Question

因此，由于缺乏对所需视频格式的支持，我使用DirectShow过滤器离开了我的想法。本机API使用OpenGL，我是初学者。我偶然发现了以下问题：

如何根据传递给OpenGL的Frame的宽度和高度自动应用信箱或邮箱（我使用bpctrlanchormap.h自动调整所有内容并获得挤压/拉伸图像）
如何录制OpenGL流的视频（我环顾四周，看到ffmpeg应该可以这样做，但我无法让它运行。）还有什么好听的是录音到同一个麦克风文件

我正在使用Blackmagic“Capture Preview”样本。

这是初始化OpenGL渲染器并传递帧

#include "stdafx.h"
#include <gl/gl.h>
#include "PreviewWindow.h"

PreviewWindow::PreviewWindow()
: m_deckLinkScreenPreviewHelper(NULL), m_refCount(1), m_previewBox(NULL), m_previewBoxDC(NULL), m_openGLctx(NULL)
{}

PreviewWindow::~PreviewWindow()
{
    if (m_deckLinkScreenPreviewHelper != NULL)
    {
        m_deckLinkScreenPreviewHelper->Release();
        m_deckLinkScreenPreviewHelper = NULL;
    }

    if (m_openGLctx != NULL)
    {
        wglDeleteContext(m_openGLctx);
        m_openGLctx = NULL;
    }

    if (m_previewBoxDC != NULL)
    {
        m_previewBox->ReleaseDC(m_previewBoxDC);
        m_previewBoxDC = NULL;
    }
}

bool        PreviewWindow::init(CStatic *previewBox)
{
    m_previewBox = previewBox;

    // Create the DeckLink screen preview helper
    if (CoCreateInstance(CLSID_CDeckLinkGLScreenPreviewHelper, NULL, CLSCTX_ALL, IID_IDeckLinkGLScreenPreviewHelper (void**)&m_deckLinkScreenPreviewHelper) != S_OK)
    return false;

    // Initialise OpenGL
    return initOpenGL();
}

bool        PreviewWindow::initOpenGL()
{
    PIXELFORMATDESCRIPTOR   pixelFormatDesc;
    int                     pixelFormat;
    bool                    result = false;

    //
    // Here, we create an OpenGL context attached to the screen preview box
    // so we can use it later on when we need to draw preview frames.

    // Get the preview box drawing context
    m_previewBoxDC = m_previewBox->GetDC();
    if (m_previewBoxDC == NULL)
        return false;

    // Ensure the preview box DC uses ARGB pixel format
    ZeroMemory(&pixelFormatDesc, sizeof(pixelFormatDesc));
    pixelFormatDesc.nSize = sizeof(pixelFormatDesc);
    pixelFormatDesc.nVersion = 1;
    pixelFormatDesc.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
    pixelFormatDesc.iPixelType = PFD_TYPE_RGBA;
    pixelFormatDesc.cColorBits = 32;
    pixelFormatDesc.cDepthBits = 16;
    pixelFormatDesc.cAlphaBits = 8;
    pixelFormatDesc.iLayerType = PFD_MAIN_PLANE;
    pixelFormat = ChoosePixelFormat(m_previewBoxDC->m_hDC, &pixelFormatDesc);
    if (SetPixelFormat(m_previewBoxDC->m_hDC, pixelFormat, &pixelFormatDesc) == false)
        return false;

    // Create OpenGL rendering context
    m_openGLctx = wglCreateContext(m_previewBoxDC->m_hDC);
    if (m_openGLctx == NULL)
        return false;
    // Make the new OpenGL context the current rendering context so
    // we can initialise the DeckLink preview helper
    if (wglMakeCurrent(m_previewBoxDC->m_hDC, m_openGLctx) == FALSE)
        return false;

    if (m_deckLinkScreenPreviewHelper->InitializeGL() == S_OK)
        result = true;

    // Reset the OpenGL rendering context
    wglMakeCurrent(NULL, NULL);

    return result;
}

HRESULT         PreviewWindow::DrawFrame(IDeckLinkVideoFrame* theFrame)
{
    // Make sure we are initialised
    if ((m_deckLinkScreenPreviewHelper == NULL) || (m_previewBoxDC == NULL) || (m_openGLctx == NULL))
        return E_FAIL;

    // First, pass the frame to the DeckLink screen preview helper
    m_deckLinkScreenPreviewHelper->SetFrame(theFrame);

    // Then set the OpenGL rendering context to the one we created before
    wglMakeCurrent(m_previewBoxDC->m_hDC, m_openGLctx);

    // and let the helper take care of the drawing
    m_deckLinkScreenPreviewHelper->PaintGL();

    // Last, reset the OpenGL rendering context
    wglMakeCurrent(NULL, NULL);

    return S_OK;
}

Blackmagic SDK - OpenGL Letterbox和FFMPEG

0 个答案: