ref: 226e1dba5c5f44b4004ffe9c438c9c24af369a01
dir: /src/cdr.c/
/* * CD-R format handler * * David Elliott, Sony Microsystems - July 5, 1991 * * Copyright 1991 David Elliott And Sundry Contributors * This source code is freely redistributable and may be used for * any purpose. This copyright notice must be maintained. * Lance Norskog And Sundry Contributors are not responsible for * the consequences of using this software. * * This code automatically handles endianness differences * * cbagwell (cbagwell@sprynet.com) - 20 April 1998 * * Changed endianness handling. Seemed to be reversed (since format * is in big endian) and made it so that user could always override * swapping no matter what endian machine they are one. * * Fixed bug were trash could be appended to end of file for certain * endian machines. * */ #include "st_i.h" #define SECTORSIZE (2352 / 2) /* Private data for SKEL file */ typedef struct cdrstuff { st_size_t samples; /* number of samples written */ } *cdr_t; /* * Do anything required before you start reading samples. * Read file header. * Find out sampling rate, * size and encoding of samples, * mono/stereo/quad. */ int st_cdrstartread(ft_t ft) { int rc; /* Needed because of rawread() */ rc = st_rawstartread(ft); if (rc) return rc; /* CDR is in Big Endian format. Swap whats read in on */ /* Little Endian machines. */ if (ST_IS_LITTLEENDIAN) { ft->swap = ft->swap ? 0 : 1; } ft->info.rate = 44100L; ft->info.size = ST_SIZE_WORD; ft->info.encoding = ST_ENCODING_SIGN2; ft->info.channels = 2; ft->comment = NULL; /* Need length for seeking */ if(ft->seekable){ ft->length = st_filelength(ft)/2; } else { ft->length = 0; } return(ST_SUCCESS); } /* * Read up to len samples from file. * Convert to signed longs. * Place in buf[]. * Return number of samples read. */ st_ssize_t st_cdrread(ft_t ft, st_sample_t *buf, st_ssize_t len) { return st_rawread(ft, buf, len); } /* * Do anything required when you stop reading samples. * Don't close input file! */ int st_cdrstopread(ft_t ft) { /* Needed because of rawread() */ return st_rawstopread(ft); } int st_cdrstartwrite(ft_t ft) { cdr_t cdr = (cdr_t) ft->priv; int rc; /* CDR is in Big Endian format. Swap whats written out on */ /* Little Endian Machines. */ if (ST_IS_LITTLEENDIAN) { ft->swap = ft->swap ? 0 : 1; } /* Needed because of rawwrite() */ rc = st_rawstartwrite(ft); if (rc) return rc; cdr->samples = 0; ft->info.rate = 44100L; ft->info.size = ST_SIZE_WORD; ft->info.encoding = ST_ENCODING_SIGN2; ft->info.channels = 2; return(ST_SUCCESS); } st_ssize_t st_cdrwrite(ft_t ft, st_sample_t *buf, st_ssize_t len) { cdr_t cdr = (cdr_t) ft->priv; cdr->samples += len; return st_rawwrite(ft, buf, len); } /* * A CD-R file needs to be padded to SECTORSIZE, which is in terms of * samples. We write -32768 for each sample to pad it out. */ int st_cdrstopwrite(ft_t ft) { cdr_t cdr = (cdr_t) ft->priv; int padsamps = SECTORSIZE - (cdr->samples % SECTORSIZE); short zero; int rc; /* Flush buffer before writing anything else */ rc = st_rawstopwrite(ft); if (rc) return rc; zero = 0; if (padsamps != SECTORSIZE) { while (padsamps > 0) { st_writew(ft, zero); padsamps--; } } return(ST_SUCCESS); }