ffmpeg+qsv如何在gpu中进行像素格式转换?能给些代码示例吗?
时间: 2024-02-12 22:05:15 浏览: 25
在使用ffmpeg+qsv进行像素格式转换时,可以利用Intel Media SDK提供的硬件加速能力。具体实现方法如下:
1. 首先需要初始化Intel Media SDK,可以参考以下代码:
```
MFXVideoSession session;
mfxInit(MFX_IMPL_HARDWARE_ANY, &version, &session);
```
2. 定义一个mfxFrameSurface1类型的变量,用于存储原始像素数据,可以参考以下代码:
```
mfxFrameSurface1 inputSurface;
memset(&inputSurface, 0, sizeof(inputSurface));
inputSurface.Info = mfxFrameInfo();
inputSurface.Info.FourCC = MFX_FOURCC_NV12; // 原始像素格式为NV12
inputSurface.Info.Width = inputWidth;
inputSurface.Info.Height = inputHeight;
inputSurface.Info.CropW = inputWidth;
inputSurface.Info.CropH = inputHeight;
inputSurface.Data.MemType = MFX_MEMTYPE_DXVA2_PROCESSOR_TARGET;
inputSurface.Data.MemId = inputSurfaceHandle; // 原始像素数据的句柄
```
3. 定义一个mfxFrameSurface1类型的变量,用于存储转换后的像素数据,可以参考以下代码:
```
mfxFrameSurface1 outputSurface;
memset(&outputSurface, 0, sizeof(outputSurface));
outputSurface.Info = mfxFrameInfo();
outputSurface.Info.FourCC = MFX_FOURCC_RGB4; // 转换后的像素格式为RGB4
outputSurface.Info.Width = outputWidth;
outputSurface.Info.Height = outputHeight;
outputSurface.Info.CropW = outputWidth;
outputSurface.Info.CropH = outputHeight;
outputSurface.Data.MemType = MFX_MEMTYPE_DXVA2_PROCESSOR_TARGET;
outputSurface.Data.MemId = outputSurfaceHandle; // 转换后的像素数据的句柄
```
4. 定义一个mfxFrameSurface1类型的变量,用于存储转换后的像素数据,可以参考以下代码:
```
mfxFrameSurface1 outputSurface;
memset(&outputSurface, 0, sizeof(outputSurface));
outputSurface.Info = mfxFrameInfo();
outputSurface.Info.FourCC = MFX_FOURCC_RGB4; // 转换后的像素格式为RGB4
outputSurface.Info.Width = outputWidth;
outputSurface.Info.Height = outputHeight;
outputSurface.Info.CropW = outputWidth;
outputSurface.Info.CropH = outputHeight;
outputSurface.Data.MemType = MFX_MEMTYPE_DXVA2_PROCESSOR_TARGET;
outputSurface.Data.MemId = outputSurfaceHandle; // 转换后的像素数据的句柄
```
5. 创建一个mfxFrameAllocator类型的变量,用于管理内存分配,可以参考以下代码:
```
mfxFrameAllocator frameAllocator;
memset(&frameAllocator, 0, sizeof(frameAllocator));
frameAllocator.pthis = &session;
frameAllocator.Alloc = FrameAllocator::Alloc;
frameAllocator.Lock = FrameAllocator::Lock;
frameAllocator.Unlock = FrameAllocator::Unlock;
frameAllocator.Free = FrameAllocator::Free;
```
6. 创建一个mfxVideoParam类型的变量,用于设置转换参数,可以参考以下代码:
```
mfxVideoParam videoParams;
memset(&videoParams, 0, sizeof(videoParams));
videoParams.IOPattern = MFX_IOPATTERN_IN_VIDEO_MEMORY | MFX_IOPATTERN_OUT_VIDEO_MEMORY;
videoParams.vpp.In = inputSurface.Info;
videoParams.vpp.Out = outputSurface.Info;
```
7. 创建一个MFXVideoVPP类型的变量,用于进行像素转换,可以参考以下代码:
```
MFXVideoVPP vpp(session);
vpp.Init(&videoParams);
vpp.QueryIOSurf(&videoParams, &surfacesRequest);
```
8. 将原始像素数据拷贝到inputSurface中,可以参考以下代码:
```
mfxFrameSurface1* pSurface = &inputSurface;
mfxFrameData* pData = &pSurface->Data;
pData->Pitch = pSurface->Info.Width;
pData->Y = (mfxU8*)inputBuffer;
pData->U = pData->Y + pData->Pitch * pSurface->Info.Height;
pData->V = pData->U + 1;
```
9. 进行像素转换,可以参考以下代码:
```
vpp.RunFrameVPPAsync(&inputSurface, &outputSurface, NULL, &syncp);
mfxStatus status = session.SyncOperation(syncp, -1);
```
10. 将转换后的像素数据从outputSurface中拷贝出来,可以参考以下代码:
```
mfxFrameSurface1* pSurface = &outputSurface;
mfxFrameData* pData = &pSurface->Data;
pData->Pitch = pSurface->Info.Width * 4; // RGB4格式,每个像素占4个字节
pData->B = (mfxU8*)outputBuffer;
```
以上是使用ffmpeg+qsv进行像素格式转换的主要流程,具体实现细节可以参考Intel Media SDK的官方文档。