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using fractions for numerical precision

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minjaesong
2023-12-12 15:21:47 +09:00
parent 4be7e728c9
commit 95225b56b4
1 changed files with 32 additions and 18 deletions
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50
src/net/torvald/terrarum/audio/AudioProcessBuf.kt
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@@ -1,5 +1,7 @@
package net.torvald.terrarum.audio
import com.jme3.math.FastMath
import net.torvald.terrarum.App.printdbg
import net.torvald.terrarum.audio.TerrarumAudioMixerTrack.Companion.AUDIO_BUFFER_SIZE
import net.torvald.terrarum.audio.TerrarumAudioMixerTrack.Companion.SAMPLING_RATE
import net.torvald.terrarum.ceilToInt
@@ -8,8 +10,16 @@ import net.torvald.terrarum.serialise.toUint
import org.dyn4j.Epsilon
import kotlin.math.PI
import kotlin.math.absoluteValue
import kotlin.math.roundToInt
import kotlin.math.sin
private data class Frac(var nom: Int, val denom: Int) {
fun toDouble() = nom.toDouble() / denom.toDouble()
fun toFloat() = this.toDouble().toFloat()
private val denomStrLen = denom.toString().length
override fun toString() = "${nom.toString().padStart(denomStrLen)} / $denom"
}
/**
* Audio is assumed to be 2 channels, 16 bits
*
@@ -39,11 +49,11 @@ class AudioProcessBuf(inputSamplingRate: Int, val audioReadFun: (ByteArray) -> I
init {
val bl = arrayOf(
1152,1380,1812,1792,2304,2634,3500,3456,4608,5137,6870,6912,
1280,1508,1939,1920,2304,2762,3630,3584,4608,5269,7000,6912,
1536,1764,2197,2176,2560,3018,3886,3840,4608,5525,7260,7168,
2048,2276,2708,2688,3072,3530,4397,4352,5120,6037,7772,7680,
4096,4553,5419,5376,6144,7061,8794,8704,10240,12035,15544,15360
1152,1379,1815,1792,2304,2633,3500,3456,4608,5141,6870,6912,
1280,1504,1943,1920,2304,2758,3630,3584,4608,5266,7000,6912,
1536,1755,2198,2176,2560,3009,3886,3840,4608,5517,7260,7168,
2048,2257,2709,2688,3072,3511,4397,4352,5120,6019,7772,7680,
4096,4514,5419,5376,6144,7022,8794,8704,10240,12038,15544,15360
)
arrayOf(48000,44100,32768,32000,24000,22050,16384,16000,12000,11025,8192,8000).forEachIndexed { ri, r ->
@@ -56,43 +66,45 @@ class AudioProcessBuf(inputSamplingRate: Int, val audioReadFun: (ByteArray) -> I
private fun getOptimalBufferSize(rate: Int) = bufLut[BS to rate]!!
}
private val denom = SAMPLING_RATE / FastMath.getGCD(inputSamplingRate, SAMPLING_RATE)
private val q = inputSamplingRate.toDouble() / SAMPLING_RATE // <= 1.0
private val fetchSize = (BS.toFloat() / MP3_CHUNK_SIZE).ceilToInt() * MP3_CHUNK_SIZE // fetchSize is always multiple of MP3_CHUNK_SIZE, even if the audio is NOT MP3
private val internalBufferSize = getOptimalBufferSize(inputSamplingRate)// fetchSize * 3
private val PADSIZE = TAPS + 1
private fun resampleBlock(innL: FloatArray, innR: FloatArray, outL: FloatArray, outR: FloatArray, outSampleCount: Int) {
fun getInnL(i: Int) = innL[i + (TAPS + 1)]
fun getInnR(i: Int) = innR[i + (TAPS + 1)]
fun getInnL(i: Int) = innL[i + PADSIZE]
fun getInnR(i: Int) = innR[i + PADSIZE]
for (sampleIdx in 0 until outSampleCount) {
val x = fPhaseL + q * sampleIdx
val x = fPhaseL.toDouble() + q * sampleIdx
var sx = 0.0
for (i in x.floorToInt() - TAPS + 1..x.floorToInt() + TAPS) {
sx += getInnL(i) * L(x - i)
}
outL[sampleIdx] = sx.toFloat()
}
fPhaseL = ((fPhaseL + q * outSampleCount) % 1.0)
fPhaseL.nom = ((fPhaseL.toDouble() + q * outSampleCount) * denom).roundToInt() % denom
for (sampleIdx in 0 until outSampleCount) {
val x = fPhaseR + q * sampleIdx
val x = fPhaseR.toDouble() + q * sampleIdx
var sx = 0.0
for (i in x.floorToInt() - TAPS + 1..x.floorToInt() + TAPS) {
sx += getInnR(i) * L(x - i)
}
outR[sampleIdx] = sx.toFloat()
}
fPhaseR = ((fPhaseR + q * outSampleCount) % 1.0)
fPhaseR.nom = ((fPhaseR.toDouble() + q * outSampleCount) * denom).roundToInt() % denom
}
var validSamplesInBuf = 0
private val finL = FloatArray(fetchSize + 2 * (TAPS + 1))
private val finR = FloatArray(fetchSize + 2 * (TAPS + 1))
private var fPhaseL = 0.0
private var fPhaseR = 0.0
private val finL = FloatArray(fetchSize + 2 * PADSIZE)
private val finR = FloatArray(fetchSize + 2 * PADSIZE)
private var fPhaseL = Frac(0, denom)
private var fPhaseR = Frac(0, denom)
private val fmidL = FloatArray((fetchSize / q + 1.0).toInt())
private val fmidR = FloatArray((fetchSize / q + 1.0).toInt())
private val foutL = FloatArray(internalBufferSize) // 640 for (44100, 48000), 512 for (48000, 48000) with BUFFER_SIZE = 512 * 4
@@ -106,7 +118,7 @@ class AudioProcessBuf(inputSamplingRate: Int, val audioReadFun: (ByteArray) -> I
fun fetchBytes() {
val readCount = if (validSamplesInBuf < BS) fetchSize else 0
val writeCount = (readCount / q + fPhaseL).toInt()
val writeCount = (readCount / q + fPhaseL.toDouble()).toInt()
fun getFromReadBuf(i: Int, bytesRead: Int) = if (i < bytesRead) readBuf[i].toUint() else 0
@@ -131,8 +143,8 @@ class AudioProcessBuf(inputSamplingRate: Int, val audioReadFun: (ByteArray) -> I
val fl = sl / 32767f
val fr = sr / 32767f
finL[2 * (TAPS + 1) + c] = fl
finR[2 * (TAPS + 1) + c] = fr
finL[2 * PADSIZE + c] = fl
finR[2 * PADSIZE + c] = fr
}
}
}
@@ -160,6 +172,8 @@ class AudioProcessBuf(inputSamplingRate: Int, val audioReadFun: (ByteArray) -> I
else {
// printdbg(this, "Reading audio zero samples; Buffer: $validSamplesInBuf / $internalBufferSize samples")
}
printdbg(this, "phase = $fPhaseL")
}
fun getLR(volume: Double): Pair<FloatArray, FloatArray> {