perf(audio): replace frame validation with ultra-fast version

Use ValidateAudioFrameUltraFast in critical audio paths to reduce processing overhead
Reduce minimum frame size to 1 byte to allow smaller frames

internal/audio/config_constants.go

@@ -2388,7 +2388,7 @@ func DefaultAudioConfig() *AudioConfigConstants {
 
 		// Validation Configuration
 		MaxValidationTime:  5 * time.Second, // 5s maximum validation timeout
-		MinFrameSize:       64,              // 64 bytes minimum frame size
+		MinFrameSize:       1,               // 1 byte minimum frame size (allow small frames)
 		FrameSizeTolerance: 512,             // 512 bytes frame size tolerance
 
 		// Device Health Monitoring Configuration

internal/audio/input.go

@@ -83,8 +83,8 @@ func (aim *AudioInputManager) WriteOpusFrame(frame []byte) error {
 		return nil // Not running, silently drop
 	}
 
-	// Validate frame before processing
-	if err := ValidateFrameData(frame); err != nil {
+	// Use ultra-fast validation for critical audio path
+	if err := ValidateAudioFrameUltraFast(frame); err != nil {
 		aim.logComponentError(AudioInputManagerComponent, err, "Frame validation failed")
 		return fmt.Errorf("input frame validation failed: %w", err)
 	}

internal/audio/input_ipc.go

@@ -477,8 +477,8 @@ func (ais *AudioInputServer) processOpusFrame(data []byte) error {
 		return nil // Empty frame, ignore
 	}
 
-	// Validate frame data before processing
-	if err := ValidateFrameData(data); err != nil {
+	// Use ultra-fast validation for critical audio path
+	if err := ValidateAudioFrameUltraFast(data); err != nil {
 		logger := logging.GetDefaultLogger().With().Str("component", AudioInputServerComponent).Logger()
 		logger.Error().Err(err).Msg("Frame validation failed")
 		return fmt.Errorf("input frame validation failed: %w", err)
@@ -635,7 +635,7 @@ func (aic *AudioInputClient) SendFrame(frame []byte) error {
 	}
 
 	// Validate frame data before sending
-	if err := ValidateFrameData(frame); err != nil {
+	if err := ValidateAudioFrameUltraFast(frame); err != nil {
 		logger := logging.GetDefaultLogger().With().Str("component", AudioInputClientComponent).Logger()
 		logger.Error().Err(err).Msg("Frame validation failed")
 		return fmt.Errorf("input frame validation failed: %w", err)

internal/audio/input_ipc_manager.go

@@ -103,7 +103,7 @@ func (aim *AudioInputIPCManager) WriteOpusFrame(frame []byte) error {
 	}
 
 	// Validate frame data
-	if err := ValidateFrameData(frame); err != nil {
+	if err := ValidateAudioFrameUltraFast(frame); err != nil {
 		atomic.AddInt64(&aim.metrics.FramesDropped, 1)
 		aim.logger.Debug().Err(err).Msg("invalid frame data")
 		return err

internal/audio/ipc.go

@@ -260,8 +260,8 @@ func (s *AudioOutputServer) Close() error {
 }
 
 func (s *AudioOutputServer) SendFrame(frame []byte) error {
-	// Comprehensive frame validation
-	if err := ValidateFrameData(frame); err != nil {
+	// Use ultra-fast validation for critical audio path
+	if err := ValidateAudioFrameUltraFast(frame); err != nil {
 		logger := logging.GetDefaultLogger().With().Str("component", AudioOutputServerComponent).Logger()
 		logger.Error().Err(err).Msg("Frame validation failed")
 		return fmt.Errorf("output frame validation failed: %w", err)

internal/audio/relay.go

@@ -170,8 +170,8 @@ func (r *AudioRelay) relayLoop() {
 
 // forwardToWebRTC forwards a frame to the WebRTC audio track
 func (r *AudioRelay) forwardToWebRTC(frame []byte) error {
-	// Validate frame data before processing
-	if err := ValidateFrameData(frame); err != nil {
+	// Use ultra-fast validation for critical audio path
+	if err := ValidateAudioFrameUltraFast(frame); err != nil {
 		r.incrementDropped()
 		r.logger.Debug().Err(err).Msg("invalid frame data in relay")
 		return err

internal/audio/validation.go

@@ -35,34 +35,6 @@ func ValidateAudioQuality(quality AudioQuality) error {
 	return nil
 }
 
-// ValidateFrameData validates audio frame data with comprehensive boundary checks
-func ValidateFrameData(data []byte) error {
-	if data == nil {
-		return fmt.Errorf("%w: frame data is nil", ErrInvalidFrameData)
-	}
-	if len(data) == 0 {
-		return fmt.Errorf("%w: frame data is empty", ErrInvalidFrameData)
-	}
-
-	config := GetConfig()
-	// Check minimum frame size
-	if len(data) < config.MinFrameSize {
-		return fmt.Errorf("%w: frame size %d below minimum %d",
-			ErrInvalidFrameSize, len(data), config.MinFrameSize)
-	}
-	// Check maximum frame size
-	if len(data) > config.MaxAudioFrameSize {
-		return fmt.Errorf("%w: frame size %d exceeds maximum %d",
-			ErrInvalidFrameSize, len(data), config.MaxAudioFrameSize)
-	}
-	// Validate frame alignment for audio samples (must be even for 16-bit samples)
-	if len(data)%2 != 0 {
-		return fmt.Errorf("%w: frame size %d not aligned for 16-bit samples",
-			ErrInvalidFrameSize, len(data))
-	}
-	return nil
-}
-
 // ValidateZeroCopyFrame validates zero-copy audio frame
 func ValidateZeroCopyFrame(frame *ZeroCopyAudioFrame) error {
 	if frame == nil {
@@ -327,6 +299,8 @@ func ValidateAudioConfigConstants(config *AudioConfigConstants) error {
 }
 
 // ValidateAudioFrameFast performs fast validation of audio frame data
+// ValidateAudioFrameFast provides minimal validation for critical audio processing paths
+// This function is optimized for performance and only checks essential safety bounds
 func ValidateAudioFrameFast(data []byte) error {
 	if len(data) == 0 {
 		return fmt.Errorf("%w: frame data is empty", ErrInvalidFrameData)
@@ -338,6 +312,17 @@ func ValidateAudioFrameFast(data []byte) error {
 	return nil
 }
 
+// ValidateAudioFrameUltraFast provides zero-overhead validation for ultra-critical paths
+// This function only checks for nil/empty data and maximum size to prevent buffer overruns
+// Use this in hot audio processing loops where every microsecond matters
+func ValidateAudioFrameUltraFast(data []byte) error {
+	// Only check for catastrophic failures that could crash the system
+	if len(data) == 0 || len(data) > 8192 { // Hard-coded 8KB safety limit
+		return ErrInvalidFrameData
+	}
+	return nil
+}
+
 // WrapWithMetadata wraps error with metadata for enhanced validation context
 func WrapWithMetadata(err error, component, operation string, metadata map[string]interface{}) error {
 	if err == nil {

internal/audio/validation_test.go

@@ -62,46 +62,25 @@ func testAudioQualityValidation(t *testing.T) {
 	}
 }
 
-// testFrameDataValidation tests frame data validation with various edge cases
+// testFrameDataValidation tests frame data validation with various edge cases using modern validation
 func testFrameDataValidation(t *testing.T) {
 	config := GetConfig()
 
-	// Test nil data
-	err := ValidateFrameData(nil)
-	assert.Error(t, err)
-	assert.Contains(t, err.Error(), "frame data is nil")
-
 	// Test empty data
-	err = ValidateFrameData([]byte{})
+	err := ValidateAudioFrameFast([]byte{})
 	assert.Error(t, err)
 	assert.Contains(t, err.Error(), "frame data is empty")
 
-	// Test data below minimum size
-	if config.MinFrameSize > 0 {
-		smallData := make([]byte, config.MinFrameSize-1)
-		err = ValidateFrameData(smallData)
-		assert.Error(t, err)
-		assert.Contains(t, err.Error(), "below minimum")
-	}
-
 	// Test data above maximum size
 	largeData := make([]byte, config.MaxAudioFrameSize+1)
-	err = ValidateFrameData(largeData)
+	err = ValidateAudioFrameFast(largeData)
 	assert.Error(t, err)
 	assert.Contains(t, err.Error(), "exceeds maximum")
 
-	// Test unaligned data (odd number of bytes for 16-bit samples)
-	oddData := make([]byte, 1001) // Odd number
-	if len(oddData) >= config.MinFrameSize {
-		err = ValidateFrameData(oddData)
-		assert.Error(t, err)
-		assert.Contains(t, err.Error(), "not aligned")
-	}
-
-	// Test valid aligned data
-	validData := make([]byte, 1000) // Even number, within bounds
-	if len(validData) >= config.MinFrameSize && len(validData) <= config.MaxAudioFrameSize {
-		err = ValidateFrameData(validData)
+	// Test valid data
+	validData := make([]byte, 1000) // Within bounds
+	if len(validData) <= config.MaxAudioFrameSize {
+		err = ValidateAudioFrameFast(validData)
 		assert.NoError(t, err)
 	}
 }