diff --git a/src/engine/AudioEngine.cpp b/src/engine/AudioEngine.cpp
index 7f7d12d..52ae6f3 100644
--- a/src/engine/AudioEngine.cpp
+++ b/src/engine/AudioEngine.cpp
@@ -85,7 +85,7 @@ void AudioEngine::initEq() {
 void AudioEngine::playbackLoop() {
     m_state = State::Playing;
 
-    engine::FFmpegDecoder decoder;
+    engine::ffmpeg::FFmpegDecoder decoder;
     if (!decoder.open(m_track.filePath)) {
         qWarning() << "[AudioEngine] Cannot open:" << m_track.filePath;
         m_state = State::Stopped;
diff --git a/src/engine/ffmpeg/CodecContext.cpp b/src/engine/ffmpeg/CodecContext.cpp
index 48b6740..611297b 100644
--- a/src/engine/ffmpeg/CodecContext.cpp
+++ b/src/engine/ffmpeg/CodecContext.cpp
@@ -5,7 +5,7 @@ extern "C" {
 #include <libavcodec/avcodec.h>
 }
 
-namespace engine {
+namespace engine::ffmpeg {
 
 void CodecContext::Deleter::operator()(AVCodecContext *p) const {
     avcodec_free_context(&p);
@@ -64,4 +64,4 @@ int CodecContext::channels() const {
     return m_ctx ? m_ctx->ch_layout.nb_channels : 0;
 }
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/CodecContext.h b/src/engine/ffmpeg/CodecContext.h
index c189aa6..4084689 100644
--- a/src/engine/ffmpeg/CodecContext.h
+++ b/src/engine/ffmpeg/CodecContext.h
@@ -6,7 +6,7 @@ struct AVCodecParameters;
 struct AVPacket;
 struct AVFrame;
 
-namespace engine {
+namespace engine::ffmpeg {
 
 class CodecContext {
 public:
@@ -35,4 +35,4 @@ private:
     std::unique_ptr<AVCodecContext, Deleter> m_ctx;
 };
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/FFmpegDecoder.cpp b/src/engine/ffmpeg/FFmpegDecoder.cpp
index e963946..a850f74 100644
--- a/src/engine/ffmpeg/FFmpegDecoder.cpp
+++ b/src/engine/ffmpeg/FFmpegDecoder.cpp
@@ -6,7 +6,7 @@ extern "C" {
 #include <libavutil/avutil.h>
 }
 
-namespace engine {
+namespace engine::ffmpeg {
 
 FFmpegDecoder::FFmpegDecoder() = default;
 
@@ -103,4 +103,4 @@ bool FFmpegDecoder::drainCodec(AudioBuffer &buf) const {
     return gotSamples;
 }
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/FFmpegDecoder.h b/src/engine/ffmpeg/FFmpegDecoder.h
index 44ebe81..5b37bec 100644
--- a/src/engine/ffmpeg/FFmpegDecoder.h
+++ b/src/engine/ffmpeg/FFmpegDecoder.h
@@ -6,10 +6,8 @@
 #include "CodecContext.h"
 #include "Resampler.h"
 
-namespace engine {
+namespace engine::ffmpeg {
 
-// Thin orchestrator: ties FormatContext, CodecContext, and Resampler together
-// to expose a simple open / seek / decodeNext interface.
 class FFmpegDecoder {
 public:
     FFmpegDecoder();
@@ -34,8 +32,7 @@ private:
 
     qint64 m_totalFrames { 0 };
 
-    // Drains all frames currently buffered in the codec into buf.
     bool drainCodec(AudioBuffer &buf) const;
 };
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/FormatContext.cpp b/src/engine/ffmpeg/FormatContext.cpp
index 309654b..fd66c1c 100644
--- a/src/engine/ffmpeg/FormatContext.cpp
+++ b/src/engine/ffmpeg/FormatContext.cpp
@@ -7,7 +7,7 @@ extern "C" {
 #include <libavutil/avutil.h>
 }
 
-namespace engine {
+namespace engine::ffmpeg {
 
 void FormatContext::Deleter::operator()(AVFormatContext *p) const {
     avformat_close_input(&p);
@@ -91,4 +91,4 @@ qint64 FormatContext::audioStreamDuration() const {
     return m_fmt->streams[m_audioIdx]->duration;
 }
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/FormatContext.h b/src/engine/ffmpeg/FormatContext.h
index 20fbec0..5d8b28a 100644
--- a/src/engine/ffmpeg/FormatContext.h
+++ b/src/engine/ffmpeg/FormatContext.h
@@ -8,7 +8,7 @@ extern "C" {
 
 struct AVPacket;
 
-namespace engine {
+namespace engine::ffmpeg {
 
 class FormatContext {
 public:
@@ -39,4 +39,4 @@ private:
     int    m_audioIdx { -1 };
 };
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/Resampler.cpp b/src/engine/ffmpeg/Resampler.cpp
index 0be6ade..8fecf55 100644
--- a/src/engine/ffmpeg/Resampler.cpp
+++ b/src/engine/ffmpeg/Resampler.cpp
@@ -7,7 +7,7 @@ extern "C" {
 #include <libavutil/channel_layout.h>
 }
 
-namespace engine {
+namespace engine::ffmpeg {
 
 void Resampler::Deleter::operator()(SwrContext *p) const {
     swr_free(&p);
@@ -65,4 +65,4 @@ int Resampler::convert(const AVFrame *frame, std::vector<float> &out) const {
     return converted;
 }
 
-} // namespace engine
+} // namespace engine::ffmpeg
diff --git a/src/engine/ffmpeg/Resampler.h b/src/engine/ffmpeg/Resampler.h
index b24db23..06d1dc7 100644
--- a/src/engine/ffmpeg/Resampler.h
+++ b/src/engine/ffmpeg/Resampler.h
@@ -6,7 +6,7 @@ struct SwrContext;
 struct AVCodecContext;
 struct AVFrame;
 
-namespace engine {
+namespace engine::ffmpeg {
 
 class Resampler {
 public:
@@ -29,4 +29,4 @@ private:
     int m_sampleRate { 0 };
 };
 
-} // namespace engine
+} // namespace engine::ffmpeg