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** Copyright (C) 2002-2005 Erik de Castro Lopo <erikd@mega-nerd.com>
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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 Lesser General Public License as published by
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** the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
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** You should have received a copy of the GNU Lesser 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 02111-1307, USA.
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** This is the OKI / Dialogic ADPCM encoder/decoder. It converts from
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** 12 bit linear sample data to a 4 bit ADPCM.
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** Implemented from the description found here:
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** http://www.comptek.ru:8100/telephony/tnotes/tt1-13.html
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** and compared against the encoder/decoder found here:
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** http://ibiblio.org/pub/linux/apps/sound/convert/vox.tar.gz
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#include "float_cast.h"
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#define VOX_DATA_LEN 2048
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#define PCM_DATA_LEN (VOX_DATA_LEN *2)
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int vox_bytes, pcm_samples ;
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unsigned char vox_data [VOX_DATA_LEN] ;
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short pcm_data [PCM_DATA_LEN] ;
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static int vox_adpcm_encode_block (VOX_ADPCM_PRIVATE *pvox) ;
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static int vox_adpcm_decode_block (VOX_ADPCM_PRIVATE *pvox) ;
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static short vox_adpcm_decode (char code, VOX_ADPCM_PRIVATE *pvox) ;
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static char vox_adpcm_encode (short samp, VOX_ADPCM_PRIVATE *pvox) ;
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static sf_count_t vox_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len) ;
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static sf_count_t vox_read_i (SF_PRIVATE *psf, int *ptr, sf_count_t len) ;
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static sf_count_t vox_read_f (SF_PRIVATE *psf, float *ptr, sf_count_t len) ;
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static sf_count_t vox_read_d (SF_PRIVATE *psf, double *ptr, sf_count_t len) ;
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static sf_count_t vox_write_s (SF_PRIVATE *psf, const short *ptr, sf_count_t len) ;
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static sf_count_t vox_write_i (SF_PRIVATE *psf, const int *ptr, sf_count_t len) ;
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static sf_count_t vox_write_f (SF_PRIVATE *psf, const float *ptr, sf_count_t len) ;
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static sf_count_t vox_write_d (SF_PRIVATE *psf, const double *ptr, sf_count_t len) ;
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static int vox_read_block (SF_PRIVATE *psf, VOX_ADPCM_PRIVATE *pvox, short *ptr, int len) ;
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/*============================================================================================
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** Predefined OKI ADPCM encoder/decoder tables.
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static short step_size_table [49] =
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{ 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60,
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66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209,
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230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658,
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724, 796, 876, 963, 1060, 1166, 1282, 1408, 1552
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} ; /* step_size_table */
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static short step_adjust_table [8] =
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{ -1, -1, -1, -1, 2, 4, 6, 8
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} ; /* step_adjust_table */
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/*------------------------------------------------------------------------------
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vox_adpcm_init (SF_PRIVATE *psf)
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{ VOX_ADPCM_PRIVATE *pvox = NULL ;
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if (psf->mode == SFM_RDWR)
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return SFE_BAD_MODE_RW ;
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if (psf->mode == SFM_WRITE && psf->sf.channels != 1)
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return SFE_CHANNEL_COUNT ;
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if ((pvox = malloc (sizeof (VOX_ADPCM_PRIVATE))) == NULL)
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return SFE_MALLOC_FAILED ;
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psf->fdata = (void*) pvox ;
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memset (pvox, 0, sizeof (VOX_ADPCM_PRIVATE)) ;
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if (psf->mode == SFM_WRITE)
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{ psf->write_short = vox_write_s ;
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psf->write_int = vox_write_i ;
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psf->write_float = vox_write_f ;
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psf->write_double = vox_write_d ;
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{ psf_log_printf (psf, "Header-less OKI Dialogic ADPCM encoded file.\n") ;
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psf_log_printf (psf, "Setting up for 8kHz, mono, Vox ADPCM.\n") ;
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psf->read_short = vox_read_s ;
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psf->read_int = vox_read_i ;
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psf->read_float = vox_read_f ;
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psf->read_double = vox_read_d ;
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/* Standard sample rate chennels etc. */
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if (psf->sf.samplerate < 1)
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psf->sf.samplerate = 8000 ;
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psf->sf.channels = 1 ;
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psf->sf.frames = psf->filelength * 2 ;
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psf->sf.seekable = SF_FALSE ;
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/* Seek back to start of data. */
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if (psf_fseek (psf, 0 , SEEK_SET) == -1)
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return SFE_BAD_SEEK ;
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} /* vox_adpcm_init */
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/*------------------------------------------------------------------------------
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vox_adpcm_encode (short samp, VOX_ADPCM_PRIVATE *pvox)
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short diff, error, stepsize ;
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stepsize = step_size_table [pvox->step_index] ;
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diff = samp - pvox->last ;
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if (error >= stepsize)
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{ code = code | 0x04 ;
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if (error >= stepsize / 2)
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{ code = code | 0x02 ;
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error -= stepsize / 2 ;
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if (error >= stepsize / 4)
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** To close the feedback loop, the deocder is used to set the
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** estimate of last sample and in doing so, also set the step_index.
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pvox->last = vox_adpcm_decode (code, pvox) ;
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} /* vox_adpcm_encode */
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vox_adpcm_decode (char code, VOX_ADPCM_PRIVATE *pvox)
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{ short diff, error, stepsize, samp ;
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stepsize = step_size_table [pvox->step_index] ;
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error = stepsize / 8 ;
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error += stepsize / 4 ;
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error += stepsize / 2 ;
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diff = (code & 0x08) ? -error : error ;
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samp = pvox->last + diff ;
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pvox->step_index += step_adjust_table [code & 0x7] ;
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if (pvox->step_index < 0)
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pvox->step_index = 0 ;
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if (pvox->step_index > 48)
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pvox->step_index = 48 ;
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} /* vox_adpcm_decode */
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vox_adpcm_encode_block (VOX_ADPCM_PRIVATE *pvox)
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{ unsigned char code ;
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/* If data_count is odd, add an extra zero valued sample. */
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if (pvox->pcm_samples & 1)
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pvox->pcm_data [pvox->pcm_samples++] = 0 ;
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for (j = k = 0 ; k < pvox->pcm_samples ; j++)
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{ code = vox_adpcm_encode (pvox->pcm_data [k++] / 16, pvox) << 4 ;
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code |= vox_adpcm_encode (pvox->pcm_data [k++] / 16, pvox) ;
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pvox->vox_data [j] = code ;
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pvox->vox_bytes = j ;
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} /* vox_adpcm_encode_block */
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vox_adpcm_decode_block (VOX_ADPCM_PRIVATE *pvox)
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{ unsigned char code ;
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for (j = k = 0 ; j < pvox->vox_bytes ; j++)
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{ code = pvox->vox_data [j] ;
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pvox->pcm_data [k++] = 16 * vox_adpcm_decode ((code >> 4) & 0x0f, pvox) ;
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pvox->pcm_data [k++] = 16 * vox_adpcm_decode (code & 0x0f, pvox) ;
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pvox->pcm_samples = k ;
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} /* vox_adpcm_decode_block */
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/*==============================================================================
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vox_read_block (SF_PRIVATE *psf, VOX_ADPCM_PRIVATE *pvox, short *ptr, int len)
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{ pvox->vox_bytes = (len - indx > PCM_DATA_LEN) ? VOX_DATA_LEN : (len - indx + 1) / 2 ;
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if ((k = psf_fread (pvox->vox_data, 1, pvox->vox_bytes, psf)) != pvox->vox_bytes)
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{ if (psf_ftell (psf) + k != psf->filelength)
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psf_log_printf (psf, "*** Warning : short read (%d != %d).\n", k, pvox->vox_bytes) ;
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pvox->vox_bytes = k ;
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vox_adpcm_decode_block (pvox) ;
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memcpy (&(ptr [indx]), pvox->pcm_data, pvox->pcm_samples * sizeof (short)) ;
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indx += pvox->pcm_samples ;
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} /* vox_read_block */
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vox_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int readcount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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{ readcount = (len > 0x10000000) ? 0x10000000 : (int) len ;
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count = vox_read_block (psf, pvox, ptr, readcount) ;
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if (count != readcount)
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vox_read_i (SF_PRIVATE *psf, int *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int k, bufferlen, readcount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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bufferlen = ARRAY_LEN (psf->u.sbuf) ;
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{ readcount = (len >= bufferlen) ? bufferlen : (int) len ;
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count = vox_read_block (psf, pvox, sptr, readcount) ;
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for (k = 0 ; k < readcount ; k++)
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ptr [total + k] = ((int) sptr [k]) << 16 ;
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if (count != readcount)
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vox_read_f (SF_PRIVATE *psf, float *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int k, bufferlen, readcount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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normfact = (psf->norm_float == SF_TRUE) ? 1.0 / ((float) 0x8000) : 1.0 ;
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bufferlen = ARRAY_LEN (psf->u.sbuf) ;
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{ readcount = (len >= bufferlen) ? bufferlen : (int) len ;
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count = vox_read_block (psf, pvox, sptr, readcount) ;
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for (k = 0 ; k < readcount ; k++)
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ptr [total + k] = normfact * (float) (sptr [k]) ;
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if (count != readcount)
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vox_read_d (SF_PRIVATE *psf, double *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int k, bufferlen, readcount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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normfact = (psf->norm_double == SF_TRUE) ? 1.0 / ((double) 0x8000) : 1.0 ;
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bufferlen = ARRAY_LEN (psf->u.sbuf) ;
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{ readcount = (len >= bufferlen) ? bufferlen : (int) len ;
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count = vox_read_block (psf, pvox, sptr, readcount) ;
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for (k = 0 ; k < readcount ; k++)
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ptr [total + k] = normfact * (double) (sptr [k]) ;
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if (count != readcount)
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/*------------------------------------------------------------------------------
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vox_write_block (SF_PRIVATE *psf, VOX_ADPCM_PRIVATE *pvox, const short *ptr, int len)
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{ pvox->pcm_samples = (len - indx > PCM_DATA_LEN) ? PCM_DATA_LEN : len - indx ;
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memcpy (pvox->pcm_data, &(ptr [indx]), pvox->pcm_samples * sizeof (short)) ;
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vox_adpcm_encode_block (pvox) ;
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if ((k = psf_fwrite (pvox->vox_data, 1, pvox->vox_bytes, psf)) != pvox->vox_bytes)
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psf_log_printf (psf, "*** Warning : short read (%d != %d).\n", k, pvox->vox_bytes) ;
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indx += pvox->pcm_samples ;
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} /* vox_write_block */
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vox_write_s (SF_PRIVATE *psf, const short *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int writecount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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{ writecount = (len > 0x10000000) ? 0x10000000 : (int) len ;
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count = vox_write_block (psf, pvox, ptr, writecount) ;
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if (count != writecount)
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vox_write_i (SF_PRIVATE *psf, const int *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int k, bufferlen, writecount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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bufferlen = ARRAY_LEN (psf->u.sbuf) ;
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{ writecount = (len >= bufferlen) ? bufferlen : (int) len ;
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for (k = 0 ; k < writecount ; k++)
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sptr [k] = ptr [total + k] >> 16 ;
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count = vox_write_block (psf, pvox, sptr, writecount) ;
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if (count != writecount)
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vox_write_f (SF_PRIVATE *psf, const float *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int k, bufferlen, writecount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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normfact = (psf->norm_float == SF_TRUE) ? (1.0 * 0x7FFF) : 1.0 ;
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bufferlen = ARRAY_LEN (psf->u.sbuf) ;
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{ writecount = (len >= bufferlen) ? bufferlen : (int) len ;
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for (k = 0 ; k < writecount ; k++)
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sptr [k] = lrintf (normfact * ptr [total + k]) ;
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count = vox_write_block (psf, pvox, sptr, writecount) ;
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if (count != writecount)
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vox_write_d (SF_PRIVATE *psf, const double *ptr, sf_count_t len)
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{ VOX_ADPCM_PRIVATE *pvox ;
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int k, bufferlen, writecount, count ;
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sf_count_t total = 0 ;
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pvox = (VOX_ADPCM_PRIVATE*) psf->fdata ;
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normfact = (psf->norm_double == SF_TRUE) ? (1.0 * 0x7FFF) : 1.0 ;
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bufferlen = ARRAY_LEN (psf->u.sbuf) ;
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{ writecount = (len >= bufferlen) ? bufferlen : (int) len ;
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for (k = 0 ; k < writecount ; k++)
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sptr [k] = lrint (normfact * ptr [total + k]) ;
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count = vox_write_block (psf, pvox, sptr, writecount) ;
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if (count != writecount)
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** Do not edit or modify anything in this comment block.
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** The arch-tag line is a file identity tag for the GNU Arch
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** revision control system.
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** arch-tag: e15e97fe-ff9d-4b46-a489-7059fb2d0b1e