ima_adpcm.c

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/*
** Copyright (C) 1999-2004 Erik de Castro Lopo <[e-mail]>
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU Lesser General Public License as published by
** the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
**
** You should have received a copy of the GNU Lesser 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.
*/

#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>

#include	"sndfile.h"
#include	"config.h"
#include	"sfendian.h"
#include	"float_cast.h"
#include	"common.h"

typedef struct IMA_ADPCM_PRIVATE_tag
{	int 			(*decode_block) (SF_PRIVATE *psf, struct IMA_ADPCM_PRIVATE_tag *pima) ;
	int 			(*encode_block) (SF_PRIVATE *psf, struct IMA_ADPCM_PRIVATE_tag *pima) ;

	int				channels, blocksize, samplesperblock, blocks ;
	int				blockcount, samplecount ;
	int				previous [2] ;
	int				stepindx [2] ;
	unsigned char	*block ;
	short			*samples ;
#if HAVE_FLEXIBLE_ARRAY
	unsigned short	data	[] ; /* ISO C99 struct flexible array. */
#else
	unsigned short	data	[0] ; /* This is a hack and might not work. */
#endif
} IMA_ADPCM_PRIVATE ;

/*============================================================================================
** Predefined IMA ADPCM data.
*/

static int ima_indx_adjust [16] =
{	-1, -1, -1, -1,		/* +0 - +3, decrease the step size */
     2,  4,  6,  8,     /* +4 - +7, increase the step size */
    -1, -1, -1, -1,		/* -0 - -3, decrease the step size */
     2,  4,  6,  8,		/* -4 - -7, increase the step size */
} ;

static int ima_step_size [89] =
{	7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
	50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230,
	253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963,
	1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
	3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630, 9493, 10442,
	11487, 12635, 13899, 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794,
	32767
} ;

static int ima_reader_init (SF_PRIVATE *psf, int blockalign, int samplesperblock) ;
static int ima_writer_init (SF_PRIVATE *psf, int blockalign) ;

static int ima_read_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima, short *ptr, int len) ;
static int ima_write_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima, short *ptr, int len) ;

static sf_count_t ima_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len) ;
static sf_count_t ima_read_i (SF_PRIVATE *psf, int *ptr, sf_count_t len) ;
static sf_count_t ima_read_f (SF_PRIVATE *psf, float *ptr, sf_count_t len) ;
static sf_count_t ima_read_d (SF_PRIVATE *psf, double *ptr, sf_count_t len) ;

static sf_count_t ima_write_s (SF_PRIVATE *psf, short *ptr, sf_count_t len) ;
static sf_count_t ima_write_i (SF_PRIVATE *psf, int *ptr, sf_count_t len) ;
static sf_count_t ima_write_f (SF_PRIVATE *psf, float *ptr, sf_count_t len) ;
static sf_count_t ima_write_d (SF_PRIVATE *psf, double *ptr, sf_count_t len) ;

static sf_count_t	ima_seek	(SF_PRIVATE *psf, int mode, sf_count_t offset) ;

static int	wav_w64_ima_close	(SF_PRIVATE *psf) ;
static int	aiff_ima_close	(SF_PRIVATE *psf) ;

static int wav_w64_ima_decode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima) ;
static int wav_w64_ima_encode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima) ;

/*-static int aiff_ima_reader_init (SF_PRIVATE *psf, int blockalign, int samplesperblock) ;-*/
static int aiff_ima_decode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima) ;
static int aiff_ima_encode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima) ;


/*============================================================================================
** IMA ADPCM Reader initialisation function.
*/

int
wav_w64_ima_init (SF_PRIVATE *psf, int blockalign, int samplesperblock)
{	int error ;

	if (psf->mode == SFM_RDWR)
		return SFE_BAD_MODE_RW ;

	if (psf->mode == SFM_READ)
		if ((error = ima_reader_init (psf, blockalign, samplesperblock)))
			return error ;

	if (psf->mode == SFM_WRITE)
		if ((error = ima_writer_init (psf, blockalign)))
			return error ;

	psf->seek = ima_seek ;
	psf->close = wav_w64_ima_close ;

	return 0 ;
} /* wav_w64_ima_init */

static int
wav_w64_ima_close	(SF_PRIVATE *psf)
{	IMA_ADPCM_PRIVATE *pima ;

	if (! psf->fdata)
		return 0 ;

	pima = (IMA_ADPCM_PRIVATE*) psf->fdata ;

	if (psf->mode == SFM_WRITE)
	{	/*	If a block has been partially assembled, write it out
		**	as the final block.
		*/
		if (pima->samplecount && pima->samplecount < pima->samplesperblock)
			pima->encode_block (psf, pima) ;

		psf->sf.frames = pima->samplesperblock * pima->blockcount / psf->sf.channels ;

		if (psf->write_header)
			psf->write_header (psf, SF_TRUE) ;
		} ;

	free (psf->fdata) ;
	psf->fdata = NULL ;

	return 0 ;
} /* wav_w64_ima_close */

int
aiff_ima_init (SF_PRIVATE *psf, int blockalign, int samplesperblock)
{	int error ;

	if (psf->mode == SFM_RDWR)
		return SFE_BAD_MODE_RW ;

	if (psf->mode == SFM_READ)
		if ((error = ima_reader_init (psf, blockalign, samplesperblock)))
			return error ;

	if (psf->mode == SFM_WRITE)
		if ((error = ima_writer_init (psf, blockalign)))
			return error ;

	psf->seek = ima_seek ;
	psf->close = aiff_ima_close ;

	return 0 ;
} /* aiff_ima_init */

static int
aiff_ima_close	(SF_PRIVATE *psf)
{	IMA_ADPCM_PRIVATE *pima ;

	if (! psf->fdata)
		return 0 ;

	pima = (IMA_ADPCM_PRIVATE*) psf->fdata ;

	if (psf->mode == SFM_WRITE)
	{	/*	If a block has been partially assembled, write it out
		**	as the final block.
		*/

		if (pima->samplecount && pima->samplecount < pima->samplesperblock)
			pima->encode_block (psf, pima) ;

		if (psf->write_header)
			psf->write_header (psf, SF_TRUE) ;
		} ;

	free (psf->fdata) ;
	psf->fdata = NULL ;

	return 0 ;
} /* aiff_ima_close */

/*============================================================================================
** IMA ADPCM Read Functions.
*/

static int
ima_reader_init (SF_PRIVATE *psf, int blockalign, int samplesperblock)
{	IMA_ADPCM_PRIVATE	*pima ;
	int		pimasize, count ;

	if (psf->mode != SFM_READ)
		return SFE_BAD_MODE_RW ;

	pimasize = sizeof (IMA_ADPCM_PRIVATE) + blockalign * psf->sf.channels + 3 * psf->sf.channels * samplesperblock ;

	if (! (pima = malloc (pimasize)))
		return SFE_MALLOC_FAILED ;

	psf->fdata = (void*) pima ;

	memset (pima, 0, pimasize) ;

	pima->samples	= pima->data ;
	pima->block		= (unsigned char*) (pima->data + samplesperblock * psf->sf.channels) ;

	pima->channels			= psf->sf.channels ;
	pima->blocksize			= blockalign ;
	pima->samplesperblock	= samplesperblock ;

	psf->filelength = psf_get_filelen (psf) ;
	psf->datalength = (psf->dataend) ? psf->dataend - psf->dataoffset :
							psf->filelength - psf->dataoffset ;

	if (psf->datalength % pima->blocksize)
		pima->blocks = psf->datalength / pima->blocksize + 1 ;
	else
		pima->blocks = psf->datalength / pima->blocksize ;

	switch (psf->sf.format & SF_FORMAT_TYPEMASK)
	{	case SF_FORMAT_WAV :
		case SF_FORMAT_W64 :
				count = 2 * (pima->blocksize - 4 * pima->channels) / pima->channels + 1 ;

				if (pima->samplesperblock != count)
					psf_log_printf (psf, "*** Warning : samplesperblock should be %d.\n", count) ;

				pima->decode_block = wav_w64_ima_decode_block ;

				psf->sf.frames = pima->samplesperblock * pima->blocks ;
				break ;

		case SF_FORMAT_AIFF :
				psf_log_printf (psf, "still need to check block count\n") ;
				pima->decode_block = aiff_ima_decode_block ;
				psf->sf.frames = pima->samplesperblock * pima->blocks / pima->channels ;
				break ;

		default :
				psf_log_printf (psf, "ima_reader_init: bad psf->sf.format\n") ;
				return SFE_INTERNAL ;
				break ;
		} ;

	pima->decode_block (psf, pima) ;	/* Read first block. */

	psf->read_short		= ima_read_s ;
	psf->read_int		= ima_read_i ;
	psf->read_float		= ima_read_f ;
	psf->read_double	= ima_read_d ;

	return 0 ;
} /* ima_reader_init */

static int
aiff_ima_decode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima)
{	unsigned char *blockdata ;
	int		chan, k, diff, bytecode ;
	short	step, stepindx, predictor, *sampledata ;

static int count = 0 ;
count ++ ;

	pima->blockcount += pima->channels ;
	pima->samplecount = 0 ;

	if (pima->blockcount > pima->blocks)
	{	memset (pima->samples, 0, pima->samplesperblock * pima->channels * sizeof (short)) ;
		return 1 ;
		} ;

	if ((k = psf_fread (pima->block, 1, pima->blocksize * pima->channels, psf)) != pima->blocksize * pima->channels)
		psf_log_printf (psf, "*** Warning : short read (%d != %d).\n", k, pima->blocksize) ;

	/* Read and check the block header. */
	for (chan = 0 ; chan < pima->channels ; chan++)
	{	blockdata = pima->block + chan * 34 ;
		sampledata = pima->samples + chan ;

		predictor = (blockdata [0] << 8) | (blockdata [1] & 0x80) ;
		stepindx = blockdata [1] & 0x7F ;

{
if (count < 5)
printf ("\nchan: %d    predictor: %d    stepindx: %d (%d)\n",
	chan, predictor, stepindx, ima_step_size [stepindx]) ;
}
		/* FIXME : Do this a better way. */
		if (stepindx < 0) stepindx = 0 ;
		else if (stepindx > 88)	stepindx = 88 ;

		/*
		**	Pull apart the packed 4 bit samples and store them in their
		**	correct sample positions.
		*/
		for (k = 0 ; k < pima->blocksize - 2 ; k++)
		{	bytecode = blockdata [k + 2] ;
			sampledata [pima->channels * (2 * k + 0)] = bytecode & 0xF ;
			sampledata [pima->channels * (2 * k + 1)] = (bytecode >> 4) & 0xF ;
			} ;

		/* Decode the encoded 4 bit samples. */
		for (k = 0 ; k < pima->samplesperblock ; k ++)
		{	step = ima_step_size [stepindx] ;

			bytecode = pima->samples [pima->channels * k + chan] ;

			stepindx += ima_indx_adjust [bytecode] ;

			if (stepindx < 0) stepindx = 0 ;
			else if (stepindx > 88) stepindx = 88 ;

			diff = step >> 3 ;
			if (bytecode & 1)	diff += step >> 2 ;
			if (bytecode & 2)	diff += step >> 1 ;
			if (bytecode & 4)	diff += step ;
			if (bytecode & 8)	diff = -diff ;

			predictor += diff ;

			pima->samples [pima->channels * k + chan] = predictor ;
			} ;
		} ;

if (count < 5)
{
	for (k = 0 ; k < 10 ; k++)
		printf ("% 7d,", pima->samples [k]) ;
	puts ("") ;
}

	return 1 ;
} /* aiff_ima_decode_block */

static int
aiff_ima_encode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima)
{	int		chan, k, step, diff, vpdiff, blockindx, indx ;
	short	bytecode, mask ;

static int count = 0 ;
if (0 && count == 0)
{	pima->samples [0] = 0 ;
	printf ("blocksize : %d\n", pima->blocksize) ;
	printf ("pima->stepindx [0] : %d\n", pima->stepindx [0]) ;
	}
count ++ ;

	/* Encode the block header. */
	for (chan = 0 ; chan < pima->channels ; chan ++)
	{	blockindx = chan * pima->blocksize ;

		pima->block [blockindx] = (pima->samples [chan] >> 8) & 0xFF ;
		pima->block [blockindx + 1] = (pima->samples [chan] & 0x80) + (pima->stepindx [chan] & 0x7F) ;

		pima->previous [chan] = pima->samples [chan] ;
		} ;

	/* Encode second and later samples for every block as a 4 bit value. */
	for (k = pima->channels ; k < (pima->samplesperblock * pima->channels) ; k ++)
	{	chan = (pima->channels > 1) ? (k % 2) : 0 ;

		diff = pima->samples [k] - pima->previous [chan] ;

		bytecode = 0 ;
		step = ima_step_size [pima->stepindx [chan]] ;
		vpdiff = step >> 3 ;
		if (diff < 0)
		{	bytecode = 8 ;
			diff = -diff ;
			} ;
		mask = 4 ;
		while (mask)
		{	if (diff >= step)
			{	bytecode |= mask ;
				diff -= step ;
				vpdiff += step ;
				} ;
			step >>= 1 ;
			mask >>= 1 ;
			} ;

		if (bytecode & 8)
			pima->previous [chan] -= vpdiff ;
		else
			pima->previous [chan] += vpdiff ;

		if (pima->previous [chan] > 32767)
			pima->previous [chan] = 32767 ;
		else if (pima->previous [chan] < -32768)
			pima->previous [chan] = -32768 ;

		pima->stepindx [chan] += ima_indx_adjust [bytecode] ;
		if (pima->stepindx [chan] < 0)
			pima->stepindx [chan] = 0 ;
		else if (pima->stepindx [chan] > 88)
			pima->stepindx [chan] = 88 ;

		pima->samples [k] = bytecode ;
		} ;

	/* Pack the 4 bit encoded samples. */

	for (chan = 0 ; chan < pima->channels ; chan ++)
	{	for (indx = pima->channels ; indx < pima->channels * pima->samplesperblock ; indx += 2 * pima->channels)
		{	blockindx = chan * pima->blocksize + 2 + indx / 2 ;

if (0 && count ++ < 5)
	printf ("chan: %d    blockindx: %3d    indx: %3d\n", chan, blockindx, indx) ;

			pima->block [blockindx] = pima->samples [indx] & 0x0F ;
			pima->block [blockindx] |= (pima->samples [indx + pima->channels] << 4) & 0xF0 ;
			} ;
		} ;

	/* Write the block to disk. */

	if ((k = psf_fwrite (pima->block, 1, pima->channels * pima->blocksize, psf)) != pima->channels * pima->blocksize)
		psf_log_printf (psf, "*** Warning : short write (%d != %d).\n", k, pima->channels * pima->blocksize) ;

	memset (pima->samples, 0, pima->channels * pima->samplesperblock * sizeof (short)) ;
	pima->samplecount = 0 ;
	pima->blockcount ++ ;

	return 1 ;
} /* aiff_ima_encode_block */

static int
wav_w64_ima_decode_block (SF_PRIVATE *psf, IMA_ADPCM_PRIVATE *pima)
{	int		chan, k, current, blockindx, indx, indxstart, diff ;
	short	step, bytecode, stepindx [2] ;

	pima->blockcount ++ ;
	pima->samplecount = 0 ;

	if (pima->blockcount > pima->blocks)
	{	memset (pima->samples, 0, pima->samplesperblock * pima->channels * sizeof (short)) ;
		return 1 ;
		} ;

	if ((k = psf_fread (pima->block, 1, pima->blocksize, psf)) != pima->blocksize)
		psf_log_printf (psf, "*** Warning : short read (%d != %d).\n", k, pima->blocksize) ;

	/* Read and check the block header. */

	for (chan = 0 ; chan < pima->channels ; chan++)
	{	current = pima->block [chan*4] | (pima->block [chan*4+1] << 8) ;
		if (current & 0x8000)
			current -= 0x10000 ;

		stepindx [chan] = pima->block [chan*4+2] ;
		if (stepindx [chan] < 0)
			stepindx [chan] = 0 ;
		else if (stepindx [chan] > 88)
			stepindx [chan] = 88 ;

		if (pima->block [chan*4+3] != 0)
			psf_log_printf (psf, "IMA ADPCM synchronisation error.\n") ;

		pima->samples [chan] = current ;
		} ;

	/*
	**	Pull apart the packed 4 bit samples and store them in their
	**	correct sample positions.
	*/

	blockindx = 4 * pima->channels ;

	indxstart = pima->channels ;
	while (blockindx < pima->blocksize)
	{	for (chan = 0 ; chan < pima->channels ; chan++)
		{	indx = indxstart + chan ;
			for (k = 0 ; k < 4 ; k++)
			{	bytecode = pima->block [blockindx++] ;
				pima->samples [indx] = bytecode & 0x0F ;
				indx += pima->channels ;
				pima->samples [indx] = (bytecode >> 4) & 0x0F ;
				indx += pima->channels ;
				} ;
			} ;
		indxstart += 8 * pima->channels ;
		} ;

	/* Decode the encoded 4 bit samples. */

	for (k = pima->channels ; k < (pima->samplesperblock * pima->channels) ; k ++)
	{	chan = (pima->channels > 1) ? (k % 2) : 0 ;

		bytecode = pima->samples [k] & 0xF ;

		step = ima_step_size [stepindx [chan]] ;