--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoders/aiff.c	Thu Sep 20 07:51:42 2001 +0000
@@ -0,0 +1,368 @@
+/*
+ * SDL_sound -- An abstract sound format decoding API.
+ * Copyright (C) 2001  Ryan C. Gordon.
+ *
+ * This library 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 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * 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.
+ *
+ * Please see the file LICENSE in the source's root directory.
+ *
+ *  This file was written by Torbjörn Andersson. (d91tan@Update.UU.SE)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "SDL.h"
+#include "SDL_endian.h"
+#include "SDL_sound.h"
+
+#define __SDL_SOUND_INTERNAL__
+#include "SDL_sound_internal.h"
+
+#if (!defined SOUND_SUPPORTS_AIFF)
+#error SOUND_SUPPORTS_AIFF must be defined.
+#endif
+
+
+static int AIFF_open(Sound_Sample *sample, const char *ext);
+static void AIFF_close(Sound_Sample *sample);
+static Uint32 AIFF_read(Sound_Sample *sample);
+
+const Sound_DecoderFunctions __Sound_DecoderFunctions_AIFF =
+{
+    {
+        "AIFF",
+        "Audio Interchange File Format",
+        "Torbjörn Andersson <d91tan@Update.UU.SE>",
+        "http://www.icculus.org/SDL_sound/"
+    },
+
+    AIFF_open,      /* open() method       */
+    AIFF_close,     /* close() method       */
+    AIFF_read       /* read() method       */
+};
+
+
+    /* this is what we store in our internal->decoder_private field... */
+typedef struct {
+    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. */
+#define commID 0x4d4d4f43  /* "COMM", in ascii. */
+
+#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;
+
+    return(1);
+} /* read_comm_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, SEEK_CUR) == -1) /* !!! FIXME: Int? Really? */
+        return(0);
+
+    return(1);
+} /* read_ssnd_chunk */
+
+
+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);
+        assert(siz > 0);
+        BAIL_IF_MACRO(SDL_RWseek(rw, siz, SEEK_CUR) == -1, NULL, 0);
+    } /* while */
+
+    return(0);  /* shouldn't hit this, but just in case... */
+} /* find_chunk */
+
+
+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);
+
+    /* !!! FIXME: This will have to change for compression types... */
+    BAIL_IF_MACRO(c.compressionType != noneID, "AIFF: Unsupported encoding.", 0);
+
+    BAIL_IF_MACRO(c.sampleRate == 0, "AIFF: Unsupported sample rate.", 0);
+
+    sample->actual.channels = (Uint8) c.numChannels;
+    sample->actual.rate = c.sampleRate;
+
+    if (c.sampleSize <= 8)
+    {
+        sample->actual.format = AUDIO_S8;
+        bytes_per_sample = 1;
+    } /* if */
+    else if (c.sampleSize <= 16)
+    {
+        sample->actual.format = AUDIO_S16MSB;
+        bytes_per_sample = 2;
+    } /* if */
+    else
+        BAIL_MACRO("AIFF: Unsupported sample size.", 0);
+
+    SDL_RWseek(rw, pos, SEEK_SET);
+
+    BAIL_IF_MACRO(!find_chunk(rw, ssndID), "AIFF: No sound data chunk.", 0);
+    BAIL_IF_MACRO(!read_ssnd_chunk(rw, &s), "AIFF: Can't read sound data chunk.", 0);
+
+    a = (aiff_t *) malloc(sizeof(aiff_t));
+    BAIL_IF_MACRO(a == NULL, ERR_OUT_OF_MEMORY, 0);
+    a->bytesLeft = bytes_per_sample * c.numSampleFrames;
+    internal->decoder_private = (void *) a;
+
+    _D(("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;
+    free(internal->decoder_private);
+} /* WAV_close */
+
+
+static Uint32 AIFF_read(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;
+
+    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)
+        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);
+} /* AIFF_read */
+
+
+/* end of aiff.c ... */