ZVISION: Boost volume for MPEG cutscenes

The high-resolution videos play back at much lower volume than the
original ones. This adds hard-coded values for how much to amplify
each cutscene. It's all done by ear, and it does introduce some
clipping, but I think it should be acceptable.

Of course, it could also be a problem with the audio decoder, so
this may be the wrong approach entirely.

5 files changed, 116 insertions, 16 deletions

diff --git a/audio/decoders/ac3.cpp b/audio/decoders/ac3.cpp
index c569179996..1b2a3bff76 100644
--- a/audio/decoders/ac3.cpp
+++ b/audio/decoders/ac3.cpp
@@ -24,6 +24,7 @@
 #include "common/ptr.h"
 #include "common/stream.h"
 #include "common/textconsole.h"
+#include "common/util.h"
 
 #include "audio/audiostream.h"
 #include "audio/decoders/ac3.h"
@@ -37,7 +38,7 @@ namespace Audio {
 
 class AC3Stream : public PacketizedAudioStream {
 public:
-	AC3Stream();
+	AC3Stream(double decibel);
 	~AC3Stream();
 
 	bool init(Common::SeekableReadStream &firstPacket);
@@ -62,9 +63,14 @@ private:
 	byte *_inBufPtr;
 	int _flags;
 	int _sampleRate;
+	double _audioGain;
 };
 
-AC3Stream::AC3Stream() : _a52State(0), _frameSize(0), _inBufPtr(0), _flags(0), _sampleRate(0) {
+AC3Stream::AC3Stream(double decibel = 0.0) : _a52State(0), _frameSize(0), _inBufPtr(0), _flags(0), _sampleRate(0) {
+	if (decibel != 0.0)
+		_audioGain = pow(2, decibel / 6);
+	else
+		_audioGain = 1.0;
 }
 
 AC3Stream::~AC3Stream() {
@@ -153,7 +159,7 @@ void AC3Stream::queuePacket(Common::SeekableReadStream *data) {
 		} else {
 			// TODO: Eventually support more than just stereo max
 			int flags = A52_STEREO | A52_ADJUST_LEVEL;
-			sample_t level = 32767;
+			sample_t level = 32767 * _audioGain;
 
 			if (a52_frame(_a52State, _inBuf, &flags, &level, 0) != 0)
 				error("Frame fail");
@@ -165,8 +171,8 @@ void AC3Stream::queuePacket(Common::SeekableReadStream *data) {
 				if (a52_block(_a52State) == 0) {
 					sample_t *samples = a52_samples(_a52State);
 					for (int j = 0; j < 256; j++) {
-						*outputPtr++ = (int16)samples[j];
-						*outputPtr++ = (int16)samples[j + 256];
+						*outputPtr++ = (int16)CLIP<sample_t>(samples[j], -32768, 32767);
+						*outputPtr++ = (int16)CLIP<sample_t>(samples[j + 256], -32768, 32767);
 					}
 
 					outputLength += 1024;
@@ -189,8 +195,8 @@ void AC3Stream::queuePacket(Common::SeekableReadStream *data) {
 	}
 }
 
-PacketizedAudioStream *makeAC3Stream(Common::SeekableReadStream &firstPacket) {
-	Common::ScopedPtr<AC3Stream> stream(new AC3Stream());
+PacketizedAudioStream *makeAC3Stream(Common::SeekableReadStream &firstPacket, double decibel) {
+	Common::ScopedPtr<AC3Stream> stream(new AC3Stream(decibel));
 	if (!stream->init(firstPacket))
 		return 0;
 
diff --git a/audio/decoders/ac3.h b/audio/decoders/ac3.h
index a51107a410..249d1dcfa2 100644
--- a/audio/decoders/ac3.h
+++ b/audio/decoders/ac3.h
@@ -41,7 +41,7 @@ class PacketizedAudioStream;
  * @param firstPacket  The stream containing the first packet of data
  * @return             A new PacketizedAudioStream, or NULL on error
  */
-PacketizedAudioStream *makeAC3Stream(Common::SeekableReadStream &firstPacket);
+PacketizedAudioStream *makeAC3Stream(Common::SeekableReadStream &firstPacket, double decibel = 0.0);
 
 } // End of namespace Audio
 
diff --git a/engines/zvision/video/video.cpp b/engines/zvision/video/video.cpp
index 01e75a4a3d..54c113dc83 100644
--- a/engines/zvision/video/video.cpp
+++ b/engines/zvision/video/video.cpp
@@ -49,8 +49,99 @@ Video::VideoDecoder *ZVision::loadAnimation(const Common::String &fileName) {
 	else if (tmpFileName.hasSuffix(".avi"))
 		animation = new ZorkAVIDecoder();
 #if defined(USE_MPEG2) && defined(USE_A52)
-	else if (tmpFileName.hasSuffix(".vob"))
-		animation = new Video::MPEGPSDecoder();
+	else if (tmpFileName.hasSuffix(".vob")) {
+		// For some reason, we get much lower volume in the hi-res
+		// videos than in the low-res ones. So we artificially boost
+		// the volume here. This is an approximation, but I've tried
+		// to match the old volumes reasonably well.
+		//
+		// Some of these will cause audio clipping. Hopefully not
+		// enough to be noticeable.
+		double amplification = 0.0;
+		if (tmpFileName == "em00d011.vob") {
+			// The finale.
+			amplification = 10.0;
+		} else if (tmpFileName == "em00d021.vob") {
+			// Jack's escape and arrival at Flathead Mesa.
+			amplification = 9.0;
+		} else if (tmpFileName == "em00d032.vob") {
+			// The Grand Inquisitor's speech.
+			amplification = 11.0;
+		} else if (tmpFileName == "em00d122.vob") {
+			// Jack orders you to the radio tower.
+			amplification = 17.0;
+		} else if (tmpFileName == "em3ed012.vob") {
+			// The Grand Inquisitor gets the Coconut of Quendor.
+			amplification = 12.0;
+		} else if (tmpFileName == "g000d101.vob") {
+			// Griff gets captured.
+			amplification = 11.0;
+		} else if (tmpFileName == "g000d111.vob") {
+			// Brog gets totemized. The music seems to be mixed
+			// much softer in this than in the low-resolution
+			// version.
+			amplification = 12.0;
+		} else if (tmpFileName == "g000d122.vob") {
+			// Lucy gets captured.
+			amplification = 14.0;
+		} else if (tmpFileName == "g000d302.vob") {
+			// The Grand Inquisitor visits Jack in his cell.
+			amplification = 13.0;
+		} else if (tmpFileName == "g000d312.vob") {
+			// You get captured.
+			amplification = 14.0;
+		} else if (tmpFileName == "g000d411.vob") {
+			// Propaganda On Parade. No need to make it as loud as
+			// the low-resolution version.
+			amplification = 11.0;
+		} else if (tmpFileName == "pe1ed012.vob") {
+			// Jack lets you in with the lantern.
+			amplification = 14.0;
+		} else if (tmpFileName.hasPrefix("pe1ed")) {
+			// Jack answers the door. Several different ways.
+			amplification = 17.0;
+		} else if (tmpFileName == "pe5ed052.vob") {
+			// You get killed by the guards
+			amplification = 12.0;
+		} else if (tmpFileName == "pe6ed012.vob") {
+			// Jack gets captured by the guards
+			amplification = 17.0;
+		} else if (tmpFileName == "pp1ed022.vob") {
+			// Jack examines the lantern
+			amplification = 10.0;
+		} else if (tmpFileName == "qb1ed012.vob") {
+			// Lucy gets invited to the back room
+			amplification = 17.0;
+		} else if (tmpFileName.hasPrefix("qe1ed")) {
+			// Floyd answers the door. Several different ways.
+			amplification = 17.0;
+		} else if (tmpFileName == "qs1ed011.vob") {
+			// Jack explains the rules of the game.
+			amplification = 16.0;
+		} else if (tmpFileName == "qs1ed021.vob") {
+			// Jack loses the game.
+			amplification = 14.0;
+		} else if (tmpFileName == "uc1gd012.vob") {
+			// Y'Gael appears.
+			amplification = 12.0;
+		} else if (tmpFileName == "ue1ud012.vob") {
+			// Jack gets totemized... or what?
+			amplification = 12.0;
+		} else if (tmpFileName == "ue2qd012.vob") {
+			// Jack agrees to totemization.
+			amplification = 10.0;
+		} else if (tmpFileName == "g000d981.vob") {
+			// The Enterprise logo. Has no low-res version. Its
+			// volume is louder than the other logo animations.
+			amplification = 6.2;
+		} else if (tmpFileName.hasPrefix("g000d")) {
+			// The Dolby Digital and Activision logos. They have no
+			// low-res versions, but I've used the low-resolution
+			// Activision logo (slightly different) as reference.
+			amplification = 8.5;
+		}
+		animation = new Video::MPEGPSDecoder(amplification);
+	}
 #endif
 	else
 		error("Unknown suffix for animation %s", fileName.c_str());
diff --git a/video/mpegps_decoder.cpp b/video/mpegps_decoder.cpp
index 361481b739..9b232ec792 100644
--- a/video/mpegps_decoder.cpp
+++ b/video/mpegps_decoder.cpp
@@ -50,7 +50,8 @@ enum {
 	kStartCodePrivateStream2 = 0x1BF
 };
 
-MPEGPSDecoder::MPEGPSDecoder() {
+MPEGPSDecoder::MPEGPSDecoder(double decibel) {
+	_decibel = decibel;
 	_demuxer = new MPEGPSDemuxer();
 }
 
@@ -104,7 +105,7 @@ MPEGPSDecoder::MPEGStream *MPEGPSDecoder::getStream(uint32 startCode, Common::Se
 
 #ifdef USE_A52
 				handled = true;
-				AC3AudioTrack *ac3Track = new AC3AudioTrack(*packet, getSoundType());
+				AC3AudioTrack *ac3Track = new AC3AudioTrack(*packet, _decibel, getSoundType());
 				stream = ac3Track;
 				_streamMap[startCode] = ac3Track;
 				addTrack(ac3Track);
@@ -704,9 +705,9 @@ Audio::AudioStream *MPEGPSDecoder::MPEGAudioTrack::getAudioStream() const {
 
 #ifdef USE_A52
 
-MPEGPSDecoder::AC3AudioTrack::AC3AudioTrack(Common::SeekableReadStream &firstPacket, Audio::Mixer::SoundType soundType) :
+MPEGPSDecoder::AC3AudioTrack::AC3AudioTrack(Common::SeekableReadStream &firstPacket, double decibel, Audio::Mixer::SoundType soundType) :
 		AudioTrack(soundType) {
-	_audStream = Audio::makeAC3Stream(firstPacket);
+	_audStream = Audio::makeAC3Stream(firstPacket, decibel);
 	if (!_audStream)
 		error("Could not create AC-3 stream");
 }
diff --git a/video/mpegps_decoder.h b/video/mpegps_decoder.h
index bd703a35ff..7960639d78 100644
--- a/video/mpegps_decoder.h
+++ b/video/mpegps_decoder.h
@@ -54,7 +54,7 @@ namespace Video {
  */
 class MPEGPSDecoder : public VideoDecoder {
 public:
-	MPEGPSDecoder();
+	MPEGPSDecoder(double decibel = 0.0);
 	virtual ~MPEGPSDecoder();
 
 	bool loadStream(Common::SeekableReadStream *stream);
@@ -166,7 +166,7 @@ private:
 #ifdef USE_A52
 	class AC3AudioTrack : public AudioTrack, public MPEGStream {
 	public:
-		AC3AudioTrack(Common::SeekableReadStream &firstPacket, Audio::Mixer::SoundType soundType);
+		AC3AudioTrack(Common::SeekableReadStream &firstPacket, double decibel, Audio::Mixer::SoundType soundType);
 		~AC3AudioTrack();
 
 		bool sendPacket(Common::SeekableReadStream *packet, uint32 pts, uint32 dts);
@@ -199,6 +199,8 @@ private:
 	// A map from stream types to stream handlers
 	typedef Common::HashMap<int, MPEGStream *> StreamMap;
 	StreamMap _streamMap;
+
+	double _decibel;
 };
 
 } // End of namespace Video