自定义 DirectShow 捕获过滤器 - 输出 YUV

发布于 2024-12-08 21:30:12 字数 1519 浏览 0 评论 0原文

我编写了一个自定义的 directshow 过滤器，它读取图像并将其输出为 RGB。目前这工作正常。

我想添加以 YUV 输出的选项。我在谈判阶段仍然遇到一些问题。在我看来，关于 DirectShow 特定功能的解释非常糟糕，尤其是对于源过滤器。

根据我的理解，我建议使用 GetMediaType() 支持哪些媒体类型。然后，当选择特定类型时，CheckMediaType() 会验证协商的媒体类型。

根据这个逻辑，我更新了 GetMediaType() 以返回 YUV 媒体类型。我找不到如何创建 yuv 媒体类型的示例，最终使用了 Pushsource RGB 示例并进行了一些更改。

HRESULT CreateYUVVideoType(CMediaType *pMediaType, long Width, long Height, double Fps)
{

if (Width < 0)
{
    return E_INVALIDARG;
}

FreeMediaType(*pMediaType);

VIDEOINFO *pvi = (VIDEOINFO*)pMediaType->AllocFormatBuffer(sizeof(VIDEOINFO));
if (pvi == 0) 
{
    return(E_OUTOFMEMORY);
}
ZeroMemory(pvi, sizeof(VIDEOINFO));

pvi->AvgTimePerFrame = Fps2FrameLength(Fps);

BITMAPINFOHEADER *pBmi = &(pvi->bmiHeader);
pBmi->biSize = sizeof(BITMAPINFOHEADER);
pBmi->biWidth = Width;
pBmi->biHeight = Height;
pBmi->biPlanes = 1;

pBmi->biBitCount = 16;
pBmi->biCompression = MAKEFOURCC('Y','U','Y','2');
pMediaType->SetSubtype(&MEDIASUBTYPE_YUY2);

pvi->bmiHeader.biSizeImage = DIBSIZE(pvi->bmiHeader);

pMediaType->SetType(&MEDIATYPE_Video);
pMediaType->SetFormatType(&FORMAT_VideoInfo);

pMediaType->SetTemporalCompression(FALSE);
pMediaType->SetSampleSize(pvi->bmiHeader.biSizeImage);

return S_OK;
}

1) 这是创建 YUV (4:2:2) 媒体类型的正确方法吗？
2）另外，当我渲染引脚时，它会将VMR与中间的AVI解压缩器连接起来？为什么？
3) 除了 GetMediaType 和 CheckMediaType 之外，我是否需要重写任何其他函数才能支持多种输出媒体类型？

谢谢

原文

I have written a custom directshow filter which read's images and outputs them as RGB. This currently works fine.

I want to add the option of outputting in YUV.
I'm still having some issues in the negotiation phase.
IMO the explanations on the specific functions of DirectShow is just horrible, especially for source filters.

From my understanding, I propose which media types I support with GetMediaType().
Afterwards, when a specific type is chosen, CheckMediaType() validates the negotiated media type.

With this logic, I updated GetMediaType() to return a YUV media type.
I couldn't find examples of how to create a yuv media type and ended up using the pushsource RGB example with some changes.

HRESULT CreateYUVVideoType(CMediaType *pMediaType, long Width, long Height, double Fps)
{

if (Width < 0)
{
    return E_INVALIDARG;
}

FreeMediaType(*pMediaType);

VIDEOINFO *pvi = (VIDEOINFO*)pMediaType->AllocFormatBuffer(sizeof(VIDEOINFO));
if (pvi == 0) 
{
    return(E_OUTOFMEMORY);
}
ZeroMemory(pvi, sizeof(VIDEOINFO));

pvi->AvgTimePerFrame = Fps2FrameLength(Fps);

BITMAPINFOHEADER *pBmi = &(pvi->bmiHeader);
pBmi->biSize = sizeof(BITMAPINFOHEADER);
pBmi->biWidth = Width;
pBmi->biHeight = Height;
pBmi->biPlanes = 1;

pBmi->biBitCount = 16;
pBmi->biCompression = MAKEFOURCC('Y','U','Y','2');
pMediaType->SetSubtype(&MEDIASUBTYPE_YUY2);

pvi->bmiHeader.biSizeImage = DIBSIZE(pvi->bmiHeader);

pMediaType->SetType(&MEDIATYPE_Video);
pMediaType->SetFormatType(&FORMAT_VideoInfo);

pMediaType->SetTemporalCompression(FALSE);
pMediaType->SetSampleSize(pvi->bmiHeader.biSizeImage);

return S_OK;
}

1) Is this the correct way to create a YUV (4:2:2) media type?
2) Also, when I render the pin, it connects the VMR with an AVI Decompressor in between? Why ?
3) Do I need to override any other functions besides GetMediaType and CheckMediaType in order to support multiple output media types?

Thanks

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