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opengl渲染yuv图像
作者:史正
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简述
直接渲染Jpeg等编码后的图像(这里使用的是Jpeg图片)是特别慢的(当张图片>40ms), 常用的做法是直接渲染yuv或者rgb的图像。
这里使用的是使用opengl渲染yuv的图像, 当然也可以通过Qt的绘图库来渲染。不过opengl默认的渲染步骤是在gpu上执行的, 而Qt的绘图库是利于cpu进行计算,gpu进行渲染, 占用cpu的资源比较多。
使用opengl渲染yuv图像的时间单帧图像为(0-2]ms
渲染完成后使主线程等待40-渲染时间, 就会呈现出视频的效果。
这一节的完整代码:
这里给出几个ffmpeg将视频分解为jpeg然后再转换为yuv的命令(由于没有找到视频直接分解为yuv图片帧的办法)
ffmpeg -i Suger.mp4 -b 3000k -ss 00:00:10 -t 10 SugerFrames/Frame_%04d.jpeg
ffmpeg -y -s 1920x1080 -i SugerFrames/yuv_0001.jpeg SugerYuvs/yuv_0001.yuv
由于没有找到直接将多张jpeg图片直接转换为多张yuv图像的方法, 这里写了一个shell脚本来处理
for((i=1;i<=480;i++))
do
index=`printf "%04d" $i`
ffmpeg -y -s 1920x1080 -i SugerFrames/yuv_$index.jpeg SugerYuvs/yuv_$index.yuv
done
ffmpeg 查看yuv图像或视频的方法
ffplay.exe -video_size 1920x1080 yuv_0001.yuv
使用QOpenGLWidget进行yuv图片渲染
除了可以选择使用QPainter和标准的OpenGL渲染图形,QOpenGLWidget类提供了在Qt应用程序中显示OpenGL图形的功能。
关于QOpenGLWidget
的介绍可以参考以下文章:
笔者对opengl基本上没什么了解, 渲染部分选自以下博客,感谢博主
另外glviewport
是opengl渲染的图片显示的位置, 坐标原点为左下角。
使用了opengl渲染之后,再使用QPainter渲染(当时只是想使用这个渲染默认的Jpeg图标)就会导致opengl和QPainter渲染的效果无法使用。
解决方法还没有找到, 所以干脆就把默认图片也转成了yuv图像。
.h文件
#ifndef VIDEOGLWIDGET_H
#define VIDEOGLWIDGET_H
#include <QWidget>
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <memory>
#include <mutex>
#include <QOpenGLShaderProgram>
#include <QOpenGLFunctions>
#include <QOpenGLTexture>
#include "fileutil.h"
class VideoGLWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
QOBJECT_H
public:
VideoGLWidget(QWidget * pParent = 0);
virtual ~VideoGLWidget();
void PictureShow(fileutil::PictureFilePtr pPicture);
void DefaultPictureShow();
protected:
void initializeGL();
void resizeGL(int w, int h);
void paintGL();
private:
//绘图是异步动作, 防止绘图过程中,图片被置为NULL,所以需要加锁
std::mutex m_mutexForShowYuvData;
bool m_bIsShowVideoIcon; //是否要显示视频默认图标
fileutil::PictureFilePtr m_pDefaultPict;//默认图片
fileutil::PictureFilePtr m_pYuvPictPtr;//当前需要显示的Yuv数据
//显示Opengl渲染后图像位置
QRect m_drawRect;
//渲染yuv图像变量
GLuint textureUniformY; //y纹理数据位置
GLuint textureUniformU; //u纹理数据位置
GLuint textureUniformV; //v纹理数据位置
GLuint id_y; //y纹理对象ID
GLuint id_u; //u纹理对象ID
GLuint id_v; //v纹理对象ID
QOpenGLTexture* m_pTextureY; //y纹理对象
QOpenGLTexture* m_pTextureU; //u纹理对象
QOpenGLTexture* m_pTextureV; //v纹理对象
QOpenGLShader * m_pVSHader; //顶点着色器程序对象
QOpenGLShader * m_pFSHader; //片段着色器对象
QOpenGLShaderProgram *m_pShaderProgram; //着色器程序容器
};
#endif // VIDEOGLWIDGET_H
PicturePtr结构如下
#include <string>
#include <stdint.h>
#include <memory>
struct FileRawData
{
FileRawData(){
m_pData = NULL;
}
FileRawData(FileRawData && filedata)
{
m_pData = filedata.m_pData;
m_uLen = filedata.m_uLen;
m_filename = filedata.m_filename;
filedata.m_pData = NULL;
filedata.m_uLen = 0;
filedata.m_filename.clear();
}
~FileRawData()
{
if(m_pData)
delete m_pData;
m_pData = NULL;
m_uLen = 0;
}
uint8_t * m_pData;
uint32_t m_uLen;
std::string m_filename;
};
typedef std::shared_ptr<FileRawData> FileRawDataPtr;
struct PictureFile: public FileRawData
{
enum PictureFormat
{
kFormatYuv,
kFormatJpeg
};
PictureFile(FileRawData & parent, uint32_t nWeight, uint32_t nHeight, PictureFormat pictFormat)
:FileRawData(std::move(parent))
,m_nWeight(nWeight)
,m_nHeight(nHeight)
,m_pictFormat(pictFormat)
{
}
uint32_t m_nWeight;
uint32_t m_nHeight;
PictureFormat m_pictFormat;
};
typedef std::shared_ptr<PictureFile> PictureFilePtr;
cpp文件
#include "videoglwidget.h"
#include <QPainter>
#include <QDebug>
#include <ctime>
#include <QOpenGLTexture>
#include <QOpenGLBuffer>
#include "logutil.h"
//opengl 渲染部分参考自Csdn博客:https://blog.csdn.net/su_vast/article/details/52214642
using namespace fileutil;
#define DEFAULT_ICO_VIEW_WIDTH 48
#define DEFAULT_ICO_VIEW_HEIGHT 48
#define DEFAULT_ICO_PIX_HEIGHT 512
#define DEFAULT_ICO_PIX_WIDTH 512
VideoGLWidget::VideoGLWidget(QWidget *pParent)
:QOpenGLWidget(pParent)
{
textureUniformY = 0;
textureUniformU = 0;
textureUniformV = 0;
id_y = 0;
id_u = 0;
id_v = 0;
m_pYuvPictPtr = NULL;
m_pVSHader = NULL;
m_pFSHader = NULL;
m_pShaderProgram = NULL;
m_pTextureY = NULL;
m_pTextureU = NULL;
m_pTextureV = NULL;
//默认显示渲染位置为默认视频图标位置
m_drawRect = QRect((width() - DEFAULT_ICO_VIEW_WIDTH)/2, height()/2, DEFAULT_ICO_VIEW_WIDTH, DEFAULT_ICO_VIEW_HEIGHT);
this->DefaultPictureShow();
}
VideoGLWidget::~VideoGLWidget()
{
if(m_pVSHader)
{
delete m_pVSHader;
m_pVSHader = NULL;
}
if(m_pFSHader)
{
delete m_pFSHader;
m_pFSHader = NULL;
}
if(m_pShaderProgram)
{
delete m_pShaderProgram;
m_pShaderProgram = NULL;
}
if(m_pTextureY)
{
delete m_pTextureY;
m_pTextureY = NULL;
}
if(m_pTextureU)
{
delete m_pTextureU;
m_pTextureU = NULL;
}
if(m_pTextureV)
{
delete m_pTextureV;
m_pTextureV = NULL;
}
}
void VideoGLWidget::PictureShow(PictureFilePtr pPicture)
{
std::unique_lock<std::mutex> locker(m_mutexForShowYuvData);
m_pYuvPictPtr = pPicture;
m_drawRect = QRect(0, 0, width(), height());
this->update();
}
void VideoGLWidget::DefaultPictureShow()
{
std::unique_lock<std::mutex> locker(m_mutexForShowYuvData);
if(!m_pDefaultPict)
{
FileRawDataPtr pFileData = fileutil::ReadFileRawData("../../images/video.yuv");
m_pDefaultPict = PictureFilePtr(new PictureFile(*pFileData.get(), DEFAULT_ICO_PIX_WIDTH, DEFAULT_ICO_PIX_HEIGHT, PictureFile::kFormatYuv));
}
m_pYuvPictPtr = m_pDefaultPict;
m_drawRect = QRect((width() - DEFAULT_ICO_VIEW_WIDTH)/2, (height() - DEFAULT_ICO_VIEW_HEIGHT) /2, DEFAULT_ICO_VIEW_WIDTH, DEFAULT_ICO_VIEW_HEIGHT);
this->update();
}
void VideoGLWidget::initializeGL()
{
initializeOpenGLFunctions();
glEnable(GL_DEPTH_TEST);
//现代opengl渲染管线依赖着色器来处理传入的数据
//着色器:就是使用openGL着色语言(OpenGL Shading Language, GLSL)编写的一个小函数,
//GLSL是构成所有OpenGL着色器的语言,具体的GLSL语言的语法需要读者查找相关资料
//初始化顶点着色器 对象
m_pVSHader = new QOpenGLShader(QOpenGLShader::Vertex, this);
const char *vsrc ="\
attribute vec4 vertexIn; \
attribute vec2 textureIn; \
varying vec2 textureOut; \
void main(void) \
{ \
gl_Position = vertexIn; \
textureOut = textureIn; \
}";
m_pVSHader->compileSourceCode(vsrc);
//初始化片段着色器 功能gpu中yuv转换成rgb
m_pFSHader = new QOpenGLShader(QOpenGLShader::Fragment, this);
//片段着色器源码
const char *fsrc = "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, 1, 1, \
0, -0.39465, 2.03211, \
1.13983, -0.58060, 0) * yuv; \
gl_FragColor = vec4(rgb, 1); \
}";
m_pFSHader->compileSourceCode(fsrc);
#define PROGRAM_VERTEX_ATTRIBUTE 0
#define PROGRAM_TEXCOORD_ATTRIBUTE 1
#define ATTRIB_VERTEX 3
#define ATTRIB_TEXTURE 4
//创建着色器程序容器
m_pShaderProgram = new QOpenGLShaderProgram;
//将片段着色器添加到程序容器
m_pShaderProgram->addShader(m_pFSHader);
//将顶点着色器添加到程序容器
m_pShaderProgram->addShader(m_pVSHader);
//绑定属性vertexIn到指定位置ATTRIB_VERTEX,该属性在顶点着色源码其中有声明
m_pShaderProgram->bindAttributeLocation("vertexIn", ATTRIB_VERTEX);
//绑定属性textureIn到指定位置ATTRIB_TEXTURE,该属性在顶点着色源码其中有声明
m_pShaderProgram->bindAttributeLocation("textureIn", ATTRIB_TEXTURE);
//链接所有所有添入到的着色器程序
m_pShaderProgram->link();
//激活所有链接
m_pShaderProgram->bind();
//读取着色器中的数据变量tex_y, tex_u, tex_v的位置,这些变量的声明可以在
//片段着色器源码中可以看到
textureUniformY = m_pShaderProgram->uniformLocation("tex_y");
textureUniformU = m_pShaderProgram->uniformLocation("tex_u");
textureUniformV = m_pShaderProgram->uniformLocation("tex_v");
// 顶点矩阵
static const GLfloat vertexVertices[] = {
-1.0f, -1.0f,
1.0f, -1.0f,
-1.0f, 1.0f,
1.0f, 1.0f,
};
//纹理矩阵
static const GLfloat textureVertices[] = {
0.0f, 1.0f,
1.0f, 1.0f,
0.0f, 0.0f,
1.0f, 0.0f,
};
//设置属性ATTRIB_VERTEX的顶点矩阵值以及格式
glVertexAttribPointer(ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, vertexVertices);
//设置属性ATTRIB_TEXTURE的纹理矩阵值以及格式
glVertexAttribPointer(ATTRIB_TEXTURE, 2, GL_FLOAT, 0, 0, textureVertices);
//启用ATTRIB_VERTEX属性的数据,默认是关闭的
glEnableVertexAttribArray(ATTRIB_VERTEX);
//启用ATTRIB_TEXTURE属性的数据,默认是关闭的
glEnableVertexAttribArray(ATTRIB_TEXTURE);
//分别创建y,u,v纹理对象
m_pTextureY = new QOpenGLTexture(QOpenGLTexture::Target2D);
m_pTextureU = new QOpenGLTexture(QOpenGLTexture::Target2D);
m_pTextureV = new QOpenGLTexture(QOpenGLTexture::Target2D);
m_pTextureY->create();
m_pTextureU->create();
m_pTextureV->create();
//获取返回y分量的纹理索引值
id_y = m_pTextureY->textureId();
//获取返回u分量的纹理索引值
id_u = m_pTextureU->textureId();
//获取返回v分量的纹理索引值
id_v = m_pTextureV->textureId();
// glClearColor(0.3,0.3,0.3,0.0);//设置背景色
}
void VideoGLWidget::resizeGL(int w, int h)
{
if(h == 0)// 防止被零除
{
h = 1;// 将高设为1
}
glViewport(0, 0, w, h);
}
void VideoGLWidget::paintGL()
{
std::unique_lock<std::mutex> locker(m_mutexForShowYuvData);
if(m_pYuvPictPtr)
{
// clock_t start = clock();
uint32_t weight = m_pYuvPictPtr->m_nWeight;
uint32_t height = m_pYuvPictPtr->m_nHeight;
glViewport(m_drawRect.x(), m_drawRect.y(), m_drawRect.width(), m_drawRect.height());
//加载y数据纹理
//激活纹理单元GL_TEXTURE0
glActiveTexture(GL_TEXTURE0);
//使用来自y数据生成纹理
glBindTexture(GL_TEXTURE_2D, id_y);
//使用内存中m_pBufYuv420p数据创建真正的y数据纹理
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, weight, height, 0, GL_RED, GL_UNSIGNED_BYTE, m_pYuvPictPtr->m_pData);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//加载u数据纹理
glActiveTexture(GL_TEXTURE1);//激活纹理单元GL_TEXTURE1
glBindTexture(GL_TEXTURE_2D, id_u);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, weight/2, height/2, 0, GL_RED, GL_UNSIGNED_BYTE, (char*)m_pYuvPictPtr->m_pData+weight*height);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//加载v数据纹理
glActiveTexture(GL_TEXTURE2);//激活纹理单元GL_TEXTURE2
glBindTexture(GL_TEXTURE_2D, id_v);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, weight/2, height/2, 0, GL_RED, GL_UNSIGNED_BYTE, (char*)m_pYuvPictPtr->m_pData+weight*height*5/4);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//指定y纹理要使用新值 只能用0,1,2等表示纹理单元的索引,这是opengl不人性化的地方
//0对应纹理单元GL_TEXTURE0 1对应纹理单元GL_TEXTURE1 2对应纹理的单元
glUniform1i(textureUniformY, 0);
//指定u纹理要使用新值
glUniform1i(textureUniformU, 1);
//指定v纹理要使用新值
glUniform1i(textureUniformV, 2);
//使用顶点数组方式绘制图形
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
// clock_t end = clock();
}
}