Initial commit.

src/transcoder/transcoder.h

@@ -0,0 +1,144 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef TRANSCODER_H
+#define TRANSCODER_H
+
+#include "config.h"
+
+#include <memory>
+
+#include <gst/gst.h>
+
+#include <QObject>
+#include <QStringList>
+#include <QEvent>
+#include <QMetaType>
+
+#include "core/song.h"
+
+struct TranscoderPreset {
+  TranscoderPreset() : type_(Song::Type_Unknown) {}
+  TranscoderPreset(Song::FileType type, const QString &name, const QString &extension, const QString &codec_mimetype, const QString &muxer_mimetype_ = QString());
+
+  Song::FileType type_;
+  QString name_;
+  QString extension_;
+  QString codec_mimetype_;
+  QString muxer_mimetype_;
+};
+Q_DECLARE_METATYPE(TranscoderPreset);
+
+class Transcoder : public QObject {
+  Q_OBJECT
+
+ public:
+  Transcoder(QObject *parent = nullptr, const QString &settings_postfix = "");
+
+  static TranscoderPreset PresetForFileType(Song::FileType type);
+  static QList<TranscoderPreset> GetAllPresets();
+  static Song::FileType PickBestFormat(QList<Song::FileType> supported);
+
+  int max_threads() const { return max_threads_; }
+  void set_max_threads(int count) { max_threads_ = count; }
+
+  void AddJob(const QString &input, const TranscoderPreset &preset, const QString &output = QString());
+  void AddTemporaryJob(const QString &input, const TranscoderPreset &preset);
+
+  QMap<QString, float> GetProgress() const;
+  int QueuedJobsCount() const { return queued_jobs_.count(); }
+
+ public slots:
+  void Start();
+  void Cancel();
+
+signals:
+  void JobComplete(const QString &input, const QString &output, bool success);
+  void LogLine(const QString &message);
+  void AllJobsComplete();
+
+ protected:
+  bool event(QEvent *e);
+
+ private:
+  // The description of a file to transcode - lives in the main thread.
+  struct Job {
+    QString input;
+    QString output;
+    TranscoderPreset preset;
+  };
+
+  // State held by a job and shared across gstreamer callbacks - lives in the
+  // job's thread.
+  struct JobState {
+    JobState(const Job &job, Transcoder *parent)
+        : job_(job),
+          parent_(parent),
+          pipeline_(nullptr),
+          convert_element_(nullptr) {}
+    ~JobState();
+
+    void PostFinished(bool success);
+    void ReportError(GstMessage *msg);
+
+    Job job_;
+    Transcoder *parent_;
+    GstElement *pipeline_;
+    GstElement *convert_element_;
+  };
+
+  // Event passed from a GStreamer callback to the Transcoder when a job
+  // finishes.
+  struct JobFinishedEvent : public QEvent {
+    JobFinishedEvent(JobState *state, bool success);
+
+    static int sEventType;
+
+    JobState *state_;
+    bool success_;
+  };
+
+  enum StartJobStatus {
+    StartedSuccessfully,
+    FailedToStart,
+    NoMoreJobs,
+    AllThreadsBusy,
+  };
+
+  StartJobStatus MaybeStartNextJob();
+  bool StartJob(const Job &job);
+
+  GstElement *CreateElement(const QString &factory_name, GstElement *bin = nullptr, const QString &name = QString());
+  GstElement *CreateElementForMimeType(const QString &element_type, const QString &mime_type, GstElement *bin = nullptr);
+  void SetElementProperties(const QString &name, GObject *element);
+
+  static void NewPadCallback(GstElement*, GstPad *pad, gpointer data);
+  static GstBusSyncReply BusCallbackSync(GstBus*, GstMessage *msg, gpointer data);
+
+ private:
+  typedef QList<std::shared_ptr<JobState>> JobStateList;
+
+  int max_threads_;
+  QList<Job> queued_jobs_;
+  JobStateList current_jobs_;
+  QString settings_postfix_;
+};
+
+#endif  // TRANSCODER_H