From 952623382154d4ce9e6df80318a42f17007bb9bb Mon Sep 17 00:00:00 2001
From: ab-tools <a-breitschopp@ab-tools.com>
Date: Sun, 18 Oct 2026 23:39:37 +0200
Subject: [PATCH] [audio] Compute frames_to_microseconds() in 64 bits (#21089)

---
 esphome/components/audio/audio.cpp            |  3 ++-
 .../audio/test_audio_stream_info.cpp          | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 tests/components/audio/test_audio_stream_info.cpp

diff --git a/esphome/components/audio/audio.cpp b/esphome/components/audio/audio.cpp
index 402e741059b..54406df2aaa 100644
--- a/esphome/components/audio/audio.cpp
+++ b/esphome/components/audio/audio.cpp
@@ -23,7 +23,8 @@ AudioStreamInfo::AudioStreamInfo(uint8_t bits_per_sample, uint8_t channels, uint
 }
 
 uint32_t AudioStreamInfo::frames_to_microseconds(uint32_t frames) const {
-  return (frames * 1000000 + (this->sample_rate_ >> 1)) / this->sample_rate_;
+  // In 64 bits: frames * 1000000 overflows 32 bits above 4294 frames, about 90 ms at 48 kHz.
+  return (static_cast<uint64_t>(frames) * 1000000 + (this->sample_rate_ >> 1)) / this->sample_rate_;
 }
 
 uint32_t AudioStreamInfo::frames_to_milliseconds_with_remainder(uint32_t *total_frames) const {
diff --git a/tests/components/audio/test_audio_stream_info.cpp b/tests/components/audio/test_audio_stream_info.cpp
new file mode 100644
index 00000000000..e948bc32b2f
--- /dev/null
+++ b/tests/components/audio/test_audio_stream_info.cpp
@@ -0,0 +1,20 @@
+#include <gtest/gtest.h>
+
+#include "esphome/components/audio/audio.h"
+
+namespace esphome::audio::testing {
+
+TEST(AudioStreamInfo, FramesToMicroseconds) {
+  AudioStreamInfo info(16, 2, 48000);
+  EXPECT_EQ(info.frames_to_microseconds(48), 1000U);
+  EXPECT_EQ(info.frames_to_microseconds(1), 21U);  // 20.83 us, rounded
+}
+
+TEST(AudioStreamInfo, FramesToMicrosecondsAboveFourThousandFrames) {
+  // frames * 1000000 no longer fits 32 bits above 4294 frames, about 90 ms at 48 kHz.
+  AudioStreamInfo info(24, 2, 48000);
+  EXPECT_EQ(info.frames_to_microseconds(4800), 100000U);
+  EXPECT_EQ(info.frames_to_microseconds(48000), 1000000U);
+}
+
+}  // namespace esphome::audio::testing