使用SDL渲染AVFrame

XVideoView.cpp

bool XVideoView::drawAVFrame(AVFrame* frame)
{
	bool ret = (frame != nullptr);

	if (ret)
	{
		switch (frame->format)
		{
			case AV_PIX_FMT_ARGB:
			case AV_PIX_FMT_RGBA:
				ret = draw(frame->data[0], frame->linesize[0]);
				break;
			case AV_PIX_FMT_YUV420P:
				ret = draw(frame->data[0], frame->linesize[0], frame->data[1], frame->linesize[1], frame->data[2], frame->linesize[2]);
				break;
			default:
				ret = false;
				break;
		}
	}

	return ret;
}

 

XSDL.cpp

bool XSDL::draw(const unsigned char* Yplane, int Ypitch,
	const unsigned char* Uplane, int Upitch,
	const unsigned char* Vplane, int Vpitch)
{
	bool ret = (Yplane && (Ypitch > 0) && Uplane && (Upitch > 0) && Vplane && (Vpitch > 0) && (m_width > 0) && (m_height > 0) && m_win && m_render && m_texture);

	if (ret)
	{
		// 复制内存到显存中
		ret = (SDL_UpdateYUVTexture(m_texture, nullptr, Yplane, Ypitch, Uplane, Upitch, Vplane, Vpitch) == 0);

		if (ret)
		{
			SDL_Rect rect;
			SDL_Rect* pr = nullptr;

			rect.x = 0;
			rect.y = 0;
			rect.w = m_scaleWid;  // rect.w, rect.h 为显示的尺寸大小
			rect.h = m_scaleHgh;

			/* 默认渲染尺寸为窗口大小，若用户设置了缩放尺寸，则使用用户设定的尺寸来渲染 */
			if ((m_scaleWid > 0) && (m_scaleHgh > 0))
			{
				pr = ▭
			}

			// 清空屏幕
			SDL_RenderClear(m_render);

			// 将材质复制到渲染器
			ret = (SDL_RenderCopy(m_render, m_texture, nullptr, pr) == 0);

			if (ret)
			{
				SDL_RenderPresent(m_render);
			}
			else
			{
				cerr << SDL_GetError() << endl;
			}
		}
		else
		{
			cerr << SDL_GetError() << endl;
		}
	}

	return ret;
}

SdlQtRGB.cpp

#include "SdlQtRGB.h"
#include "XVideoView.h"
#include 
#include 
#include 

extern "C"
{
#include "libavcodec/avcodec.h"
}

using namespace std;

static AVFrame* frame = nullptr;;
static int sdl_width = 0;
static int sdl_height = 0;
static int pixel_size = 2;
static ifstream yuv_file;
static XVideoView* view = nullptr;

SdlQtRGB::SdlQtRGB(QWidget *parent)
    : QWidget(parent)
{
    int r = 0;

    yuv_file.open("400_300_25.yuv", ios::in | ios::binary);

    if (!yuv_file)
    {
        QMessageBox::information(this, "information", "open 400_300_25.yuv failed!");

        return;
    }

    ui.setupUi(this);
 
    sdl_width = 400;
    sdl_height = 300;

    ui.label->resize(400, 300);

    view = XVideoView::create();

    if (view)
    {    
        view->init(sdl_width, sdl_height, XVideoView::YUV420P);
        view->init(sdl_width, sdl_height, XVideoView::YUV420P, (void*)ui.label->winId());
    }
    
    frame = av_frame_alloc();

    frame->width = 400;
    frame->height = 300;
    frame->format = AV_PIX_FMT_YUV420P;

    
    //  Y Y
    //   UV
    //  Y Y
    frame->linesize[0] = sdl_width;      // Y
    frame->linesize[1] = sdl_width / 2;  // U
    frame->linesize[2] = sdl_width / 2;  // V

    r = av_frame_get_buffer(frame, 0);

    if (r != 0)
    {
        char buf[1024] = {0};

        av_strerror(r, buf, sizeof(buf));

        cerr << buf << endl;
    }

    startTimer(10);  // 每过10ms就会调用一次 timerEvent，1s大约有100帧的图像
}

void SdlQtRGB::timerEvent(QTimerEvent* evt)
{
    /* AVFrame 中 YUV 是单独存放的，所以需要分开进行读取 */
    yuv_file.read((char*)frame->data[0], sdl_width * sdl_height);      // Y
    yuv_file.read((char*)frame->data[1], sdl_width * sdl_height / 4);  // U
    yuv_file.read((char*)frame->data[2], sdl_width * sdl_height / 4);  // V

    if (view)
    {
        view->drawAVFrame(frame);

        if (view->isExit())
        {
            view->close();
            delete view;

            exit(0);
        }
    }
}

void SdlQtRGB::resizeEvent(QResizeEvent* evt)
{
    ui.label->resize(size());
    ui.label->move(0, 0);
    // view->scale(width(), height());
}

SdlQtRGB::~SdlQtRGB()
{
    av_frame_free(&frame);
}

测试结果