Render AVPicture in QGLWidget

ichdyan

Hi,

i want to learn how create video player using ffmpeg. after successfully render AVPicture using QPainter + QImage, then i decide to try opengl. but i don't know anything about opengl. using Qt opengl example as reference and google, i come up with this code.
@#include "videoglrenderer.h"

#include <QGLShaderProgram>
#include <QGLShader>

#include "picture.h"

static const GLfloat vertices[] = {
-1.0f, 1.0f,
1.0f, 1.0f,
1.0f, -1.0f,
-1.0f, -1.0f
};

static const GLfloat texCoordsVertices[] = {
0.0f, 0.0f,
1.0f, 0.0f,
1.0f, 1.0f,
0.0f, 1.0f,
};

VideoGLRenderer::VideoGLRenderer(QWidget *parent)
: QGLWidget(parent)
{
}

QSize VideoGLRenderer::size()
{
return QGLWidget::size();
}

void VideoGLRenderer::initializeGL()
{
glEnable(GL_TEXTURE_2D);
glDisable(GL_BLEND);

#define PROGRAM_POSITION_ATTRIBUTE 0
#define PROGRAM_TEXCOORD_ATTRIBUTE 1

QGLShader *vshader = new QGLShader(QGLShader::Vertex, this);
const char *vsrc =
        "attribute vec4 position;\n"
        "attribute vec2 texCoord;\n"
        "varying vec2 v_texCoord;\n"

        "void main()\n"
        "{\n"
            "gl_Position = position;\n"
            "v_texCoord = texCoord;\n"
        "}\n";
vshader->compileSourceCode(vsrc);

QGLShader *fshader = new QGLShader(QGLShader::Fragment, this);
const char *fsrc =
        "varying highp vec2 v_texCoord;\n"
        "uniform sampler2D texture;\n"

        "void main()\n"
        "{\n"
            "gl_FragColor = texture2D(texture, v_texCoord);\n"
        "}\n";
fshader->compileSourceCode(fsrc);

mProgram = new QGLShaderProgram(this);
mProgram->addShader(vshader);
mProgram->addShader(fshader);
mProgram->bindAttributeLocation("position", PROGRAM_POSITION_ATTRIBUTE);
mProgram->bindAttributeLocation("texCoord", PROGRAM_TEXCOORD_ATTRIBUTE);
mProgram->link();

mProgram->bind();

glGenTextures(1, &mTexture);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mTexture);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width(), height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);

mProgram->setUniformValue("texture", 0);

}

void VideoGLRenderer::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

mProgram->enableAttributeArray(PROGRAM_POSITION_ATTRIBUTE);
mProgram->enableAttributeArray(PROGRAM_TEXCOORD_ATTRIBUTE);
mProgram->setAttributeArray(PROGRAM_POSITION_ATTRIBUTE, vertices, 2);
mProgram->setAttributeArray(PROGRAM_TEXCOORD_ATTRIBUTE, texCoordsVertices, 2);

glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

}

void VideoGLRenderer::resizeGL(int width, int height)
{
glViewport(0, 0, width, height);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
}

void VideoGLRenderer::setFrame(Picture *frame)
{
if (!frame)
return;

glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mTexture);
for (int y = 0; y &lt; frame-&gt;height; y++)
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, y, frame->width, 1, GL_RGB, GL_UNSIGNED_BYTE, frame->picture.data[0] + (y * frame->picture.linesize[0]));

}
@
it doesn't render anything yet, i know there must be something that not right. so maybe someone can help me. can someone give me a little explanation about why it doesn't render anything....?
FYI frame that will be rendered already in AV_PIX_FMT_RGB24 format.