fix(core): fix TS clocks computation to avoid an overflow after 94h

core/src/main/java/io/github/thibaultbee/streampack/core/elements/endpoints/composites/muxers/ts/descriptors/AdaptationField.kt

@@ -16,12 +16,11 @@
 package io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.descriptors
 
 import io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.data.ITSElement
-import io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils.TSConst
+import io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils.TSTimeUtils
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.put
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.putShort
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.shl
 import java.nio.ByteBuffer
-import kotlin.math.pow
 
 class AdaptationField(
     private val discontinuityIndicator: Boolean = false,
@@ -53,15 +52,16 @@ class AdaptationField(
         val buffer = ByteBuffer.allocate(size)
 
         buffer.put(adaptationFieldLength)
-        buffer.put(((discontinuityIndicator shl 7)
-                or (randomAccessIndicator shl 6)
-                or (elementaryStreamPriorityIndicator shl 5)
-                or ((programClockReference?.let { 1 } ?: 0) shl 4)
-                or ((originalProgramClockReference?.let { 1 } ?: 0) shl 3)
-                or ((spliceCountdown?.let { 1 } ?: 0) shl 2)
-                or ((transportPrivateData?.let { 1 } ?: 0) shl 1)
-                or (adaptationFieldExtension?.let { 1 } ?: 0)
-                ))
+        buffer.put(
+            ((discontinuityIndicator shl 7)
+                    or (randomAccessIndicator shl 6)
+                    or (elementaryStreamPriorityIndicator shl 5)
+                    or ((programClockReference?.let { 1 } ?: 0) shl 4)
+                    or ((originalProgramClockReference?.let { 1 } ?: 0) shl 3)
+                    or ((spliceCountdown?.let { 1 } ?: 0) shl 2)
+                    or ((transportPrivateData?.let { 1 } ?: 0) shl 1)
+                    or (adaptationFieldExtension?.let { 1 } ?: 0)
+                    ))
 
         programClockReference?.let {
             addClockReference(buffer, it)
@@ -86,23 +86,22 @@ class AdaptationField(
         return buffer
     }
 
-    private fun addClockReference(buffer: ByteBuffer, timestamp: Long) {
-        val pcrBase =
-            (TSConst.SYSTEM_CLOCK_FREQ * timestamp / 1000000 /* µs -> s */ / 300) % 2.toDouble()
-                .pow(33)
-                .toLong()
-        val pcrExt = (TSConst.SYSTEM_CLOCK_FREQ * timestamp / 1000000 /* µs -> s */) % 300
+    companion object {
+        private fun addClockReference(buffer: ByteBuffer, timestamp: Long) {
+            val pcrBase = TSTimeUtils.computeTimestamp90kHz(timestamp)
+            val pcrExt = TSTimeUtils.computePcrExt(timestamp)
 
-        /**
-         * PCR Base -> 33 bits
-         * Reserved -> 6 bits (0b111111)
-         * PCR Ext -> 9 bits
-         */
-        buffer.putInt((pcrBase shr 1).toInt())
-        buffer.putShort(
-            (((pcrBase and 0x1) shl 15)
-                    or (0b111111 shl 9)
-                    or (pcrExt and 0x1FF))
-        )
+            /**
+             * PCR Base -> 33 bits
+             * Reserved -> 6 bits (0b111111)
+             * PCR Ext -> 9 bits
+             */
+            buffer.putInt((pcrBase shr 1).toInt())
+            buffer.putShort(
+                (((pcrBase and 0x1) shl 15)
+                        or (0b111111 shl 9)
+                        or (pcrExt and 0x1FF))
+            )
+        }
     }
 }

core/src/main/java/io/github/thibaultbee/streampack/core/elements/endpoints/composites/muxers/ts/packets/PesHeader.kt

@@ -16,14 +16,13 @@
 package io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.packets
 
 import io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.data.ITSElement
-import io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils.TSConst
+import io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils.TSTimeUtils
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.put
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.putShort
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.shl
 import io.github.thibaultbee.streampack.core.elements.utils.extensions.toInt
 import java.nio.ByteBuffer
 import kotlin.experimental.and
-import kotlin.math.pow
 
 class PesHeader(
     private val streamId: Short,
@@ -129,10 +128,7 @@ class PesHeader(
     }
 
     private fun addTimestamp(buffer: ByteBuffer, timestamp: Long, fourBits: Byte) {
-        val pts =
-            (TSConst.SYSTEM_CLOCK_FREQ * timestamp / 1000000 /* µs -> s */ / 300) % 2.toDouble()
-                .pow(33)
-                .toLong()
+        val pts = TSTimeUtils.computeTimestamp90kHz(timestamp)
 
         buffer.put(
             (((fourBits and 0xF).toInt() shl 4)

core/src/main/java/io/github/thibaultbee/streampack/core/elements/endpoints/composites/muxers/ts/utils/TSConst.kt

@@ -16,6 +16,5 @@
 package io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils
 
 object TSConst {
-    const val SYSTEM_CLOCK_FREQ = 27000000
     const val BASE_PID = 0x00020.toShort()
 }

core/src/main/java/io/github/thibaultbee/streampack/core/elements/endpoints/composites/muxers/ts/utils/TSTimeUtils.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2026 Thibault B.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils
+
+object TSTimeUtils {
+    private const val PCR_BASE_MASK = 0x1FFFFFFFFL // 33 bits mask
+
+    /**
+     * Converts a timestamp in microseconds to a 33-bit 90 kHz timestamp.
+     * Used for PCR Base, PTS, and DTS.
+     */
+    fun computeTimestamp90kHz(timestamp: Long): Long {
+        // 90 kHz ticks per microsecond = 90,000 / 1,000,000 = 9 / 100
+        return (timestamp * 9 / 100) and PCR_BASE_MASK
+    }
+
+    /**
+     * Converts a timestamp in microseconds to a 9-bit 27 MHz extension clock.
+     * Used for PCR Ext.
+     */
+    fun computePcrExt(timestamp: Long): Long {
+        // To convert microseconds to clock ticks, we use fractions to avoid early integer overflow.
+        // 27 MHz ticks per microsecond = 27,000,000 / 1,000,000 = 27
+        return (timestamp * 27 % 300)
+    }
+}

core/src/test/java/io/github/thibaultbee/streampack/core/elements/endpoints/composites/muxers/ts/utils/TSTimeUtilsTest.kt

@@ -0,0 +1,21 @@
+package io.github.thibaultbee.streampack.core.elements.endpoints.composites.muxers.ts.utils
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class TSTimeUtilsTest {
+    @Test
+    fun `test computeTimestamp90kHz with very large timestamp avoiding overflow`() {
+        // 400,000,000,000 µs (about 111 hours)
+        val timestamp = 400_000_000_000L
+        val expectedPcrBase = 1_640_261_632L
+        assertEquals(expectedPcrBase, TSTimeUtils.computeTimestamp90kHz(timestamp))
+    }
+
+    @Test
+    fun `test computePcrExt with very large timestamp avoiding overflow`() {
+        val timestamp = 400_000_000_000L
+        val expectedPcrExt = 0L 
+        assertEquals(expectedPcrExt, TSTimeUtils.computePcrExt(timestamp))
+    }
+}