rather large commit, it now handles memory and threading properly.

---

more thorough commit message which was generated by the wonderful copilot AI tool:

Refactor and enhance audio encoding and decoding pipelines

- Introduced CodecUtils.h for utility functions related to audio codec selection, including sample format and bitrate clamping.
- Added DecoderPipeline.h to manage audio decoding, including opening files and retrieving audio stream information.
- Implemented EncoderPipeline.h to handle audio encoding, including encoder setup, resampling, and writing output files.
- Created OutputPathBuilder.h to generate output file paths based on reencode job specifications.
- Refactored SpectrogramWidget to improve OpenGL handling and ensure safe context usage.
- Updated ReencodeDialog.h to enhance code readability and maintainability.
- Improved error handling and logging throughout the audio processing components.

src/gui/ReencodeDialog.h

@@ -1,6 +1,8 @@
 #pragma once
+
 #include <QDialog>
 #include <QList>
+
 #include "engine/Track.h"
 #include "engine/encoder/ReencodeJob.h"
 
@@ -12,20 +14,23 @@ class QLabel;
 class QProgressBar;
 
 namespace engine { class AlbumReencoder; }
-class ReencodeDialog : public QDialog {
+
+class ReencodeDialog : public QDialog
+{
     Q_OBJECT
+
 public:
     explicit ReencodeDialog(const QList<engine::Track> &tracks,
                             QWidget *parent = nullptr);
-    ~ReencodeDialog();
+    ~ReencodeDialog() override;
 
 private slots:
     void onPresetChanged(int index);
     void onBrowseOutput();
     void onStartStop();
     void onTrackStarted (int index, const QString &title);
-    void onTrackFinished(int index, bool ok, const QString &outPath,
-                         const QString &err);
+    void onTrackFinished(int index, bool ok,
+                         const QString &outPath, const QString &err);
     void onAllFinished  (int succeeded, int failed);
 
 private:
@@ -34,21 +39,21 @@ private:
     void setRunning(bool running);
     void updateOverallProgress();
 
-    QList<engine::Track>         m_tracks;
-    QList<engine::EncodePreset>  m_presets;
+    QList<engine::Track>        m_tracks;
+    QList<engine::EncodePreset> m_presets;
 
-    QComboBox    *m_presetCombo   { nullptr };
-    QLabel       *m_presetDesc    { nullptr };
-    QLineEdit    *m_outputDir     { nullptr };
-    QPushButton  *m_browseBtn     { nullptr };
-    QTableWidget *m_table         { nullptr };
-    QProgressBar *m_overallBar    { nullptr };
-    QLabel       *m_statusLabel   { nullptr };
-    QPushButton  *m_startStopBtn  { nullptr };
-    QPushButton  *m_closeBtn      { nullptr };
+    QComboBox    *m_presetCombo  { nullptr };
+    QLabel       *m_presetDesc   { nullptr };
+    QLineEdit    *m_outputDir    { nullptr };
+    QPushButton  *m_browseBtn    { nullptr };
+    QTableWidget *m_table        { nullptr };
+    QProgressBar *m_overallBar   { nullptr };
+    QLabel       *m_statusLabel  { nullptr };
+    QPushButton  *m_startStopBtn { nullptr };
+    QPushButton  *m_closeBtn     { nullptr };
 
     engine::AlbumReencoder *m_reencoder { nullptr };
 
-    int m_doneCount  { 0 };
-    int m_totalCount { 0 };
+    qsizetype m_doneCount  { 0 };
+    qsizetype m_totalCount { 0 };
 };