--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoders/wav.c	Wed Sep 19 08:22:33 2001 +0000
@@ -0,0 +1,268 @@
+/*
+ * 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
+ */
+
+/*
+ * WAV decoder for SDL_sound.
+ *
+ * This driver handles Microsoft .WAVs, in as many of the thousands of
+ *  variations as we can.
+ *
+ * Please see the file LICENSE in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon. (icculus@clutteredmind.org)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "SDL_sound.h"
+
+#define __SDL_SOUND_INTERNAL__
+#include "SDL_sound_internal.h"
+
+#if (!defined SOUND_SUPPORTS_WAV)
+#error SOUND_SUPPORTS_WAV must be defined.
+#endif
+
+static int WAV_open(Sound_Sample *sample, const char *ext);
+static void WAV_close(Sound_Sample *sample);
+static Uint32 WAV_read(Sound_Sample *sample);
+
+const Sound_DecoderFunctions __Sound_DecoderFunctions_WAV =
+{
+    {
+        "WAV",
+        "Microsoft WAVE audio format",
+        "Ryan C. Gordon <icculus@clutteredmind.org>",
+        "http://www.icculus.org/SDL_sound/"
+    },
+
+    WAV_open,       /* open() method       */
+    WAV_close,      /* close() method       */
+    WAV_read        /* read() method       */
+};
+
+
+    /* this is what we store in our internal->decoder_private field... */
+typedef struct
+{
+    Sint32 bytesLeft;
+} wav_t;
+
+
+    /* Chunk management code... */
+
+#define riffID 0x46464952  /* "RIFF", in ascii. */
+#define waveID 0x45564157  /* "WAVE", in ascii. */
+
+
+#define fmtID  0x20746D66  /* "fmt ", in ascii. */
+
+#define FMT_NORMAL 1    /* Uncompressed waveform data. */
+
+typedef struct
+{
+    Uint32 chunkID;
+    Sint32 chunkSize;
+    Sint16 wFormatTag;
+    Uint16 wChannels;
+    Uint32 dwSamplesPerSec;
+    Uint32 dwAvgBytesPerSec;
+    Uint16 wBlockAlign;
+    Uint16 wBitsPerSample;
+} fmt_t;
+
+
+/*
+ * Read in a fmt_t from disk. This makes this process safe regardless of
+ *  the processor's byte order or how the fmt_t structure is packed.
+ */
+static int read_fmt_chunk(SDL_RWops *rw, fmt_t *fmt)
+{
+    /* skip reading the chunk ID, since it was already read at this point... */
+    fmt->chunkID = fmtID;
+
+    if (SDL_RWread(rw, &fmt->chunkSize, sizeof (fmt->chunkSize), 1) != 1)
+        return(0);
+    fmt->chunkSize = SDL_SwapLE32(fmt->chunkSize);
+
+    if (SDL_RWread(rw, &fmt->wFormatTag, sizeof (fmt->wFormatTag), 1) != 1)
+        return(0);
+    fmt->wFormatTag = SDL_SwapLE16(fmt->wFormatTag);
+
+    if (SDL_RWread(rw, &fmt->wChannels, sizeof (fmt->wChannels), 1) != 1)
+        return(0);
+    fmt->wChannels = SDL_SwapLE16(fmt->wChannels);
+
+    if (SDL_RWread(rw, &fmt->dwSamplesPerSec,
+                   sizeof (fmt->dwSamplesPerSec), 1) != 1)
+        return(0);
+    fmt->dwSamplesPerSec = SDL_SwapLE32(fmt->dwSamplesPerSec);
+
+    if (SDL_RWread(rw, &fmt->dwAvgBytesPerSec,
+                   sizeof (fmt->dwAvgBytesPerSec), 1) != 1)
+        return(0);
+    fmt->dwAvgBytesPerSec = SDL_SwapLE32(fmt->dwAvgBytesPerSec);
+
+    if (SDL_RWread(rw, &fmt->wBlockAlign, sizeof (fmt->wBlockAlign), 1) != 1)
+        return(0);
+    fmt->wBlockAlign = SDL_SwapLE16(fmt->wBlockAlign);
+
+    if (SDL_RWread(rw, &fmt->wBitsPerSample,
+                   sizeof (fmt->wBitsPerSample), 1) != 1)
+        return(0);
+    fmt->wBitsPerSample = SDL_SwapLE16(fmt->wBitsPerSample);
+
+    return(1);
+} /* read_fmt_chunk */
+
+
+#define dataID 0x61746164  /* "data", in ascii. */
+
+typedef struct
+{
+    Uint32 chunkID;
+    Sint32 chunkSize;
+    /* Then, (chunkSize) bytes of waveform data... */
+} data_t;
+
+
+/*
+ * Read in a fmt_t from disk. This makes this process safe regardless of
+ *  the processor's byte order or how the fmt_t structure is packed.
+ */
+static int read_data_chunk(SDL_RWops *rw, data_t *data)
+{
+    /* skip reading the chunk ID, since it was already read at this point... */
+    data->chunkID = dataID;
+
+    if (SDL_RWread(rw, &data->chunkSize, sizeof (data->chunkSize), 1) != 1)
+        return(0);
+    data->chunkSize = SDL_SwapLE32(data->chunkSize);
+
+    return(1);
+} /* read_fmt_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_SwapLE32(siz);
+        assert(siz > 0);
+        BAIL_IF_MACRO(SDL_RWseek(rw, siz, SEEK_SET) != siz, NULL, 0);
+    } /* while */
+
+    return(0);  /* shouldn't hit this, but just in case... */
+} /* find_chunk */
+
+
+static int WAV_open(Sound_Sample *sample, const char *ext)
+{
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    SDL_RWops *rw = internal->rw;
+    fmt_t f;
+    data_t d;
+    wav_t *w;
+
+    BAIL_IF_MACRO(SDL_ReadLE32(rw) != riffID, "WAV: Not a RIFF file.", 0);
+	SDL_ReadLE32(rw);  /* throw the length away; we get this info later. */
+    BAIL_IF_MACRO(SDL_ReadLE32(rw) != waveID, "WAV: Not a WAVE file.", 0);
+    BAIL_IF_MACRO(!find_chunk(rw, fmtID), "WAV: No format chunk.", 0);
+    BAIL_IF_MACRO(!read_fmt_chunk(rw, &f), "WAV: Can't read format chunk.", 0);
+
+    /* !!! FIXME: This will have to change for compression types... */
+    BAIL_IF_MACRO(f.wFormatTag != FMT_NORMAL, "WAV: Unsupported encoding.", 0);
+
+    sample->actual.channels = (Uint8) f.wChannels;
+    sample->actual.rate = f.dwSamplesPerSec;
+
+    if (f.wBitsPerSample <= 8)
+        sample->actual.format = AUDIO_U8;
+    else if (f.wBitsPerSample <= 16)
+        sample->actual.format = AUDIO_S16LSB;
+    else
+        BAIL_MACRO("WAV: Unsupported sample size.", 0);
+
+    BAIL_IF_MACRO(!find_chunk(rw, dataID), "WAV: No data chunk.", 0);
+    BAIL_IF_MACRO(!read_data_chunk(rw, &d), "WAV: Can't read data chunk.", 0);
+
+    w = (wav_t *) malloc(sizeof(wav_t));
+    BAIL_IF_MACRO(w == NULL, ERR_OUT_OF_MEMORY, 0);
+    w->bytesLeft = d.chunkSize;
+    internal->decoder_private = (void *) w;
+
+    sample->flags = SOUND_SAMPLEFLAG_NONE;
+
+    _D(("WAV: Accepting data stream.\n"));
+    return(1); /* we'll handle this data. */
+} /* WAV_open */
+
+
+static void WAV_close(Sound_Sample *sample)
+{
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    free(internal->decoder_private);
+} /* WAV_close */
+
+
+static Uint32 WAV_read(Sound_Sample *sample)
+{
+    Uint32 retval;
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    wav_t *w = (wav_t *) internal->decoder_private;
+    Uint32 max = (internal->buffer_size < (Uint32) w->bytesLeft) ?
+                    internal->buffer_size : (Uint32) w->bytesLeft;
+
+    assert(max > 0);
+
+        /*
+         * We don't actually do any decoding, so we read the wav data
+         *  directly into the internal buffer...
+         */
+    retval = SDL_RWread(internal->rw, internal->buffer, 1, max);
+
+    w->bytesLeft -= retval;
+
+        /* Make sure the read went smoothly... */
+    if ((retval == 0) || (w->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);
+} /* WAV_read */
+
+
+/* end of wav.c ... */
+