Support different chroma positioning for Cb and Cr. The test is slightly shaky, so...
[movit] / ycbcr_input.h
1 #ifndef _YCBCR_INPUT_H
2 #define _YCBCR_INPUT_H 1
3
4 // YCbCrInput is for handling planar 8-bit Y'CbCr (also sometimes, usually rather
5 // imprecisely, called “YUV”), which is typically what you get from a video decoder.
6 // It upsamples planes as needed, using the default linear upsampling OpenGL gives you.
7
8 #include "input.h"
9
10 struct YCbCrFormat {
11         // Which formula for Y' to use.
12         YCbCrLumaCoefficients luma_coefficients;
13
14         // If true, assume Y'CbCr coefficients are full-range, ie. go from 0 to 255
15         // instead of the limited 220/225 steps in classic MPEG. For instance,
16         // JPEG uses the Rec. 601 luma coefficients, but full range.
17         bool full_range;
18
19         // Sampling factors for chroma components. For no subsampling (4:4:4),
20         // set both to 1.
21         unsigned chroma_subsampling_x, chroma_subsampling_y;
22
23         // Positioning of the chroma samples. MPEG-1 and JPEG is (0.5, 0.5);
24         // MPEG-2 and newer typically are (0.0, 0.5).
25         float cb_x_position, cb_y_position;
26         float cr_x_position, cr_y_position;
27 };
28
29 class YCbCrInput : public Input {
30 public:
31         YCbCrInput(const ImageFormat &image_format,
32                    const YCbCrFormat &ycbcr_format,
33                    unsigned width, unsigned height);
34         ~YCbCrInput();
35
36         virtual std::string effect_type_id() const { return "YCbCrInput"; }
37
38         // Create the texture itself. We cannot do this in the constructor,
39         // because we don't necessarily know all the settings (sRGB texture,
40         // mipmap generation) at that point.
41         void finalize();
42
43         virtual bool can_output_linear_gamma() const { return false; }
44
45         std::string output_fragment_shader();
46
47         // Uploads the texture if it has changed since last time.
48         void set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num);
49
50         unsigned get_width() const { return width; }
51         unsigned get_height() const { return height; }
52         Colorspace get_color_space() const { return image_format.color_space; }
53         GammaCurve get_gamma_curve() const { return image_format.gamma_curve; }
54
55         // Tells the input where to fetch the actual pixel data. Note that if you change
56         // this data, you must either call set_pixel_data() again (using the same pointer
57         // is fine), or invalidate_pixel_data(). Otherwise, the texture won't be re-uploaded
58         // on subsequent frames.
59         void set_pixel_data(unsigned channel, const unsigned char *pixel_data)
60         {
61                 assert(channel >= 0 && channel < 3);
62                 this->pixel_data[channel] = pixel_data;
63                 invalidate_pixel_data();
64         }
65
66         void invalidate_pixel_data()
67         {
68                 needs_update = true;
69         }
70
71         void set_pitch(unsigned channel, unsigned pitch) {
72                 assert(channel >= 0 && channel < 3);
73                 if (this->pitch[channel] != pitch) {
74                         this->pitch[channel] = pitch;
75                         needs_pbo_recreate = true;
76                 }
77         }
78
79 private:
80         ImageFormat image_format;
81         YCbCrFormat ycbcr_format;
82         GLuint pbos[3], texture_num[3];
83         bool needs_update, needs_pbo_recreate, finalized;
84
85         int needs_mipmaps;
86
87         unsigned width, height, widths[3], heights[3];
88         const unsigned char *pixel_data[3];
89         unsigned pitch[3];
90 };
91
92 #endif // !defined(_YCBCR_INPUT_H)