diff decoders/raw.c @ 4:341cea3e13c6

Initial add.
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 17 Sep 2001 18:12:03 +0000
parents
children 29313c20963d
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoders/raw.c	Mon Sep 17 18:12:03 2001 +0000
@@ -0,0 +1,121 @@
+/*
+ * 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
+ */
+
+/*
+ * RAW decoder for SDL_sound. This is as simple as it gets.
+ *
+ * This driver handles raw audio data. You must, regardless of where the
+ *  data is actually coming from, specify the string "RAW" in the extension
+ *  parameter of Sound_NewSample() (or, alternately, open a file with the
+ *  extension ".raw" in Sound_NewSampleFromFile()). The string is checked
+ *  case-insensitive. We need this check, because raw data, being raw, has
+ *  no headers or magic number we can use to determine if we should handle a
+ *  given file, so we needed some way to have this "decoder" discriminate.
+ *
+ * When calling Sound_NewSample*(), you must also specify a "desired"
+ *  audio format. The "actual" format will always match what you specify, so
+ *  there will be no conversion overhead, but these routines need to know how
+ *  to treat the bits, since it's all random garbage otherwise.
+ *
+ * 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_RAW)
+#error SOUND_SUPPORTS_RAW must be defined.
+#endif
+
+
+static int RAW_open(Sound_Sample *sample, const char *ext);
+static void RAW_close(Sound_Sample *sample);
+static int RAW_read(Sound_Sample *sample);
+
+const Sound_DecoderFunctions __Sound_DecoderFunctions_RAW =
+{
+    {
+        "RAW",
+        "Raw audio",
+        "Ryan C. Gordon <icculus@clutteredmind.org>",
+        "http://www.icculus.org/SDL_sound/"
+    },
+
+    RAW_open,       /* open() method       */
+    RAW_close,      /* close() method       */
+    RAW_read        /* read() method       */
+};
+
+
+static int RAW_open(Sound_Sample *sample, const char *ext)
+{
+    if (__Sound_strcasecmp(ext, "RAW") != 0)
+        return(0);
+
+    if ( (sample->desired.channels < 1)  ||
+         (sample->desired.channels > 2)  ||
+         (sample->desired.rate == 0)     ||
+         (sample->desired.format == 0) )
+    {
+        return(0);
+    } /* if */
+
+    memcpy(&sample->actual, &sample->desired, sizeof (Sound_AudioInfo));
+    sample->flags = SOUND_SAMPLEFLAG_NONE;
+    return(1);
+} /* RAW_open */
+
+
+static void RAW_close(Sound_Sample *sample)
+{
+    /* we don't allocate anything. That's easy, eh? */
+} /* RAW_close */
+
+
+static int RAW_read(Sound_Sample *sample)
+{
+    int retval;
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    retval = SDL_RWread(internal->rw, internal->buffer,
+                        1, internal->buffer_size);
+
+    if (retval == 0)
+        sample->flags |= SOUND_SAMPLEFLAG_EOF;
+
+    else if (retval == -1)
+        sample->flags |= SOUND_SAMPLEFLAG_ERROR;
+
+        /* next call this may be a EOF or error... */
+    else if (retval < internal->buffer_size)
+        sample->flags |= SOUND_SAMPLEFLAG_EAGAIN;
+
+    return(retval);
+} /* RAW_read */
+
+
+/* end of raw.c ... */
+