Fix a bug where intermediate phase outputs could get too low height.

[movit] / effect_chain.cpp

diff --git a/effect_chain.cpp b/effect_chain.cpp
index a8c2e52c564679872ad92d31c48f391a45e699be..f6266d741e63c0308ea841952a6ec23816f30406 100644 (file)
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -571,16 +571,30 @@ void EffectChain::output_dot_edge(FILE *fp,
        }
 }
 
-unsigned EffectChain::fit_rectangle_to_aspect(unsigned width, unsigned height)
+void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
 {
+       unsigned scaled_width, scaled_height;
+
        if (float(width) * aspect_denom >= float(height) * aspect_nom) {
                // Same aspect, or W/H > aspect (image is wider than the frame).
-               // In either case, keep width.
-               return width;
+               // In either case, keep width, and adjust height.
+               scaled_width = width;
+               scaled_height = lrintf(width * aspect_denom / aspect_nom);
        } else {
                // W/H < aspect (image is taller than the frame), so keep height,
-               // and adjust width correspondingly.
-               return lrintf(height * aspect_nom / aspect_denom);
+               // and adjust width.
+               scaled_width = lrintf(height * aspect_nom / aspect_denom);
+               scaled_height = height;
+       }
+
+       // We should be consistently larger or smaller then the existing choice,
+       // since we have the same aspect.
+       assert(!(scaled_width < *output_width && scaled_height > *output_height));
+       assert(!(scaled_height < *output_height && scaled_width > *output_width));
+
+       if (scaled_width >= *output_width && scaled_height >= *output_height) {
+               *output_width = scaled_width;
+               *output_height = scaled_height;
        }
 }
 
@@ -652,17 +666,15 @@ void EffectChain::find_output_size(Phase *phase)
                return;
        }
 
+       unsigned output_width = 0, output_height = 0;
+
        // If not, look at the input phases and textures.
        // We select the largest one (by fit into the current aspect).
-       unsigned best_width = 0;
        for (unsigned i = 0; i < phase->inputs.size(); ++i) {
                Node *input = phase->inputs[i];
                assert(input->phase->output_width != 0);
                assert(input->phase->output_height != 0);
-               unsigned width = fit_rectangle_to_aspect(input->phase->output_width, input->phase->output_height);
-               if (width > best_width) {
-                       best_width = width;
-               }
+               size_rectangle_to_fit(input->phase->output_width, input->phase->output_height, &output_width, &output_height);
        }
        for (unsigned i = 0; i < phase->effects.size(); ++i) {
                Effect *effect = phase->effects[i]->effect;
@@ -671,14 +683,12 @@ void EffectChain::find_output_size(Phase *phase)
                }
 
                Input *input = static_cast<Input *>(effect);
-               unsigned width = fit_rectangle_to_aspect(input->get_width(), input->get_height());
-               if (width > best_width) {
-                       best_width = width;
-               }
+               size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
        }
-       assert(best_width != 0);
-       phase->output_width = best_width;
-       phase->output_height = best_width * aspect_denom / aspect_nom;
+       assert(output_width != 0);
+       assert(output_height != 0);
+       phase->output_width = output_width;
+       phase->output_height = output_height;
 }
 
 void EffectChain::sort_all_nodes_topologically()