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Autres articles (38)
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Support audio et vidéo HTML5
10 avril 2011MediaSPIP utilise les balises HTML5 video et audio pour la lecture de documents multimedia en profitant des dernières innovations du W3C supportées par les navigateurs modernes.
Pour les navigateurs plus anciens, le lecteur flash Flowplayer est utilisé.
Le lecteur HTML5 utilisé a été spécifiquement créé pour MediaSPIP : il est complètement modifiable graphiquement pour correspondre à un thème choisi.
Ces technologies permettent de distribuer vidéo et son à la fois sur des ordinateurs conventionnels (...) -
HTML5 audio and video support
13 avril 2011, parMediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
For older browsers the Flowplayer flash fallback is used.
MediaSPIP allows for media playback on major mobile platforms with the above (...) -
De l’upload à la vidéo finale [version standalone]
31 janvier 2010, parLe chemin d’un document audio ou vidéo dans SPIPMotion est divisé en trois étapes distinctes.
Upload et récupération d’informations de la vidéo source
Dans un premier temps, il est nécessaire de créer un article SPIP et de lui joindre le document vidéo "source".
Au moment où ce document est joint à l’article, deux actions supplémentaires au comportement normal sont exécutées : La récupération des informations techniques des flux audio et video du fichier ; La génération d’une vignette : extraction d’une (...)
Sur d’autres sites (4374)
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Rendering YUV420P ffmpeg decoded images on QT with OpenGL, only see black screen
17 février 2019, par Lucas ZanellaI’ve found this QT OpenGL Widget which should render a 420PYUV image on screen. I’m feeding a ffmpeg decoded buffer into its
paintGL()
function but I see nothing. Neither noises or correct images, only a black screen. I’m trying to understand why.I want to exclude the possibilities of other things being wrong, but I need to be sure first that my code will produce anything. I
std::cout
ed some bytes from the ffmpeg just to see if they were arriving and they were. So I should see at least some noise.Can you see anything wrong with my code that wouldn’t make it able to render images on screen ?
This is the widget that should output the image :
#include "XVideoWidget.h"
#include <qdebug>
#include <qtimer>
#include <iostream>
//自动加双引号
#define GET_STR(x) #x
#define A_VER 3
#define T_VER 4
//顶点shader
const char *vString = GET_STR(
attribute vec4 vertexIn;
attribute vec2 textureIn;
varying vec2 textureOut;
void main(void)
{
gl_Position = vertexIn;
textureOut = textureIn;
}
);
//片元shader
const char *tString = 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);
}
);
//准备yuv数据
// ffmpeg -i v1080.mp4 -t 10 -s 240x128 -pix_fmt yuv420p out240x128.yuv
XVideoWidget::XVideoWidget(QWidget * parent)
{
// setWindowFlags (Qt::WindowFullscreenButtonHint);
// showFullScreen();
}
XVideoWidget::~XVideoWidget()
{
}
//初始化opengl
void XVideoWidget::initializeGL()
{
//qDebug() << "initializeGL";
std::cout << "initializing gl" << std::endl;
//初始化opengl (QOpenGLFunctions继承)函数
initializeOpenGLFunctions();
this->m_F = QOpenGLContext::currentContext()->functions();
//program加载shader(顶点和片元)脚本
//片元(像素)
std::cout << program.addShaderFromSourceCode(QOpenGLShader::Fragment, tString) << std::endl;
//顶点shader
std::cout << program.addShaderFromSourceCode(QOpenGLShader::Vertex, vString) << std::endl;
//设置顶点坐标的变量
program.bindAttributeLocation("vertexIn",A_VER);
//设置材质坐标
program.bindAttributeLocation("textureIn",T_VER);
//编译shader
std::cout << "program.link() = " << program.link() << std::endl;
std::cout << "program.bind() = " << program.bind() << std::endl;
//传递顶点和材质坐标
//顶点
static const GLfloat ver[] = {
-1.0f,-1.0f,
1.0f,-1.0f,
-1.0f, 1.0f,
1.0f,1.0f
};
//材质
static const GLfloat tex[] = {
0.0f, 1.0f,
1.0f, 1.0f,
0.0f, 0.0f,
1.0f, 0.0f
};
//顶点
glVertexAttribPointer(A_VER, 2, GL_FLOAT, 0, 0, ver);
glEnableVertexAttribArray(A_VER);
//材质
glVertexAttribPointer(T_VER, 2, GL_FLOAT, 0, 0, tex);
glEnableVertexAttribArray(T_VER);
//glUseProgram(&program);
//从shader获取材质
unis[0] = program.uniformLocation("tex_y");
unis[1] = program.uniformLocation("tex_u");
unis[2] = program.uniformLocation("tex_v");
//创建材质
glGenTextures(3, texs);
//Y
glBindTexture(GL_TEXTURE_2D, texs[0]);
//放大过滤,线性插值 GL_NEAREST(效率高,但马赛克严重)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//创建材质显卡空间
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//U
glBindTexture(GL_TEXTURE_2D, texs[1]);
//放大过滤,线性插值
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//创建材质显卡空间
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width/2, height / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//V
glBindTexture(GL_TEXTURE_2D, texs[2]);
//放大过滤,线性插值
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//创建材质显卡空间
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width / 2, height / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
///分配材质内存空间
datas[0] = new unsigned char[width*height]; //Y
datas[1] = new unsigned char[width*height/4]; //U
datas[2] = new unsigned char[width*height/4]; //V
}
//刷新显示
void XVideoWidget::paintGL(unsigned char**data)
//void QFFmpegGLWidget::updateData(unsigned char**data)
{
std::cout << "painting!" << std::endl;
memcpy(datas[0], data[0], width*height);
memcpy(datas[1], data[1], width*height/4);
memcpy(datas[2], data[2], width*height/4);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texs[0]); //0层绑定到Y材质
//修改材质内容(复制内存内容)
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, datas[0]);
//与shader uni遍历关联
glUniform1i(unis[0], 0);
glActiveTexture(GL_TEXTURE0+1);
glBindTexture(GL_TEXTURE_2D, texs[1]); //1层绑定到U材质
//修改材质内容(复制内存内容)
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width/2, height / 2, GL_RED, GL_UNSIGNED_BYTE, datas[1]);
//与shader uni遍历关联
glUniform1i(unis[1],1);
glActiveTexture(GL_TEXTURE0+2);
glBindTexture(GL_TEXTURE_2D, texs[2]); //2层绑定到V材质
//修改材质内容(复制内存内容)
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width / 2, height / 2, GL_RED, GL_UNSIGNED_BYTE, datas[2]);
//与shader uni遍历关联
glUniform1i(unis[2], 2);
glDrawArrays(GL_TRIANGLE_STRIP,0,4);
qDebug() << "paintGL";
}
// 窗口尺寸变化
void XVideoWidget::resizeGL(int width, int height)
{
m_F->glViewport(0, 0, width, height);
qDebug() << "resizeGL "<code></iostream></qtimer></qdebug>Here’s a bit of code from my MainWindow :
MainWindow::MainWindow(QWidget *parent):
QMainWindow(parent)
{
FfmpegDecoder* ffmpegDecoder = new FfmpegDecoder();
if(!ffmpegDecoder->Init()) {
std::cout << "problem with ffmpeg decoder init" << std::endl;
} else {
std::cout << "fmmpeg decoder initiated" << std::endl;
}
XVideoWidget * xVideoWidget = new XVideoWidget(parent);
ffmpegDecoder->setOpenGLWidget(xVideoWidget);
mediaStream = new MediaStream(uri, ffmpegDecoder, videoConsumer);//= new MediaStream(uri, ffmpegDecoder, videoConsumer);
//...
}
void MainWindow::run()
{
mediaStream->receiveFrame();
}My main.cpp makes sure my window
run()
method runs in the background.MainWindow w;
w.setFixedSize(1280,720);
w.show();
boost::thread mediaThread(&MainWindow::run, &w);
std::cout << "mediaThread running" << std::endl;If someone wants to view the entire code, please feel free to visit the commit I just did : https://github.com/lucaszanella/orwell/tree/bbd74e42bd42df685bacc5d51cacbee3a178689f
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mss1 : validate number of changeable palette entries
27 juin 2012, par Kostya Shishkovmss1 : validate number of changeable palette entries
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mss1 : validate number of changeable palette entries
27 juin 2012, par Kostya Shishkovmss1 : validate number of changeable palette entries