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/*****************************************************************************
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* float32tos16.c : converter from float32 to signed 16 bits integer
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*****************************************************************************
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* Copyright (C) 2002 VideoLAN
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* $Id: float32tos16.c 6961 2004-03-05 17:34:23Z sam $
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* Authors: Christophe Massiot <massiot@via.ecp.fr>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
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*****************************************************************************/
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/*****************************************************************************
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*****************************************************************************/
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#include <stdlib.h> /* malloc(), free() */
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#include "audio_output.h"
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#include "aout_internal.h"
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/*****************************************************************************
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*****************************************************************************/
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static int Create ( vlc_object_t * );
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static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
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/*****************************************************************************
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*****************************************************************************/
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set_description( _("audio filter for float32->s16 conversion") );
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set_capability( "audio filter", 1 );
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set_callbacks( Create, NULL );
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/*****************************************************************************
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* Create: allocate trivial mixer
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*****************************************************************************/
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static int Create( vlc_object_t *p_this )
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aout_filter_t * p_filter = (aout_filter_t *)p_this;
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if ( p_filter->input.i_format != VLC_FOURCC('f','l','3','2')
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|| p_filter->output.i_format != AOUT_FMT_S16_NE )
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if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
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p_filter->pf_do_work = DoWork;
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p_filter->b_in_place = 1;
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/*****************************************************************************
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* DoWork: convert a buffer
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*****************************************************************************/
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static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
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aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
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float * p_in = (float *)p_in_buf->p_buffer;
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int16_t * p_out = (int16_t *)p_out_buf->p_buffer;
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for ( i = p_in_buf->i_nb_samples
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* aout_FormatNbChannels( &p_filter->input ); i-- ; )
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if ( *p_in >= 1.0 ) *p_out = 32767;
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else if ( *p_in < -1.0 ) *p_out = -32768;
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else *p_out = *p_in * 32768.0;
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/* This is walken's trick based on IEEE float format. */
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float f_in = *p_in + 384.0;
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i_in = *(int32_t *)(intptr_t)&f_in;
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if ( i_in > 0x43c07fff ) *p_out = 32767;
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else if ( i_in < 0x43bf8000 ) *p_out = -32768;
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else *p_out = i_in - 0x43c00000;
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p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
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p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes / 2;