/** * SDL_sound; An abstract sound format decoding API. * * Please see the file LICENSE.txt in the source's root directory. * * This file written by Torbjörn Andersson. */ /* * AIFF decoder for SDL_sound * * [Insert something profound about the AIFF file format here.] * * This code was ripped from a decoder I had written for SDL_mixer, which was * based on SDL_mixer's old AIFF music loader. (This loader was unfortunately * completely broken, but it was still useful because all the pieces were * still there, so to speak.) * * When rewriting it for SDL_sound, I changed its structure to be more like * the WAV loader Ryan wrote. Had they not both been part of the same project * it would have been embarrassing how similar they are. * * It is not the most feature-complete AIFF loader the world has ever seen. * For instance, it only makes a token attempt at implementing the AIFF-C * standard; basically the parts of it that I can easily understand and test. * It's a start, though. */ #define __SDL_SOUND_INTERNAL__ #include "SDL_sound_internal.h" #if SOUND_SUPPORTS_AIFF /***************************************************************************** * aiff_t is what we store in our internal->decoder_private field... * *****************************************************************************/ typedef struct S_AIFF_FMT_T { Uint32 type; Uint32 total_bytes; Uint32 data_starting_offset; void (*free)(struct S_AIFF_FMT_T *fmt); Uint32 (*read_sample)(Sound_Sample *sample); int (*rewind_sample)(Sound_Sample *sample); int (*seek_sample)(Sound_Sample *sample, Uint32 ms); #if 0 /* this is ripped from wav.c as ann example of format-specific data. please replace with something more appropriate when the need arises. */ union { struct { Uint16 cbSize; Uint16 wSamplesPerBlock; Uint16 wNumCoef; ADPCMCOEFSET *aCoeff; } adpcm; /* put other format-specific data here... */ } fmt; #endif } fmt_t; typedef struct { fmt_t fmt; Sint32 bytesLeft; } aiff_t; /* Chunk management code... */ #define formID 0x4D524F46 /* "FORM", in ascii. */ #define aiffID 0x46464941 /* "AIFF", in ascii. */ #define aifcID 0x43464941 /* "AIFC", in ascii. */ #define ssndID 0x444E5353 /* "SSND", in ascii. */ /***************************************************************************** * The COMM chunk... * *****************************************************************************/ #define commID 0x4D4D4F43 /* "COMM", in ascii. */ /* format/compression types... */ #define noneID 0x454E4F4E /* "NONE", in ascii. */ typedef struct { Uint32 ckID; Uint32 ckDataSize; Uint16 numChannels; Uint32 numSampleFrames; Uint16 sampleSize; Uint32 sampleRate; /* * We don't handle AIFF-C compressed audio yet, but for those * interested the allowed compression types are supposed to be * * compressionType compressionName meaning * --------------------------------------------------------------- * 'NONE' "not compressed" uncompressed, that is, * straight digitized samples * 'ACE2' "ACE 2-to-1" 2-to-1 IIGS ACE (Audio * Compression / Expansion) * 'ACE8' "ACE 8-to-3" 8-to-3 IIGS ACE (Audio * Compression / Expansion) * 'MAC3' "MACE 3-to-1" 3-to-1 Macintosh Audio * Compression / Expansion * 'MAC6' "MACE 6-to-1" 6-to-1 Macintosh Audio * Compression / Expansion * * A pstring is a "Pascal-style string", that is, "one byte followed * by test bytes followed when needed by one pad byte. The total * number of bytes in a pstring must be even. The pad byte is * included when the number of text bytes is even, so the total of * text bytes + one count byte + one pad byte will be even. This pad * byte is not reflected in the count." * * As for how these compression algorithms work, your guess is as * good as mine. */ Uint32 compressionType; #if 0 pstring compressionName; #endif } comm_t; /* * Sample rate is encoded as an "80 bit IEEE Standard 754 floating point * number (Standard Apple Numeric Environment [SANE] data type Extended)". * Whose bright idea was that? * * This function was adapted from libsndfile, and while I do know a little * bit about the IEEE floating point standard I don't pretend to fully * understand this. */ static Uint32 SANE_to_Uint32 (Uint8 *sanebuf) { /* Is the frequency outside of what we can represent with Uint32? */ if ( (sanebuf[0] & 0x80) || (sanebuf[0] <= 0x3F) || (sanebuf[0] > 0x40) || (sanebuf[0] == 0x40 && sanebuf[1] > 0x1C) ) return 0; return ((sanebuf[2] << 23) | (sanebuf[3] << 15) | (sanebuf[4] << 7) | (sanebuf[5] >> 1)) >> (29 - sanebuf[1]); } /* SANE_to_Uint32 */ /* * Read in a comm_t from disk. This makes this process safe regardless of * the processor's byte order or how the comm_t structure is packed. */ static int read_comm_chunk(SDL_RWops *rw, comm_t *comm) { Uint8 sampleRate[10]; /* skip reading the chunk ID, since it was already read at this point... */ comm->ckID = commID; if (SDL_RWread(rw, &comm->ckDataSize, sizeof (comm->ckDataSize), 1) != 1) return 0; comm->ckDataSize = SDL_SwapBE32(comm->ckDataSize); if (SDL_RWread(rw, &comm->numChannels, sizeof (comm->numChannels), 1) != 1) return 0; comm->numChannels = SDL_SwapBE16(comm->numChannels); if (SDL_RWread(rw, &comm->numSampleFrames, sizeof (comm->numSampleFrames), 1) != 1) return 0; comm->numSampleFrames = SDL_SwapBE32(comm->numSampleFrames); if (SDL_RWread(rw, &comm->sampleSize, sizeof (comm->sampleSize), 1) != 1) return 0; comm->sampleSize = SDL_SwapBE16(comm->sampleSize); if (SDL_RWread(rw, sampleRate, sizeof (sampleRate), 1) != 1) return 0; comm->sampleRate = SANE_to_Uint32(sampleRate); if (comm->ckDataSize > sizeof(comm->numChannels) + sizeof(comm->numSampleFrames) + sizeof(comm->sampleSize) + sizeof(sampleRate)) { if (SDL_RWread(rw, &comm->compressionType, sizeof (comm->compressionType), 1) != 1) return 0; comm->compressionType = SDL_SwapBE32(comm->compressionType); } /* if */ else { comm->compressionType = noneID; } /* else */ return 1; } /* read_comm_chunk */ /***************************************************************************** * The SSND chunk... * *****************************************************************************/ typedef struct { Uint32 ckID; Uint32 ckDataSize; Uint32 offset; Uint32 blockSize; /* * Then, comm->numSampleFrames sample frames. (It's better to get the * length from numSampleFrames than from ckDataSize.) */ } ssnd_t; static int read_ssnd_chunk(SDL_RWops *rw, ssnd_t *ssnd) { /* skip reading the chunk ID, since it was already read at this point... */ ssnd->ckID = ssndID; if (SDL_RWread(rw, &ssnd->ckDataSize, sizeof (ssnd->ckDataSize), 1) != 1) return 0; ssnd->ckDataSize = SDL_SwapBE32(ssnd->ckDataSize); if (SDL_RWread(rw, &ssnd->offset, sizeof (ssnd->offset), 1) != 1) return 0; ssnd->offset = SDL_SwapBE32(ssnd->offset); if (SDL_RWread(rw, &ssnd->blockSize, sizeof (ssnd->blockSize), 1) != 1) return 0; ssnd->blockSize = SDL_SwapBE32(ssnd->blockSize); /* Leave the SDL_RWops position indicator at the start of the samples */ if (SDL_RWseek(rw, (int) ssnd->offset, RW_SEEK_CUR) == -1) return 0; return 1; } /* read_ssnd_chunk */ /***************************************************************************** * Normal, uncompressed aiff handler... * *****************************************************************************/ static Uint32 read_sample_fmt_normal(Sound_Sample *sample) { Uint32 retval; Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; aiff_t *a = (aiff_t *) internal->decoder_private; Uint32 max = (internal->buffer_size < (Uint32) a->bytesLeft) ? internal->buffer_size : (Uint32) a->bytesLeft; SDL_assert(max > 0); /* * We don't actually do any decoding, so we read the AIFF data * directly into the internal buffer... */ retval = SDL_RWread(internal->rw, internal->buffer, 1, max); a->bytesLeft -= retval; /* Make sure the read went smoothly... */ if ((retval == 0) || (a->bytesLeft == 0)) sample->flags |= SOUND_SAMPLEFLAG_EOF; else if (retval == -1) /** FIXME: this error check is broken **/ sample->flags |= SOUND_SAMPLEFLAG_ERROR; /* (next call this EAGAIN may turn into an EOF or error.) */ else if (retval < internal->buffer_size) sample->flags |= SOUND_SAMPLEFLAG_EAGAIN; return retval; } /* read_sample_fmt_normal */ static int rewind_sample_fmt_normal(Sound_Sample *sample) { /* no-op. */ return 1; } /* rewind_sample_fmt_normal */ static int seek_sample_fmt_normal(Sound_Sample *sample, Uint32 ms) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; aiff_t *a = (aiff_t *) internal->decoder_private; fmt_t *fmt = &a->fmt; int offset = __Sound_convertMsToBytePos(&sample->actual, ms); int pos = (int) (fmt->data_starting_offset + offset); int rc = SDL_RWseek(internal->rw, pos, RW_SEEK_SET); BAIL_IF_MACRO(rc != pos, ERR_IO_ERROR, 0); a->bytesLeft = fmt->total_bytes - offset; return 1; /* success. */ } /* seek_sample_fmt_normal */ static void free_fmt_normal(fmt_t *fmt) { /* it's a no-op. */ } /* free_fmt_normal */ static int read_fmt_normal(SDL_RWops *rw, fmt_t *fmt) { /* (don't need to read more from the RWops...) */ fmt->free = free_fmt_normal; fmt->read_sample = read_sample_fmt_normal; fmt->rewind_sample = rewind_sample_fmt_normal; fmt->seek_sample = seek_sample_fmt_normal; return 1; } /* read_fmt_normal */ /***************************************************************************** * Everything else... * *****************************************************************************/ static int AIFF_init(void) { return 1; /* always succeeds. */ } /* AIFF_init */ static void AIFF_quit(void) { /* it's a no-op. */ } /* AIFF_quit */ static int find_chunk(SDL_RWops *rw, Uint32 id) { Sint32 siz = 0; Uint32 _id = 0; while (1) { BAIL_IF_MACRO(SDL_RWread(rw, &_id, sizeof (_id), 1) != 1, NULL, 0); if (SDL_SwapLE32(_id) == id) return 1; BAIL_IF_MACRO(SDL_RWread(rw, &siz, sizeof (siz), 1) != 1, NULL, 0); siz = SDL_SwapBE32(siz); SDL_assert(siz > 0); BAIL_IF_MACRO(SDL_RWseek(rw, siz, RW_SEEK_CUR) == -1, NULL, 0); } /* while */ return 0; /* shouldn't hit this, but just in case... */ } /* find_chunk */ static int read_fmt(SDL_RWops *rw, comm_t *c, fmt_t *fmt) { fmt->type = c->compressionType; /* if it's in this switch statement, we support the format. */ switch (fmt->type) { case noneID: SNDDBG(("AIFF: Appears to be uncompressed audio.\n")); return read_fmt_normal(rw, fmt); /* add other types here. */ } /* switch */ SNDDBG(("AIFF: Format %u is unknown.\n", (unsigned int) fmt->type)); BAIL_MACRO("AIFF: Unsupported format", 0); } /* read_fmt */ static int AIFF_open(Sound_Sample *sample, const char *ext) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; SDL_RWops *rw = internal->rw; Uint32 chunk_id; int bytes_per_sample; long pos; comm_t c; ssnd_t s; aiff_t *a; BAIL_IF_MACRO(SDL_ReadLE32(rw) != formID, "AIFF: Not a FORM file.", 0); SDL_ReadBE32(rw); /* throw the length away; we don't need it. */ chunk_id = SDL_ReadLE32(rw); BAIL_IF_MACRO(chunk_id != aiffID && chunk_id != aifcID, "AIFF: Not an AIFF or AIFC file.", 0); /* Chunks may appear in any order, so we establish base camp here. */ pos = SDL_RWtell(rw); BAIL_IF_MACRO(!find_chunk(rw, commID), "AIFF: No common chunk.", 0); BAIL_IF_MACRO(!read_comm_chunk(rw, &c), "AIFF: Can't read common chunk.", 0); sample->actual.channels = (Uint8) c.numChannels; sample->actual.rate = c.sampleRate; /* Really, sample->total_time = (c.numSampleFrames*1000) c.sampleRate */ internal->total_time = (c.numSampleFrames / c.sampleRate) * 1000; internal->total_time += (c.numSampleFrames % c.sampleRate) * 1000 / c.sampleRate; if (c.sampleSize <= 8) { sample->actual.format = AUDIO_S8; bytes_per_sample = c.numChannels; } /* if */ else if (c.sampleSize <= 16) { sample->actual.format = AUDIO_S16MSB; bytes_per_sample = 2 * c.numChannels; } /* if */ else { BAIL_MACRO("AIFF: Unsupported sample size.", 0); } /* else */ BAIL_IF_MACRO(c.sampleRate == 0, "AIFF: Unsupported sample rate.", 0); a = (aiff_t *) SDL_malloc(sizeof(aiff_t)); BAIL_IF_MACRO(a == NULL, ERR_OUT_OF_MEMORY, 0); if (!read_fmt(rw, &c, &(a->fmt))) { SDL_free(a); return 0; } /* if */ SDL_RWseek(rw, pos, RW_SEEK_SET); /* if the seek fails, let it go... */ if (!find_chunk(rw, ssndID)) { SDL_free(a); BAIL_MACRO("AIFF: No sound data chunk.", 0); } /* if */ if (!read_ssnd_chunk(rw, &s)) { SDL_free(a); BAIL_MACRO("AIFF: Can't read sound data chunk.", 0); } /* if */ a->fmt.total_bytes = a->bytesLeft = bytes_per_sample * c.numSampleFrames; a->fmt.data_starting_offset = SDL_RWtell(rw); internal->decoder_private = (void *) a; sample->flags = SOUND_SAMPLEFLAG_CANSEEK; SNDDBG(("AIFF: Accepting data stream.\n")); return 1; /* we'll handle this data. */ } /* AIFF_open */ static void AIFF_close(Sound_Sample *sample) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; aiff_t *a = (aiff_t *) internal->decoder_private; a->fmt.free(&(a->fmt)); SDL_free(a); } /* AIFF_close */ static Uint32 AIFF_read(Sound_Sample *sample) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; aiff_t *a = (aiff_t *) internal->decoder_private; return a->fmt.read_sample(sample); } /* AIFF_read */ static int AIFF_rewind(Sound_Sample *sample) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; aiff_t *a = (aiff_t *) internal->decoder_private; fmt_t *fmt = &a->fmt; int rc = SDL_RWseek(internal->rw, fmt->data_starting_offset, RW_SEEK_SET); BAIL_IF_MACRO(rc != fmt->data_starting_offset, ERR_IO_ERROR, 0); a->bytesLeft = fmt->total_bytes; return fmt->rewind_sample(sample); } /* AIFF_rewind */ static int AIFF_seek(Sound_Sample *sample, Uint32 ms) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; aiff_t *a = (aiff_t *) internal->decoder_private; return a->fmt.seek_sample(sample, ms); } /* AIFF_seek */ static const char *extensions_aiff[] = { "AIFF", "AIF", NULL }; const Sound_DecoderFunctions __Sound_DecoderFunctions_AIFF = { { extensions_aiff, "Audio Interchange File Format", "Torbjörn Andersson ", "https://icculus.org/SDL_sound/" }, AIFF_init, /* init() method */ AIFF_quit, /* quit() method */ AIFF_open, /* open() method */ AIFF_close, /* close() method */ AIFF_read, /* read() method */ AIFF_rewind, /* rewind() method */ AIFF_seek /* seek() method */ }; #endif /* SOUND_SUPPORTS_AIFF */ /* end of SDL_sound_aiff.c ... */