added a new resampler based on linear interpolation, giving a fair tradeoff

between sound quality and speed
parent d472b3e2
......@@ -553,7 +553,7 @@ PLUGINS="${PLUGINS} idct idctclassic motion mpeg_video spudec mpeg_audio"
PLUGINS="${PLUGINS} lpcm a52"
PLUGINS="${PLUGINS} deinterlace invert yuv wall transform distort clone crop motionblur"
PLUGINS="${PLUGINS} float32tos16 float32tos8 float32tou16 float32tou8 a52tospdif fixed32tofloat32 fixed32tos16 s16tofloat32 s16tofloat32swab"
PLUGINS="${PLUGINS} trivial_resampler ugly_resampler"
PLUGINS="${PLUGINS} trivial_resampler ugly_resampler linear_resampler"
PLUGINS="${PLUGINS} trivial_channel_mixer"
PLUGINS="${PLUGINS} trivial_mixer spdif_mixer"
PLUGINS="${PLUGINS} aout_file"
......
SOURCES_trivial_resampler = modules/audio_filter/resampler/trivial.c
SOURCES_ugly_resampler = modules/audio_filter/resampler/ugly.c
SOURCES_linear_resampler = modules/audio_filter/resampler/linear.c
#SOURCES_fast = modules/audio_filter/resampler/fast.c
/*****************************************************************************
* ugly.c : linear interpolation resampler
*****************************************************************************
* Copyright (C) 2002 VideoLAN
* $Id: linear.c,v 1.1 2002/11/07 21:09:59 sigmunau Exp $
*
* Authors: 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
* 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.
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#include <errno.h>
#include <stdlib.h> /* malloc(), free() */
#include <string.h>
#include <vlc/vlc.h>
#include "audio_output.h"
#include "aout_internal.h"
/*****************************************************************************
* Local prototypes
*****************************************************************************/
static int Create ( vlc_object_t * );
static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
aout_buffer_t * );
/*****************************************************************************
* Module descriptor
*****************************************************************************/
vlc_module_begin();
set_description( _("audio filter for linear interpolation resampling") );
set_capability( "audio filter", 10 );
set_callbacks( Create, NULL );
vlc_module_end();
/*****************************************************************************
* Create: allocate ugly 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_format != VLC_FOURCC('f','l','3','2') )
{
return VLC_EGENERIC;
}
p_filter->pf_do_work = DoWork;
p_filter->b_in_place = VLC_FALSE;
return VLC_SUCCESS;
}
/*****************************************************************************
* DoWork: convert 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* p_in = (float*)p_in_buf->p_buffer;
float* p_out = (float*)p_out_buf->p_buffer;
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++ )
{
f_pos--;
while( f_pos < 1 )
{
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++;
}
f_pos += f_step;
p_out += i_nb_channels;
}
p_in += i_nb_channels;
}
if ( f_step < 1 ) {
for( i_chan = i_nb_channels ; i_chan ; )
{
i_chan--;
p_out[i_chan] = p_in[i_chan];
i_out++;
}
}
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);
}
p_out_buf->i_nb_samples = i_out_nb;
p_out_buf->i_nb_bytes = i_out_nb * i_frame_bytes;
}
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