mirror of
https://code.videolan.org/videolan/vlc
synced 2024-10-07 03:56:28 +02:00
cf891bad55
* modules/codec/a52.c: Fixed detection of A/52 sound. * modules/audio_filter/converter/a52tofloat32.c: Fixed a bug related to downmixing. * ALL: Added hooks for audio volume management.
184 lines
6.6 KiB
C
184 lines
6.6 KiB
C
/*****************************************************************************
|
|
* float32.c : precise float32 audio mixer implementation
|
|
*****************************************************************************
|
|
* Copyright (C) 2002 VideoLAN
|
|
* $Id: float32.c,v 1.2 2002/09/16 20:46:37 massiot Exp $
|
|
*
|
|
* Authors: Christophe Massiot <massiot@via.ecp.fr>
|
|
*
|
|
* 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_buffer_t * );
|
|
|
|
/*****************************************************************************
|
|
* Module descriptor
|
|
*****************************************************************************/
|
|
vlc_module_begin();
|
|
set_description( _("float32 audio mixer module") );
|
|
set_capability( "audio mixer", 10 );
|
|
set_callbacks( Create, NULL );
|
|
vlc_module_end();
|
|
|
|
/*****************************************************************************
|
|
* Create: allocate trivial mixer
|
|
*****************************************************************************/
|
|
static int Create( vlc_object_t *p_this )
|
|
{
|
|
aout_instance_t * p_aout = (aout_instance_t *)p_this;
|
|
|
|
if ( p_aout->mixer.mixer.i_format != AOUT_FMT_FLOAT32 )
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
if ( p_aout->i_nb_inputs == 1 && p_aout->mixer.f_multiplier == 1.0 )
|
|
{
|
|
/* Tell the trivial mixer to go for it. */
|
|
return -1;
|
|
}
|
|
|
|
p_aout->mixer.pf_do_work = DoWork;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* ScaleWords: prepare input words for averaging
|
|
*****************************************************************************/
|
|
static void ScaleWords( float * p_out, const float * p_in, size_t i_nb_words,
|
|
int i_nb_inputs, float f_multiplier )
|
|
{
|
|
int i;
|
|
f_multiplier /= i_nb_inputs;
|
|
|
|
for ( i = i_nb_words; i--; )
|
|
{
|
|
*p_out++ = *p_in++ * f_multiplier;
|
|
}
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* MeanWords: average input words
|
|
*****************************************************************************/
|
|
static void MeanWords( float * p_out, const float * p_in, size_t i_nb_words,
|
|
int i_nb_inputs, float f_multiplier )
|
|
{
|
|
int i;
|
|
f_multiplier /= i_nb_inputs;
|
|
|
|
for ( i = i_nb_words; i--; )
|
|
{
|
|
*p_out++ += *p_in++ * f_multiplier;
|
|
}
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* DoWork: mix a new output buffer
|
|
*****************************************************************************
|
|
* Terminology : in this function a word designates a single float32, eg.
|
|
* a stereo sample is consituted of two words.
|
|
*****************************************************************************/
|
|
static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
|
|
{
|
|
int i_nb_inputs = p_aout->i_nb_inputs;
|
|
int i_input;
|
|
|
|
for ( i_input = 0; i_input < i_nb_inputs; i_input++ )
|
|
{
|
|
int i_nb_words = p_buffer->i_nb_samples
|
|
* p_aout->mixer.mixer.i_channels;
|
|
aout_input_t * p_input = p_aout->pp_inputs[i_input];
|
|
float * p_out = (float *)p_buffer->p_buffer;
|
|
float * p_in = (float *)p_input->p_first_byte_to_mix;
|
|
|
|
for ( ; ; )
|
|
{
|
|
ptrdiff_t i_available_words = (
|
|
(float *)p_input->fifo.p_first->p_buffer - p_in)
|
|
+ p_input->fifo.p_first->i_nb_samples
|
|
* p_aout->mixer.mixer.i_channels;
|
|
|
|
if ( i_available_words < i_nb_words )
|
|
{
|
|
aout_buffer_t * p_old_buffer;
|
|
|
|
if ( i_available_words > 0 )
|
|
{
|
|
if ( !i_input )
|
|
{
|
|
ScaleWords( p_out, p_in, i_available_words,
|
|
i_nb_inputs, p_aout->mixer.f_multiplier );
|
|
}
|
|
else
|
|
{
|
|
MeanWords( p_out, p_in, i_available_words,
|
|
i_nb_inputs, p_aout->mixer.f_multiplier );
|
|
}
|
|
}
|
|
|
|
i_nb_words -= i_available_words;
|
|
p_out += i_available_words;
|
|
|
|
/* Next buffer */
|
|
p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
|
|
aout_BufferFree( p_old_buffer );
|
|
if ( p_input->fifo.p_first == NULL )
|
|
{
|
|
msg_Err( p_aout, "internal amix error" );
|
|
return;
|
|
}
|
|
p_in = (float *)p_input->fifo.p_first->p_buffer;
|
|
}
|
|
else
|
|
{
|
|
if ( i_nb_words > 0 )
|
|
{
|
|
if ( !i_input )
|
|
{
|
|
ScaleWords( p_out, p_in, i_nb_words, i_nb_inputs,
|
|
p_aout->mixer.f_multiplier );
|
|
}
|
|
else
|
|
{
|
|
MeanWords( p_out, p_in, i_nb_words, i_nb_inputs,
|
|
p_aout->mixer.f_multiplier );
|
|
}
|
|
}
|
|
p_input->p_first_byte_to_mix = (void *)(p_in
|
|
+ i_nb_words);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|