[vlc-devel] [PATCH] chorus_flanger.c : bit of cleanup
Sukrit Sangwan
sukritsangwan at gmail.com
Wed Mar 14 02:16:36 CET 2012
I have fixed some issues(sustained noise of drum beats) and some TODOs and
added callback.
I have attached the patch
*>>> Inline explanations*
diff --git a/modules/audio_filter/chorus_flanger.c
b/modules/audio_filter/chorus_flanger.c
index efeade6..5f82f23 100644
--- a/modules/audio_filter/chorus_flanger.c
+++ b/modules/audio_filter/chorus_flanger.c
@@ -5,6 +5,7 @@
* $Id$
*
* Author: Srikanth Raju < srikiraju at gmail dot com >
+ * Modified : Sukrit Sangwan < sukritsangwan 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
@@ -43,10 +44,11 @@
/*****************************************************************************
* Local prototypes
*****************************************************************************/
-
static int Open ( vlc_object_t * );
static void Close ( vlc_object_t * );
static block_t *DoWork( filter_t *, block_t * );
+static int paramCallback( vlc_object_t *, char const *, vlc_value_t ,
+ vlc_value_t , void * );
struct filter_sys_t
{
@@ -57,8 +59,8 @@ struct filter_sys_t
float f_wetLevel, f_dryLevel;
float f_sweepDepth, f_sweepRate;
- float f_step,f_offset;
- int i_step,i_offset;
+ float f_offset;
+ int i_step;
float f_temp;
float f_sinMultiplier;
@@ -66,13 +68,15 @@ struct filter_sys_t
int i_bufferLength;
float * pf_delayLineStart, * pf_delayLineEnd;
float * pf_write;
+
+ /* Used if callback fails to allocate buffer, *
+ * in that case dont free the buffer twice */
+ bool b_free_buf;
};
/*****************************************************************************
* Module descriptor
*****************************************************************************/
-
-
vlc_module_begin ()
set_description( N_("Sound Delay") )
set_shortname( N_("Delay") )
@@ -80,7 +84,7 @@ vlc_module_begin ()
set_category( CAT_AUDIO )
set_subcategory( SUBCAT_AUDIO_AFILTER )
add_shortcut( "delay" )
- add_float( "delay-time", 40, N_("Delay time"),
+ add_float( "delay-time", 20, N_("Delay time"),
*>>> 20 ms avg delay is better for the effect, so default value changed*
N_("Time in milliseconds of the average delay. Note average"),
true )
add_float( "sweep-depth", 6, N_("Sweep Depth"),
N_("Time in milliseconds of the maximum sweep depth. Thus, the
sweep "
@@ -138,12 +142,16 @@ static int Open( vlc_object_t *p_this )
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" );
+
+#define CREATE_VAR( stor, var ) \
+ p_sys->stor = var_CreateGetFloat( p_filter, var ); \
+ var_AddCallback( p_filter, var, paramCallback, p_sys );
+ CREATE_VAR( f_delayTime, "delay-time" );
+ CREATE_VAR( f_sweepDepth, "sweep-depth" );
+ CREATE_VAR( f_sweepRate, "sweep-rate" );
+ CREATE_VAR( f_feedbackGain, "feedback-gain" );
+ CREATE_VAR( f_dryLevel, "dry-mix" );
+ CREATE_VAR( f_wetLevel, "wet-mix" );
if( p_sys->f_delayTime < 0.0)
{
@@ -176,7 +184,7 @@ static int Open( vlc_object_t *p_this )
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" );
+ msg_Err( p_filter, "Delay-time, Sample rate or Channels was
incorrect" );
free(p_sys);
return VLC_EGENERIC;
}
@@ -187,12 +195,11 @@ static int Open( vlc_object_t *p_this )
free( p_sys );
return VLC_ENOMEM;
}
+ p_sys->b_free_buf = true;
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;
*>>> Drop unused variables*
p_sys->f_temp = 0;
p_sys->pf_delayLineEnd = p_sys->pf_delayLineStart +
p_sys->i_bufferLength;
@@ -211,7 +218,6 @@ static int Open( vlc_object_t *p_this )
return VLC_SUCCESS;
}
-
/**
* sanitize: Helper function to eliminate small amplitudes
* @param f_value pointer to value to clean
@@ -244,23 +250,19 @@ static block_t *DoWork( filter_t *p_filter, block_t
*p_in_buf )
/* 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;
+ /* Sine function as a oscillator wave to calculate sweep */
+ p_sys->i_cumulative += p_sys->i_step;
+ p_sys->f_offset = sinf( (p_sys->i_cumulative) *
p_sys->f_sinMultiplier )
+ * (int)floor(p_sys->f_sweepDepth * p_sys->i_sampleRate /
1000);
if( abs( p_sys->i_step ) > 0 )
{
- if( p_sys->i_offset >= floor( p_sys->f_sweepDepth *
+ if( p_sys->i_cumulative >= 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 *
+ if( p_sys->i_cumulative <= floor( -1 * p_sys->f_sweepDepth *
p_sys->i_sampleRate / p_sys->f_sweepRate ) )
{
p_sys->f_offset = -i_maxOffset;
@@ -269,8 +271,7 @@ static block_t *DoWork( filter_t *p_filter, block_t
*p_in_buf )
}
/* 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;
+ pf_ptr = p_sys->pf_write + ( i_maxOffset - offset ) *
p_sys->i_channels;
*>>> although i_maxOffset +/- offset produce same effect, i changed to "-"
so that it seems what it really is
>>> (for more delay the pf_ptr should point more backwards in the buffer)
>>> +/- produce same effect because its value oscillates between +max and
-max*
/* Handle Overflow */
if( pf_ptr < p_sys->pf_delayLineStart )
@@ -285,15 +286,18 @@ static block_t *DoWork( filter_t *p_filter, block_t
*p_in_buf )
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 */
*>>> i changed pf_ptr + i_channels to pf_ptr - i_channels because to access
previous sample you must point backwards*
+ if( pf_ptr <= p_sys->pf_delayLineStart + p_sys->i_channels )
+ f_diff = *(p_sys->pf_delayLineEnd + i_chan) - *(pf_ptr +
i_chan);
+ else
+ f_diff = *( pf_ptr - p_sys->i_channels + i_chan )
+ - *( pf_ptr + i_chan );
*>>> although it was written to fix linear interpolation, i have still used
it because it wasn't the cause of noise.*
+ /* Linear Interpolation. */
+ f_temp = *( pf_ptr + i_chan ) + f_diff * f_frac;
sanitize(&f_temp);
+ *( p_sys->pf_write + i_chan ) = p_in[i_chan] +
+ p_sys->f_feedbackGain * *(pf_ptr + i_chan);
p_out[i_chan] = p_sys->f_dryLevel * p_in[i_chan] +
p_sys->f_wetLevel * f_temp;
*>>> The real cause of noise. copying the current sample after modifying
it. i have copied it first and then modified*
- *( 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++ )
@@ -320,7 +324,83 @@ 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;
+#define DEL_VAR( var ) \
+ var_DelCallback( p_filter, var, paramCallback, p_sys ); \
+ var_Destroy( p_filter, var );
+ DEL_VAR( "delay-time" );
+ DEL_VAR( "sweep-depth" );
+ DEL_VAR( "sweep-rate" );
+ DEL_VAR( "feedback-gain" );
+ DEL_VAR( "wet-mix" );
+ DEL_VAR( "dry-mix" );
+
+ if( p_sys->b_free_buf == true )
+ free( p_sys->pf_delayLineStart );
+ free( p_sys );
+}
+
+/******************************************************************************
+ * Callback to update parameters on the fly
+
******************************************************************************/
+static int paramCallback( vlc_object_t *p_this, char const *psz_var,
+ vlc_value_t oldval, vlc_value_t newval, void
*p_data )
+{
+ VLC_UNUSED(oldval);
+ filter_t *p_filter = (filter_t *)p_this;
+ filter_sys_t *p_sys = (filter_sys_t *) p_data;
+
+ if( !strcmp( psz_var, "delay-time" ) )
+ {
+ /* if invalid value pretend everything is OK without updating
value */
+ if( newval.f_float < 0 )
+ return VLC_SUCCESS;
+ p_sys->f_delayTime = newval.f_float;
+ goto allocate_new_buffer;
+ }
+ else if( !strcmp( psz_var, "sweep-depth" ) )
+ {
+ if( newval.f_float < 0 || newval.f_float > p_sys->f_delayTime)
+ return VLC_SUCCESS;
+ p_sys->f_sweepDepth = newval.f_float;
+ goto allocate_new_buffer;
+ }
+ else if( !strcmp( psz_var, "sweep-rate" ) )
+ {
+ if( newval.f_float > p_sys->f_sweepDepth )
+ return VLC_SUCCESS;
+ p_sys->f_sweepRate = newval.f_float;
+ /* Calculate new f_sinMultiplier */
+ 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
) ;
+ }
+ }
+ else if( !strcmp( psz_var, "feedback-gain" ) )
+ p_sys->f_feedbackGain = newval.f_float;
+ else if( !strcmp( psz_var, "wet-mix" ) )
+ p_sys->f_wetLevel = newval.f_float;
+ else if( !strcmp( psz_var, "dry-mix" ) )
+ p_sys->f_dryLevel = newval.f_float;
+
+ return VLC_SUCCESS;
+
+allocate_new_buffer:
+ 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 );
free( p_sys->pf_delayLineStart );
- free( p_sys );
+ p_sys->pf_delayLineStart = calloc( p_sys->i_bufferLength, sizeof(
float ) );
+ if( !p_sys->pf_delayLineStart )
+ {
+ p_sys->b_free_buf = false;
+ msg_Dbg( p_filter, "Couldnt allocate buffer for delay" );
+ Close( p_this );
+ }
+ p_sys->pf_delayLineEnd = p_sys->pf_delayLineStart +
p_sys->i_bufferLength;
+
+ return VLC_SUCCESS;
}
*>>> I have also added a small patch for stereo_widen.c
>>> i had earlier provided a long description which doesnt fit in the
preferences box
>>> (box becomes very large to accomodate full description in a single line)
>>> i changed a description into help and a added a small description*
diff --git a/modules/audio_filter/stereo_widen.c
b/modules/audio_filter/stereo_widen.c
index 5aa97f2..974bd45 100644
--- a/modules/audio_filter/stereo_widen.c
+++ b/modules/audio_filter/stereo_widen.c
@@ -52,7 +52,7 @@ struct filter_sys_t
* allocate buffer, then dont free it twice */
};
-#define DESCRIPTION N_("This filter enhances stereo effect by \
+#define HELP_TEXT N_("This filter enhances stereo effect by \
suppressing mono,i.e. signal common to both channels, \
and by delaying the signal of left into right and vice versa \
thereby widening stereo effect")
@@ -75,7 +75,8 @@ struct filter_sys_t
*****************************************************************************/
vlc_module_begin ()
set_shortname( N_("stereo_widen") )
- set_description( DESCRIPTION )
+ set_description( N_("Stereo Enhancer") )
+ set_help( HELP_TEXT )
set_category( CAT_AUDIO )
set_subcategory( SUBCAT_AUDIO_AFILTER )
set_capability( "audio filter", 0 )
--
Regards
Sukrit Sangwan
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