Move chroma subsampling into its own class.

[nageru] / chroma_subsampler.h

diff --git a/chroma_subsampler.h b/chroma_subsampler.h
new file mode 100644 (file)
index 0000000..ea2b781
--- /dev/null
+++ b/chroma_subsampler.h
@@ -0,0 +1,31 @@
+#ifndef _CHROMA_SUBSAMPLER_H
+#define _CHROMA_SUBSAMPLER_H 1
+
+#include <epoxy/gl.h>
+
+namespace movit {
+
+class ResourcePool;
+
+}  // namespace movit
+
+class ChromaSubsampler {
+public:
+       ChromaSubsampler(movit::ResourcePool *resource_pool);
+       ~ChromaSubsampler();
+
+       // Subsamples chroma (packed Cb and Cr) 2x2 to yield chroma suitable for
+       // NV12 (semiplanar 4:2:0). Chroma positioning is left/center (H.264 convention).
+       // width and height are the dimensions (in pixels) of the input texture.
+       void subsample_chroma(GLuint cbcr_tex, unsigned width, unsigned height, GLuint dst_tex);
+
+private:
+       movit::ResourcePool *resource_pool;
+
+       GLuint cbcr_program_num;  // Owned by <resource_pool>.
+       GLuint cbcr_texture_sampler_uniform;
+       GLuint cbcr_vbo;  // Holds position and texcoord data.
+       GLuint cbcr_position_attribute_index, cbcr_texcoord_attribute_index;
+};
+
+#endif  // !defined(_CHROMA_SUBSAMPLER_H)