c++ - What's the proper way to bind a QImage to a texture to display video in QOpenGLWidget -

i'm trying implement efficient video player, started qt's textures example.

i have:

void hud::initializegl() {     initializeopenglfunctions();      makeobject();      glenable(gl_depth_test);     glenable(gl_cull_face);  #define program_vertex_attribute 0 #define program_texcoord_attribute 1      qopenglshader *vshader = new qopenglshader(qopenglshader::vertex, this);     const char *vsrc =         "attribute highp vec4 vertex;\n"         "attribute mediump vec4 texcoord;\n"         "varying mediump vec4 texc;\n"         "uniform mediump mat4 matrix;\n"         "void main(void)\n"         "{\n"         "    gl_position = matrix * vertex;\n"         "    texc = texcoord;\n"         "}\n";     vshader->compilesourcecode(vsrc);      qopenglshader *fshader = new qopenglshader(qopenglshader::fragment, this);     const char *fsrc =         "uniform sampler2d texture;\n"         "varying mediump vec4 texc;\n"         "void main(void)\n"         "{\n"         "    gl_fragcolor = texture2d(texture, texc.st);\n"         "}\n";     fshader->compilesourcecode(fsrc);      program = new qopenglshaderprogram;     program->addshader(vshader);     program->addshader(fshader);     program->bindattributelocation("vertex", program_vertex_attribute);     program->bindattributelocation("texcoord", program_texcoord_attribute);     program->link();      program->bind();     program->setuniformvalue("texture", 0); }  void hud::paintgl() {     clock_t begin = clock();     glclearcolor(clearcolor.redf(), clearcolor.greenf(), clearcolor.bluef(), clearcolor.alphaf());     glclear(gl_color_buffer_bit | gl_depth_buffer_bit);     static int ctt = 0;     qmatrix4x4 m;     m.ortho(-0.2f, +0.2f, +0.2f, -0.2f, 4.0f, 15.0f);     m.translate(0.0f, 0.0f, -5.0f);      program->setuniformvalue("matrix", m);     program->enableattributearray(program_vertex_attribute);     program->enableattributearray(program_texcoord_attribute);     program->setattributebuffer(program_vertex_attribute, gl_float, 0, 3, 5 * sizeof(glfloat));     program->setattributebuffer(program_texcoord_attribute, gl_float, 3 * sizeof(glfloat), 2, 5 * sizeof(glfloat));      //???//     //how bind qimage texture efficiently???     //???//     textures->bind();// textures qopengltexture     gldrawarrays(gl_triangle_fan, 0 * 4, 4);     clock_t end = clock();     double elapsed_secs = double(end - begin) / clocks_per_sec;     qdebug() << elapsed_secs;  } 

the example used qopengltexture read 1 single qimage , bind quad painted paintgl() function.

however, how update content of texture display video @ 30 hz?

you should take @ qt video widget example basic video player. can stream video qgraphicsvideoitem can display in qgraphicsview, can contain other graphics items , can render opengl content if provide qopenglwidget viewport.
if want roll own might want use qt video functionalities , implement class based on qabstractvideosurface receive video frames media player. take @ handletype() of qvideoframe. if qabstractvideobuffer::gltexturehandle or qabstractvideobuffer::eglimagehandle might able draw screen using quad shader handle() texture id. if not write data qopengltexture. can upload textures in thread prevent blocking gui thread.