Initial commit

audio/decoders/mac_snd.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*
+ * The code in this file is based on information found at
+ * https://developer.apple.com/library/archive/documentation/mac/Sound/Sound-60.html#HEADING60-15
+ *
+ * We implement both type 1 and type 2 snd resources, but only those that are sampled
+ */
+
+#include "common/textconsole.h"
+#include "common/stream.h"
+#include "common/substream.h"
+
+#include "audio/decoders/mac_snd.h"
+#include "audio/decoders/raw.h"
+
+namespace Audio {
+
+SeekableAudioStream *makeMacSndStream(Common::SeekableReadStream *stream,
+	DisposeAfterUse::Flag disposeAfterUse) {
+
+	uint16 sndType = stream->readUint16BE();
+
+	if (sndType == 1) {
+		// "normal" snd resources
+		if (stream->readUint16BE() != 1) {
+			warning("makeMacSndStream(): Unsupported data type count");
+			return nullptr;
+		}
+
+		if (stream->readUint16BE() != 5) {
+			// 5 == sampled
+			warning("makeMacSndStream(): Unsupported data type");
+			return nullptr;
+		}
+
+		stream->readUint32BE(); // initialization option
+	} else if (sndType == 2) {
+		// old HyperCard snd resources
+		stream->readUint16BE(); // reference count (unused)
+	} else {
+		warning("makeMacSndStream(): Unknown format type %d", sndType);
+		return nullptr;
+	}
+
+	// We really should never get this as long as we have sampled data only
+	if (stream->readUint16BE() != 1) {
+		warning("makeMacSndStream(): Unsupported command count");
+		return nullptr;
+	}
+
+	uint16 command = stream->readUint16BE();
+
+	// 0x8050 - soundCmd  (with dataOffsetFlag set): install a sampled sound as a voice
+	// 0x8051 - bufferCmd (with dataOffsetFlag set): play a sample sound
+	if (command != 0x8050 && command != 0x8051) {
+		warning("makeMacSndStream(): Unsupported command %04x", command);
+		return nullptr;
+	}
+
+	stream->readUint16BE(); // 0
+	uint32 soundHeaderOffset = stream->readUint32BE();
+
+	stream->seek(soundHeaderOffset);
+
+	uint32 soundDataOffset = stream->readUint32BE();
+	uint32 size = stream->readUint32BE();
+	uint16 rate = stream->readUint32BE() >> 16; // Really fixed point, but we only support integer rates
+	stream->readUint32BE(); // loop start
+	stream->readUint32BE(); // loop end
+	byte encoding = stream->readByte();
+	stream->readByte(); // base frequency
+
+	if (encoding != 0) {
+		// 0 == PCM
+		warning("makeMacSndStream(): Unsupported compression %d", encoding);
+		return nullptr;
+	}
+
+	stream->skip(soundDataOffset);
+
+	Common::SeekableReadStream *dataStream = new Common::SeekableSubReadStream(stream, stream->pos(), stream->pos() + size, disposeAfterUse);
+
+	// Since we allocated our own stream for the data, we must specify DisposeAfterUse::YES.
+	return makeRawStream(dataStream, rate, Audio::FLAG_UNSIGNED);
+}
+
+} // End of namespace Audio