Add YCbCr input. Required a bit of reworking of the sRGB extension stuff, but seems...

[movit] / ycbcr_input.h

diff --git a/ycbcr_input.h b/ycbcr_input.h
new file mode 100644 (file)
index 0000000..fd9db27
--- /dev/null
+++ b/ycbcr_input.h
@@ -0,0 +1,95 @@
+#ifndef _YCBCR_INPUT_H
+#define _YCBCR_INPUT_H 1
+
+// YCbCrInput is for handling planar 8-bit Y'CbCr (also sometimes, usually rather
+// imprecisely, called “YUV”), which is typically what you get from a video decoder.
+// It upsamples planes as needed, using the default linear upsampling OpenGL gives you.
+
+#include "input.h"
+
+struct YCbCrFormat {
+       // Which formula for Y' to use.
+       YCbCrLumaCoefficients luma_coefficients;
+
+       // If true, assume Y'CbCr coefficients are full-range, ie. go from 0 to 255
+       // instead of the limited 220/225 steps in classic MPEG. For instance,
+       // JPEG uses the Rec. 601 luma coefficients, but full range.
+       bool full_range;
+
+       // Sampling factors for chroma components. For no subsampling (4:4:4),
+       // set both to 1.
+       unsigned chroma_subsampling_x, chroma_subsampling_y;
+
+       // Positioning of the chroma samples. MPEG-1 and JPEG is (0.5, 0.5);
+       // MPEG-2 and newer typically are (0.0, 0.5).
+       float chroma_x_position, chroma_y_position;
+};
+
+class YCbCrInput : public Input {
+public:
+       YCbCrInput(const ImageFormat &image_format,
+                  const YCbCrFormat &ycbcr_format,
+                  unsigned width, unsigned height);
+
+       // Create the texture itself. We cannot do this in the constructor,
+       // because we don't necessarily know all the settings (sRGB texture,
+       // mipmap generation) at that point.
+       void finalize();
+
+       virtual bool can_output_linear_gamma() const { return false; }
+
+       std::string output_fragment_shader();
+
+       // Uploads the texture if it has changed since last time.
+       void set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num);
+
+       ColorSpace get_color_space() const { return image_format.color_space; }
+       GammaCurve get_gamma_curve() const { return image_format.gamma_curve; }
+
+       // Tells the input where to fetch the actual pixel data. Note that if you change
+       // this data, you must either call set_pixel_data() again (using the same pointer
+       // is fine), or invalidate_pixel_data(). Otherwise, the texture won't be re-uploaded
+       // on subsequent frames.
+       void set_pixel_data(unsigned channel, const unsigned char *pixel_data)
+       {
+               assert(channel >= 0 && channel < 3);
+               this->pixel_data[channel] = pixel_data;
+               invalidate_pixel_data();
+       }
+
+       void invalidate_pixel_data()
+       {
+               needs_update = true;
+       }
+
+       const unsigned char *get_pixel_data(unsigned channel) const
+       {
+               assert(channel >= 0 && channel < 3);
+               return pixel_data[channel];
+       }
+
+       void set_pitch(unsigned channel, unsigned pitch) {
+               assert(!finalized);
+               assert(channel >= 0 && channel < 3);
+               this->pitch[channel] = pitch;
+       }
+
+       unsigned get_pitch(unsigned channel) {
+               assert(channel >= 0 && channel < 3);
+               return pitch[channel];
+       }
+
+private:
+       ImageFormat image_format;
+       YCbCrFormat ycbcr_format;
+       GLuint pbos[3], texture_num[3];
+       bool needs_update, finalized;
+
+       int needs_mipmaps;
+
+       unsigned width, height, widths[3], heights[3];
+       const unsigned char *pixel_data[3];
+       unsigned pitch[3];
+};
+
+#endif // !defined(_YCBCR_INPUT_H)