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Refactor: Remove smoothing and throttling from visualizer

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The visualizer components (FftBarsView and WaveformView) now directly render the raw data received from the `VisualizerController`.

- Removed the smoothing logic (using `LaunchedEffect` and `mutableStateOf`) from both `FftBarsView` and `WaveformView`.
- The `Canvas` drawing logic in both views now directly processes the input `data` byte array.
- In `VisualizerController`, removed the manual throttling mechanism (using `Handler`, `minIntervalMs`, `lastWaveformDispatch`, `lastFftDispatch`).
- The `Visualizer.OnDataCaptureListener` now directly invokes the `onWaveform` and `onFft` callbacks with the received data.
- The capture rate for the Visualizer is now set to half of the maximum rate.
This commit is contained in:
GitHub Actions Bot
2025-08-29 11:49:04 +02:00
parent 2a46c6143b
commit ba634095d9
3 changed files with 18 additions and 101 deletions
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29
app/src/main/java/dev/adriankuta/visualizer/VisualizerController.kt
View File

@@ -1,9 +1,6 @@
package dev.adriankuta.visualizer
import android.media.audiofx.Visualizer
import android.os.Handler
import android.os.Looper
import android.os.SystemClock
/**
* Simple wrapper over Android Visualizer to capture global output mix (audio session 0).
@@ -15,12 +12,6 @@ class VisualizerController(
) {
private var visualizer: Visualizer? = null
// Ensure UI updates happen on the main thread and at a reasonable frame rate
private val mainHandler = Handler(Looper.getMainLooper())
private val minIntervalMs = 16L // ~60 FPS
@Volatile private var lastWaveformDispatch = 0L
@Volatile private var lastFftDispatch = 0L
/**
* Starts capturing audio data via [Visualizer].
*
@@ -36,20 +27,14 @@ class VisualizerController(
// Use the maximum supported capture size for better resolution
val captureSize = Visualizer.getCaptureSizeRange().let { it[1] }
v.captureSize = captureSize
val rate = Visualizer.getMaxCaptureRate() // allow max rate; we'll throttle ourselves
val rate = Visualizer.getMaxCaptureRate() / 2 // decent rate
v.setDataCaptureListener(object : Visualizer.OnDataCaptureListener {
override fun onWaveFormDataCapture(
visualizer: Visualizer?,
waveform: ByteArray?,
samplingRate: Int
) {
if (waveform == null) return
val now = SystemClock.uptimeMillis()
if (now - lastWaveformDispatch >= minIntervalMs) {
lastWaveformDispatch = now
val copy = waveform.copyOf()
mainHandler.post { onWaveform(copy) }
}
if (waveform != null) onWaveform(waveform)
}
override fun onFftDataCapture(
@@ -57,13 +42,7 @@ class VisualizerController(
fft: ByteArray?,
samplingRate: Int
) {
if (fft == null) return
val now = SystemClock.uptimeMillis()
if (now - lastFftDispatch >= minIntervalMs) {
lastFftDispatch = now
val copy = fft.copyOf()
mainHandler.post { onFft(copy) }
}
if (fft != null) onFft(fft)
}
}, rate, true, true)
v.enabled = true
@@ -84,7 +63,5 @@ class VisualizerController(
visualizer?.enabled = false
visualizer?.release()
visualizer = null
lastWaveformDispatch = 0L
lastFftDispatch = 0L
}
}

51
app/src/main/java/dev/adriankuta/visualizer/components/FftBarsView.kt
View File

@@ -7,11 +7,6 @@ import androidx.compose.foundation.layout.padding
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
@@ -19,7 +14,7 @@ import kotlin.math.hypot
import kotlin.math.min
/**
* Renders FFT magnitude as vertical bars with smoothing for natural transitions.
* Renders FFT magnitude as vertical bars.
*
* The input is the raw FFT byte array from Visualizer where values are interleaved
* real and imaginary parts: [re0, im0, re1, im1, ...]. This composable computes the
@@ -34,37 +29,6 @@ fun FftBarsView(
modifier: Modifier = Modifier,
) {
Text("FFT (magnitude bars)", style = MaterialTheme.typography.titleMedium)
var smoothed by remember { mutableStateOf<FloatArray?>(null) }
// Update smoothed magnitudes whenever new FFT data arrives
LaunchedEffect(data) {
val bytes = data ?: return@LaunchedEffect
if (bytes.size < 2) return@LaunchedEffect
val n = bytes.size / 2
val barCount = min(64, n)
val target = FloatArray(barCount) { i ->
val re = bytes[2 * i].toInt()
val im = bytes[2 * i + 1].toInt()
val mag = hypot(re.toDouble(), im.toDouble()).toFloat()
// Scale to 0..1 range (with a bit of headroom capped later in draw)
(mag / 128f).coerceIn(0f, 1.5f).coerceAtMost(1f)
}
val prev = smoothed
val rise = 0.35f
val decay = 0.12f
smoothed = if (prev == null || prev.size != target.size) {
target
} else {
val out = FloatArray(target.size)
for (i in target.indices) {
val a = if (target[i] > prev[i]) rise else decay
out[i] = prev[i] + (target[i] - prev[i]) * a
}
out
}
}
Canvas(
modifier = modifier
.fillMaxWidth()
@@ -73,13 +37,16 @@ fun FftBarsView(
) {
val w = size.width
val h = size.height
val values = smoothed
if (values != null && values.isNotEmpty()) {
val barCount = values.size
if (data != null && data.size >= 2) {
val n = data.size / 2 // real/imag pairs count
val barCount = min(64, n) // limit bars for readability
val barWidth = w / barCount
for (i in 0 until barCount) {
val v = values[i].coerceIn(0f, 1f)
val barHeight = h * v
val re = data[2 * i].toInt()
val im = data[2 * i + 1].toInt()
val mag = hypot(re.toDouble(), im.toDouble()).toFloat()
val scaled = (mag / 128f).coerceIn(0f, 1.5f)
val barHeight = h * (scaled.coerceAtMost(1f))
val left = i * barWidth
drawRect(
color = Color(0xFF8BC34A),

39
app/src/main/java/dev/adriankuta/visualizer/components/WaveformView.kt
View File

@@ -7,11 +7,6 @@ import androidx.compose.foundation.layout.padding
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.getValue
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Path
@@ -19,7 +14,7 @@ import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.unit.dp
/**
* Displays the most recent audio waveform as a continuous path with smoothing to reduce jitter.
* Displays the most recent audio waveform as a continuous path.
*
* @param data Waveform bytes where each value is 0..255 (unsigned), as provided by Visualizer.
* Pass null to render an idle baseline.
@@ -31,28 +26,6 @@ fun WaveformView(
modifier: Modifier = Modifier,
) {
Text("Waveform", style = MaterialTheme.typography.titleMedium)
// Keep a smoothed copy of the latest waveform for softer transitions
var smoothed by remember { mutableStateOf<FloatArray?>(null) }
// Update smoothed values whenever new data arrives using exponential smoothing
LaunchedEffect(data) {
val bytes = data ?: return@LaunchedEffect
if (bytes.isEmpty()) return@LaunchedEffect
val target = FloatArray(bytes.size) { i -> ((bytes[i].toInt() and 0xFF) / 255f) }
val prev = smoothed
val alpha = 0.22f // smoothing factor; lower = smoother
smoothed = if (prev == null || prev.size != target.size) {
target
} else {
val out = FloatArray(target.size)
for (i in target.indices) {
out[i] = prev[i] + (target[i] - prev[i]) * alpha
}
out
}
}
Canvas(
modifier = modifier
.fillMaxWidth()
@@ -61,8 +34,7 @@ fun WaveformView(
) {
val w = size.width
val h = size.height
val values = smoothed
if (values == null || values.isEmpty()) {
if (data == null || data.isEmpty()) {
drawLine(
color = Color.Gray,
start = androidx.compose.ui.geometry.Offset(0f, h / 2),
@@ -71,10 +43,11 @@ fun WaveformView(
)
} else {
val path = Path()
val stepX = w / (values.size - 1).coerceAtLeast(1)
for (i in values.indices) {
val stepX = w / (data.size - 1).coerceAtLeast(1)
for (i in data.indices) {
val x = i * stepX
val y = h * (1f - values[i])
val normalized = (data[i].toInt() and 0xFF) / 255f
val y = h * (1f - normalized)
if (i == 0) path.moveTo(x, y) else path.lineTo(x, y)
}
drawPath(path = path, color = Color.Cyan, style = Stroke(width = 2f))