ref: 941d0237545be9f19b8881d78e0799ab7ce1af8d
dir: /src/xa.c/
/* * xa.c Support for Maxis .XA file format * * Copyright (C) 2006 Dwayne C. Litzenberger <dlitz@dlitz.net> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 * USA * */ /* Thanks to Valery V. Anisimovsky <samael@avn.mccme.ru> for the * "Maxis XA Audio File Format Description", dated 5-01-2002. */ #include <string.h> #include <stdlib.h> #include <stdio.h> #ifdef HAVE_UNISTD_H #include <unistd.h> /* For SEEK_* defines if not found in stdio */ #endif #include "sox_i.h" #define HNIBBLE(byte) (((byte) >> 4) & 0xf) #define LNIBBLE(byte) ((byte) & 0xf) /* .xa file header */ typedef struct { char magic[4]; /* "XA\0\0", "XAI\0" (sound/speech), or "XAJ\0" (music) */ uint32_t outSize; /* decompressed size of the stream (in bytes) */ /* WAVEFORMATEX structure for the decompressed data */ uint16_t tag; /* 0x0001 - PCM data */ uint16_t channels; /* number of channels */ uint32_t sampleRate; /* sample rate (samples/sec) */ uint32_t avgByteRate; /* sampleRate * align */ uint16_t align; /* bits / 8 * channels */ uint16_t bits; /* 8 or 16 */ } xa_header_t; typedef struct { int32_t curSample; /* current sample */ int32_t prevSample; /* previous sample */ int32_t c1; int32_t c2; unsigned int shift; } xa_state_t; /* Private data for .xa file */ typedef struct xastuff { xa_header_t header; xa_state_t *state; unsigned int blockSize; unsigned int bufPos; /* position within the current block */ unsigned char *buf; /* buffer for the current block */ unsigned int bytesDecoded; /* number of decompressed bytes read */ } *xa_t; /* coefficients for EA ADPCM */ static int32_t EA_ADPCM_Table[]= { 0, 240, 460, 392, 0, 0, -208, -220, 0, 1, 3, 4, 7, 8, 10, 11, 0, -1, -3, -4 }; /* Clip sample to 16 bits */ static inline int32_t clip16(int32_t sample) { if (sample > 32767) { return 32767; } else if (sample < -32768) { return -32768; } else { return sample; } } static int sox_xastartread(sox_format_t * ft) { xa_t xa = (xa_t) ft->priv; char *magic = xa->header.magic; /* Check for the magic value */ if (sox_readbuf(ft, xa->header.magic, 4) != 4 || (memcmp("XA\0\0", xa->header.magic, 4) != 0 && memcmp("XAI\0", xa->header.magic, 4) != 0 && memcmp("XAJ\0", xa->header.magic, 4) != 0)) { sox_fail_errno(ft, SOX_EHDR, "XA: Header not found"); return SOX_EOF; } /* Read the rest of the header */ if (sox_readdw(ft, &xa->header.outSize) != SOX_SUCCESS) return SOX_EOF; if (sox_readw(ft, &xa->header.tag) != SOX_SUCCESS) return SOX_EOF; if (sox_readw(ft, &xa->header.channels) != SOX_SUCCESS) return SOX_EOF; if (sox_readdw(ft, &xa->header.sampleRate) != SOX_SUCCESS) return SOX_EOF; if (sox_readdw(ft, &xa->header.avgByteRate) != SOX_SUCCESS) return SOX_EOF; if (sox_readw(ft, &xa->header.align) != SOX_SUCCESS) return SOX_EOF; if (sox_readw(ft, &xa->header.bits) != SOX_SUCCESS) return SOX_EOF; /* Output the data from the header */ sox_debug("XA Header:"); sox_debug(" szID: %02x %02x %02x %02x |%c%c%c%c|", magic[0], magic[1], magic[2], magic[3], (magic[0] >= 0x20 && magic[0] <= 0x7e) ? magic[0] : '.', (magic[1] >= 0x20 && magic[1] <= 0x7e) ? magic[1] : '.', (magic[2] >= 0x20 && magic[2] <= 0x7e) ? magic[2] : '.', (magic[3] >= 0x20 && magic[3] <= 0x7e) ? magic[3] : '.'); sox_debug(" dwOutSize: %u", xa->header.outSize); sox_debug(" wTag: 0x%04x", xa->header.tag); sox_debug(" wChannels: %u", xa->header.channels); sox_debug(" dwSampleRate: %u", xa->header.sampleRate); sox_debug(" dwAvgByteRate: %u", xa->header.avgByteRate); sox_debug(" wAlign: %u", xa->header.align); sox_debug(" wBits: %u", xa->header.bits); /* Populate the sox_soundstream structure */ ft->signal.encoding = SOX_ENCODING_SIGN2; if (!ft->signal.size || ft->signal.size == (xa->header.bits >> 3)) { ft->signal.size = xa->header.bits >> 3; } else { sox_report("User options overriding size read in .xa header"); } if (ft->signal.channels == 0 || ft->signal.channels == xa->header.channels) { ft->signal.channels = xa->header.channels; } else { sox_report("User options overriding channels read in .xa header"); } if (ft->signal.rate == 0 || ft->signal.rate == xa->header.sampleRate) { ft->signal.rate = xa->header.sampleRate; } else { sox_report("User options overriding rate read in .xa header"); } /* Check for supported formats */ if (ft->signal.size != 2) { sox_fail_errno(ft, SOX_EFMT, "%d-bit sample resolution not supported.", ft->signal.size << 3); return SOX_EOF; } /* Validate the header */ if (xa->header.bits != ft->signal.size << 3) { sox_report("Invalid sample resolution %d bits. Assuming %d bits.", xa->header.bits, ft->signal.size << 3); xa->header.bits = ft->signal.size << 3; } if (xa->header.align != ft->signal.size * xa->header.channels) { sox_report("Invalid sample alignment value %d. Assuming %d.", xa->header.align, ft->signal.size * xa->header.channels); xa->header.align = ft->signal.size * xa->header.channels; } if (xa->header.avgByteRate != (xa->header.align * xa->header.sampleRate)) { sox_report("Invalid dwAvgByteRate value %d. Assuming %d.", xa->header.avgByteRate, xa->header.align * xa->header.sampleRate); xa->header.avgByteRate = xa->header.align * xa->header.sampleRate; } /* Set up the block buffer */ xa->blockSize = ft->signal.channels * 0xf; xa->bufPos = xa->blockSize; /* Allocate memory for the block buffer */ xa->buf = (unsigned char *)xcalloc(1, xa->blockSize); /* Allocate memory for the state */ xa->state = (xa_state_t *)xcalloc(sizeof(xa_state_t), ft->signal.channels); /* Final initialization */ xa->bytesDecoded = 0; return SOX_SUCCESS; } /* * Read up to len samples from a file, converted to signed longs. * Return the number of samples read. */ static sox_size_t sox_xaread(sox_format_t * ft, sox_sample_t *buf, sox_size_t len) { xa_t xa = (xa_t) ft->priv; int32_t sample; unsigned char inByte; size_t i, done, bytes; ft->sox_errno = SOX_SUCCESS; done = 0; while (done < len) { if (xa->bufPos >= xa->blockSize) { /* Read the next block */ bytes = sox_readbuf(ft, xa->buf, xa->blockSize); if (bytes < xa->blockSize) { if (sox_eof(ft)) { if (done > 0) { return done; } sox_fail_errno(ft,SOX_EOF,"Premature EOF on .xa input file"); return 0; } else { /* error */ sox_fail_errno(ft,SOX_EOF,"read error on input stream"); return 0; } } xa->bufPos = 0; for (i = 0; i < ft->signal.channels; i++) { inByte = xa->buf[i]; xa->state[i].c1 = EA_ADPCM_Table[HNIBBLE(inByte)]; xa->state[i].c2 = EA_ADPCM_Table[HNIBBLE(inByte) + 4]; xa->state[i].shift = LNIBBLE(inByte) + 8; } xa->bufPos += ft->signal.channels; } else { /* Process the block */ for (i = 0; i < ft->signal.channels && done < len; i++) { /* high nibble */ sample = HNIBBLE(xa->buf[xa->bufPos+i]); sample = (sample << 28) >> xa->state[i].shift; sample = (sample + xa->state[i].curSample * xa->state[i].c1 + xa->state[i].prevSample * xa->state[i].c2 + 0x80) >> 8; sample = clip16(sample); xa->state[i].prevSample = xa->state[i].curSample; xa->state[i].curSample = sample; buf[done++] = SOX_SIGNED_16BIT_TO_SAMPLE(sample,); xa->bytesDecoded += ft->signal.size; } for (i = 0; i < ft->signal.channels && done < len; i++) { /* low nibble */ sample = LNIBBLE(xa->buf[xa->bufPos+i]); sample = (sample << 28) >> xa->state[i].shift; sample = (sample + xa->state[i].curSample * xa->state[i].c1 + xa->state[i].prevSample * xa->state[i].c2 + 0x80) >> 8; sample = clip16(sample); xa->state[i].prevSample = xa->state[i].curSample; xa->state[i].curSample = sample; buf[done++] = SOX_SIGNED_16BIT_TO_SAMPLE(sample,); xa->bytesDecoded += ft->signal.size; } xa->bufPos += ft->signal.channels; } } if (done == 0) { return 0; } return done; } static int sox_xastopread(sox_format_t * ft) { xa_t xa = (xa_t) ft->priv; ft->sox_errno = SOX_SUCCESS; /* Free memory */ free(xa->buf); xa->buf = NULL; free(xa->state); xa->state = NULL; return SOX_SUCCESS; } static int sox_xastartwrite(sox_format_t * ft) { sox_fail_errno(ft, SOX_ENOTSUP, ".XA writing not supported"); return SOX_EOF; } static sox_size_t sox_xawrite(sox_format_t * ft, const sox_sample_t *buf UNUSED, sox_size_t len UNUSED) { sox_fail_errno(ft, SOX_ENOTSUP, ".XA writing not supported"); return 0; } static int sox_xastopwrite(sox_format_t * ft) { sox_fail_errno(ft, SOX_ENOTSUP, ".XA writing not supported"); return SOX_EOF; } static int sox_xaseek(sox_format_t * ft, sox_size_t offset) { return sox_format_nothing_seek(ft, offset); } /* Maxis .xa */ static const char *xanames[] = { "xa", NULL }; sox_format_handler_t sox_xa_format = { xanames, SOX_FILE_LIT_END, sox_xastartread, sox_xaread, sox_xastopread, sox_xastartwrite, sox_xawrite, sox_xastopwrite, sox_xaseek }; const sox_format_handler_t *sox_xa_format_fn(void); const sox_format_handler_t *sox_xa_format_fn(void) { return &sox_xa_format; }