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/* gap_audio_util.c
*
* GAP common encoder audio utility procedures
*
*/
/* The GIMP -- an image manipulation program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 02111-1307, USA.
*/
/* 2002.01.05 hof removed p_get_wavparams
*/
/* SYTEM (UNIX) includes */
#include <stdio.h>
#include <stdlib.h>
/* GIMP includes */
#include "gtk/gtk.h"
#include "libgimp/gimp.h"
/* GAP includes */
#include "gap_audio_util.h"
extern int gap_debug; /* ==0 ... dont print debug infos */
/* --------------------------------
* gap_audio_util_stereo_split16to16
* --------------------------------
*/
void
gap_audio_util_stereo_split16to16(unsigned char *l_left_ptr, unsigned char *l_right_ptr, unsigned char *l_aud_ptr, long l_data_len)
{
long l_idx;
/* split stereo 16 bit data from wave data (sequence is 2 bytes left channel, 2 right, 2 left, 2 right ...)
* into 2 separate datablocks for left and right channel of 16 bit per sample
*/
l_idx = 0;
while(l_idx < l_data_len)
{
*(l_left_ptr++) = l_aud_ptr[l_idx++];
*(l_left_ptr++) = l_aud_ptr[l_idx++];
*(l_right_ptr++) = l_aud_ptr[l_idx++];
*(l_right_ptr++) = l_aud_ptr[l_idx++];
}
} /* end gap_audio_util_stereo_split16to16 */
/* --------------------------------
* gap_audio_util_dbl_sample_8_to_16
* --------------------------------
*/
void
gap_audio_util_dbl_sample_8_to_16(unsigned char insample8,
unsigned char *lsb_out,
unsigned char *msb_out)
{
/* 16 bit audiodata is signed,
* 8 bit audiodata is unsigned
*/
/* this conversion uses only positive 16bit values
*/
*msb_out = (insample8 >> 1);
*lsb_out = ((insample8 << 7) & 0x80);
return;
/* this conversion makes use of negative 16bit values
* and the full sample range
* (somehow it sounds not as good as the other one)
*/
*msb_out = (insample8 -64);
*lsb_out = 0;
} /* end gap_audio_util_dbl_sample_8_to_16 */
/* --------------------------------
* gap_audio_util_stereo_split8to16
* --------------------------------
*/
void
gap_audio_util_stereo_split8to16(unsigned char *l_left_ptr, unsigned char *l_right_ptr, unsigned char *l_aud_ptr, long l_data_len)
{
long l_idx;
unsigned char l_lsb, l_msb;
/* split stereo 8 bit data from wave data (sequence is 2 bytes left channel, 2 right, 2 left, 2 right ...)
* into 2 separate datablocks for left and right channel of 16 bit per sample
*/
l_idx = 0;
while(l_idx < l_data_len)
{
gap_audio_util_dbl_sample_8_to_16(l_aud_ptr[l_idx], &l_lsb, &l_msb);
l_idx++;
*(l_left_ptr++) = l_lsb;
*(l_left_ptr++) = l_msb;
gap_audio_util_dbl_sample_8_to_16(l_aud_ptr[l_idx], &l_lsb, &l_msb);
l_idx++;
*(l_left_ptr++) = l_lsb;
*(l_left_ptr++) = l_msb;
}
} /* end gap_audio_util_stereo_split8to16 */
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