Add support for Y'CbCr output.

[movit] / effect_chain.cpp

diff --git a/effect_chain.cpp b/effect_chain.cpp
index 519cb2c6b9ea1c5816ead123b05260904519f96e..e1ae832e934a0deedb482b152e4a452f99f47b17 100644 (file)
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -25,6 +25,7 @@
 #include "input.h"
 #include "resource_pool.h"
 #include "util.h"
+#include "ycbcr_conversion_effect.h"
 
 using namespace std;
 
@@ -74,6 +75,20 @@ void EffectChain::add_output(const ImageFormat &format, OutputAlphaFormat alpha_
        assert(!finalized);
        output_format = format;
        output_alpha_format = alpha_format;
+       output_color_type = OUTPUT_COLOR_RGB;
+}
+
+void EffectChain::add_ycbcr_output(const ImageFormat &format, OutputAlphaFormat alpha_format,
+                                   const YCbCrFormat &ycbcr_format)
+{
+       assert(!finalized);
+       output_format = format;
+       output_alpha_format = alpha_format;
+       output_color_type = OUTPUT_COLOR_YCBCR;
+       output_ycbcr_format = ycbcr_format;
+
+       assert(ycbcr_format.chroma_subsampling_x == 1);
+       assert(ycbcr_format.chroma_subsampling_y == 1);
 }
 
 Node *EffectChain::add_node(Effect *effect)
@@ -1363,6 +1378,22 @@ void EffectChain::fix_output_gamma()
                connect_nodes(output, conversion);
        }
 }
+
+// If the user has requested Y'CbCr output, we need to do this conversion
+// _after_ GammaCompressionEffect etc., but before dither (see below).
+// This is because Y'CbCr, with the exception of a special optional mode
+// in Rec. 2020 (which we currently don't support), is defined to work on
+// gamma-encoded data.
+void EffectChain::add_ycbcr_conversion_if_needed()
+{
+       assert(output_color_type == OUTPUT_COLOR_RGB || output_color_type == OUTPUT_COLOR_YCBCR);
+       if (output_color_type != OUTPUT_COLOR_YCBCR) {
+               return;
+       }
+       Node *output = find_output_node();
+       Node *ycbcr = add_node(new YCbCrConversionEffect(output_ycbcr_format));
+       connect_nodes(output, ycbcr);
+}
        
 // If the user has requested dither, add a DitherEffect right at the end
 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
@@ -1445,11 +1476,13 @@ void EffectChain::finalize()
        fix_internal_gamma_by_asking_inputs(15);
        fix_internal_gamma_by_inserting_nodes(16);
 
-       output_dot("step17-before-dither.dot");
+       output_dot("step17-before-ycbcr.dot");
+       add_ycbcr_conversion_if_needed();
 
+       output_dot("step18-before-dither.dot");
        add_dither_if_needed();
 
-       output_dot("step18-final.dot");
+       output_dot("step19-final.dot");
        
        // Construct all needed GLSL programs, starting at the output.
        // We need to keep track of which effects have already been computed,
@@ -1458,7 +1491,7 @@ void EffectChain::finalize()
        map<Node *, Phase *> completed_effects;
        construct_phase(find_output_node(), &completed_effects);
 
-       output_dot("step19-split-to-phases.dot");
+       output_dot("step20-split-to-phases.dot");
 
        assert(phases[0]->inputs.empty());