diff --git a/ui/viewerwidget.cpp b/ui/viewerwidget.cpp
index 0b09a009c..5e45f77d7 100644
--- a/ui/viewerwidget.cpp
+++ b/ui/viewerwidget.cpp
@@ -29,7 +29,7 @@ ViewerWidget::ViewerWidget(QWidget *parent) : QOpenGLWidget(parent) {
 	format.setDepthBufferSize(24);
 	setFormat(format);
 
-	// error handler - retries after 200ms if we couldn't get the entire image
+    // error handler - retries after 250ms if we couldn't get the entire image
     retry_timer.setInterval(250);
 	connect(&retry_timer, SIGNAL(timeout()), this, SLOT(retry()));
 }
@@ -76,6 +76,156 @@ void ViewerWidget::paintEvent(QPaintEvent *e) {
     if (enable_paint) QOpenGLWidget::paintEvent(e);
 }
 
+void ViewerWidget::compose_sequence(Sequence *s, bool render_audio) {
+    QVector<Clip*> current_clips;
+
+    for (int i=0;i<s->clip_count();i++) {
+        Clip* c = s->get_clip(i);
+
+        // if clip starts within one second and/or hasn't finished yet
+        if (c != NULL) {
+            if (c->media->ready
+                    && c->media->get_stream_from_file_index(c->media_stream) != NULL
+                    && is_clip_active(c, panel_timeline->playhead)) {
+                // if thread is already working, we don't want to touch this,
+                // but we also don't want to hang the UI thread
+                if (!c->open) {
+                    open_clip(c, multithreaded);
+                }
+
+                bool added = false;
+                for (int j=0;j<current_clips.size();j++) {
+                    if (current_clips.at(j)->track < c->track) {
+                        current_clips.insert(j, c);
+                        added = true;
+                        break;
+                    }
+                }
+                if (!added) {
+                    current_clips.append(c);
+                }
+            } else if (c->open) {
+                close_clip(c);
+            }
+        }
+    }
+
+    for (int i=0;i<current_clips.size();i++) {
+        Clip* c = current_clips.at(i);
+
+        if (!c->finished_opening) {
+            qDebug() << "[WARNING] Tried to display clip" << i << "but it's closed";
+            texture_failed = true;
+        } else if (is_clip_active(c, panel_timeline->playhead)) {
+            if (c->stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+                // start preparing cache
+                get_clip_frame(c, panel_timeline->playhead);
+
+                if (c->texture == NULL) {
+                    qDebug() << "[WARNING] Texture hasn't been created yet";
+                    texture_failed = true;
+                } else if (panel_timeline->playhead >= c->timeline_in) {
+                    MediaStream* ms = c->media->get_stream_from_file_index(c->media_stream);
+
+                    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+                    glColor4f(1.0, 1.0, 1.0, 1.0);
+                    glLoadIdentity();
+
+                    int half_width = s->width/2;
+                    int half_height = s->height/2;
+                    if (flip) {
+                        glOrtho(-half_width, half_width, -half_height, half_height, -1, 1);
+                    } else {
+                        glOrtho(-half_width, half_width, half_height, -half_height, -1, 1);
+                    }
+                    int anchor_x = ms->video_width/2;
+                    int anchor_y = ms->video_height/2;
+
+                    // perform all transform effects
+                    for (int j=0;j<c->effects.size();j++) {
+                        if (c->effects.at(j)->is_enabled()) c->effects.at(j)->process_gl(&anchor_x, &anchor_y);
+                    }
+
+                    if (c->opening_transition != NULL) {
+                        int transition_progress = panel_timeline->playhead-c->timeline_in;
+                        if (transition_progress < c->opening_transition->length) {
+                            c->opening_transition->process_transition((float)transition_progress/(float)c->opening_transition->length);
+                        }
+                    }
+                    if (c->closing_transition != NULL) {
+                        int transition_progress = c->closing_transition->length-(panel_timeline->playhead-c->timeline_in-c->getLength()+c->closing_transition->length);
+                        if (transition_progress < c->closing_transition->length) {
+                            c->closing_transition->process_transition((float)transition_progress/(float)c->closing_transition->length);
+                        }
+                    }
+
+                    int anchor_right = ms->video_width - anchor_x;
+                    int anchor_bottom = ms->video_height - anchor_y;
+
+                    c->texture->bind();
+
+                    glBegin(GL_QUADS);
+                    glTexCoord2f(0.0, 0.0);
+                    glVertex2f(-anchor_x, -anchor_y);
+                    glTexCoord2f(1.0, 0.0);
+                    glVertex2f(anchor_right, -anchor_y);
+                    glTexCoord2f(1.0, 1.0);
+                    glVertex2f(anchor_right, anchor_bottom);
+                    glTexCoord2f(0.0, 1.0);
+                    glVertex2f(-anchor_x, anchor_bottom);
+                    glEnd();
+
+                    c->texture->release();
+
+                    // perform all transform effects
+                    for (int j=0;j<c->effects.size();j++) {
+                        if (c->effects.at(j)->is_enabled()) c->effects.at(j)->post_gl();
+                    }
+                }
+            } else if (render_audio &&
+                       c->stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
+                       c->lock.tryLock()) {
+                // clip is not caching, start caching audio
+                cache_clip(c, panel_timeline->playhead, false, false, c->reset_audio);
+                c->lock.unlock();
+            }
+        }
+    }
+}
+
+int ViewerWidget::send_audio_to_output(int offset, int max) {
+    // send audio to device
+    int actual_write = audio_io_device->write((const char*) audio_ibuffer+offset, max);
+    audio_ibuffer_read += actual_write;
+
+    // send samples to audio monitor cache
+    if (panel_timeline->ui->audio_monitor->sample_cache_offset == -1) {
+        panel_timeline->ui->audio_monitor->sample_cache_offset = panel_timeline->playhead;
+    }
+    long sample_cache_playhead = panel_timeline->ui->audio_monitor->sample_cache_offset + panel_timeline->ui->audio_monitor->sample_cache.size();
+    int next_buffer_offset, buffer_offset_adjusted, i;
+    int buffer_offset = get_buffer_offset_from_frame(sample_cache_playhead);
+    samples.resize(av_get_channel_layout_nb_channels(sequence->audio_layout));
+    samples.fill(0);
+    while (buffer_offset < audio_ibuffer_read) {
+        sample_cache_playhead++;
+        next_buffer_offset = qMin(get_buffer_offset_from_frame(sample_cache_playhead), audio_ibuffer_read);
+        while (buffer_offset < next_buffer_offset) {
+            for (i=0;i<samples.size();i++) {
+                buffer_offset_adjusted = buffer_offset%audio_ibuffer_size;
+                samples[i] = qMax(qAbs((qint16) (((audio_ibuffer[buffer_offset_adjusted+1] & 0xFF) << 8) | (audio_ibuffer[buffer_offset_adjusted] & 0xFF))), samples[i]);
+                buffer_offset += 2;
+            }
+        }
+        panel_timeline->ui->audio_monitor->sample_cache.append(samples);
+        buffer_offset = next_buffer_offset;
+    }
+
+    memset(audio_ibuffer+offset, 0, actual_write);
+
+    return actual_write;
+}
+
 void ViewerWidget::paintGL() {
     bool loop = true;
     while (loop) {
@@ -86,160 +236,16 @@ void ViewerWidget::paintGL() {
 
         glClear(GL_COLOR_BUFFER_BIT);
 
-        current_clips.clear();
-
-        for (int i=0;i<sequence->clip_count();i++) {
-            Clip* c = sequence->get_clip(i);
-
-            // if clip starts within one second and/or hasn't finished yet
-            if (c != NULL) {
-                if (c->media->ready
-                        && c->media->get_stream_from_file_index(c->media_stream) != NULL
-                        && is_clip_active(c, panel_timeline->playhead)) {
-                    // if thread is already working, we don't want to touch this,
-                    // but we also don't want to hang the UI thread
-                    if (!c->open) {
-                        open_clip(c, multithreaded);
-                    }
-
-                    bool added = false;
-                    for (int j=0;j<current_clips.size();j++) {
-                        if (current_clips.at(j)->track < c->track) {
-                            current_clips.insert(j, c);
-                            added = true;
-                            break;
-                        }
-                    }
-                    if (!added) {
-                        current_clips.append(c);
-                    }
-                } else if (c->open) {
-                    close_clip(c);
-                }
-            }
-        }
-
-        bool render_audio = (panel_timeline->playing || force_audio);
-
-        for (int i=0;i<current_clips.size();i++) {
-            Clip* c = current_clips.at(i);
-
-            if (!c->finished_opening) {
-                qDebug() << "[WARNING] Tried to display clip" << i << "but it's closed";
-                texture_failed = true;
-            } else if (is_clip_active(c, panel_timeline->playhead)) {
-                if (c->stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
-                    // start preparing cache
-                    get_clip_frame(c, panel_timeline->playhead);
-
-                    if (c->texture == NULL) {
-                        qDebug() << "[WARNING] Texture hasn't been created yet";
-                        texture_failed = true;
-                    } else if (panel_timeline->playhead >= c->timeline_in) {
-                        MediaStream* ms = c->media->get_stream_from_file_index(c->media_stream);
-
-                        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-                        glColor4f(1.0, 1.0, 1.0, 1.0);
-                        glLoadIdentity();
-
-                        int half_width = c->sequence->width/2;
-                        int half_height = c->sequence->height/2;
-                        if (flip) {
-                            glOrtho(-half_width, half_width, -half_height, half_height, -1, 1);
-                        } else {
-                            glOrtho(-half_width, half_width, half_height, -half_height, -1, 1);
-                        }
-                        int anchor_x = ms->video_width/2;
-                        int anchor_y = ms->video_height/2;
-
-                        // perform all transform effects
-                        for (int j=0;j<c->effects.size();j++) {
-                            if (c->effects.at(j)->is_enabled()) c->effects.at(j)->process_gl(&anchor_x, &anchor_y);
-                        }
-
-                        if (c->opening_transition != NULL) {
-                            int transition_progress = panel_timeline->playhead-c->timeline_in;
-                            if (transition_progress < c->opening_transition->length) {
-                                c->opening_transition->process_transition((float)transition_progress/(float)c->opening_transition->length);
-                            }
-                        }
-                        if (c->closing_transition != NULL) {
-                            int transition_progress = c->closing_transition->length-(panel_timeline->playhead-c->timeline_in-c->getLength()+c->closing_transition->length);
-                            if (transition_progress < c->closing_transition->length) {
-                                c->closing_transition->process_transition((float)transition_progress/(float)c->closing_transition->length);
-                            }
-                        }
-
-                        int anchor_right = ms->video_width - anchor_x;
-                        int anchor_bottom = ms->video_height - anchor_y;
-
-                        c->texture->bind();
-
-                        glBegin(GL_QUADS);
-                        glTexCoord2f(0.0, 0.0);
-                        glVertex2f(-anchor_x, -anchor_y);
-                        glTexCoord2f(1.0, 0.0);
-                        glVertex2f(anchor_right, -anchor_y);
-                        glTexCoord2f(1.0, 1.0);
-                        glVertex2f(anchor_right, anchor_bottom);
-                        glTexCoord2f(0.0, 1.0);
-                        glVertex2f(-anchor_x, anchor_bottom);
-                        glEnd();
-
-                        c->texture->release();
-
-                        // perform all transform effects
-                        for (int j=0;j<c->effects.size();j++) {
-                            if (c->effects.at(j)->is_enabled()) c->effects.at(j)->post_gl();
-                        }
-                    }
-                } else if (render_audio &&
-                           c->stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
-                           c->lock.tryLock()) {
-                    // clip is not caching, start caching audio
-                    cache_clip(c, panel_timeline->playhead, false, false, c->reset_audio);
-                    c->lock.unlock();
-                }
-            }
-        }
+        // compose video preview
+        compose_sequence(sequence, (panel_timeline->playing || force_audio));
 
+        // send audio to IO device
         if (panel_timeline->playing) {
             int adjusted_read_index = audio_ibuffer_read%audio_ibuffer_size;
             int max_write = audio_ibuffer_size - adjusted_read_index;
-            int actual_write = audio_io_device->write((const char*) audio_ibuffer+adjusted_read_index, max_write);
-            audio_ibuffer_read += actual_write;
-
-            // send samples to audio monitor cache
-            if (panel_timeline->ui->audio_monitor->sample_cache_offset == -1) {
-                panel_timeline->ui->audio_monitor->sample_cache_offset = panel_timeline->playhead;
-            }
-            long sample_cache_playhead = panel_timeline->ui->audio_monitor->sample_cache_offset + panel_timeline->ui->audio_monitor->sample_cache.size();
-            int next_buffer_offset, buffer_offset_adjusted, i;
-            int buffer_offset = get_buffer_offset_from_frame(sample_cache_playhead);
-            samples.resize(av_get_channel_layout_nb_channels(sequence->audio_layout));
-            samples.fill(0);
-            while (buffer_offset < audio_ibuffer_read) {
-                sample_cache_playhead++;
-                next_buffer_offset = qMin(get_buffer_offset_from_frame(sample_cache_playhead), audio_ibuffer_read);
-                while (buffer_offset < next_buffer_offset) {
-                    for (i=0;i<samples.size();i++) {
-                        buffer_offset_adjusted = buffer_offset%audio_ibuffer_size;
-                        samples[i] = qMax(qAbs((qint16) (((audio_ibuffer[buffer_offset_adjusted+1] & 0xFF) << 8) | (audio_ibuffer[buffer_offset_adjusted] & 0xFF))), samples[i]);
-                        buffer_offset += 2;
-                    }
-                }
-                for (i=0;i<samples.size();i++) {
-                    panel_timeline->ui->audio_monitor->sample_cache.append(samples.at(i));
-                }
-                buffer_offset = next_buffer_offset;
-            }
-
-            memset(audio_ibuffer+adjusted_read_index, 0, actual_write);
-            if (actual_write == max_write) {
+            if (send_audio_to_output(adjusted_read_index, max_write) == max_write) {
                 // got all the bytes, write again
-                actual_write = audio_io_device->write((const char*) audio_ibuffer, audio_ibuffer_size);
-                memset(audio_ibuffer, 0, actual_write);
-                audio_ibuffer_read += actual_write;
+                send_audio_to_output(0, audio_ibuffer_size);
             }
         }
 
diff --git a/ui/viewerwidget.h b/ui/viewerwidget.h
index 3b4136203..2c29c461e 100644
--- a/ui/viewerwidget.h
+++ b/ui/viewerwidget.h
@@ -8,6 +8,7 @@
 #include <QTimer>
 
 struct Clip;
+struct Sequence;
 
 class Viewer;
 
@@ -28,11 +29,12 @@ protected:
 //    void resizeGL(int w, int h);
 private:
 	QTimer retry_timer;
-    QVector<Clip*> current_clips;
     QVector<qint16> samples;
 private slots:
 	void retry();
     void deleteFunction();
+    void compose_sequence(Sequence* s, bool render_audio);
+    int send_audio_to_output(int offset, int max);
 };
 
 #endif // VIEWERWIDGET_H