SCI32: Rewrite digital audio engine

This provides a complete implementation of kDoAudio through
SCI2.1mid, plus partial implementation of SCI3 features.

Digital audio calls shunted through kDoSound have also been
updated to go through the SCI32 audio mixer, though these shunts
are a bit hacky because the ScummVM implementation of kDoSound
does not currently match how SSCI kDoSound is designed.

It is probably possible in the future to just replace the SCI1.1
audio code (audio.cpp) with the new SCI32 code, since the major
differences seem to be that (1) SCI1.1 only supported one digital
audio playback channel (this is configurable already), (2) it
had extra commands for CD audio playback and queued sample
playback.

1 files changed, 89 insertions, 0 deletions

diff --git a/engines/sci/sound/decoders/sol.h b/engines/sci/sound/decoders/sol.h
new file mode 100644
index 0000000000..1046d0b213
--- /dev/null
+++ b/engines/sci/sound/decoders/sol.h
@@ -0,0 +1,89 @@
+/* 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 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef SCI_SOUND_DECODERS_SOL_H
+#define SCI_SOUND_DECODERS_SOL_H
+#include "audio/audiostream.h"
+#include "common/stream.h"
+
+namespace Sci {
+
+enum SOLFlags {
+	kCompressed = 1,
+	k16Bit      = 4,
+	kStereo     = 16
+};
+
+template <bool STEREO, bool S16BIT>
+class SOLStream : public Audio::SeekableAudioStream {
+private:
+	/**
+	 * Read stream containing possibly-compressed SOL audio.
+	 */
+	Common::DisposablePtr<Common::SeekableReadStream> _stream;
+
+	/**
+	 * Start offset of the audio data in the read stream.
+	 */
+	int32 _dataOffset;
+
+	/**
+	 * Sample rate of audio data.
+	 */
+	uint16 _sampleRate;
+
+	/**
+	 * The raw (possibly-compressed) size of audio data in
+	 * the stream.
+	 */
+	int32 _rawDataSize;
+
+	/**
+	 * The last sample from the previous DPCM decode.
+	 */
+	union {
+		int16 _dpcmCarry16;
+		uint8 _dpcmCarry8;
+	};
+
+	/**
+	 * The calculated length of the stream.
+	 */
+	Audio::Timestamp _length;
+
+	virtual bool seek(const Audio::Timestamp &where) override;
+	virtual Audio::Timestamp getLength() const override;
+	virtual int readBuffer(int16 *buffer, const int numSamples) override;
+	virtual bool isStereo() const override;
+	virtual int getRate() const override;
+	virtual bool endOfData() const override;
+	virtual bool rewind() override;
+
+public:
+	SOLStream(Common::SeekableReadStream *stream, const DisposeAfterUse::Flag disposeAfterUse, const int32 dataOffset, const uint16 sampleRate, const int32 rawDataSize);
+};
+
+Audio::SeekableAudioStream *makeSOLStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse);
+
+Audio::SeekableAudioStream *makeSOLStream(Common::SeekableReadStream *headerStream, Common::SeekableReadStream *dataStream, DisposeAfterUse::Flag disposeAfterUse);
+}
+#endif