feat(apu): Add config for buffer size

config_example.toml

@@ -77,6 +77,8 @@ b_turbo = 'Numpad5'
 enabled = true
 # Output volume (between 0 and 1).
 volume = 1.0
+# Audio buffer size. Try increasing this if audio pops or stutters.
+buffer_size = '70 KiB'
 
 # Toggles specific audio channels.
 [audio.channels]

go.mod

@@ -3,7 +3,7 @@ module gabe565.com/gones
 go 1.23.5
 
 require (
-	gabe565.com/utils v0.0.0-20241022183714-230f1ea91e9c
+	gabe565.com/utils v0.0.0-20250130072635-ed882da6fcdd
 	github.com/Masterminds/sprig/v3 v3.3.0
 	github.com/PuerkitoBio/goquery v1.10.1
 	github.com/dmarkham/enumer v1.5.10

go.sum

@@ -1,7 +1,7 @@
 dario.cat/mergo v1.0.1 h1:Ra4+bf83h2ztPIQYNP99R6m+Y7KfnARDfID+a+vLl4s=
 dario.cat/mergo v1.0.1/go.mod h1:uNxQE+84aUszobStD9th8a29P2fMDhsBdgRYvZOxGmk=
-gabe565.com/utils v0.0.0-20241022183714-230f1ea91e9c h1:ORHS+E/RxziZ625EvarvowzMHfrnsJiaHAiAhBgllxk=
-gabe565.com/utils v0.0.0-20241022183714-230f1ea91e9c/go.mod h1:85awzsVzCoWcZgBZmKtE6kMiOAYd2aKrNyt1gNSV2Kg=
+gabe565.com/utils v0.0.0-20250130072635-ed882da6fcdd h1:ATna6PCWp9+8x3hBC/miPdvu4uVDRj4zw2QYNW6OaV0=
+gabe565.com/utils v0.0.0-20250130072635-ed882da6fcdd/go.mod h1:6FZP8OeF0k3hTsPClyDGEILcBg3hvGcSp4u4pmjMusY=
 github.com/Masterminds/goutils v1.1.1 h1:5nUrii3FMTL5diU80unEVvNevw1nH4+ZV4DSLVJLSYI=
 github.com/Masterminds/goutils v1.1.1/go.mod h1:8cTjp+g8YejhMuvIA5y2vz3BpJxksy863GQaJW2MFNU=
 github.com/Masterminds/semver/v3 v3.3.0 h1:B8LGeaivUe71a5qox1ICM/JLl0NqZSW5CHyL+hmvYS0=

internal/apu/apu.go

@@ -18,8 +18,7 @@ type CPU interface {
 
 const (
 	FrameCounterRate  = float64(consts.CPUFrequency) / 240.0
-	DefaultSampleRate = float64(consts.CPUFrequency) / float64(consts.AudioSampleRate) * consts.FrameRateDifference
-	BufferCap         = consts.AudioSampleRate / 5 * 8
+	DefaultSampleRate = float64(consts.CPUFrequency) / float64(consts.AudioSampleRate) * consts.FrameRateDiff
 )
 
 //nolint:gochecknoglobals
@@ -57,7 +56,7 @@ func New(conf *config.Config) *APU {
 		Enabled:    true,
 		SampleRate: DefaultSampleRate,
 		conf:       &conf.Audio,
-		buf:        newRingBuffer(BufferCap),
+		buf:        newRingBuffer(int(conf.Audio.BufferSize)),
 
 		Square: [2]Square{{Channel1: true}, {}},
 		Noise:  Noise{ShiftRegister: 1},

internal/config/bytes.go

@@ -0,0 +1,24 @@
+package config
+
+import (
+	"strings"
+
+	"gabe565.com/utils/bytefmt"
+)
+
+type Bytes int64
+
+func (b Bytes) MarshalText() ([]byte, error) {
+	formatted := bytefmt.Encode(int64(b))
+	formatted = strings.Replace(formatted, ".00", "", 1)
+	return []byte(formatted), nil
+}
+
+func (b *Bytes) UnmarshalText(text []byte) error {
+	v, err := bytefmt.Decode(string(text))
+	if err != nil {
+		return err
+	}
+	*b = Bytes(v)
+	return nil
+}

internal/config/config.go

@@ -68,9 +68,10 @@ func (i Input) ResetHoldFrames() int {
 }
 
 type Audio struct {
-	Enabled  bool          `toml:"enabled" comment:"Enables audio output."`
-	Volume   float64       `toml:"volume" comment:"Output volume (between 0 and 1)."`
-	Channels AudioChannels `toml:"channels" comment:"Toggles specific audio channels."`
+	Enabled    bool          `toml:"enabled" comment:"Enables audio output."`
+	Volume     float64       `toml:"volume" comment:"Output volume (between 0 and 1)."`
+	Channels   AudioChannels `toml:"channels" comment:"Toggles specific audio channels."`
+	BufferSize Bytes         `toml:"buffer_size" comment:"Audio buffer size. Try increasing this if audio pops or stutters."`
 }
 
 type AudioChannels struct {

internal/config/default.go

@@ -3,6 +3,7 @@ package config
 import (
 	"time"
 
+	"gabe565.com/utils/bytefmt"
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
@@ -70,6 +71,7 @@ func NewDefault() *Config {
 				Noise:    true,
 				PCM:      true,
 			},
+			BufferSize: 70 * bytefmt.KiB,
 		},
 	}
 }

internal/config/load.go

@@ -241,5 +241,23 @@ func fixConfig(k *koanf.Koanf) error {
 		}
 	}
 
+	// Audio buffer size
+	if raw := k.String("audio.buffer_size"); raw != "" {
+		var b Bytes
+		if err := b.UnmarshalText([]byte(raw)); err != nil {
+			return err
+		}
+		if int(b) < consts.AudioBufferBytes {
+			minVal, err := Bytes(consts.AudioBufferBytes).MarshalText()
+			if err != nil {
+				return err
+			}
+			slog.Warn("The minimum allowed buffer size is " + string(minVal) + ". Setting to default.")
+			if err := k.Set("audio.buffer_size", NewDefault().Audio.BufferSize); err != nil {
+				return err
+			}
+		}
+	}
+
 	return nil
 }

internal/consts/consts.go

@@ -1,5 +1,7 @@
 package consts
 
+import "time"
+
 const (
 	// PRGROMAddr is the memory address that PRG begins.
 	PRGROMAddr = 0x600
@@ -12,13 +14,14 @@ const (
 
 	CPUFrequency = 1789773
 
-	AudioSampleRate = 44100
-
-	FrameRate = 60
-
-	RealFrameRate = 60.0988118623484
+	AudioSampleRate     = 44100
+	AudioBufferSize     = time.Second / 20
+	AudioBytesPerSample = 4 * 2
+	AudioBufferBytes    = int(AudioBufferSize * AudioBytesPerSample * AudioSampleRate / time.Second)
 
-	FrameRateDifference = FrameRate / RealFrameRate
+	TargetFrameRate   = 60
+	HardwareFrameRate = 60.0988118623484
+	FrameRateDiff     = TargetFrameRate / HardwareFrameRate
 
 	Width  = 256
 	Height = 240