Commit da38b336 authored by zorglub's avatar zorglub
Browse files

Added a very trivial volume normalizer

parent f8c95ffa
SOURCES_equalizer = equalizer.c
SOURCES_normvol = normvol.c
/*****************************************************************************
* normvol.c : volume normalizer
*****************************************************************************
* Copyright (C) 2001 VideoLAN
* $Id: equalizer.c,v 1.21 2003/07/31 23:44:49 zorglub Exp $
*
* Authors: Clment Stenac <zorglub@videolan.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*****************************************************************************/
/*
* TODO:
*
* We should detect fast power increases and react faster to these
* This way, we can increase the buffer size to get a more stable filter */
/*****************************************************************************
* Preamble
*****************************************************************************/
#include <stdlib.h> /* malloc(), free() */
#include <string.h>
#include <errno.h> /* ENOMEM */
#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#include <math.h>
#include <vlc/vlc.h>
#include <vlc/aout.h>
#include <aout_internal.h>
/*****************************************************************************
* Local prototypes
*****************************************************************************/
static int Open ( vlc_object_t * );
static void Close ( vlc_object_t * );
static void DoWork ( aout_instance_t * , aout_filter_t *,
aout_buffer_t * , aout_buffer_t *);
struct aout_filter_sys_t {
int i_nb;
float *p_last;
float f_max;
};
/*****************************************************************************
* Module descriptor
*****************************************************************************/
#define BUFF_TEXT N_("Number of audio buffers" )
#define BUFF_LONGTEXT N_("This is the number of audio buffers on which the " \
"power measurement is made. A higher number of buffers will " \
"increase the response time of the filter to a high " \
"power but will make it less sensitive to short variations " )
#define LEVEL_TEXT N_("Max level" )
#define LEVEL_LONGTEXT N_("If the average power over the last N buffers " \
"is higher than this value, the volume will be normalized." \
"This value is a positive floating point number. A value " \
"between 0.5 and 10 seems sensible." )
vlc_module_begin();
set_description( _("Volume normalizer") );
add_shortcut("volnorm");
add_integer("norm-buff-size" , 20 , NULL , BUFF_TEXT, BUFF_LONGTEXT,
VLC_TRUE);
add_float("norm-max-level",2.0,NULL,"pouet","pouetpouet",VLC_TRUE);
set_capability( "audio filter", 0 );
set_callbacks( Open, Close );
vlc_module_end();
/*****************************************************************************
* Open: initialize and create stuff
*****************************************************************************/
static int Open( vlc_object_t *p_this )
{
aout_filter_t *p_filter = (aout_filter_t*)p_this;
struct aout_filter_sys_t *p_sys = p_filter->p_sys =
malloc( sizeof( struct aout_filter_sys_t ) );
if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2' ) ||
p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
{
msg_Warn( p_filter, "Bad input or output format" );
return VLC_EGENERIC;
}
if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
{
msg_Warn( p_filter, "input and output formats are not similar" );
return VLC_EGENERIC;
}
p_filter->pf_do_work = DoWork;
p_filter->b_in_place = VLC_TRUE;
int i_channels = aout_FormatNbChannels( &p_filter->input );
p_sys->i_nb = var_CreateGetInteger( p_filter->p_parent, "norm-buff-size" );
p_sys->f_max = var_CreateGetFloat( p_filter->p_parent, "norm-max-level" );
if( p_sys->f_max <= 0 )
{
p_sys->f_max = 0.01;
}
/* We need to store (nb_buffers+1)*nb_channels floats */
p_sys->p_last = malloc( sizeof( float ) * (i_channels) *
(p_filter->p_sys->i_nb + 2) );
memset( p_sys->p_last, 0 , sizeof( float ) * (i_channels) *
(p_filter->p_sys->i_nb + 2) );
return VLC_SUCCESS;
}
/*****************************************************************************
* DoWork : normalizes and sends a buffer
*****************************************************************************/
static void DoWork( aout_instance_t *p_aout, aout_filter_t *p_filter,
aout_buffer_t *p_in_buf, aout_buffer_t *p_out_buf )
{
float *pf_sum;
float *pf_gain;
float f_average = 0;
int i, i_chan;
int i_samples = p_in_buf->i_nb_samples;
int i_channels = aout_FormatNbChannels( &p_filter->input );
float *p_out = (float*)p_out_buf->p_buffer;
float *p_in = (float*)p_in_buf->p_buffer;
struct aout_filter_sys_t *p_sys = p_filter->p_sys;
pf_sum = (float *)malloc( sizeof(float) * i_channels );
memset( pf_sum, 0, sizeof(float) * i_channels );
pf_gain = (float *)malloc( sizeof(float) * i_channels );
p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes;
/* Calculate the average power level on this buffer */
for( i = 0 ; i < i_samples; i++ )
{
for( i_chan = 0; i_chan < i_channels; i_chan++ )
{
float f_sample = p_in[i_chan];
float f_square = pow( f_sample, 2 );
pf_sum[i_chan] += f_square;
}
p_in += i_channels;
}
/* sum now contains for each channel the sigma(value) */
for( i_chan = 0; i_chan < i_channels; i_chan++ )
{
/* Shift our lastbuff */
memmove( &p_sys->p_last[ i_chan * p_sys->i_nb],
&p_sys->p_last[i_chan * p_sys->i_nb + 1],
(p_sys->i_nb-1) * sizeof( float ) );
/* Insert the new average : sqrt(sigma(value)) */
p_sys->p_last[ i_chan * p_sys->i_nb + p_sys->i_nb - 1] =
sqrt( pf_sum[i_chan] );
pf_sum[i_chan] = 0;
/* Get the average power on the lastbuff */
f_average = 0;
for( i = 0; i < p_sys->i_nb ; i++)
{
f_average += p_sys->p_last[ i_chan * p_sys->i_nb + i ];
}
f_average = f_average / p_sys->i_nb;
/* Seuil arbitraire */
p_sys->f_max = var_GetFloat( p_aout, "norm-max-level" );
// fprintf(stderr,"Average %f, max %f\n", f_average, p_sys->f_max );
if( f_average > p_sys->f_max )
{
pf_gain[i_chan] = f_average / p_sys->f_max;
}
else
{
pf_gain[i_chan] = 1;
}
}
/* Apply gain */
for( i = 0 ; i < i_samples ; i++)
{
for( i_chan = 0; i_chan < i_channels; i_chan++ )
{
p_out[i_chan] /= pf_gain[i_chan];
}
p_out += i_channels;
}
free( pf_sum );
free( pf_gain );
return;
}
/**********************************************************************
* Close
**********************************************************************/
static void Close( vlc_object_t *p_this )
{
aout_filter_t *p_filter = (aout_filter_t*)p_this;
struct aout_filter_sys_t *p_sys = p_filter->p_sys;
if( p_sys )
{
if( p_sys->p_last)
{
free( p_sys->p_last );
}
free( p_sys );
}
}
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment