFIX "silence" );
 123     p_sys->time_window = var_CreateGetInteger( p_filter, CFG_PREFIX "time_window" ) * 1000;
 124     p_sys->alarm_threshold = var_CreateGetFloat( p_filter, CFG_PREFIX "alarm_threshold" );
 125     p_sys->repetition_time = var_CreateGetInteger( p_filter, CFG_PREFIX "repetition_time" ) * 1000;
 126     p_sys->counter = 0;
 127     p_sys->first = NULL;
 128     p_sys->last = NULL;
 129     p_sys->started = 0;
 130     p_sys->lastAlarm = 0;
 131
 132     p_filter->fmt_in.audio.i_format = VLC_CODEC_FL32;
 133     p_filter->fmt_out.audio = p_filter->fmt_in.audio;
 134     p_filter->pf_audio_filter = DoWork;
 135
 136     var_Create( p_filter->p_libvlc, "audiobargraph_v-alarm", VLC_VAR_BOOL );
 137     var_Create( p_filter->p_libvlc, "audiobargraph_v-i_values", VLC_VAR_STRING );
 138
 139     return VLC_SUCCESS;
 140 }
 141
 142 /*****************************************************************************
 143  * DoWork: treat an audio buffer
 144  ****************************************************************************/
 145 static block_t *DoWork( filter_t *p_filter, block_t *p_in_buf )
 146 {
 147     filter_sys_t *p_sys = p_filter->p_sys;
 148     float *p_sample = (float *)p_in_buf->p_buffer;
 149     float i_value[AOUT_CHAN_MAX];
 150
 151     int nbChannels = aout_FormatNbChannels(&p_filter->fmt_in.audio);
 152
 153     for (int i = 0; i < nbChannels; i++)
 154         i_value[i] = 0.;
 155
 156     /* 1 - Compute the peak values */
 157     float max = 0.0;
 158     for (size_t i = 0; i < p_in_buf->i_nb_samples; i++) {
 159         for (int j = 0; j<nbChannels; j++) {
 160             float ch = (*p_sample++);
 161             if (ch > i_value[j])
 162                 i_value[j] = ch;
 163             if (ch > max)
 164                 max = ch;
 165         }
 166     }
 167     max *= max;
 168
 169     if (p_sys->silence) {
 170         /* 2 - store the new value */
 171         ValueDate_t *new = xmalloc(sizeof(*new));
 172         new->value = max;
 173         new->date = p_in_buf->i_pts;
 174         new->next = NULL;
 175         if (p_sys->last != NULL)
 176             p_sys->last->next = new;
 177         p_sys->last = new;
 178         if (p_sys->first == NULL)
 179             p_sys->first = new;
 180
 181         /* 3 - delete too old values */
 182         while (p_sys->first->date < new->date - p_sys->time_window) {
 183             p_sys->started = 1; // we have enough values to compute a valid total
 184             ValueDate_t *current = p_sys->first;
 185             p_sys->first = p_sys->first->next;
 186             free(current);
 187         }
 188
 189         /* If last message was sent enough time ago */
 190         if (p_sys->started && p_in_buf->i_pts > p_sys->lastAlarm + p_sys->repetition_time) {
 191
 192             /* 4 - compute the RMS */
 193             ValueDate_t *current = p_sys->first;
 194             float sum = 0.0;
 195             int count = 0;
 196             while (current != NULL) {
 197                 sum += current->value;
 198                 count++;
 199                 current = current->next;
 200             }
 201             sum /= count;
 202             sum = sqrtf(sum);
 203
 204             /* 5 - compare it to the threshold */
 205             var_SetBool(p_filter->p_libvlc, "audiobargraph_v-alarm",
 206                         sum < p_sys->alarm_threshold);
 207
 208             p_sys->lastAlarm = p_in_buf->i_pts;
 209         }
 210     }
 211
 212     if (p_sys->bargraph && nbChannels > 0 && p_sys->counter++ > p_sys->bargraph_repetition) {
 213         /* 6 - send the message with the values for the BarGraph */
 214         p_sys->counter = 0;
 215         char message[256];
 216         size_t j = 0;
 217
 218         for (int i = 0; i < nbChannels; i++) {
 219             if (j >= sizeof(message))
 220                 break;
 221             j += snprintf(message + j, sizeof (message),"%f:", i_value[i]);
 222         }
 223
 224         message[--j] = '\0';
 225         msg_Dbg(p_filter, "values: %s", message);
 226
 227         var_SetString(p_filter->p_libvlc, "audiobargraph_v-i_values",
 228                 message);
 229     }
 230
 231     return p_in_buf;
 232 }
 233
 234 /*****************************************************************************
 235  * Close: close the plugin
 236  *****************************************************************************/
 237 static void Close( vlc_object_t *p_this )
 238 {
 239     filter_t * p_filter = (filter_t *)p_this;
 240     filter_sys_t *p_sys = p_filter->p_sys;
 241
 242     var_Destroy( p_filter->p_libvlc, "audiobargraph_v-i_values" );
 243     var_Destroy( p_filter->p_libvlc, "audiobargraph_v-alarm" );
 244
 245     while (p_sys->first != NULL) {
 246         ValueDate_t *current = p_sys->first;
 247         p_sys->first = p_sys->first->next;
 248         free(current);
 249     }
 250     free( p_sys );
 251 }