【发布时间】：2019-03-12 02:13:37
【问题描述】：
我知道通常需要一个最小的完整且可验证的示例，但这个示例不能分解为一个较小的示例，因为从我的安全摄像头获取和解码视频所需的库太多。我希望有人可以通过指出使用 QQuickFrameBufferObject 进行渲染时可能出现的简单错误来帮助我。
我遇到的两个问题是图像是红色的，一个物体的图像以一种非常莫名其妙的方式侵入了另一个物体的空间。在上图中，您可以看到什么应该是通过 QML 实例化的 4 个不同的相机源。
这是渲染所有内容的类。 YUV420P 数据使用update() 函数提供。您可以看到将 YUV420P 解码为 RGB 的简单着色器。每个 QML 对象（相机流）都是此类的一个实例。
#include "OpenGlBufferQtQuick.h"
#include <QOpenGLFramebufferObjectFormat>
#include <QRunnable>
#include <QEventLoop>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QMutexLocker>
#include <memory>
#include <iostream>
#include <QTimer>
#define GET_STR(x) #x
#define A_VER 3
#define T_VER 4
static const GLfloat ver[] = {
-1.0f,-1.0f,
1.0f,-1.0f,
-1.0f, 1.0f,
1.0f, 1.0f
};
static const GLfloat tex[] = {
0.0f, 1.0f,
1.0f, 1.0f,
0.0f, 0.0f,
1.0f, 0.0f
};
//Simple shader. Outpus the same location as input, I guess
const char *vString3 = GET_STR(
attribute vec4 vertexIn;
attribute vec2 textureIn;
varying vec2 textureOut;
uniform mat4 u_transform;
void main(void)
{
gl_Position = u_transform * vertexIn;
textureOut = textureIn;
}
);
//The matrix below does YUV420P to RGB conversion https://en.wikipedia.org/wiki/YUV#Y%E2%80%B2UV420p_(and_Y%E2%80%B2V12_or_YV12)_to_RGB888_conversion
//This texture shader replaces the color of the pixel with the new color, but in RGB. (I guess)
const char *tString3 = GET_STR(
varying vec2 textureOut;
uniform sampler2D tex_y;
uniform sampler2D tex_u;
uniform sampler2D tex_v;
void main(void)
{
vec3 yuv;
vec3 rgb;
yuv.x = texture2D(tex_y, textureOut).r;
yuv.y = texture2D(tex_u, textureOut).r - 0.5;
yuv.z = texture2D(tex_v, textureOut).r - 0.5;
rgb = mat3(1.0, 1.0, 1.0,
0.0, -0.39465, 2.03211,
1.13983, -0.58060, 0.0) * yuv;
gl_FragColor = vec4(rgb, 1.0);
}
);
OpenGlBufferItemRenderer::OpenGlBufferItemRenderer(string uri){
this->uri = uri;
}
void OpenGlBufferItemRenderer::render() {
QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
if (firstFrameReceived) {
if (this->firstRender) {
std::cout << "Creating QOpenGLShaderProgram " << std::endl;
program = new QOpenGLShaderProgram();
f->initializeOpenGLFunctions();
//this->m_F = QOpenGLContext::currentContext()->functions();
std::cout << "frameWidth: " << frameWidth << + " frameHeight: " << frameHeight << std::endl;
std::cout << "Fragment Shader compilation: " << program->addShaderFromSourceCode(QOpenGLShader::Fragment, tString3) << std::endl;
std::cout << "Vertex Shader compilation: " << program->addShaderFromSourceCode(QOpenGLShader::Vertex, vString3) << std::endl;
program->bindAttributeLocation("vertexIn",A_VER);
program->bindAttributeLocation("textureIn",T_VER);
std::cout << "program->link() = " << program->link() << std::endl;
f->glGenTextures(3, texs);//TODO: ERASE THIS WITH glDeleteTextures
this->firstRender = false;
}
// Not strictly needed for this example, but generally useful for when
// mixing with raw OpenGL.
//m_window->resetOpenGLState();//COMMENT OR NOT?
program->bind();
QMatrix4x4 transform;
transform.setToIdentity();
program->setUniformValue("u_transform", transform);
f->glVertexAttribPointer(A_VER, 2, GL_FLOAT, 0, 0, ver);
f->glEnableVertexAttribArray(A_VER);
f->glVertexAttribPointer(T_VER, 2, GL_FLOAT, 0, 0, tex);
f->glEnableVertexAttribArray(T_VER);
unis[0] = program->uniformLocation("tex_y");
unis[1] = program->uniformLocation("tex_u");
unis[2] = program->uniformLocation("tex_v");
//Y
f->glBindTexture(GL_TEXTURE_2D, texs[0]);
f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, frameWidth, frameHeight, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//U
f->glBindTexture(GL_TEXTURE_2D, texs[1]);
f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, frameWidth/2, frameHeight / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//V
f->glBindTexture(GL_TEXTURE_2D, texs[2]);
f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, frameWidth / 2, frameHeight / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
f->glActiveTexture(GL_TEXTURE0);
f->glBindTexture(GL_TEXTURE_2D, texs[0]);
f->glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, frameWidth, frameHeight, GL_RED, GL_UNSIGNED_BYTE, datas[0]);
f->glUniform1i(unis[0], 0);
f->glActiveTexture(GL_TEXTURE0+1);
f->glBindTexture(GL_TEXTURE_2D, texs[1]);
f->glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, frameWidth/2, frameHeight / 2, GL_RED, GL_UNSIGNED_BYTE, datas[1]);
f->glUniform1i(unis[1],1);
f->glActiveTexture(GL_TEXTURE0+2);
f->glBindTexture(GL_TEXTURE_2D, texs[2]);
f->glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, frameWidth / 2, frameHeight / 2, GL_RED, GL_UNSIGNED_BYTE, datas[2]);
f->glUniform1i(unis[2], 2);
f->glDrawArrays(GL_TRIANGLE_STRIP,0,4);
program->disableAttributeArray(A_VER);
program->disableAttributeArray(T_VER);
program->release();
}
update();
}
QOpenGLFramebufferObject *OpenGlBufferItemRenderer::createFramebufferObject(const QSize &size)
{
QOpenGLFramebufferObjectFormat format;
format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
//format.setSamples(16);
return new QOpenGLFramebufferObject(size, format);
}
//https://blog.qt.io/blog/2015/05/11/integrating-custom-opengl-rendering-with-qt-quick-via-qquickframebufferobject/
void OpenGlBufferItemRenderer::synchronize(QQuickFramebufferObject *item)
{
OpenGlBufferItem *openGlBufferItem = static_cast<OpenGlBufferItem*>(item);
std::cout << "synchronize called " << std::endl;
std::cout << "starting new renderer for uri " << this-> uri << std::endl;
MediaStream* camera1 = new MediaStream(this->uri);
camera1->setFrameUpdater((FrameUpdater *) this);
//TODO: put mutex on std::cout of this thread
//TODO: make this thread actualy run here instead of on a thread, I guess.
boost::thread mediaThread(&MediaStream::run, camera1);
}
OpenGlBufferItem::OpenGlBufferItem(){}
void OpenGlBufferItemRenderer::updateData(unsigned char**data, int frameWidth, int frameHeight)
{
this->frameWidth = frameWidth;
this->frameHeight = frameHeight;
//Before first render, datas pointer isn't even created yet
if (!firstFrameReceived) {
datas[0] = new unsigned char[frameWidth*frameHeight]; //Y
datas[1] = new unsigned char[frameWidth*frameHeight/4]; //U
datas[2] = new unsigned char[frameWidth*frameHeight/4]; //V
firstFrameReceived = true;
} else {
memcpy(datas[0], data[0], frameWidth*frameHeight);
memcpy(datas[1], data[1], frameWidth*frameHeight/4);
memcpy(datas[2], data[2], frameWidth*frameHeight/4);
}
}
QQuickFramebufferObject::Renderer *OpenGlBufferItem::createRenderer() const
{
//std::cout << "createRenderer called ------------------------" << std::endl;
return new OpenGlBufferItemRenderer(this->uri);
}
这里是main.qml：
import QtQuick 2.0
import OpenGlBufferQtQuick 1.0
Grid {
columns: 2
spacing: 2
width: 1280
height: 720
OpenGlBufferQtQuick {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.0.103:10554/tcp/av0_0"
}
OpenGlBufferQtQuick {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.0.101:10554/tcp/av0_0"
}
OpenGlBufferQtQuick {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.0.104:10554/tcp/av0_0"
}
OpenGlBufferQtQuick {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.1.43:10554/tcp/av0_0"
}
}
如您所见，我调用了 4 个不同的摄像头流，但来自第一个摄像头的流会侵入其他流的空间，即使每个流都是完全不同的对象。
另外，图像是红色的。我使用几乎相同的代码使用 OpenGlVideoQtQuickRenderer : public QObject, protected QOpenGLFunctions 类进行渲染，并且它可以在没有任何红屏或 opengl 侵入其他空间的情况下工作。
【问题讨论】：