/*****************************************************************************
- * ugly.c : linear interpolation resampler
+ * linear.c : linear interpolation resampler
*****************************************************************************
* Copyright (C) 2002 VideoLAN
- * $Id: linear.c,v 1.1 2002/11/07 21:09:59 sigmunau Exp $
+ * $Id: linear.c,v 1.6 2002/11/20 16:43:32 sam Exp $
*
- * Authors: Sigmund Augdal <sigmunau@idi.ntnu.no>
+ * Authors: Gildas Bazin <gbazin@netcourrier.com>
+ * Sigmund Augdal <sigmunau@idi.ntnu.no>
*
* 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
/*****************************************************************************
* Preamble
*****************************************************************************/
-#include <errno.h>
#include <stdlib.h> /* malloc(), free() */
#include <string.h>
* Local prototypes
*****************************************************************************/
static int Create ( vlc_object_t * );
-
+static void Close ( vlc_object_t * );
static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
aout_buffer_t * );
+/*****************************************************************************
+ * Local structures
+ *****************************************************************************/
+struct aout_filter_sys_t
+{
+ int32_t *p_prev_sample; /* this filter introduces a 1 sample delay */
+
+ int i_remainder; /* remainder of previous sample */
+
+ audio_date_t end_date;
+};
+
/*****************************************************************************
* Module descriptor
*****************************************************************************/
vlc_module_begin();
set_description( _("audio filter for linear interpolation resampling") );
set_capability( "audio filter", 10 );
- set_callbacks( Create, NULL );
+ set_callbacks( Create, Close );
vlc_module_end();
/*****************************************************************************
- * Create: allocate ugly resampler
+ * Create: allocate linear resampler
*****************************************************************************/
static int Create( vlc_object_t *p_this )
{
aout_filter_t * p_filter = (aout_filter_t *)p_this;
- msg_Dbg( p_this, " trying the linear resampler");
if ( p_filter->input.i_rate == p_filter->output.i_rate
|| p_filter->input.i_format != p_filter->output.i_format
- || p_filter->input.i_channels != p_filter->output.i_channels
+ || p_filter->input.i_physical_channels
+ != p_filter->output.i_physical_channels
+ || p_filter->input.i_original_channels
+ != p_filter->output.i_original_channels
|| p_filter->input.i_format != VLC_FOURCC('f','l','3','2') )
{
return VLC_EGENERIC;
}
+ /* Allocate the memory needed to store the module's structure */
+ p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
+ if( p_filter->p_sys == NULL )
+ {
+ msg_Err( p_filter, "out of memory" );
+ return VLC_ENOMEM;
+ }
+ p_filter->p_sys->p_prev_sample = malloc(
+ p_filter->input.i_physical_channels * sizeof(int32_t) );
+ if( p_filter->p_sys->p_prev_sample == NULL )
+ {
+ msg_Err( p_filter, "out of memory" );
+ return VLC_ENOMEM;
+ }
+
p_filter->pf_do_work = DoWork;
p_filter->b_in_place = VLC_FALSE;
return VLC_SUCCESS;
}
+/*****************************************************************************
+ * Close: free our resources
+ *****************************************************************************/
+static void Close( vlc_object_t * p_this )
+{
+ aout_filter_t * p_filter = (aout_filter_t *)p_this;
+ free( p_filter->p_sys->p_prev_sample );
+ free( p_filter->p_sys );
+}
+
/*****************************************************************************
* DoWork: convert a buffer
*****************************************************************************/
{
float* p_in = (float*)p_in_buf->p_buffer;
float* p_out = (float*)p_out_buf->p_buffer;
+ float* p_prev_sample = (float*)p_filter->p_sys->p_prev_sample;
int i_nb_channels = aout_FormatNbChannels( &p_filter->input );
int i_in_nb = p_in_buf->i_nb_samples;
- int i_out_nb = i_in_nb * p_filter->output.i_rate
- / p_filter->input.i_rate;
- int i_frame_bytes = i_nb_channels * sizeof(s32);
- int i_in, i_chan, i_out = 0;
- double f_step = (float)i_in_nb/i_out_nb;
- float f_pos = 1;
- for( i_in = 0 ; i_in < i_in_nb - 1; i_in++ )
+ int i_chan, i_in, i_out = 0;
+
+ /* Take care of the previous input sample (if any) */
+ if( p_filter->b_reinit )
{
- f_pos--;
- while( f_pos < 1 )
+ p_filter->b_reinit = VLC_FALSE;
+ p_filter->p_sys->i_remainder = 0;
+ aout_DateInit( &p_filter->p_sys->end_date, p_filter->output.i_rate );
+ }
+ else
+ {
+ while( p_filter->p_sys->i_remainder < p_filter->output.i_rate )
{
for( i_chan = i_nb_channels ; i_chan ; )
{
i_chan--;
- p_out[i_chan] = p_in[i_chan] +
- ( p_in[i_chan + i_nb_channels] - p_in[i_chan] ) * f_pos;
- i_out++;
+ p_out[i_chan] = p_prev_sample[i_chan];
+ p_out[i_chan] += ( (p_prev_sample[i_chan] - p_in[i_chan])
+ * p_filter->p_sys->i_remainder
+ / p_filter->output.i_rate );
}
- f_pos += f_step;
p_out += i_nb_channels;
+ i_out++;
+
+ p_filter->p_sys->i_remainder += p_filter->input.i_rate;
}
- p_in += i_nb_channels;
+ p_filter->p_sys->i_remainder -= p_filter->output.i_rate;
}
- if ( f_step < 1 ) {
- for( i_chan = i_nb_channels ; i_chan ; )
+
+ /* Take care of the current input samples (minus last one) */
+ for( i_in = 0; i_in < i_in_nb - 1; i_in++ )
+ {
+ while( p_filter->p_sys->i_remainder < p_filter->output.i_rate )
{
- i_chan--;
- p_out[i_chan] = p_in[i_chan];
- i_out++;
+ for( i_chan = i_nb_channels ; i_chan ; )
+ {
+ i_chan--;
+ p_out[i_chan] = p_in[i_chan];
+ p_out[i_chan] += ( (p_in[i_chan] -
+ p_in[i_chan + i_nb_channels])
+ * p_filter->p_sys->i_remainder / p_filter->output.i_rate );
+ }
+ p_out += i_nb_channels;
+ i_out++;
+
+ p_filter->p_sys->i_remainder += p_filter->input.i_rate;
}
+
+ p_in += i_nb_channels;
+ p_filter->p_sys->i_remainder -= p_filter->output.i_rate;
}
- if ( i_out != i_out_nb * i_nb_channels ) {
- msg_Warn( p_aout, "mismatch in sample nubers: %d requested, %d generated", i_out_nb* i_nb_channels, i_out);
+
+ /* Backup the last input sample for next time */
+ for( i_chan = i_nb_channels ; i_chan ; )
+ {
+ i_chan--;
+ p_prev_sample[i_chan] = p_in[i_chan];
}
-
- p_out_buf->i_nb_samples = i_out_nb;
- p_out_buf->i_nb_bytes = i_out_nb * i_frame_bytes;
-}
+ p_out_buf->i_nb_samples = i_out;
+ p_out_buf->start_date = p_in_buf->start_date;
+
+ if( p_in_buf->start_date !=
+ aout_DateGet( &p_filter->p_sys->end_date ) )
+ {
+ aout_DateSet( &p_filter->p_sys->end_date, p_in_buf->start_date );
+ }
+
+ p_out_buf->end_date = aout_DateIncrement( &p_filter->p_sys->end_date,
+ p_out_buf->i_nb_samples );
+
+ p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples *
+ i_nb_channels * sizeof(int32_t);
+
+}
projects / vlc / blobdiff