with Block::set_length_and_* functions, keep the speeds correct

With differently set speeds, these functions would mess with the timing in ways
that would be confusing to the user. Now they act in a much more intuitive way
and also prevent negative media times.

app/dialog/speedduration/speedduration.h

@@ -6,6 +6,7 @@
 #include <QUndoCommand>
 
 #include "node/block/clip/clip.h"
+#include "node/output/track/track.h"
 #include "widget/slider/floatslider.h"
 #include "widget/slider/timeslider.h"
 

app/node/block/block.cpp

@@ -97,7 +97,14 @@ void Block::set_length_and_media_out(const rational &length)
     return;
   }
 
-  set_media_out(media_out() + (length - this->length()));
+  rational media_out_diff = length - this->length();
+
+  // Try to maintain the same speed (which is determined by the media in to out points)
+  if (media_length() != this->length()) {
+    media_out_diff  = media_out_diff / this->length() * media_length();
+  }
+
+  set_media_out(media_out() + media_out_diff);
 
   set_length(length);
 }
@@ -110,8 +117,15 @@ void Block::set_length_and_media_in(const rational &length)
     return;
   }
 
+  rational media_in_diff = this->length() - length;
+
+  // Try to maintain the same speed (which is determined by the media in to out points)
+  if (media_length() != this->length()) {
+    media_in_diff  = media_in_diff / this->length() * media_length();
+  }
+
   // Calculate media_in adjustment
-  set_media_in(media_in() + (this->length() - length));
+  set_media_in(media_in() + media_in_diff);
 
   // Set the length without setting media out
   set_length(length);

app/render/backend/audiorenderworker.cpp

@@ -54,19 +54,15 @@ NodeValueTable AudioRenderWorker::RenderBlock(const TrackOutput *track, const Ti
       // Stretch samples here
       if (b->media_length() != b->length()) {
         QByteArray speed_adjusted_samples;
-        double clip_speed = b->speed();
-        int sample_count = audio_params_.bytes_to_samples(samples_from_this_block.size());
 
-        qDebug() << "Adjusting audio to speed" << clip_speed;
+        double clip_speed = b->speed();
+
+        int sample_count = audio_params_.bytes_to_samples(samples_from_this_block.size());
 
         for (double i=0;i<sample_count;i+=clip_speed) {
           int sample_index = qFloor(i);
           int byte_index = audio_params_.samples_to_bytes(sample_index);
 
-          if (byte_index >= samples_from_this_block.size() || (byte_index + audio_params_.samples_to_bytes(1)) > samples_from_this_block.size()) {
-            qDebug() << "Tried to access" << byte_index << "-" << (byte_index + audio_params_.samples_to_bytes(1)) << "of" << samples_from_this_block.size();
-          }
-
           QByteArray sample_at_this_index = samples_from_this_block.mid(byte_index, audio_params_.samples_to_bytes(1));
           speed_adjusted_samples.append(sample_at_this_index);
         }