modules/video_output/opengl/interop.h

   1 /*****************************************************************************
   2  * interop.h
   3  *****************************************************************************
   4  * Copyright (C) 2019 Videolabs
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifndef VLC_GL_INTEROP_H
  22 #define VLC_GL_INTEROP_H
  23
  24 #include <vlc_common.h>
  25 #include <vlc_opengl.h>
  26 #include <vlc_picture.h>
  27 #include <vlc_picture_pool.h>
  28
  29 #include "gl_common.h"
  30
  31 struct vlc_gl_interop;
  32
  33 struct vlc_gl_interop_ops {
  34     /**
  35      * Callback to allocate data for bound textures
  36      *
  37      * This function pointer can be NULL. Software converters should call
  38      * glTexImage2D() to allocate textures data (it will be deallocated by the
  39      * caller when calling glDeleteTextures()). Won't be called if
  40      * handle_texs_gen is true.
  41      *
  42      * \param interop the OpenGL interop
  43      * \param textures array of textures to bind (one per plane)
  44      * \param tex_width array of tex width (one per plane)
  45      * \param tex_height array of tex height (one per plane)
  46      * \return VLC_SUCCESS or a VLC error
  47      */
  48     int
  49     (*allocate_textures)(const struct vlc_gl_interop *interoporter,
  50                          GLuint textures[], const GLsizei tex_width[],
  51                          const GLsizei tex_height[]);
  52
  53     /**
  54      * Callback to update a picture
  55      *
  56      * This function pointer cannot be NULL. The implementation should upload
  57      * every planes of the picture.
  58      *
  59      * \param interop the OpenGL interop
  60      * \param textures array of textures to bind (one per plane)
  61      * \param tex_width array of tex width (one per plane)
  62      * \param tex_height array of tex height (one per plane)
  63      * \param pic picture to update
  64      * \param plane_offset offsets of each picture planes to read data from
  65      * (one per plane, can be NULL)
  66      * \return VLC_SUCCESS or a VLC error
  67      */
  68     int
  69     (*update_textures)(const struct vlc_gl_interop *interoporter,
  70                        GLuint textures[], const GLsizei tex_width[],
  71                        const GLsizei tex_height[], picture_t *pic,
  72                        const size_t plane_offsets[]);
  73
  74     /**
  75      * Callback to retrieve the transform matrix to apply to texture coordinates
  76      *
  77      * This function pointer can be NULL. If it is set, it may return NULL.
  78      *
  79      * Otherwise, it must return a 4x4 matrix, as an array of 16 floats in
  80      * column-major order.
  81      *
  82      * This transform matrix maps 2D homogeneous texture coordinates of the
  83      * form (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the
  84      * texture coordinate that should be used to sample that location from the
  85      * texture.
  86      *
  87      * The returned pointer is owned by the converter module, and must not be
  88      * freed before the module is closed.
  89      *
  90      * \param interop the OpenGL interop
  91      * \return a 4x4 transformatoin matrix (possibly NULL)
  92      */
  93     const float *
  94     (*get_transform_matrix)(const struct vlc_gl_interop *interoporter);
  95 };
  96
  97 struct vlc_gl_interop {
  98     vlc_gl_t *gl;
  99     const opengl_vtable_t *vt;
 100     GLenum tex_target;
 101
 102     /* True if the current API is OpenGL ES, set by the caller */
 103     bool is_gles;
 104
 105     /* Available gl extensions (from GL_EXTENSIONS) */
 106     const char *glexts;
 107
 108     /* Can only be changed from the module open function */
 109     video_format_t fmt;
 110
 111     /* Software format (useful if fmt only exposes opaque chroma) */
 112     video_format_t sw_fmt;
 113
 114     /* Pointer to decoder video context, set by the caller (can be NULL) */
 115     vlc_video_context *vctx;
 116
 117     /* Set to true if textures are generated from pf_update() */
 118     bool handle_texs_gen;
 119
 120     /* Initialized by the interop */
 121     struct vlc_gl_tex_cfg {
 122         /*
 123          * Texture scale factor, cannot be 0.
 124          * In 4:2:0, 1/1 for the Y texture and 1/2 for the UV texture(s)
 125          */
 126         vlc_rational_t w;
 127         vlc_rational_t h;
 128
 129         GLint internal;
 130         GLenum format;
 131         GLenum type;
 132     } texs[PICTURE_PLANE_MAX];
 133     unsigned tex_count;
 134
 135     void *priv;
 136     const struct vlc_gl_interop_ops *ops;
 137
 138     /* Set by the caller to opengl_interop_init_impl().
 139      * This avoids each module to link against opengl_interop_init_impl()
 140      * directly. */
 141     int
 142     (*init)(struct vlc_gl_interop *interop, GLenum tex_target,
 143             vlc_fourcc_t chroma, video_color_space_t yuv_space);
 144 };
 145
 146 static inline int
 147 opengl_interop_init(struct vlc_gl_interop *interop, GLenum tex_target,
 148                      vlc_fourcc_t chroma, video_color_space_t yuv_space)
 149 {
 150     return interop->init(interop, tex_target, chroma, yuv_space);
 151 }
 152
 153 #endif