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  * $Id$
   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", 0.02, 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     vlc_tick_t date;
  92     struct ValueDate_t* next;
  93 } ValueDate_t;
  94
  95 typedef struct
  96 {
  97     bool            bargraph;
  98     int             bargraph_repetition;
  99     bool            silence;
 100     vlc_tick_t      time_window;
 101     float           alarm_threshold;
 102     vlc_tick_t      repetition_time;
 103     int             counter;
 104     ValueDate_t*    first;
 105     ValueDate_t*    last;
 106     int             started;
 107     vlc_tick_t      lastAlarm;
 108 } filter_sys_t;
 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     static const char *const options[] = {
 121         "bargraph", "bargraph_repetition", "silence", "time_window",
 122         "alarm_threshold", "repetition_time", NULL
 123     };
 124     config_ChainParse(p_filter, CFG_PREFIX, options, p_filter->p_cfg);
 125
 126     p_sys->bargraph = !!var_CreateGetInteger(p_filter, CFG_PREFIX "bargraph");
 127     p_sys->bargraph_repetition = var_CreateGetInteger(p_filter, CFG_PREFIX "bargraph_repetition");
 128     p_sys->silence = !!var_CreateGetInteger(p_filter, CFG_PREFIX "silence");
 129     p_sys->time_window = VLC_TICK_FROM_MS( var_CreateGetInteger(p_filter, CFG_PREFIX "time_window") );
 130     p_sys->alarm_threshold = var_CreateGetFloat(p_filter, CFG_PREFIX "alarm_threshold");
 131     p_sys->repetition_time = VLC_TICK_FROM_MS( var_CreateGetInteger(p_filter, CFG_PREFIX "repetition_time") );
 132     p_sys->counter = 0;
 133     p_sys->first = NULL;
 134     p_sys->last = NULL;
 135     p_sys->started = 0;
 136     p_sys->lastAlarm = 0;
 137
 138     p_filter->fmt_in.audio.i_format = VLC_CODEC_FL32;
 139     aout_FormatPrepare(&p_filter->fmt_in.audio);
 140     p_filter->fmt_out.audio = p_filter->fmt_in.audio;
 141     p_filter->pf_audio_filter = DoWork;
 142
 143     var_Create(p_filter->obj.libvlc, "audiobargraph_v-alarm", VLC_VAR_BOOL);
 144     var_Create(p_filter->obj.libvlc, "audiobargraph_v-i_values", VLC_VAR_STRING);
 145
 146     return VLC_SUCCESS;
 147 }
 148
 149 static void SendValues(filter_t *p_filter, float *value, int nbChannels)
 150 {
 151     char msg[256];
 152     size_t len = 0;
 153
 154     for (int i = 0; i < nbChannels; i++) {
 155         if (len >= sizeof (msg))
 156             break;
 157         len += snprintf(msg + len, sizeof (msg) - len, "%f:", value[i]);
 158     }
 159
 160     //msg_Dbg(p_filter, "values: %s", msg);
 161     var_SetString(p_filter->obj.libvlc, "audiobargraph_v-i_values", msg);
 162 }
 163
 164 /*****************************************************************************
 165  * DoWork: treat an audio buffer
 166  ****************************************************************************/
 167 static block_t *DoWork( filter_t *p_filter, block_t *p_in_buf )
 168 {
 169     filter_sys_t *p_sys = p_filter->p_sys;
 170     float *p_sample = (float *)p_in_buf->p_buffer;
 171     float i_value[AOUT_CHAN_MAX];
 172
 173     int nbChannels = aout_FormatNbChannels(&p_filter->fmt_in.audio);
 174
 175     for (int i = 0; i < nbChannels; i++)
 176         i_value[i] = 0.;
 177
 178     /* 1 - Compute the peak values */
 179     for (size_t i = 0; i < p_in_buf->i_nb_samples; i++)
 180         for (int j = 0; j<nbChannels; j++) {
 181             float ch = *p_sample++;
 182             if (ch > i_value[j])
 183                 i_value[j] = ch;
 184         }
 185
 186     if (p_sys->silence) {
 187         /* 2 - store the new value */
 188         ValueDate_t *new = xmalloc(sizeof(*new));
 189         new->value = 0.0;
 190         for (int j = 0; j<nbChannels; j++) {
 191             float ch = i_value[j];
 192             if (ch > new->value)
 193                 new->value = ch;
 194         }
 195         new->value *= new->value;
 196         new->date = p_in_buf->i_pts;
 197         new->next = NULL;
 198         if (p_sys->last != NULL)
 199             p_sys->last->next = new;
 200         p_sys->last = new;
 201         if (p_sys->first == NULL)
 202             p_sys->first = new;
 203
 204         /* 3 - delete too old values */
 205         while (p_sys->first->date < new->date - p_sys->time_window) {
 206             p_sys->started = 1; // we have enough values to compute a valid total
 207             ValueDate_t *current = p_sys->first;
 208             p_sys->first = p_sys->first->next;
 209             free(current);
 210         }
 211
 212         /* If last message was sent enough time ago */
 213         if (p_sys->started && p_in_buf->i_pts > p_sys->lastAlarm + p_sys->repetition_time) {
 214
 215             /* 4 - compute the RMS */
 216             ValueDate_t *current = p_sys->first;
 217             float sum = 0.0;
 218             int count = 0;
 219             while (current != NULL) {
 220                 sum += current->value;
 221                 count++;
 222                 current = current->next;
 223             }
 224             sum /= count;
 225             sum = sqrtf(sum);
 226
 227             /* 5 - compare it to the threshold */
 228             var_SetBool(p_filter->obj.libvlc, "audiobargraph_v-alarm",
 229                         sum < p_sys->alarm_threshold);
 230
 231             p_sys->lastAlarm = p_in_buf->i_pts;
 232         }
 233     }
 234
 235     if (p_sys->bargraph && nbChannels > 0 && p_sys->counter++ > p_sys->bargraph_repetition) {
 236         SendValues(p_filter, i_value, nbChannels);
 237         p_sys->counter = 0;
 238     }
 239
 240     return p_in_buf;
 241 }
 242
 243 /*****************************************************************************
 244  * Close: close the plugin
 245  *****************************************************************************/
 246 static void Close( vlc_object_t *p_this )
 247 {
 248     filter_t * p_filter = (filter_t *)p_this;
 249     filter_sys_t *p_sys = p_filter->p_sys;
 250
 251     var_Destroy(p_filter->obj.libvlc, "audiobargraph_v-i_values");
 252     var_Destroy(p_filter->obj.libvlc, "audiobargraph_v-alarm");
 253
 254     while (p_sys->first != NULL) {
 255         ValueDate_t *current = p_sys->first;
 256         p_sys->first = p_sys->first->next;
 257         free(current);
 258     }
 259     free(p_sys);
 260 }