fix more instances where sample counts used int instead of size_t

app/node/block/transition/crossdissolve/crossdissolvetransition.cpp

@@ -70,9 +70,9 @@ void CrossDissolveTransition::SampleJobEvent(const SampleBuffer &from_samples, c
 
       if (to_samples.is_allocated()) {
         // Offset input samples from the end
-        int in_index = i - (out_samples.sample_count() - to_samples.sample_count());
-
-        if (in_index >= 0) {
+        size_t remain = (out_samples.sample_count() - to_samples.sample_count());
+        if (i >= remain) {
+          qint64 in_index = i - remain;
           out_samples.data(j)[i] += to_samples.data(j)[in_index] * TransformCurve(progress);
         }
       }

app/render/renderprocessor.cpp

@@ -558,7 +558,7 @@ void RenderProcessor::ProcessSamples(SampleBuffer &destination, const Node *node
 
   const AudioParams& audio_params = GetCacheAudioParams();
 
-  for (int i=0;i<job.samples().sample_count();i++) {
+  for (size_t i=0;i<job.samples().sample_count();i++) {
     // Calculate the exact rational time at this sample
     double sample_to_second = static_cast<double>(i) / static_cast<double>(audio_params.sample_rate());