refactor(audio): move hardcoded values to config for better flexibility

- Replace hardcoded values with configurable parameters in audio components
- Add new config fields for adaptive buffer sizes and frame pool settings
- Implement memory guard in ZeroCopyFramePool to prevent excessive allocations

internal/audio/adaptive_buffer.go

@@ -37,9 +37,9 @@ type AdaptiveBufferConfig struct {
 func DefaultAdaptiveBufferConfig() AdaptiveBufferConfig {
 	return AdaptiveBufferConfig{
 		// Conservative buffer sizes for 256MB RAM constraint
-		MinBufferSize:     3,  // Minimum 3 frames (slightly higher for stability)
-		MaxBufferSize:     20, // Maximum 20 frames (increased for high load scenarios)
-		DefaultBufferSize: 6,  // Default 6 frames (increased for better stability)
+		MinBufferSize:     GetConfig().AdaptiveMinBufferSize,
+		MaxBufferSize:     GetConfig().AdaptiveMaxBufferSize,
+		DefaultBufferSize: GetConfig().AdaptiveDefaultBufferSize,
 
 		// CPU thresholds optimized for single-core ARM Cortex A7 under load
 		LowCPUThreshold:  GetConfig().LowCPUThreshold * 100,  // Below 20% CPU

internal/audio/config_constants.go

@@ -698,6 +698,28 @@ type AudioConfigConstants struct {
 	OutputSizeThreshold int
 	TargetLevel         float64
 
+	// Adaptive Buffer Configuration - Controls dynamic buffer sizing for optimal performance
+	// Used in: adaptive_buffer.go for dynamic buffer management
+	// Impact: Controls buffer size adaptation based on system load and latency
+
+	// AdaptiveMinBufferSize defines minimum buffer size in frames for adaptive buffering.
+	// Used in: adaptive_buffer.go DefaultAdaptiveBufferConfig()
+	// Impact: Lower values reduce latency but may cause underruns under high load.
+	// Default 3 frames provides stability while maintaining low latency.
+	AdaptiveMinBufferSize int
+
+	// AdaptiveMaxBufferSize defines maximum buffer size in frames for adaptive buffering.
+	// Used in: adaptive_buffer.go DefaultAdaptiveBufferConfig()
+	// Impact: Higher values handle load spikes but increase maximum latency.
+	// Default 20 frames accommodates high load scenarios without excessive latency.
+	AdaptiveMaxBufferSize int
+
+	// AdaptiveDefaultBufferSize defines default buffer size in frames for adaptive buffering.
+	// Used in: adaptive_buffer.go DefaultAdaptiveBufferConfig()
+	// Impact: Starting point for buffer adaptation, affects initial latency.
+	// Default 6 frames balances initial latency with adaptation headroom.
+	AdaptiveDefaultBufferSize int
+
 	// Priority Scheduling
 	AudioHighPriority   int
 	AudioMediumPriority int
@@ -1159,6 +1181,11 @@ func DefaultAudioConfig() *AudioConfigConstants {
 		HighMemoryThreshold: 0.75,
 		TargetLatency:       20 * time.Millisecond,
 
+		// Adaptive Buffer Size Configuration
+		AdaptiveMinBufferSize:     3,  // Minimum 3 frames for stability
+		AdaptiveMaxBufferSize:     20, // Maximum 20 frames for high load
+		AdaptiveDefaultBufferSize: 6,  // Default 6 frames for balanced performance
+
 		// Adaptive Optimizer Configuration
 		CooldownPeriod:    30 * time.Second,
 		RollbackThreshold: 300 * time.Millisecond,

internal/audio/input_ipc.go

@@ -19,11 +19,11 @@ import (
 var (
 	inputMagicNumber uint32 = GetConfig().InputMagicNumber // "JKMI" (JetKVM Microphone Input)
 	inputSocketName         = "audio_input.sock"
-	writeTimeout            = 15 * time.Millisecond // Non-blocking write timeout (increased for high load)
+	writeTimeout            = GetConfig().WriteTimeout // Non-blocking write timeout
 )
 
 const (
-	headerSize = 17 // Fixed header size: 4+1+4+8 bytes
+	headerSize = 17 // Fixed header size: 4+1+4+8 bytes - matches GetConfig().HeaderSize
 )
 
 var (
@@ -503,10 +503,12 @@ func (aic *AudioInputClient) Connect() error {
 			aic.running = true
 			return nil
 		}
-		// Exponential backoff starting at 50ms
-		delay := time.Duration(50*(1<<uint(i/3))) * time.Millisecond
-		if delay > 500*time.Millisecond {
-			delay = 500 * time.Millisecond
+		// Exponential backoff starting from config
+		backoffStart := GetConfig().BackoffStart
+		delay := time.Duration(backoffStart.Nanoseconds()*(1<<uint(i/3))) * time.Nanosecond
+		maxDelay := GetConfig().MaxRetryDelay
+		if delay > maxDelay {
+			delay = maxDelay
 		}
 		time.Sleep(delay)
 	}

internal/audio/ipc.go

@@ -422,10 +422,12 @@ func (c *AudioClient) Connect() error {
 			c.running = true
 			return nil
 		}
-		// Exponential backoff starting at 50ms
-		delay := time.Duration(50*(1<<uint(i/3))) * time.Millisecond
-		if delay > 400*time.Millisecond {
-			delay = 400 * time.Millisecond
+		// Exponential backoff starting from config
+		backoffStart := GetConfig().BackoffStart
+		delay := time.Duration(backoffStart.Nanoseconds()*(1<<uint(i/3))) * time.Nanosecond
+		maxDelay := GetConfig().MaxRetryDelay
+		if delay > maxDelay {
+			delay = maxDelay
 		}
 		time.Sleep(delay)
 	}

internal/audio/relay.go

@@ -132,7 +132,7 @@ func (r *AudioRelay) relayLoop() {
 	defer r.wg.Done()
 	r.logger.Debug().Msg("Audio relay loop started")
 
-	const maxConsecutiveErrors = 10
+	var maxConsecutiveErrors = GetConfig().MaxConsecutiveErrors
 	consecutiveErrors := 0
 
 	for {

internal/audio/zero_copy.go

@@ -23,6 +23,7 @@ type ZeroCopyFramePool struct {
 	counter   int64 // Frame counter (atomic)
 	hitCount  int64 // Pool hit counter (atomic)
 	missCount int64 // Pool miss counter (atomic)
+	allocationCount int64 // Total allocations counter (atomic)
 
 	// Other fields
 	pool    sync.Pool
@@ -36,13 +37,23 @@ type ZeroCopyFramePool struct {
 
 // NewZeroCopyFramePool creates a new zero-copy frame pool
 func NewZeroCopyFramePool(maxFrameSize int) *ZeroCopyFramePool {
-	// Pre-allocate 15 frames for immediate availability
-	preallocSize := 15
-	maxPoolSize := 50 // Limit total pool size
-	preallocated := make([]*ZeroCopyAudioFrame, 0, preallocSize)
+	// Pre-allocate frames for immediate availability
+	preallocSizeBytes := GetConfig().PreallocSize
+	maxPoolSize := GetConfig().MaxPoolSize // Limit total pool size
+
+	// Calculate number of frames based on memory budget, not frame count
+	preallocFrameCount := preallocSizeBytes / maxFrameSize
+	if preallocFrameCount > maxPoolSize {
+		preallocFrameCount = maxPoolSize
+	}
+	if preallocFrameCount < 1 {
+		preallocFrameCount = 1 // Always preallocate at least one frame
+	}
+
+	preallocated := make([]*ZeroCopyAudioFrame, 0, preallocFrameCount)
 
 	// Pre-allocate frames to reduce initial allocation overhead
-	for i := 0; i < preallocSize; i++ {
+	for i := 0; i < preallocFrameCount; i++ {
 		frame := &ZeroCopyAudioFrame{
 			data:     make([]byte, 0, maxFrameSize),
 			capacity: maxFrameSize,
@@ -54,7 +65,7 @@ func NewZeroCopyFramePool(maxFrameSize int) *ZeroCopyFramePool {
 	return &ZeroCopyFramePool{
 		maxSize:      maxFrameSize,
 		preallocated: preallocated,
-		preallocSize: preallocSize,
+		preallocSize: preallocFrameCount,
 		maxPoolSize:  maxPoolSize,
 		pool: sync.Pool{
 			New: func() interface{} {
@@ -70,6 +81,20 @@ func NewZeroCopyFramePool(maxFrameSize int) *ZeroCopyFramePool {
 
 // Get retrieves a zero-copy frame from the pool
 func (p *ZeroCopyFramePool) Get() *ZeroCopyAudioFrame {
+	// Memory guard: Track allocation count to prevent excessive memory usage
+	allocationCount := atomic.LoadInt64(&p.allocationCount)
+	if allocationCount > int64(p.maxPoolSize*2) {
+		// If we've allocated too many frames, force pool reuse
+		atomic.AddInt64(&p.missCount, 1)
+		frame := p.pool.Get().(*ZeroCopyAudioFrame)
+		frame.mutex.Lock()
+		frame.refCount = 1
+		frame.length = 0
+		frame.data = frame.data[:0]
+		frame.mutex.Unlock()
+		return frame
+	}
+	
 	// First try pre-allocated frames for fastest access
 	p.mutex.Lock()
 	if len(p.preallocated) > 0 {
@@ -88,7 +113,8 @@ func (p *ZeroCopyFramePool) Get() *ZeroCopyAudioFrame {
 	}
 	p.mutex.Unlock()
 
-	// Try sync.Pool next
+	// Try sync.Pool next and track allocation
+	atomic.AddInt64(&p.allocationCount, 1)
 	frame := p.pool.Get().(*ZeroCopyAudioFrame)
 	frame.mutex.Lock()
 	frame.refCount = 1
@@ -230,6 +256,7 @@ func (p *ZeroCopyFramePool) GetZeroCopyPoolStats() ZeroCopyFramePoolStats {
 
 	hitCount := atomic.LoadInt64(&p.hitCount)
 	missCount := atomic.LoadInt64(&p.missCount)
+	allocationCount := atomic.LoadInt64(&p.allocationCount)
 	totalRequests := hitCount + missCount
 
 	var hitRate float64
@@ -245,6 +272,7 @@ func (p *ZeroCopyFramePool) GetZeroCopyPoolStats() ZeroCopyFramePoolStats {
 		PreallocatedMax:   int64(p.preallocSize),
 		HitCount:          hitCount,
 		MissCount:         missCount,
+		AllocationCount:   allocationCount,
 		HitRate:           hitRate,
 	}
 }
@@ -258,6 +286,7 @@ type ZeroCopyFramePoolStats struct {
 	PreallocatedMax   int64
 	HitCount          int64
 	MissCount         int64
+	AllocationCount   int64
 	HitRate           float64 // Percentage
 }