/*------------------------------------------------------------------------------ File : AIFF.c Author : Stéphane TAVENARD $VER: AIFF.c 1.0 (23/06/1995) (C) Copyright 1995-1995 Stéphane TAVENARD All Rights Reserved #Rev| Date | Comment ----|----------|-------------------------------------------------------- 0 |05/06/1995| Initial revision from file common.c of | | MPEG/audio software simulation group ST 1 |23/06/1995| Aminet release ST ------------------------------------------------------------------------ AIFF utilities ------------------------------------------------------------------------------*/ #include #include #include #include "AIFF.h" #define BITS_IN_A_BYTE 8 /**************************************************************************** * * Routines to convert between the Apple SANE extended floating point format * and the IEEE double precision floating point format. These routines are * called from within the Audio Interchange File Format (AIFF) routines. * *****************************************************************************/ /* *** Apple's 80-bit SANE extended has the following format: 1 15 1 63 +-+-------------+-+-----------------------------+ |s| e |i| f | +-+-------------+-+-----------------------------+ msb lsb msb lsb The value v of the number is determined by these fields as follows: If 0 <= e < 32767, then v = (-1)^s * 2^(e-16383) * (i.f). If e == 32767 and f == 0, then v = (-1)^s * (infinity), regardless of i. If e == 32767 and f != 0, then v is a NaN, regardless of i. *** IEEE Draft Standard 754 Double Precision has the following format: MSB +-+---------+-----------------------------+ |1| 11 Bits | 52 Bits | +-+---------+-----------------------------+ ^ ^ ^ | | | Sign Exponent Mantissa */ /***************************************************************************** * * double_to_extended() * * Purpose: Convert from IEEE double precision format to SANE extended * format. * * Passed: Pointer to the double precision number and a pointer to what * will hold the Apple SANE extended format value. * * Outputs: The SANE extended format pointer will be filled with the * converted value. * * Returned: Nothing. * *****************************************************************************/ static void double_to_extended( double *pd, char ps[ 10 ] ) { register unsigned long top2bits; register unsigned short *ps2; register IEEE_DBL *p_dbl; register SANE_EXT *p_ext; p_dbl = (IEEE_DBL *) pd; p_ext = (SANE_EXT *) ps; top2bits = p_dbl->hi & 0xc0000000; p_ext->l1 = ((p_dbl->hi >> 4) & 0x3ff0000) | top2bits; p_ext->l1 |= ((p_dbl->hi >> 5) & 0x7fff) | 0x8000; p_ext->l2 = (p_dbl->hi << 27) & 0xf8000000; p_ext->l2 |= ((p_dbl->lo >> 5) & 0x07ffffff); ps2 = (unsigned short *) & (p_dbl->lo); ps2++; p_ext->s1 = (*ps2 << 11) & 0xf800; } /***************************************************************************** * * extended_to_double() * * Purpose: Convert from SANE extended format to IEEE double precision * format. * * Passed: Pointer to the Apple SANE extended format value and a pointer * to what will hold the the IEEE double precision number. * * Outputs: The IEEE double precision format pointer will be filled with * the converted value. * * Returned: Nothing. * *****************************************************************************/ static void extended_to_double( char ps[ 10 ], double *pd ) { register unsigned long top2bits; register IEEE_DBL *p_dbl; register SANE_EXT *p_ext; p_dbl = (IEEE_DBL *) pd; p_ext = (SANE_EXT *) ps; top2bits = p_ext->l1 & 0xc0000000; p_dbl->hi = ((p_ext->l1 << 4) & 0x3ff00000) | top2bits; p_dbl->hi |= (p_ext->l1 << 5) & 0xffff0; p_dbl->hi |= (p_ext->l2 >> 27) & 0x1f; p_dbl->lo = (p_ext->l2 << 5) & 0xffffffe0; p_dbl->lo |= (unsigned long) ((p_ext->s1 >> 11) & 0x1f); } /***************************************************************************** * * Read Audio Interchange File Format (AIFF) headers. * *****************************************************************************/ int AIFF_read_headers( FILE *file_ptr, IFF_AIFF *aiff_ptr ) { register long seek_offset; register long sound_position; ChunkHeader Header; Chunk FormChunk; CommonChunk CommChunk; SoundDataChunk SndDChunk; if( fseek( file_ptr, 0, SEEK_SET ) != 0 ) return -1; if( fread( &FormChunk, sizeof(Chunk), 1, file_ptr ) != 1 ) return -1; if( (FormChunk.ckID != IFF_ID_FORM) || (FormChunk.formType != IFF_ID_AIFF) ) return -1; /* * chunks need not be in any particular order */ while( fread( &Header, sizeof(ChunkHeader), 1, file_ptr ) == 1 ) { if( Header.ckID == IFF_ID_COMM ) { /* * read comm chunk */ if( fread( &CommChunk.numChannels, sizeof(CommonChunk) - sizeof(ChunkHeader), 1, file_ptr ) != 1 ) return -1; extended_to_double( CommChunk.sampleRate, &aiff_ptr->sampleRate); aiff_ptr->numChannels = CommChunk.numChannels; aiff_ptr->numSampleFrames = CommChunk.numSampleFrames; aiff_ptr->sampleSize = CommChunk.sampleSize; } else if( Header.ckID == IFF_ID_SSND ) { /* * read ssnd chunk */ if( fread( &SndDChunk.offset, sizeof(SoundDataChunk) - sizeof(ChunkHeader), 1, file_ptr ) != 1 ) return -1; aiff_ptr->blkAlgn.offset = SndDChunk.offset; aiff_ptr->blkAlgn.blockSize = SndDChunk.blockSize; aiff_ptr->sampleType = *(unsigned long *)Header.ckID; /* * record position of sound data */ sound_position = ftell(file_ptr); /* * skip over sound data to look at remaining chunks */ seek_offset = Header.ckSize - sizeof(SoundDataChunk) + sizeof(ChunkHeader); if( fseek( file_ptr, seek_offset, SEEK_CUR ) != 0 ) return -1; } else { /* * skip unknown chunk */ seek_offset = Header.ckSize; if( fseek( file_ptr, seek_offset, SEEK_CUR ) != 0 ) return -1; } } return sound_position ; } /***************************************************************************** * * Seek past some Audio Interchange File Format (AIFF) headers to sound data. * *****************************************************************************/ int AIFF_seek_to_sound_data( FILE *file_ptr ) { if( fwrite( NULL, sizeof(Chunk) + sizeof(CommonChunk) + sizeof(SoundDataChunk), 1, file_ptr ) != 1) return -1; return 0; } /******************************************************************************* * * Write Audio Interchange File Format (AIFF) headers. * *******************************************************************************/ int AIFF_write_headers( FILE *file_ptr, IFF_AIFF *aiff_ptr ) { Chunk FormChunk; CommonChunk CommChunk; SoundDataChunk SndDChunk; FormChunk.ckID = IFF_ID_FORM; FormChunk.formType = IFF_ID_AIFF; CommChunk.ckID = IFF_ID_COMM; double_to_extended( &aiff_ptr->sampleRate, CommChunk.sampleRate ); CommChunk.numChannels = aiff_ptr->numChannels; CommChunk.numSampleFrames = aiff_ptr->numSampleFrames; CommChunk.sampleSize = aiff_ptr->sampleSize; SndDChunk.offset = aiff_ptr->blkAlgn.offset; SndDChunk.blockSize = aiff_ptr->blkAlgn.blockSize; SndDChunk.ckID = aiff_ptr->sampleType; CommChunk.ckSize = sizeof(CommonChunk) - sizeof(ChunkHeader); SndDChunk.ckSize = sizeof(SoundDataChunk) - sizeof(ChunkHeader) + (CommChunk.sampleSize + BITS_IN_A_BYTE - 1) / BITS_IN_A_BYTE * CommChunk.numChannels * CommChunk.numSampleFrames; FormChunk.ckSize = sizeof(Chunk) + SndDChunk.ckSize + sizeof(ChunkHeader) + CommChunk.ckSize; if( fseek( file_ptr, 0, SEEK_SET ) != 0 ) return -1; if( fwrite( &FormChunk, sizeof(Chunk), 1, file_ptr ) != 1 ) return -1; if( fwrite( &CommChunk, sizeof(CommChunk), 1, file_ptr) != 1 ) return -1; if( fwrite( &SndDChunk, sizeof(SoundDataChunk), 1, file_ptr) != 1 ) return -1; return 0; }