Audio Phase 2 (AUDIO_FIDELITY F1/F2/F13/F14): full-zone soundbank -- key-splits,

layers, baked tuning, loop regions, release fades

Extractor rewrite (tools/sf2extract.py): every sample-bearing instrument zone
becomes a SAMPLEINFO slot -- 603 zones / 241 presets (68/115 + 94/126 multi-
zone, matching the audit exactly).  Per zone: keyRange(43), sampleModes(54),
SBK samplePitch(55) + rootKey(58) + coarse/fineTune(51/52), attenuation(48,
INVERTED SBK scale, 0.375 dB/step [T3], baked into the PCM), releaseVolEnv(38),
pan(17), shdr loop region.

F2 pitch (algebraically exact): WAV rate = round(44100 * 2^(((6000 -
rootCents) + tune)/1200)) -- EMU8000 v1 base 44100.  Cross-checks: FootFall
17300 Hz (the audit's +4.2 st), MissileLoaded low zone 88200 (-24 st),
Warnings01 8-way klaxon split w/ 3 looped zones, Death01 162 Hz extremes.

F1 zone selection: SetupPatch/PlayNote take the authored note;
attach/play only zones whose [keyLo,keyHi] contains it (detach the rest so a
rewound source can't replay a stale buffer).  Live-verified: LaserLoaded/
MissileLoaded note 36 -> low clunk zone, note 84 -> high blip zone (pitch 4);
LaserCFire plays all 3 authored layers incl the looping sustain.  Stereo-pair
zones pan via listener-relative AL_POSITION (distance model is AL_NONE).
MAX_PRESET_SAMPLES=25 (AllExplosion); fixed PRESET_isImplemented's >=5 bound.

F13 loops + releases: authored [loopStart,loopEnd] applied via
AL_SOFT_loop_points at buffer load (0 rejections; kills the latent boom-loop
on MechExplosion's 1.5% sustain slice + the ~2.4 Hz LaserBSustain wrap tick);
StopNote now honors the authored releaseVolEnv (1.1-3.9 s on ~20 looping
presets) with a dB-linear fade serviced from AudioHead::Execute; restarts
reclaim fading sources.  One-shots keep the instant stop (faithful).

Regression (40s drive+fire): stable, loop points accepted, key-splits + layers
verified in the delivery trace, chirp still dead, footfalls fire.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

engine/MUNGA/AUDIO.cpp

@@ -158,6 +158,21 @@ void
 	if (getenv("BT_AUDIO_SPATIAL")) { static long s_hx=0; if ((++s_hx % 300)==0)
 		DEBUG_STREAM << "[audioclock] frame=" << audioFrameCount << " execs=" << s_hx << "\n" << std::flush; }
 
+	// (task #50, AUDIO_FIDELITY F13) service the authored release fades
+	// registered by PatchLevelOfDetail::StopNote (dB-linear note-off ramps).
+	{
+		extern void PRESET_serviceReleaseFades(float elapsed_seconds);
+		static long s_lastFadeTicks = 0;
+		long now_ticks = Now().ticks;
+		if (s_lastFadeTicks != 0 && now_ticks > s_lastFadeTicks)
+		{
+			double tps = (double)SystemClock::GetTicksPerSecond();
+			if (tps <= 0.0) tps = 1000.0;
+			PRESET_serviceReleaseFades((float)((now_ticks - s_lastFadeTicks) / tps));
+		}
+		s_lastFadeTicks = now_ticks;
+	}
+
    //set current listener orientation
    Vector3D headVelocity;
    

engine/MUNGA_L4/L4AUDIO.cpp

@@ -935,7 +935,7 @@ void
 	patch_resource = Cast_Object(PatchResource*, GetAudioResource());
 	Check(patch_resource);
 	patch_resource->SetDistance(GetDistanceToSource());
-	patch_resource->SetupPatch(channelSet);
+	patch_resource->SetupPatch(channelSet, (int)GetCurrentNoteValue());
 
 	{	// apply the requested note's pitch to the freshly attached sources
 		float note_pitch = BTNotePitchFactor((int)GetCurrentNoteValue());
@@ -999,7 +999,7 @@ void
 	//
 	//TODO:  Start OpenAL source playing
 //	channel->SendNoteOn(GetCurrentNoteValue(), midi_velocity);
-	patch_resource->PlayNote(channelSet);
+	patch_resource->PlayNote(channelSet, (int)GetCurrentNoteValue());
 
 	#if 0
 		Tell("On " << (int)GetCurrentNoteValue() << "\n");
@@ -1231,7 +1231,7 @@ void
 	patch_resource = Cast_Object(PatchResource*, GetAudioResource());
 	Check(patch_resource);
 	patch_resource->SetDistance(GetDistanceToSource());
-	patch_resource->SetupPatch(channelSet);
+	patch_resource->SetupPatch(channelSet, (int)GetCurrentNoteValue());
 
 	{	// apply the requested note's pitch to the freshly attached sources
 		float note_pitch = BTNotePitchFactor((int)GetCurrentNoteValue());
@@ -1332,7 +1332,7 @@ void
 		Check(channel);
 		channel->SendNoteOn(GetCurrentNoteValue(), midi_velocity);
 	}*/
-	patch_resource->PlayNote(channelSet);
+	patch_resource->PlayNote(channelSet, (int)GetCurrentNoteValue());
 }
 
 //
@@ -1755,7 +1755,7 @@ void
 	patch_resource = Cast_Object(PatchResource*, GetAudioResource());
 	Check(patch_resource);
 	patch_resource->SetDistance(GetDistanceToSource());
-	patch_resource->SetupPatch(channelSet);
+	patch_resource->SetupPatch(channelSet, (int)GetCurrentNoteValue());
 
 	{	// apply the requested note's pitch to the freshly attached sources
 		float note_pitch = BTNotePitchFactor((int)GetCurrentNoteValue());
@@ -1918,7 +1918,7 @@ void
 			channel->SendNoteOn(GetCurrentNoteValue(), midi_velocity);
 		}
 	}*/
-	patch_resource->PlayNote(channelSet);
+	patch_resource->PlayNote(channelSet, (int)GetCurrentNoteValue());
 
 }
 

engine/MUNGA_L4/L4AUDLVL.cpp

@@ -9,6 +9,100 @@
 #include "..\munga\namelist.h"
 #include "openal/al.h"
 
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Release fades ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// (task #50, AUDIO_FIDELITY F13) ~20 looping presets author a releaseVolEnv of
+// 1.1-3.9 s the AWE32 applied as a note-off fade while the loop continued;
+// StopNote registers a dB-linear ramp here instead of cutting.  Serviced once
+// per frame from AudioHead::Execute; a fade finishing (or being reclaimed by a
+// restart) stops + rewinds the source so the next SetupPatch sees AL_INITIAL.
+//
+namespace
+{
+	struct ReleaseFade
+	{
+		ALuint source;
+		float gain0;
+		float duration;
+		float elapsed;
+		bool active;
+	};
+	const int MAX_RELEASE_FADES = 64;
+	ReleaseFade s_releaseFades[MAX_RELEASE_FADES];
+
+	void FinishFade(ReleaseFade &fade)
+	{
+		alSourceStop(fade.source);
+		alSourceRewind(fade.source);
+		alSourcef(fade.source, AL_GAIN, fade.gain0);
+		fade.active = false;
+	}
+
+	void StartReleaseFade(ALuint source, float duration)
+	{
+		for (int i = 0; i < MAX_RELEASE_FADES; i++)
+		{
+			if (s_releaseFades[i].active && s_releaseFades[i].source == source)
+			{
+				return;		// already releasing
+			}
+		}
+		for (int i = 0; i < MAX_RELEASE_FADES; i++)
+		{
+			if (!s_releaseFades[i].active)
+			{
+				ReleaseFade &fade = s_releaseFades[i];
+				fade.source = source;
+				alGetSourcef(source, AL_GAIN, &fade.gain0);
+				fade.duration = duration;
+				fade.elapsed = 0.0f;
+				fade.active = true;
+				return;
+			}
+		}
+		// table full -- fall back to the instant cut
+		alSourceStop(source);
+		alSourceRewind(source);
+	}
+
+	// A restart wants this source back NOW: finalize any fade so the caller
+	// sees AL_INITIAL with the pre-fade gain restored.
+	void ReclaimFadingSource(ALuint source)
+	{
+		for (int i = 0; i < MAX_RELEASE_FADES; i++)
+		{
+			if (s_releaseFades[i].active && s_releaseFades[i].source == source)
+			{
+				FinishFade(s_releaseFades[i]);
+				return;
+			}
+		}
+	}
+}
+
+void PRESET_serviceReleaseFades(float elapsed_seconds)
+{
+	for (int i = 0; i < MAX_RELEASE_FADES; i++)
+	{
+		ReleaseFade &fade = s_releaseFades[i];
+		if (!fade.active)
+		{
+			continue;
+		}
+		fade.elapsed += elapsed_seconds;
+		if (fade.elapsed >= fade.duration)
+		{
+			FinishFade(fade);
+		}
+		else
+		{
+			// dB-linear ramp to -96 dB over the authored release time
+			float attenuation = powf(10.0f, -4.8f * (fade.elapsed / fade.duration));
+			alSourcef(fade.source, AL_GAIN, fade.gain0 * attenuation);
+		}
+	}
+}
+
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PatchLevelOfDetail ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 #if DEBUG_LEVEL>0
@@ -27,7 +121,10 @@ PatchLevelOfDetail::PatchLevelOfDetail(PlugStream *stream):
 	MemoryStream_Read(stream, &patchID);
 	MemoryStream_Read(stream, &maxMIDIFilterCutoff);
 
-	Warn(GetVoiceCount() > 4); // HACK - AWE appears to only play 1st 4 voices
+	// (task #50) the AWE 4-voice comment applied to layers SHARING a key range;
+	// full-zone presets legitimately carry up to MAX_PRESET_SAMPLES zones
+	// (key-splits select at most a few per note).
+	Warn(GetVoiceCount() > MAX_PRESET_SAMPLES);
 
 	#ifdef LAB_ONLY
 		setupCount = 0;
@@ -119,7 +216,7 @@ Logical
 //#############################################################################
 //
 void
-	PatchLevelOfDetail::SetupPatch(SourceSet sourceSet)
+	PatchLevelOfDetail::SetupPatch(SourceSet sourceSet, int note)
 {
 //	Check(this);
 ////	Check(channel);
@@ -129,30 +226,44 @@ void
 //	#endif
    SAMPLEINFO info;
 
-	//Attach buffers
+	// (task #50, AUDIO_FIDELITY F1) the authored MIDI note SELECTS zones:
+	// attach only samples whose [keyLo,keyHi] contains the note (key-splits
+	// pick one band, layers attach together); detach the rest so a rewound
+	// source can't replay a stale buffer from a previous note.
 	for (int i=0; i < sourceSet.count; i++)
 	{
 		info = PRESET_getSampleInfo(bankID,patchID,i);
 		if (info.bufferIndex >= 0)
 		{
+			ReclaimFadingSource(sourceSet.sources[i]);
+
 			ALenum sourceState;
 			alGetSourcei(sourceSet.sources[i], AL_SOURCE_STATE, &sourceState);
 
+			bool zone_matches = (note >= info.keyLo && note <= info.keyHi);
+
 			if (getenv("BT_AUDIO_SPATIAL")) { static int s_se=0; if (s_se++<200)
 				DEBUG_STREAM << "[audio] SetupPatch ENTRY bank=" << (int)bankID << " patch=" << (int)patchID << " src=" << sourceSet.sources[i]
-					<< " file=" << (info.file?info.file:"?")
+					<< " file=" << (info.file?info.file:"?") << " note=" << note << (zone_matches?"":" ZONESKIP")
 					<< " state=" << sourceState << " (INITIAL=" << AL_INITIAL << ")" << "\n" << std::flush; }
 
 			if (sourceState == AL_INITIAL)
 			{
-				alSourcei(sourceSet.sources[i],AL_BUFFER,AL_getBuffer(info.bufferIndex));
+				alSourcei(sourceSet.sources[i],AL_BUFFER,
+					zone_matches ? AL_getBuffer(info.bufferIndex) : 0);
 				{ static int s_a=0; if (getenv("BT_AUDIO_LOG") && s_a++<24) DEBUG_STREAM << "[audio] SetupPatch src=" << sourceSet.sources[i] << " file=" << (info.file?info.file:"?") << " loop=" << (info.loop==ForceStatic?0:1) << "\n" << std::flush; }
 				alSourcei(sourceSet.sources[i],AL_SOURCE_RELATIVE,AL_TRUE);
 
 				AudioRenderer *render = application->GetAudioRenderer();
 				AudioHead *head = render->GetAudioHead();
 
-				alSource3f(sourceSet.sources[i],AL_POSITION,0,0,0);
+				// (F1) authored stereo pairs: pan hard-left/right zones via a
+				// listener-relative offset (the distance model is AL_NONE, so
+				// this affects direction only, never gain).
+				float pan_x =
+					(info.chan == CHANNEL_LEFT) ? -0.5f :
+					(info.chan == CHANNEL_RIGHT) ? 0.5f : 0.0f;
+				alSource3f(sourceSet.sources[i],AL_POSITION,pan_x,0,0);
 				alSource3f(sourceSet.sources[i],AL_VELOCITY,0,0,0);
 
 				if (info.loop == ForceStatic)
@@ -180,7 +291,7 @@ void
 	#endif*/
 }
 
-void PatchLevelOfDetail::PlayNote(SourceSet sourceSet)
+void PatchLevelOfDetail::PlayNote(SourceSet sourceSet, int note)
 {
 	if (sourceSet.count > 0 && sourceSet.sources != NULL)
 	{
@@ -189,13 +300,21 @@ void PatchLevelOfDetail::PlayNote(SourceSet sourceSet)
 
 		for (int i = 0; i < sourceSet.count; i++)
 		{
+			// (F1) play only the zones SetupPatch attached for this note
+			ALint attached = 0;
+			alGetSourcei(sourceSet.sources[i], AL_BUFFER, &attached);
+			if (attached == 0)
+			{
+				continue;
+			}
+
 			ALenum state;
 			alGetSourcei(sourceSet.sources[i], AL_SOURCE_STATE, &state);
 
 			if (state != AL_PLAYING)
 			{
 				alSourcePlay(sourceSet.sources[i]);
-				{ static int s_p=0; if (getenv("BT_AUDIO_LOG") && s_p++<30) DEBUG_STREAM << "[audio] PlayNote alSourcePlay src=" << sourceSet.sources[i] << "\n" << std::flush; }
+				{ static int s_p=0; if (getenv("BT_AUDIO_LOG") && s_p++<30) DEBUG_STREAM << "[audio] PlayNote alSourcePlay src=" << sourceSet.sources[i] << " note=" << note << "\n" << std::flush; }
 			}
 
 			ALenum error = alGetError();
@@ -213,8 +332,24 @@ void PatchLevelOfDetail::StopNote(SourceSet sourceSet)
 	if (getenv("BT_AUDIO_LOG")) { static int s_s=0; if (s_s++<400) { DEBUG_STREAM << "[audio] StopNote"; for (int _i=0;_i<sourceSet.count;_i++) DEBUG_STREAM << " src=" << sourceSet.sources[_i]; DEBUG_STREAM << "\n" << std::flush; } }
 	if (sourceSet.count >0 && sourceSet.sources != NULL)
 	{
-		alSourceStopv(sourceSet.count, sourceSet.sources);
-		alSourceRewindv(sourceSet.count, sourceSet.sources);
+		// (task #50, AUDIO_FIDELITY F13) honor the authored releaseVolEnv:
+		// a playing zone with a release time fades out dB-linearly instead of
+		// cutting; everything else stops instantly (faithful for one-shots).
+		for (int i = 0; i < sourceSet.count; i++)
+		{
+			SAMPLEINFO info = PRESET_getSampleInfo(bankID,patchID,i);
+			ALenum state;
+			alGetSourcei(sourceSet.sources[i], AL_SOURCE_STATE, &state);
+			if (state == AL_PLAYING && info.releaseSec > 0.05f)
+			{
+				StartReleaseFade(sourceSet.sources[i], info.releaseSec);
+			}
+			else
+			{
+				alSourceStop(sourceSet.sources[i]);
+				alSourceRewind(sourceSet.sources[i]);
+			}
+		}
 	}
 }
 
@@ -268,7 +403,7 @@ Logical
 //#############################################################################
 //
 void
-	PatchResource::SetupPatch(SourceSet sourceSet)
+	PatchResource::SetupPatch(SourceSet sourceSet, int note)
 {
 	Check(this);
 //	Check(channel);
@@ -277,10 +412,10 @@ void
 		Cast_Object(PatchLevelOfDetail*, GetAudioLevelOfDetail());
 
 	Check(patch_level_of_detail);
-	patch_level_of_detail->SetupPatch(sourceSet);
+	patch_level_of_detail->SetupPatch(sourceSet, note);
 }
 
-void PatchResource::PlayNote(SourceSet sourceSet)
+void PatchResource::PlayNote(SourceSet sourceSet, int note)
 {
 	Check(this);
 //	Check(channel);
@@ -289,7 +424,7 @@ void PatchResource::PlayNote(SourceSet sourceSet)
 		Cast_Object(PatchLevelOfDetail*, GetAudioLevelOfDetail());
 
 	Check(patch_level_of_detail);
-	patch_level_of_detail->PlayNote(sourceSet);
+	patch_level_of_detail->PlayNote(sourceSet, note);
 }
 
 void PatchResource::StopNote(SourceSet sourceSet)

engine/MUNGA_L4/L4AUDLVL.h

@@ -26,12 +26,24 @@ struct SAMPLEINFO
 	const char *file;
 	SampleChannel chan;
 	SampleLoop loop;
+	// (task #50, AUDIO_FIDELITY F1/F13) full-zone metadata from the SF2 banks:
+	// the authored MIDI note SELECTS zones by [keyLo,keyHi]; loop regions are
+	// sub-ranges in sample frames (AL_SOFT_loop_points); releaseSec is the
+	// authored releaseVolEnv fade applied on Stop instead of an instant cut.
+	int keyLo;
+	int keyHi;
+	int loopStart;
+	int loopEnd;
+	float releaseSec;
 };
 
+// AllExplosion (bank2 p125) authors 25 layered zones -- the largest preset.
+const int MAX_PRESET_SAMPLES = 25;
+
 struct PRESETINFO
 {
 	int sampleNum;
-	SAMPLEINFO samples[5];
+	SAMPLEINFO samples[MAX_PRESET_SAMPLES];
 	bool is3d;
 };
 
@@ -42,6 +54,10 @@ int PRESET_getNumSamples(int bank, int preset);
 SAMPLEINFO PRESET_getSampleInfo(int bank, int preset, int sampleInd);
 void PRESET_setBufferIndex(int bank, int preset, int sampleInd, int index);
 
+// (task #50, AUDIO_FIDELITY F13) authored release fades: StopNote registers a
+// dB-linear gain ramp instead of cutting; AudioHead::Execute services them.
+void PRESET_serviceReleaseFades(float elapsed_seconds);
+
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PatchLevelOfDetail ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 typedef MIDIValue	SBKPatchID;
@@ -59,7 +75,7 @@ public:
 	PatchLevelOfDetail(PlugStream *stream);
 	~PatchLevelOfDetail();
 
-	void PlayNote(SourceSet sourceSet);
+	void PlayNote(SourceSet sourceSet, int note);
 	void StopNote(SourceSet sourceSet);
 
 	Logical
@@ -93,7 +109,7 @@ public:
 	//-----------------------------------------------------------------------
 	//
 	void
-		SetupPatch(SourceSet sourceSet);
+		SetupPatch(SourceSet sourceSet, int note);
 
 	MIDINRPNValue
 		GetMaxMIDIFilterCutoff()
@@ -141,7 +157,7 @@ public:
 	PatchResource(PlugStream *stream);
 	~PatchResource();
 
-	void PlayNote(SourceSet sourceSet);
+	void PlayNote(SourceSet sourceSet, int note);
 	void StopNote(SourceSet sourceSet);
 
 	Logical
@@ -166,7 +182,7 @@ public:
 	//-----------------------------------------------------------------------
 	//
 	void
-		SetupPatch(SourceSet sourceSet);
+		SetupPatch(SourceSet sourceSet, int note);
 
 	MIDINRPNValue
 		GetMaxMIDIFilterCutoff();

engine/MUNGA_L4/L4AUDRES.cpp

@@ -672,6 +672,26 @@ void
 
 					//Feed the buffer with the real PCM sample data
 					alBufferData(g_buffers[bufferInd], format, data, size, wavRate);
+
+					// (task #50, AUDIO_FIDELITY F13) honor the authored loop
+					// REGION -- the EMU8000 looped [dwStartLoop,dwEndLoop], not
+					// the whole sample (MechExplosion's boom carries a ~16 ms
+					// sustain slice that must not replay the full boom).
+					#ifndef AL_LOOP_POINTS_SOFT
+					#define AL_LOOP_POINTS_SOFT 0x2015
+					#endif
+					if (info.loop != ForceStatic && info.loopEnd > info.loopStart)
+					{
+						ALint loop_points[2] = { info.loopStart, info.loopEnd };
+						alGetError();
+						alBufferiv(g_buffers[bufferInd], AL_LOOP_POINTS_SOFT, loop_points);
+						ALenum lpErr = alGetError();
+						if (lpErr != AL_NO_ERROR && getenv("BT_AUDIO_LOG"))
+							DEBUG_STREAM << "[audio] loop-points REJECTED buf" << bufferInd
+								<< " " << info.file << " [" << info.loopStart << ","
+								<< info.loopEnd << "] err=" << lpErr << "\n" << std::flush;
+					}
+
 					if (bufferInd < 512) g_bufferNames[bufferInd] = info.file;
 					if (getenv("BT_AUDIO_LOG") && bufferInd < 3)
 						DEBUG_STREAM << "[audio] loaded buf" << bufferInd << " " << info.file

engine/MUNGA_L4/WTPresets.cpp

@@ -4,7 +4,7 @@ bool PRESET_isImplemented(int bank, int presetn)
 {
 	PRESETINFO preset = allPresets[bank-1][presetn];
 
-	if (preset.sampleNum <= 0 || preset.sampleNum >= 5)
+	if (preset.sampleNum <= 0 || preset.sampleNum > MAX_PRESET_SAMPLES)
 	{
 		return false;
 	}
@@ -27,15 +27,20 @@ int PRESET_getNumSamples(int bank, int preset)
 
 SAMPLEINFO PRESET_getSampleInfo(int bank, int preset, int sampleInd)
 {
-	SAMPLEINFO default;
-	default.chan = SampleChannel::CHANNEL_CENTER;
-	default.file = "";
-	default.implemented = false;
-	default.loop = SampleLoop::LoopAtWill;
-
 	if (sampleInd < 0 || sampleInd >= allPresets[bank-1][preset].sampleNum)
 	{
-		return default;
+		SAMPLEINFO none;
+		none.bufferIndex = -1;
+		none.implemented = false;
+		none.file = "";
+		none.chan = SampleChannel::CHANNEL_CENTER;
+		none.loop = SampleLoop::LoopAtWill;
+		none.keyLo = 0;
+		none.keyHi = 127;
+		none.loopStart = 0;
+		none.loopEnd = 0;
+		none.releaseSec = 0.0f;
+		return none;
 	}
 
 	return allPresets[bank-1][preset].samples[sampleInd];
@@ -44,4 +49,4 @@ SAMPLEINFO PRESET_getSampleInfo(int bank, int preset, int sampleInd)
 void PRESET_setBufferIndex(int bank, int preset, int sampleInd, int index)
 {
 	allPresets[bank-1][preset].samples[sampleInd].bufferIndex = index;
-}
+}