src/nist.c

/*
** Copyright (C) 1999-2017 Erik de Castro Lopo <erikd@mega-nerd.com>
**
** 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.
*/

/*
**	Some of the information used to read NIST files was gleaned from
**	reading the code of Bill Schottstaedt's sndlib library
**		ftp://ccrma-ftp.stanford.edu/pub/Lisp/sndlib.tar.gz
**	However, no code from that package was used.
*/

#include	"sfconfig.h"

#include	<stdio.h>
#include	<fcntl.h>
#include	<string.h>
#include	<ctype.h>

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

/*------------------------------------------------------------------------------
*/

#define	NIST_HEADER_LENGTH	1024

/*------------------------------------------------------------------------------
** Private static functions.
*/

static	int	nist_close	(SF_PRIVATE *psf) ;
static	int nist_write_header	(SF_PRIVATE *psf, int calc_length) ;
static	int nist_read_header	(SF_PRIVATE *psf) ;

/*------------------------------------------------------------------------------
*/

int
nist_open	(SF_PRIVATE *psf)
{	int error ;

	if (psf->file.mode == SFM_READ || (psf->file.mode == SFM_RDWR && psf->filelength > 0))
	{	if ((error = nist_read_header (psf)))
			return error ;
		} ;

	if (psf->file.mode == SFM_WRITE || psf->file.mode == SFM_RDWR)
	{	if (psf->is_pipe)
			return SFE_NO_PIPE_WRITE ;

		if ((SF_CONTAINER (psf->sf.format)) != SF_FORMAT_NIST)
			return	SFE_BAD_OPEN_FORMAT ;

		psf->endian = SF_ENDIAN (psf->sf.format) ;
		if (psf->endian == 0 || psf->endian == SF_ENDIAN_CPU)
			psf->endian = (CPU_IS_BIG_ENDIAN) ? SF_ENDIAN_BIG : SF_ENDIAN_LITTLE ;

		psf->blockwidth = psf->bytewidth * psf->sf.channels ;
		psf->sf.frames = 0 ;

		if ((error = nist_write_header (psf, SF_FALSE)))
			return error ;

		psf->write_header = nist_write_header ;
		} ;

	psf->container_close = nist_close ;

	switch (SF_CODEC (psf->sf.format))
	{	case SF_FORMAT_PCM_S8 :
				error = pcm_init (psf) ;
				break ;

		case SF_FORMAT_PCM_16 :
		case SF_FORMAT_PCM_24 :
		case SF_FORMAT_PCM_32 :
				error = pcm_init (psf) ;
				break ;

		case SF_FORMAT_ULAW :
				error = ulaw_init (psf) ;
				break ;

		case SF_FORMAT_ALAW :
				error = alaw_init (psf) ;
				break ;

		default : error = SFE_UNIMPLEMENTED ;
				break ;
		} ;

	return error ;
} /* nist_open */

/*------------------------------------------------------------------------------
*/

static char bad_header [] =
{	'N', 'I', 'S', 'T', '_', '1', 'A', 0x0d, 0x0a,
	' ', ' ', ' ', '1', '0', '2', '4', 0x0d, 0x0a,
	0
} ;

	static int
nist_read_header (SF_PRIVATE *psf)
{	char	psf_header [NIST_HEADER_LENGTH + 2] ;
	int		bitwidth = 0, count, encoding ;
	unsigned bytes = 0 ;
	char 	str [64], *cptr ;
	long	samples ;

	/* Go to start of file and read in the whole header. */
	psf_binheader_readf (psf, "pb", 0, psf_header, NIST_HEADER_LENGTH) ;

	/* Header is a string, so make sure it is null terminated. */
	psf_header [NIST_HEADER_LENGTH] = 0 ;

	/* Now trim the header after the end marker. */
	if ((cptr = strstr (psf_header, "end_head")))
	{	cptr += strlen ("end_head") + 1 ;
		cptr [0] = 0 ;
		} ;

	if (strstr (psf_header, bad_header) == psf_header)
		return SFE_NIST_CRLF_CONVERISON ;

	/* Make sure its a NIST file. */
	if (strstr (psf_header, "NIST_1A\n") != psf_header)
	{	psf_log_printf (psf, "Not a NIST file.\n") ;
		return SFE_NIST_BAD_HEADER ;
		} ;

	if (sscanf (psf_header, "NIST_1A\n%d\n", &count) == 1)
		psf->dataoffset = count ;
	else
	{	psf_log_printf (psf, "*** Suspicious header length.\n") ;
		psf->dataoffset = NIST_HEADER_LENGTH ;
		} ;

	/* Determine sample encoding, start by assuming PCM. */
	encoding = SF_FORMAT_PCM_U8 ;
	if ((cptr = strstr (psf_header, "sample_coding -s")))
	{	sscanf (cptr, "sample_coding -s%d %63s", &count, str) ;

		if (strcmp (str, "pcm") == 0)
		{	/* Correct this later when we find out the bitwidth. */
			encoding = SF_FORMAT_PCM_U8 ;
			}
		else if (strcmp (str, "alaw") == 0)
			encoding = SF_FORMAT_ALAW ;
		else if ((strcmp (str, "ulaw") == 0) || (strcmp (str, "mu-law") == 0))
			encoding = SF_FORMAT_ULAW ;
		else
		{	psf_log_printf (psf, "*** Unknown encoding : %s\n", str) ;
			encoding = 0 ;
			} ;
		} ;

	if ((cptr = strstr (psf_header, "channel_count -i ")) != NULL)
		sscanf (cptr, "channel_count -i %d", &(psf->sf.channels)) ;

	if ((cptr = strstr (psf_header, "sample_rate -i ")) != NULL)
		sscanf (cptr, "sample_rate -i %d", &(psf->sf.samplerate)) ;

	if ((cptr = strstr (psf_header, "sample_count -i ")) != NULL)
	{	sscanf (cptr, "sample_count -i %ld", &samples) ;
		psf->sf.frames = samples ;
		} ;

	if ((cptr = strstr (psf_header, "sample_n_bytes -i ")) != NULL)
		sscanf (cptr, "sample_n_bytes -i %d", &(psf->bytewidth)) ;

	/* Default endian-ness (for 8 bit, u-law, A-law. */
	psf->endian = (CPU_IS_BIG_ENDIAN) ? SF_ENDIAN_BIG : SF_ENDIAN_LITTLE ;

	/* This is where we figure out endian-ness. */
	if ((cptr = strstr (psf_header, "sample_byte_format -s"))
		&& sscanf (cptr, "sample_byte_format -s%u %8s", &bytes, str) == 2)
	{
		if (bytes != strlen (str))
			psf_log_printf (psf, "Weird sample_byte_format : strlen '%s' != %d\n", str, bytes) ;

		if (bytes > 1)
		{	if (psf->bytewidth == 0)
				psf->bytewidth = bytes ;
			else if (psf->bytewidth - bytes != 0)
			{	psf_log_printf (psf, "psf->bytewidth (%d) != bytes (%d)\n", psf->bytewidth, bytes) ;
				return SFE_NIST_BAD_ENCODING ;
				} ;

			if (strcmp (str, "01") == 0)
				psf->endian = SF_ENDIAN_LITTLE ;
			else if (strcmp (str, "10") == 0)
				psf->endian = SF_ENDIAN_BIG ;
			else
			{	psf_log_printf (psf, "Weird endian-ness : %s\n", str) ;
				return SFE_NIST_BAD_ENCODING ;
				} ;
			} ;

		psf->sf.format |= psf->endian ;
		} ;

	if ((cptr = strstr (psf_header, "sample_sig_bits -i ")))
		sscanf (cptr, "sample_sig_bits -i %d", &bitwidth) ;

	if (strstr (psf_header, "channels_interleaved -s5 FALSE"))
	{	psf_log_printf (psf, "Non-interleaved data unsupported.\n", str) ;
		return SFE_NIST_BAD_ENCODING ;
		} ;

	psf->blockwidth = psf->sf.channels * psf->bytewidth ;
	psf->datalength = psf->filelength - psf->dataoffset ;

	psf_fseek (psf, psf->dataoffset, SEEK_SET) ;

	if (encoding == SF_FORMAT_PCM_U8)
	{	switch (psf->bytewidth)
		{	case 1 :
					psf->sf.format |= SF_FORMAT_PCM_S8 ;
					break ;

			case 2 :
					psf->sf.format |= SF_FORMAT_PCM_16 ;
					break ;

			case 3 :
					psf->sf.format |= SF_FORMAT_PCM_24 ;
					break ;

			case 4 :
					psf->sf.format |= SF_FORMAT_PCM_32 ;
					break ;

			default : break ;
			} ;
		}
	else if (encoding != 0)
		psf->sf.format |= encoding ;
	else
		return SFE_UNIMPLEMENTED ;

	/* Sanitize psf->sf.format. */
	switch (SF_CODEC (psf->sf.format))
	{	case SF_FORMAT_ULAW :
		case SF_FORMAT_ALAW :
		case SF_FORMAT_PCM_U8 :
			/* Blank out endian bits. */
			psf->sf.format = SF_FORMAT_NIST | SF_CODEC (psf->sf.format) ;
			break ;

		default :
			break ;
		} ;

	return 0 ;
} /* nist_read_header */

static int
nist_close	(SF_PRIVATE *psf)
{
	if (psf->file.mode == SFM_WRITE || psf->file.mode == SFM_RDWR)
		nist_write_header (psf, SF_TRUE) ;

	return 0 ;
} /* nist_close */

/*=========================================================================
*/

static int
nist_write_header (SF_PRIVATE *psf, int calc_length)
{	const char	*end_str ;
	long		samples ;
	sf_count_t	current ;

	current = psf_ftell (psf) ;

	if (calc_length)
	{	psf->filelength = psf_get_filelen (psf) ;

		psf->datalength = psf->filelength - psf->dataoffset ;

		if (psf->dataend)
			psf->datalength -= psf->filelength - psf->dataend ;

		if (psf->bytewidth > 0)
			psf->sf.frames = psf->datalength / (psf->bytewidth * psf->sf.channels) ;
		} ;

	if (psf->endian == SF_ENDIAN_BIG)
		end_str = "10" ;
	else if (psf->endian == SF_ENDIAN_LITTLE)
		end_str = "01" ;
	else
		end_str = "error" ;

	/* Clear the whole header. */
	memset (psf->header.ptr, 0, psf->header.len) ;
	psf->header.indx = 0 ;

	psf_fseek (psf, 0, SEEK_SET) ;

	psf_asciiheader_printf (psf, "NIST_1A\n   1024\n") ;
	psf_asciiheader_printf (psf, "channel_count -i %d\n", psf->sf.channels) ;
	psf_asciiheader_printf (psf, "sample_rate -i %d\n", psf->sf.samplerate) ;

	switch (SF_CODEC (psf->sf.format))
	{	case SF_FORMAT_PCM_S8 :
				psf_asciiheader_printf (psf, "sample_coding -s3 pcm\n") ;
				psf_asciiheader_printf (psf, "sample_n_bytes -i 1\n"
											"sample_sig_bits -i 8\n") ;
				break ;

		case SF_FORMAT_PCM_16 :
		case SF_FORMAT_PCM_24 :
		case SF_FORMAT_PCM_32 :
				psf_asciiheader_printf (psf, "sample_n_bytes -i %d\n", psf->bytewidth) ;
				psf_asciiheader_printf (psf, "sample_sig_bits -i %d\n", psf->bytewidth * 8) ;
				psf_asciiheader_printf (psf, "sample_coding -s3 pcm\n"
								"sample_byte_format -s%d %s\n", psf->bytewidth, end_str) ;
				break ;

		case SF_FORMAT_ALAW :
				psf_asciiheader_printf (psf, "sample_coding -s4 alaw\n") ;
				psf_asciiheader_printf (psf, "sample_n_bytes -s1 1\n") ;
				break ;

		case SF_FORMAT_ULAW :
				psf_asciiheader_printf (psf, "sample_coding -s4 ulaw\n") ;
				psf_asciiheader_printf (psf, "sample_n_bytes -s1 1\n") ;
				break ;

		default : return SFE_UNIMPLEMENTED ;
		} ;

	psf->dataoffset = NIST_HEADER_LENGTH ;

	/* Fix this */
	samples = psf->sf.frames ;
	psf_asciiheader_printf (psf, "sample_count -i %ld\n", samples) ;
	psf_asciiheader_printf (psf, "end_head\n") ;

	/* Zero fill to dataoffset. */
	psf_binheader_writef (psf, "z", BHWz ((size_t) (NIST_HEADER_LENGTH - psf->header.indx))) ;

	psf_fwrite (psf->header.ptr, psf->header.indx, 1, psf) ;

	if (psf->error)
		return psf->error ;

	if (current > 0)
		psf_fseek (psf, current, SEEK_SET) ;

	return psf->error ;
} /* nist_write_header */