SCUMM: Add support for CD audio tracks in the Steam versions of Loom

Many Thanks to Ben Castricum for the original patch

engines/scumm/cdda.cpp

@@ -0,0 +1,120 @@
+/* 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.
+ *
+ */
+
+#include "scumm/cdda.h"
+#include "common/stream.h"
+#include "audio/audiostream.h"
+
+namespace Scumm {
+
+
+#pragma mark -
+#pragma mark --- CDDA stream ---
+#pragma mark -
+
+#define START_OF_CDDA_DATA 800
+#define BLOCK_SIZE 1177
+
+class CDDAStream : public Audio::SeekableAudioStream {
+private:
+	Common::SeekableReadStream *_stream;
+	DisposeAfterUse::Flag _disposeAfterUse;
+	byte _shiftLeft;
+	byte _shiftRight;
+	uint32 _pos;
+	Audio::Timestamp _length;
+
+public:
+	CDDAStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse);
+	virtual ~CDDAStream();
+	
+	int readBuffer(int16 *buffer, const int numSamples);
+	bool isStereo() const { return true; }
+	int getRate() const { return 44100; }
+	bool endOfData() const { return _stream->eos(); }
+	bool seek(const Audio::Timestamp &where);
+	Audio::Timestamp getLength() const { return _length; }
+};
+
+CDDAStream::CDDAStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse) :
+	_stream(stream), _disposeAfterUse(disposeAfterUse), _pos(START_OF_CDDA_DATA) {
+	_stream->seek(START_OF_CDDA_DATA, SEEK_SET);
+	// The total size of CDDA.SOU is 289,808,802 bytes or (289808802 - 800) / 1177 = 246226 blocks
+	// We also deduct the shift values to return the correct length
+	uint32 blocks = (_stream->size() - START_OF_CDDA_DATA) / BLOCK_SIZE;
+	_length = Audio::Timestamp(0, (_stream->size() - START_OF_CDDA_DATA - blocks) / (isStereo() ? 2 : 1), getRate());
+}
+
+CDDAStream::~CDDAStream() {
+	if (_disposeAfterUse == DisposeAfterUse::YES)
+		delete _stream;
+}
+
+bool CDDAStream::seek(const Audio::Timestamp &where) {
+	const uint32 seekSample = convertTimeToStreamPos(where, getRate(), isStereo()).totalNumberOfFrames();
+	uint32 blocks = seekSample / 1176;
+
+	// Before seeking, read the shift values from the beginning of that block
+	_stream->seek(START_OF_CDDA_DATA + blocks * BLOCK_SIZE, SEEK_SET);
+	byte shiftVal = _stream->readByte();
+	_shiftLeft = shiftVal >> 4;
+	_shiftRight = shiftVal & 0x0F;
+
+	_pos = START_OF_CDDA_DATA + blocks + seekSample;
+	return _stream->seek(_pos, SEEK_SET);
+}
+
+int CDDAStream::readBuffer(int16 *buffer, const int numSamples) {
+	int samples;
+
+	for (samples = 0 ; samples < numSamples && !_stream->eos() ; ) {
+		if (!((_pos - START_OF_CDDA_DATA) % BLOCK_SIZE)) {
+			byte shiftVal = _stream->readByte();
+			_shiftLeft = shiftVal >> 4;
+			_shiftRight = shiftVal & 0x0F;
+			_pos++;
+		}
+		buffer[samples++] = _stream->readSByte() << _shiftLeft;
+		buffer[samples++] = _stream->readSByte() << _shiftRight;
+		_pos += 2;
+	}
+	return samples;
+}
+
+#pragma mark -
+#pragma mark --- CDDA factory functions ---
+#pragma mark -
+
+Audio::SeekableAudioStream *makeCDDAStream(
+	Common::SeekableReadStream *stream,
+	DisposeAfterUse::Flag disposeAfterUse) {
+	Audio::SeekableAudioStream *s = new CDDAStream(stream, disposeAfterUse);
+	if (s && s->endOfData()) {
+		delete s;
+		return 0;
+	} else {
+		return s;
+	}
+	return 0;
+}
+
+} // End of namespace Scumm

engines/scumm/cdda.h

@@ -0,0 +1,58 @@
+
+/* 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.
+ *
+ */
+
+/**
+ * @file
+ * CD audio decoder used in the Steam versions of Loom
+ */
+
+#ifndef SCUMM_CDDA_H
+#define SCUMM_CDDA_H
+
+#include "common/types.h"
+
+namespace Common {
+class SeekableReadStream;
+}
+
+namespace Audio {
+class SeekableAudioStream;
+}
+
+namespace Scumm {
+
+/**
+ * Create a new SeekableAudioStream from the CDDA data in the given stream.
+ * Allows for seeking (which is why we require a SeekableReadStream).
+ *
+ * @param stream			the SeekableReadStream from which to read the CDDA data
+ * @param disposeAfterUse	whether to delete the stream after use
+ * @return	a new SeekableAudioStream, or NULL, if an error occurred
+ */
+Audio::SeekableAudioStream *makeCDDAStream(
+	Common::SeekableReadStream *stream,
+	DisposeAfterUse::Flag disposeAfterUse);
+
+} // End of namespace Audio
+
+#endif // #ifndef SCUMM_CDDA_H

engines/scumm/module.mk

@@ -7,6 +7,7 @@ MODULE_OBJS := \
 	bomp.o \
 	boxes.o \
 	camera.o \
+	cdda.o \
 	charset.o \
 	charset-fontdata.o \
 	costume.o \

engines/scumm/saveload.cpp

@@ -1453,7 +1453,7 @@ void ScummEngine::saveOrLoad(Serializer *s) {
 		// forever, then resume playing it. This helps a lot when the audio CD
 		// is used to provide ambient music (see bug #788195).
 		if (s->isLoading() && info.playing && info.numLoops < 0)
-			_system->getAudioCDManager()->play(info.track, info.numLoops, info.start, info.duration);
+			_sound->playCDTrackInternal(info.track, info.numLoops, info.start, info.duration);
 	}
 
 

engines/scumm/sound.cpp

@@ -27,6 +27,7 @@
 #include "common/substream.h"
 
 #include "scumm/actor.h"
+#include "scumm/cdda.h"
 #include "scumm/file.h"
 #include "scumm/imuse/imuse.h"
 #include "scumm/imuse_digi/dimuse.h"
@@ -36,8 +37,6 @@
 #include "scumm/sound.h"
 #include "scumm/util.h"
 
-#include "backends/audiocd/audiocd.h"
-
 #include "audio/decoders/adpcm.h"
 #include "audio/decoders/flac.h"
 #include "audio/mididrv.h"
@@ -89,11 +88,21 @@ Sound::Sound(ScummEngine *parent, Audio::Mixer *mixer)
 	memset(_mouthSyncTimes, 0, sizeof(_mouthSyncTimes));
 
 	_musicType = MDT_NONE;
+
+	_loomSteamCD.playing = false;
+	_loomSteamCD.track = 0;
+	_loomSteamCD.start = 0;
+	_loomSteamCD.duration = 0;
+	_loomSteamCD.numLoops = 0;
+	_loomSteamCD.volume = Audio::Mixer::kMaxChannelVolume;
+	_loomSteamCD.balance = 0;
+
+	_isLoomSteam = _vm->_game.id == GID_LOOM && Common::File::exists("CDDA.SOU");
 }
 
 Sound::~Sound() {
 	stopCDTimer();
-	g_system->getAudioCDManager()->stop();
+	stopCD();
 	free(_offsetTable);
 }
 
@@ -1033,7 +1042,7 @@ void Sound::playCDTrack(int track, int numLoops, int startFrame, int duration) {
 
 	// Play it
 	if (!_soundsPaused)
-		g_system->getAudioCDManager()->play(track, numLoops, startFrame, duration);
+		playCDTrackInternal(track, numLoops, startFrame, duration);
 
 	// Start the timer after starting the track. Starting an MP3 track is
 	// almost instantaneous, but a CD player may take some time. Hopefully
@@ -1041,16 +1050,59 @@ void Sound::playCDTrack(int track, int numLoops, int startFrame, int duration) {
 	startCDTimer();
 }
 
+void Sound::playCDTrackInternal(int track, int numLoops, int startFrame, int duration) {
+	_loomSteamCD.track = track;
+	_loomSteamCD.numLoops = numLoops;
+	_loomSteamCD.start = startFrame;
+	_loomSteamCD.duration = duration;
+
+	if (!_isLoomSteam) {
+		g_system->getAudioCDManager()->play(track, numLoops, startFrame, duration);
+	} else {
+		// Stop any currently playing track
+		_mixer->stopHandle(_loomSteamCDAudioHandle);
+
+		Common::File *cddaFile = new Common::File();
+		if (cddaFile->open("CDDA.SOU")) {
+			Audio::Timestamp start = Audio::Timestamp(0, startFrame, 75);
+			Audio::Timestamp end = Audio::Timestamp(0, startFrame + duration, 75);				
+			Audio::SeekableAudioStream *stream = makeCDDAStream(cddaFile, DisposeAfterUse::YES);
+			
+			_mixer->playStream(Audio::Mixer::kMusicSoundType, &_loomSteamCDAudioHandle,
+			                    Audio::makeLoopingAudioStream(stream, start, end, (numLoops < 1) ? numLoops + 1 : numLoops));
+		} else {
+			delete cddaFile;
+		}
+	}
+}
+
 void Sound::stopCD() {
-	g_system->getAudioCDManager()->stop();
+	if (!_isLoomSteam)
+		g_system->getAudioCDManager()->stop();
+	else
+		_mixer->stopHandle(_loomSteamCDAudioHandle);
 }
 
 int Sound::pollCD() const {
-	return g_system->getAudioCDManager()->isPlaying();
+	if (!_isLoomSteam)
+		return g_system->getAudioCDManager()->isPlaying();
+	else
+		return _mixer->isSoundHandleActive(_loomSteamCDAudioHandle);
 }
 
 void Sound::updateCD() {
-	g_system->getAudioCDManager()->updateCD();
+	if (!_isLoomSteam)
+		g_system->getAudioCDManager()->updateCD();
+}
+
+AudioCDManager::Status Sound::getCDStatus() {
+	if (!_isLoomSteam)
+		return g_system->getAudioCDManager()->getStatus();
+	else {
+		AudioCDManager::Status info = _loomSteamCD;
+		_loomSteamCD.playing = _mixer->isSoundHandleActive(_loomSteamCDAudioHandle);
+		return info;
+	}
 }
 
 void Sound::saveLoadWithSerializer(Serializer *ser) {

engines/scumm/sound.h

@@ -27,6 +27,7 @@
 #include "audio/audiostream.h"
 #include "audio/mididrv.h"
 #include "audio/mixer.h"
+#include "backends/audiocd/audiocd.h"
 #include "scumm/saveload.h"
 
 namespace Audio {
@@ -86,6 +87,10 @@ protected:
 	int16 _currentCDSound;
 	int16 _currentMusic;
 
+	Audio::SoundHandle _loomSteamCDAudioHandle;
+	bool _isLoomSteam;
+	AudioCDManager::Status _loomSteamCD;
+
 public:
 	Audio::SoundHandle _talkChannelHandle;	// Handle of mixer channel actor is talking on
 
@@ -119,9 +124,11 @@ public:
 	void stopCDTimer();
 
 	void playCDTrack(int track, int numLoops, int startFrame, int duration);
+	void playCDTrackInternal(int track, int numLoops, int startFrame, int duration);
 	void stopCD();
 	int pollCD() const;
 	void updateCD();
+	AudioCDManager::Status getCDStatus();
 	int getCurrentCDSound() const { return _currentCDSound; }
 
 	// Used by the save/load system: