From 8f1ef5eb6b285d981385368cc1b115cc096f1fb2 Mon Sep 17 00:00:00 2001
From: Christopher Snowhill <kode54@gmail.com>
Date: Tue, 11 Feb 2025 18:11:26 -0800
Subject: [PATCH] Audio: Adjust node buffering behavior a bit

Change one remaining semaphore wait to 500us, and change the buffering
so that it can always overflow the requested duration by one chunk, so
that at least one chunk will always fit in the buffer. This also allows
the DSP nodes to flush at the end of the stream without losing their
output.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>
---
 Audio/Chain/Node.m | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/Audio/Chain/Node.m b/Audio/Chain/Node.m
index b0fd1b21f..919ec1b91 100644
--- a/Audio/Chain/Node.m
+++ b/Audio/Chain/Node.m
@@ -67,11 +67,10 @@
 	[chunk setLossless:nodeLossless];
 	[chunk assignSamples:ptr frameCount:amount / nodeFormat.mBytesPerPacket];
 
-	const double chunkDuration = [chunk duration];
 	double durationList = [buffer listDuration];
 	double durationLeft = [buffer maxDuration] - durationList;
 
-	if(shouldContinue == YES && durationList > durationPrebuffer) {
+	if(shouldContinue == YES && durationList >= durationPrebuffer) {
 		if(initialBufferFilled == NO) {
 			initialBufferFilled = YES;
 			if([controller respondsToSelector:@selector(initialBufferFilled:)])
@@ -79,10 +78,10 @@
 		}
 	}
 
-	while(shouldContinue == YES && chunkDuration > durationLeft) {
-		if(durationLeft < chunkDuration || shouldReset) {
+	while(shouldContinue == YES && durationLeft <= 0.0) {
+		if(durationLeft <= 0.0 || shouldReset) {
 			[accessLock unlock];
-			[semaphore wait];
+			[semaphore timedWait:500];
 			[accessLock lock];
 		}
 
@@ -97,11 +96,10 @@
 - (void)writeChunk:(AudioChunk *)chunk {
 	[accessLock lock];
 
-	const double chunkDuration = [chunk duration];
 	double durationList = [buffer listDuration];
 	double durationLeft = [buffer maxDuration] - durationList;
 
-	if(shouldContinue == YES && durationList > durationPrebuffer) {
+	if(shouldContinue == YES && durationList >= durationPrebuffer) {
 		if(initialBufferFilled == NO) {
 			initialBufferFilled = YES;
 			if([controller respondsToSelector:@selector(initialBufferFilled:)])
@@ -109,13 +107,13 @@
 		}
 	}
 
-	while(shouldContinue == YES && chunkDuration > durationLeft) {
+	while(shouldContinue == YES && durationLeft <= 0.0) {
 		if(previousNode && [previousNode shouldContinue] == NO) {
 			shouldContinue = NO;
 			break;
 		}
 
-		if(durationLeft < chunkDuration || shouldReset) {
+		if(durationLeft <= 0.0 || shouldReset) {
 			[accessLock unlock];
 			[semaphore timedWait:500];
 			[accessLock lock];