From 92d29e7acf94cad15e2d5df15faab22ad632e76b Mon Sep 17 00:00:00 2001
From: Christopher Snowhill <kode54@gmail.com>
Date: Thu, 13 Jan 2022 19:43:18 -0800
Subject: [PATCH] Cog Audio: Now preserves already resampled output when
 switching output formats

---
 Audio/Chain/ConverterNode.h              |  6 +++
 Audio/Chain/ConverterNode.m              | 56 ++++++++++++++++++++----
 Audio/Chain/OutputNode.m                 |  7 ++-
 Audio/Chain/RefillNode.h                 | 26 +++++++++++
 Audio/Chain/RefillNode.m                 | 34 ++++++++++++++
 Audio/CogAudio.xcodeproj/project.pbxproj | 12 +++--
 6 files changed, 129 insertions(+), 12 deletions(-)
 create mode 100644 Audio/Chain/RefillNode.h
 create mode 100644 Audio/Chain/RefillNode.m

diff --git a/Audio/Chain/ConverterNode.h b/Audio/Chain/ConverterNode.h
index 9b4334433..8d5ab1bc5 100644
--- a/Audio/Chain/ConverterNode.h
+++ b/Audio/Chain/ConverterNode.h
@@ -15,6 +15,7 @@
 #import <audio/audio_resampler.h>
 
 #import "Node.h"
+#import "RefillNode.h"
 
 @interface ConverterNode : Node {
     NSDictionary * rgInfo;
@@ -49,6 +50,11 @@
     AudioStreamBasicDescription floatFormat;
     AudioStreamBasicDescription dmFloatFormat; // downmixed/upmixed float format
 	AudioStreamBasicDescription outputFormat;
+    
+    AudioStreamBasicDescription previousOutputFormat;
+    AudioStreamBasicDescription rememberedInputFormat;
+    RefillNode *refillNode;
+    id __weak originalPreviousNode;
 }
 
 - (id)initWithController:(id)c previous:(id)p;
diff --git a/Audio/Chain/ConverterNode.m b/Audio/Chain/ConverterNode.m
index 4c3c83148..5f76af1d1 100644
--- a/Audio/Chain/ConverterNode.m
+++ b/Audio/Chain/ConverterNode.m
@@ -59,6 +59,9 @@ void PrintStreamDesc (AudioStreamBasicDescription *inDesc)
         latencyStarted = -1;
         latencyEaten = 0;
         latencyPostfill = NO;
+        
+        refillNode = nil;
+        originalPreviousNode = nil;
 
         [[NSUserDefaultsController sharedUserDefaultsController] addObserver:self forKeyPath:@"values.volumeScaling"		options:0 context:nil];
         [[NSUserDefaultsController sharedUserDefaultsController] addObserver:self forKeyPath:@"values.outputResampling" options:0 context:nil];
@@ -415,6 +418,17 @@ static void extrapolate(float *buffer, size_t channels, size_t frameSize, size_t
                     usleep(500);
                 continue;
             }
+            else if (refillNode)
+            {
+                // refill node just ended, file resumes
+                [self setPreviousNode:originalPreviousNode];
+                [self setEndOfStream:NO];
+                [self setShouldContinue:YES];
+                refillNode = nil;
+                [self cleanUp];
+                [self setupWithInputFormat:rememberedInputFormat outputFormat:outputFormat];
+                continue;
+            }
             else break;
         }
 		[self writeData:writeBuf amount:amountConverted];
@@ -429,7 +443,6 @@ static void extrapolate(float *buffer, size_t channels, size_t frameSize, size_t
     int extrapolateStart = 0;
     int extrapolateEnd = 0;
     size_t amountToSkip = 0;
-    BOOL endOfInputStream = NO;
 
     if (stopping)
         return 0;
@@ -530,7 +543,12 @@ tryagain:
             size_t bytesRead = [self readData:inputBuffer + amountToSkip + bytesReadFromInput amount:(int)(amountToWrite - bytesReadFromInput)];
             bytesReadFromInput += bytesRead;
             if (!bytesRead)
-                usleep(500);
+            {
+                if (refillNode)
+                    [self setEndOfStream:YES];
+                else
+                    usleep(500);
+            }
         }
         
         bytesReadFromInput += amountToSkip;
@@ -612,7 +630,7 @@ tryagain:
         inpOffset = 0;
     }
     
-    if (floatOffset == floatSize)
+    if (inpOffset != inpSize && floatOffset == floatSize)
     {
         struct resampler_data src_data;
         
@@ -875,6 +893,7 @@ static float db_to_scale(float db)
 - (void)setOutputFormat:(AudioStreamBasicDescription)format
 {
 	DLog(@"SETTING OUTPUT FORMAT!");
+    previousOutputFormat = outputFormat;
 	outputFormat = format;
     outputFormatChanged = YES;
 }
@@ -884,13 +903,34 @@ static float db_to_scale(float db)
 	DLog(@"FORMAT CHANGED");
     paused = YES;
 	[self cleanUp];
-    if (outputFormatChanged)
+    if (outputFormatChanged && ![buffer isEmpty])
     {
-        [writeLock lock];
-        [buffer empty];
-        [writeLock unlock];
+        // Transfer previously buffered data, remember input format
+        rememberedInputFormat = format;
+        originalPreviousNode = previousNode;
+        refillNode = [[RefillNode alloc] initWithController:controller previous:nil];
+        [self setPreviousNode:refillNode];
+
+        int dataRead = 0;
+
+        for (;;)
+        {
+            void * ptr;
+            dataRead = [buffer lengthAvailableToReadReturningPointer:&ptr];
+            if (dataRead) {
+                [refillNode writeData:(float*)ptr floatCount:dataRead / sizeof(float)];
+                [buffer didReadLength:dataRead];
+            }
+            else
+                break;
+        }
+        
+        [self setupWithInputFormat:previousOutputFormat outputFormat:outputFormat];
+    }
+    else
+    {
+        [self setupWithInputFormat:format outputFormat:outputFormat];
     }
-	[self setupWithInputFormat:format outputFormat:outputFormat];
 }
 
 - (void)setRGInfo:(NSDictionary *)rgi
diff --git a/Audio/Chain/OutputNode.m b/Audio/Chain/OutputNode.m
index a8a6c1b21..92e8ff05b 100644
--- a/Audio/Chain/OutputNode.m
+++ b/Audio/Chain/OutputNode.m
@@ -91,7 +91,7 @@
 {
 	format = *f;
     // Calculate a ratio and add to double(seconds) instead, as format may change
-    double oldSampleRatio = sampleRatio;
+    // double oldSampleRatio = sampleRatio;
     sampleRatio = 1.0 / (format.mSampleRate * format.mBytesPerPacket);
     BufferChain *bufferChain = [controller bufferChain];
     if (bufferChain)
@@ -102,8 +102,13 @@
             // This clears the resampler buffer, but not the input buffer
             // We also have to jump the play position ahead accounting for
             // the data we are flushing
+#if 0
+            // We no longer need to do this, because outputchanged converter
+            // now uses the RefillNode to slap the previous samples into
+            // itself
             if (oldSampleRatio)
                 amountPlayed += oldSampleRatio * [[converter buffer] bufferedLength];
+#endif
             [converter setOutputFormat:format];
             [converter inputFormatDidChange:[bufferChain inputFormat]];
         }
diff --git a/Audio/Chain/RefillNode.h b/Audio/Chain/RefillNode.h
new file mode 100644
index 000000000..6cb803090
--- /dev/null
+++ b/Audio/Chain/RefillNode.h
@@ -0,0 +1,26 @@
+//
+//  RefillNode.h
+//  Cog
+//
+//  Created by Christopher SNowhill on 1/13/22.
+//  Copyright 2022 __LoSnoCo__. All rights reserved.
+//
+
+#import <Cocoa/Cocoa.h>
+
+#import <CoreAudio/AudioHardware.h>
+#import <AudioToolbox/AudioToolbox.h>
+#import <AudioUnit/AudioUnit.h>
+
+#import "Node.h"
+#import "Plugin.h"
+
+#define INPUT_NODE_SEEK
+
+@interface RefillNode : Node {
+    // This node just slaps pre-converted data into its buffer for re-buffering
+}
+
+- (void)writeData:(float *)data floatCount:(size_t)count;
+
+@end
diff --git a/Audio/Chain/RefillNode.m b/Audio/Chain/RefillNode.m
new file mode 100644
index 000000000..0b81935af
--- /dev/null
+++ b/Audio/Chain/RefillNode.m
@@ -0,0 +1,34 @@
+//
+//  RefillNode.m
+//  Cog
+//
+//  Created by Christopher Snowhill on 1/13/22.
+//  Copyright 2022 __LoSnoCo__. All rights reserved.
+//
+
+#import "Plugin.h"
+#import "RefillNode.h"
+
+#import "Logging.h"
+
+@implementation RefillNode
+
+- (id)initWithController:(id)c previous:(id)p {
+    self = [super initWithController:c previous:p];
+
+    return self;
+}
+
+
+- (void)writeData:(float *)data floatCount:(size_t)count
+{
+    [self writeData:data amount:(int)(count * sizeof(float))];
+}
+
+
+- (void)dealloc
+{
+	DLog(@"Refill Node dealloc");
+}
+
+@end
diff --git a/Audio/CogAudio.xcodeproj/project.pbxproj b/Audio/CogAudio.xcodeproj/project.pbxproj
index 438a5f718..2b9e4dc8e 100644
--- a/Audio/CogAudio.xcodeproj/project.pbxproj
+++ b/Audio/CogAudio.xcodeproj/project.pbxproj
@@ -87,6 +87,8 @@
 		8389F2A4278E646E0074164C /* lpc.c in Sources */ = {isa = PBXBuildFile; fileRef = 8389F2A2278E646E0074164C /* lpc.c */; };
 		839366671815923C006DD712 /* CogPluginMulti.h in Headers */ = {isa = PBXBuildFile; fileRef = 839366651815923C006DD712 /* CogPluginMulti.h */; };
 		839366681815923C006DD712 /* CogPluginMulti.m in Sources */ = {isa = PBXBuildFile; fileRef = 839366661815923C006DD712 /* CogPluginMulti.m */; };
+		83A44A01279119B50049B6E2 /* RefillNode.m in Sources */ = {isa = PBXBuildFile; fileRef = 83A449FF279119B50049B6E2 /* RefillNode.m */; };
+		83A44A02279119B50049B6E2 /* RefillNode.h in Headers */ = {isa = PBXBuildFile; fileRef = 83A44A00279119B50049B6E2 /* RefillNode.h */; };
 		8DC2EF570486A6940098B216 /* Cocoa.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 1058C7B1FEA5585E11CA2CBB /* Cocoa.framework */; };
 		8E8D3D2F0CBAEE6E00135C1B /* AudioContainer.h in Headers */ = {isa = PBXBuildFile; fileRef = 8E8D3D2D0CBAEE6E00135C1B /* AudioContainer.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		8E8D3D300CBAEE6E00135C1B /* AudioContainer.m in Sources */ = {isa = PBXBuildFile; fileRef = 8E8D3D2E0CBAEE6E00135C1B /* AudioContainer.m */; };
@@ -203,6 +205,8 @@
 		8389F2A2278E646E0074164C /* lpc.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = lpc.c; sourceTree = "<group>"; };
 		839366651815923C006DD712 /* CogPluginMulti.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = CogPluginMulti.h; sourceTree = "<group>"; };
 		839366661815923C006DD712 /* CogPluginMulti.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = CogPluginMulti.m; sourceTree = "<group>"; };
+		83A449FF279119B50049B6E2 /* RefillNode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RefillNode.m; sourceTree = "<group>"; };
+		83A44A00279119B50049B6E2 /* RefillNode.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = RefillNode.h; sourceTree = "<group>"; };
 		8DC2EF5A0486A6940098B216 /* Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist; path = Info.plist; sourceTree = "<group>"; };
 		8DC2EF5B0486A6940098B216 /* CogAudio.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = CogAudio.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		8E8D3D2D0CBAEE6E00135C1B /* AudioContainer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = AudioContainer.h; sourceTree = "<group>"; };
@@ -328,6 +332,8 @@
 		17D21C750B8BE4BA00D1EBDE /* Chain */ = {
 			isa = PBXGroup;
 			children = (
+				83A44A00279119B50049B6E2 /* RefillNode.h */,
+				83A449FF279119B50049B6E2 /* RefillNode.m */,
 				17D21C760B8BE4BA00D1EBDE /* BufferChain.h */,
 				17D21C770B8BE4BA00D1EBDE /* BufferChain.m */,
 				8EC1225D0B993BD500C5B3AD /* ConverterNode.h */,
@@ -748,6 +754,7 @@
 				8389F292278E64590074164C /* s16_to_float.h in Headers */,
 				8389F279278E64590074164C /* utf.h in Headers */,
 				8389F288278E64590074164C /* retro_environment.h in Headers */,
+				83A44A02279119B50049B6E2 /* RefillNode.h in Headers */,
 				8EC1225F0B993BD500C5B3AD /* ConverterNode.h in Headers */,
 				8389F28C278E64590074164C /* file_stream.h in Headers */,
 				8384912718080FF100E7332D /* Logging.h in Headers */,
@@ -850,6 +857,7 @@
 				17C940240B900909008627D6 /* AudioMetadataReader.m in Sources */,
 				17B619310B909BC300BC003F /* AudioPropertiesReader.m in Sources */,
 				17ADB13D0B97926D00257CA2 /* AudioSource.m in Sources */,
+				83A44A01279119B50049B6E2 /* RefillNode.m in Sources */,
 				8EC122600B993BD500C5B3AD /* ConverterNode.m in Sources */,
 				8E8D3D300CBAEE6E00135C1B /* AudioContainer.m in Sources */,
 				B0575F300D687A4000411D77 /* Helper.m in Sources */,
@@ -998,9 +1006,7 @@
 				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
-				GCC_PREPROCESSOR_DEFINITIONS = (
-					"HAVE_CONFIG_H=1",
-				);
+				GCC_PREPROCESSOR_DEFINITIONS = "HAVE_CONFIG_H=1";
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;