mirror of
https://code.videolan.org/videolan/vlc
synced 2024-09-04 09:11:33 +02:00
327 lines
11 KiB
C
327 lines
11 KiB
C
/*****************************************************************************
|
|
* chorus_flanger.c
|
|
*****************************************************************************
|
|
* Copyright (C) 2009 the VideoLAN team
|
|
* $Id$
|
|
*
|
|
* Author: Srikanth Raju < srikiraju at gmail dot com >
|
|
*
|
|
* 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
|
|
*****************************************************************************/
|
|
|
|
/**
|
|
* Basic chorus/flanger/delay audio filter
|
|
* This implements a variable delay filter for VLC. It has some issues with
|
|
* interpolation and sounding 'correct'.
|
|
*/
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#include <math.h>
|
|
|
|
#include <vlc_common.h>
|
|
#include <vlc_plugin.h>
|
|
|
|
#include <vlc_aout.h>
|
|
#include <vlc_filter.h>
|
|
|
|
/*****************************************************************************
|
|
* Local prototypes
|
|
*****************************************************************************/
|
|
|
|
static int Open ( vlc_object_t * );
|
|
static void Close ( vlc_object_t * );
|
|
static block_t *DoWork( filter_t *, block_t * );
|
|
|
|
struct filter_sys_t
|
|
{
|
|
/* TODO: Cleanup and optimise */
|
|
int i_cumulative;
|
|
int i_channels, i_sampleRate;
|
|
float f_delayTime, f_feedbackGain; /* delayTime is in milliseconds */
|
|
float f_wetLevel, f_dryLevel;
|
|
float f_sweepDepth, f_sweepRate;
|
|
|
|
float f_step,f_offset;
|
|
int i_step,i_offset;
|
|
float f_temp;
|
|
float f_sinMultiplier;
|
|
|
|
/* This data is for the the circular queue which stores the samples. */
|
|
int i_bufferLength;
|
|
float * pf_delayLineStart, * pf_delayLineEnd;
|
|
float * pf_write;
|
|
};
|
|
|
|
/*****************************************************************************
|
|
* Module descriptor
|
|
*****************************************************************************/
|
|
|
|
|
|
vlc_module_begin ()
|
|
set_description( N_("Sound Delay") )
|
|
set_shortname( N_("Delay") )
|
|
set_help( N_("Add a delay effect to the sound") )
|
|
set_category( CAT_AUDIO )
|
|
set_subcategory( SUBCAT_AUDIO_AFILTER )
|
|
add_shortcut( "delay" )
|
|
add_float( "delay-time", 40, NULL, N_("Delay time"),
|
|
N_("Time in milliseconds of the average delay. Note average"), true )
|
|
add_float( "sweep-depth", 6, NULL, N_("Sweep Depth"),
|
|
N_("Time in milliseconds of the maximum sweep depth. Thus, the sweep "
|
|
"range will be delay-time +/- sweep-depth."), true )
|
|
add_float( "sweep-rate", 6, NULL, N_("Sweep Rate"),
|
|
N_("Rate of change of sweep depth in milliseconds shift per second "
|
|
"of play"), true )
|
|
add_float_with_range( "feedback-gain", 0.5, -0.9, 0.9, NULL,
|
|
N_("Feedback Gain"), N_("Gain on Feedback loop"), true )
|
|
add_float_with_range( "wet-mix", 0.4, -0.999, 0.999, NULL,
|
|
N_("Wet mix"), N_("Level of delayed signal"), true )
|
|
add_float_with_range( "dry-mix", 0.4, -0.999, 0.999, NULL,
|
|
N_("Dry Mix"), N_("Level of input signal"), true )
|
|
set_capability( "audio filter", 0 )
|
|
set_callbacks( Open, Close )
|
|
vlc_module_end ()
|
|
|
|
/**
|
|
* small_value: Helper function
|
|
* return high pass cutoff
|
|
*/
|
|
static inline float small_value()
|
|
{
|
|
/* allows for 2^-24, should be enough for 24-bit DACs at least */
|
|
return ( 1.0 / 16777216.0 );
|
|
}
|
|
|
|
/**
|
|
* Open: initialize and create stuff
|
|
* @param p_this
|
|
*/
|
|
static int Open( vlc_object_t *p_this )
|
|
{
|
|
filter_t *p_filter = (filter_t*)p_this;
|
|
filter_sys_t *p_sys;
|
|
|
|
if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
|
|
{
|
|
msg_Err( p_filter, "input and output formats are not similar" );
|
|
return VLC_EGENERIC;
|
|
}
|
|
|
|
if( p_filter->fmt_in.audio.i_format != VLC_CODEC_FL32 ||
|
|
p_filter->fmt_out.audio.i_format != VLC_CODEC_FL32 )
|
|
{
|
|
p_filter->fmt_in.audio.i_format = VLC_CODEC_FL32;
|
|
p_filter->fmt_out.audio.i_format = VLC_CODEC_FL32;
|
|
msg_Warn( p_filter, "bad input or output format" );
|
|
}
|
|
|
|
p_filter->pf_audio_filter = DoWork;
|
|
|
|
p_sys = p_filter->p_sys = malloc( sizeof( *p_sys ) );
|
|
if( !p_sys )
|
|
return VLC_ENOMEM;
|
|
|
|
p_sys->i_channels = aout_FormatNbChannels( &p_filter->fmt_in.audio );
|
|
p_sys->f_delayTime = var_CreateGetFloat( p_this, "delay-time" );
|
|
p_sys->f_sweepDepth = var_CreateGetFloat( p_this, "sweep-depth" );
|
|
p_sys->f_sweepRate = var_CreateGetFloat( p_this, "sweep-rate" );
|
|
p_sys->f_feedbackGain = var_CreateGetFloat( p_this, "feedback-gain" );
|
|
p_sys->f_dryLevel = var_CreateGetFloat( p_this, "dry-mix" );
|
|
p_sys->f_wetLevel = var_CreateGetFloat( p_this, "wet-mix" );
|
|
|
|
if( p_sys->f_delayTime < 0.0)
|
|
{
|
|
msg_Err( p_filter, "Delay Time is invalid" );
|
|
free(p_sys);
|
|
return VLC_EGENERIC;
|
|
}
|
|
|
|
if( p_sys->f_sweepDepth > p_sys->f_delayTime || p_sys->f_sweepDepth < 0.0 )
|
|
{
|
|
msg_Err( p_filter, "Sweep Depth is invalid" );
|
|
free( p_sys );
|
|
return VLC_EGENERIC;
|
|
}
|
|
|
|
if( p_sys->f_sweepRate < 0.0 )
|
|
{
|
|
msg_Err( p_filter, "Sweep Rate is invalid" );
|
|
free( p_sys );
|
|
return VLC_EGENERIC;
|
|
}
|
|
|
|
/* Max delay = delay + depth. Min = delay - depth */
|
|
p_sys->i_bufferLength = p_sys->i_channels * ( (int)( ( p_sys->f_delayTime
|
|
+ p_sys->f_sweepDepth ) * p_filter->fmt_in.audio.i_rate/1000 ) + 1 );
|
|
|
|
msg_Dbg( p_filter , "Buffer length:%d, Channels:%d, Sweep Depth:%f, Delay "
|
|
"time:%f, Sweep Rate:%f, Sample Rate: %d", p_sys->i_bufferLength,
|
|
p_sys->i_channels, p_sys->f_sweepDepth, p_sys->f_delayTime,
|
|
p_sys->f_sweepRate, p_filter->fmt_in.audio.i_rate );
|
|
if( p_sys->i_bufferLength <= 0 )
|
|
{
|
|
msg_Err( p_filter, "Delay-time, Sampl rate or Channels was incorrect" );
|
|
free(p_sys);
|
|
return VLC_EGENERIC;
|
|
}
|
|
|
|
p_sys->pf_delayLineStart = calloc( p_sys->i_bufferLength, sizeof( float ) );
|
|
if( !p_sys->pf_delayLineStart )
|
|
{
|
|
free( p_sys );
|
|
return VLC_ENOMEM;
|
|
}
|
|
|
|
p_sys->i_cumulative = 0;
|
|
p_sys->f_step = p_sys->f_sweepRate / 1000.0;
|
|
p_sys->i_step = p_sys->f_sweepRate > 0 ? 1 : 0;
|
|
p_sys->f_offset = 0;
|
|
p_sys->i_offset = 0;
|
|
p_sys->f_temp = 0;
|
|
|
|
p_sys->pf_delayLineEnd = p_sys->pf_delayLineStart + p_sys->i_bufferLength;
|
|
p_sys->pf_write = p_sys->pf_delayLineStart;
|
|
|
|
if( p_sys->f_sweepDepth < small_value() ||
|
|
p_filter->fmt_in.audio.i_rate < small_value() ) {
|
|
p_sys->f_sinMultiplier = 0.0;
|
|
}
|
|
else {
|
|
p_sys->f_sinMultiplier = 11 * p_sys->f_sweepRate /
|
|
( 7 * p_sys->f_sweepDepth * p_filter->fmt_in.audio.i_rate ) ;
|
|
}
|
|
p_sys->i_sampleRate = p_filter->fmt_in.audio.i_rate;
|
|
|
|
return VLC_SUCCESS;
|
|
}
|
|
|
|
|
|
/**
|
|
* sanitize: Helper function to eliminate small amplitudes
|
|
* @param f_value pointer to value to clean
|
|
*/
|
|
static inline void sanitize( float * f_value )
|
|
{
|
|
if ( fabs( *f_value ) < small_value() )
|
|
*f_value = 0.0f;
|
|
}
|
|
|
|
|
|
/**
|
|
* DoWork : delays and finds the value of the current frame
|
|
* @param p_filter This filter object
|
|
* @param p_in_buf Input buffer
|
|
* @return Output buffer
|
|
*/
|
|
static block_t *DoWork( filter_t *p_filter, block_t *p_in_buf )
|
|
{
|
|
struct filter_sys_t *p_sys = p_filter->p_sys;
|
|
int i_chan;
|
|
unsigned i_samples = p_in_buf->i_nb_samples; /* number of samples */
|
|
/* maximum number of samples to offset in buffer */
|
|
int i_maxOffset = floor( p_sys->f_sweepDepth * p_sys->i_sampleRate / 1000 );
|
|
float *p_out = (float*)p_in_buf->p_buffer;
|
|
float *p_in = (float*)p_in_buf->p_buffer;
|
|
|
|
float *pf_ptr, f_diff = 0, f_frac = 0, f_temp = 0 ;
|
|
|
|
/* Process each sample */
|
|
for( unsigned i = 0; i < i_samples ; i++ )
|
|
{
|
|
/* Use a sine function as a oscillator wave. TODO */
|
|
/* f_offset = sinf( ( p_sys->i_cumulative ) * p_sys->f_sinMultiplier ) *
|
|
* (int)floor(p_sys->f_sweepDepth * p_sys->i_sampleRate / 1000);
|
|
*/
|
|
|
|
/* Triangle oscillator. Step using ints, because floats give rounding */
|
|
p_sys->i_offset+=p_sys->i_step;
|
|
p_sys->f_offset = p_sys->i_offset * p_sys->f_step;
|
|
if( abs( p_sys->i_step ) > 0 )
|
|
{
|
|
if( p_sys->i_offset >= floor( p_sys->f_sweepDepth *
|
|
p_sys->i_sampleRate / p_sys->f_sweepRate ))
|
|
{
|
|
p_sys->f_offset = i_maxOffset;
|
|
p_sys->i_step = -1 * ( p_sys->i_step );
|
|
}
|
|
if( p_sys->i_offset <= floor( -1 * p_sys->f_sweepDepth *
|
|
p_sys->i_sampleRate / p_sys->f_sweepRate ) )
|
|
{
|
|
p_sys->f_offset = -i_maxOffset;
|
|
p_sys->i_step = -1 * ( p_sys->i_step );
|
|
}
|
|
}
|
|
/* Calculate position in delay */
|
|
int offset = floor( p_sys->f_offset );
|
|
pf_ptr = p_sys->pf_write + i_maxOffset * p_sys->i_channels +
|
|
offset * p_sys->i_channels;
|
|
|
|
/* Handle Overflow */
|
|
if( pf_ptr < p_sys->pf_delayLineStart )
|
|
{
|
|
pf_ptr += p_sys->i_bufferLength - p_sys->i_channels;
|
|
}
|
|
if( pf_ptr > p_sys->pf_delayLineEnd - 2*p_sys->i_channels )
|
|
{
|
|
pf_ptr -= p_sys->i_bufferLength - p_sys->i_channels;
|
|
}
|
|
/* For interpolation */
|
|
f_frac = ( p_sys->f_offset - (int)p_sys->f_offset );
|
|
for( i_chan = 0; i_chan < p_sys->i_channels; i_chan++ )
|
|
{
|
|
f_diff = *( pf_ptr + p_sys->i_channels + i_chan )
|
|
- *( pf_ptr + i_chan );
|
|
f_temp = ( *( pf_ptr + i_chan ) );//+ f_diff * f_frac);
|
|
/*Linear Interpolation. FIXME. This creates LOTS of noise */
|
|
sanitize(&f_temp);
|
|
p_out[i_chan] = p_sys->f_dryLevel * p_in[i_chan] +
|
|
p_sys->f_wetLevel * f_temp;
|
|
*( p_sys->pf_write + i_chan ) = p_in[i_chan] +
|
|
p_sys->f_feedbackGain * f_temp;
|
|
}
|
|
if( p_sys->pf_write == p_sys->pf_delayLineStart )
|
|
for( i_chan = 0; i_chan < p_sys->i_channels; i_chan++ )
|
|
*( p_sys->pf_delayLineEnd - p_sys->i_channels + i_chan )
|
|
= *( p_sys->pf_delayLineStart + i_chan );
|
|
|
|
p_in += p_sys->i_channels;
|
|
p_out += p_sys->i_channels;
|
|
p_sys->pf_write += p_sys->i_channels;
|
|
if( p_sys->pf_write == p_sys->pf_delayLineEnd - p_sys->i_channels )
|
|
{
|
|
p_sys->pf_write = p_sys->pf_delayLineStart;
|
|
}
|
|
|
|
}
|
|
return p_in_buf;
|
|
}
|
|
|
|
/**
|
|
* Close: Destructor
|
|
* @param p_this pointer to this filter object
|
|
*/
|
|
static void Close( vlc_object_t *p_this )
|
|
{
|
|
filter_t *p_filter = ( filter_t* )p_this;
|
|
filter_sys_t *p_sys = p_filter->p_sys;
|
|
|
|
free( p_sys->pf_delayLineStart );
|
|
free( p_sys );
|
|
}
|