Added shared code to load WAV(E) data from arbitrary seekable streams (files or memory)

svn-id: r16502

1 files changed, 162 insertions, 0 deletions

diff --git a/sound/wave.cpp b/sound/wave.cpp
new file mode 100644
index 0000000000..0388d0a757
--- /dev/null
+++ b/sound/wave.cpp
@@ -0,0 +1,162 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2001  Ludvig Strigeus
+ * Copyright (C) 2001-2005 The ScummVM project
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program 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 General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+#include "stdafx.h"
+#include "common/util.h"
+#include "common/stream.h"
+
+#include "sound/audiostream.h"
+#include "sound/mixer.h"
+#include "sound/wave.h"
+
+bool loadWAVFromStream(Common::SeekableReadStream &stream, int &size, int &rate, byte &flags) {
+	const uint32 initialPos = stream.pos();
+	byte buf[4+1];
+
+	buf[4] = 0;
+
+	stream.read(buf, 4);
+	if (memcmp(buf, "RIFF", 4) != 0) {
+		warning("getWavInfo: No 'RIFF' header");
+		return false;
+	}
+
+	uint32 wavLength = stream.readUint32LE();
+
+	stream.read(buf, 4);
+	if (memcmp(buf, "WAVE", 4) != 0) {
+		warning("getWavInfo: No 'WAVE' header");
+		return false;
+	}
+
+	stream.read(buf, 4);
+	if (memcmp(buf, "fmt ", 4) != 0) {
+		warning("getWavInfo: No 'fmt' header");
+		return false;
+	}
+	
+	uint32 fmtLength = stream.readUint32LE();
+	if (fmtLength < 16) {
+		// A valid fmt chunk always contains at least 16 bytes
+		warning("getWavInfo: 'fmt' header is too short");
+		return false;
+	}
+
+	// Next comes the "type" field of the fmt header. Some typical
+	// values for it:
+	// 1  -> uncompressed PCM 
+	// See <http://www.sonicspot.com/guide/wavefiles.html> for a more complete
+	// list of common WAVE compression formats...
+	uint16 type = stream.readUint16LE();	// == 1 for PCM data
+	uint16 numChannels = stream.readUint16LE();	// 1 for mono, 2 for stereo
+	uint32 samplesPerSec = stream.readUint32LE();	// in Hz
+	uint32 avgBytesPerSec = stream.readUint32LE();	// == SampleRate * NumChannels * BitsPerSample/8
+
+	uint16 blockAlign = stream.readUint16LE();	// == NumChannels * BitsPerSample/8
+	uint16 bitsPerSample = stream.readUint16LE();	// 8, 16 ...
+	// 8 bit data is unsigned, 16 bit data signed
+
+#if 0	
+	printf("WAVE information:\n");
+	printf("  total size: %d\n", wavLength);
+	printf("  fmt size: %d\n", fmtLength);
+	printf("  type: %d\n", type);
+	printf("  numChannels: %d\n", numChannels);
+	printf("  samplesPerSec: %d\n", samplesPerSec);
+	printf("  avgBytesPerSec: %d\n", avgBytesPerSec);
+	printf("  blockAlign: %d\n", blockAlign);
+	printf("  bitsPerSample: %d\n", bitsPerSample);
+#endif
+
+	if (type != 1) {
+		warning("getWavInfo: only PCM data is supported (type %d)", type);
+		return false;
+	}
+
+	if (blockAlign != numChannels * bitsPerSample / 8) {
+		debug(0, "getWavInfo: blockAlign is invalid");
+	}
+
+	if (avgBytesPerSec != samplesPerSec * blockAlign) {
+		debug(0, "getWavInfo: avgBytesPerSec is invalid");
+	}
+
+	// Prepare the return values.
+	rate = samplesPerSec;
+
+	flags = 0;
+	if (bitsPerSample == 8)		// 8 bit data is unsigned
+		flags |= SoundMixer::FLAG_UNSIGNED;
+	else if (bitsPerSample == 16)	// 16 bit data is signed
+		flags |= SoundMixer::FLAG_16BITS;
+	else {
+		warning("getWavInfo: unsupported bitsPerSample %d", bitsPerSample);
+		return false;
+	}
+	
+	if (numChannels == 2)
+		flags |= SoundMixer::FLAG_STEREO;
+	else if (numChannels != 1) {
+		warning("getWavInfo: unsupported number of channels %d", numChannels);
+		return false;
+	}
+
+	// It's almost certainly a WAV file, but we still need to find its
+	// 'data' chunk.
+
+	// Skip over the rest of the fmt chunk.
+	int offset = fmtLength - 16;
+
+	do {
+		stream.seek(offset, SEEK_CUR);
+		if (stream.pos() >= initialPos + wavLength + 8) {
+			warning("getWavInfo: Can't find 'data' chunk");
+			return false;
+		}
+		stream.read(buf, 4);
+		offset = stream.readUint32LE();
+
+#if 0
+		printf("  found a '%s' tag of size %d\n", buf, offset);
+#endif
+	} while (memcmp(buf, "data", 4) != 0);
+	
+	// Stream now points at 'offset' bytes of sample data...
+	size = offset;
+
+	return true;
+}
+
+AudioStream *makeWAVStream(Common::SeekableReadStream &stream) {
+	int size, rate;
+	byte flags;
+	
+	if (!loadWAVFromStream(stream, size, rate, flags))
+		return 0;
+	
+	byte *data = (byte *)malloc(size);
+	assert(data);
+	stream.read(data, size);
+	flags |= SoundMixer::FLAG_AUTOFREE;
+
+	return makeLinearInputStream(rate, flags, data, size, 0, 0);
+}