DirectDraw를 이용한 YUV -> RGB 고속 변환출력 - YUV -> RGB Converting by using DirectDraw

< DirectDraw YUV Surface 생성 - creating directdraw surfaces >

DDPIXELFORMAT g_ddpfFormats[] = 

{{sizeof(DDPIXELFORMAT), DDPF_FOURCC,MAKEFOURCC('Y','V','1','2'),0,0,0,0,0}}; 

...
IDirectDraw7 *pDD;
IDirectDrawSurface7 *lpPrimary;
IDirectDrawClipper      *lpClipper;
IDirectDrawSurface7   *lpYUVBuffer;

int g_width, g_height;

initDraw(HWND hWnd, int width, int height)
{
HRESULT hr;

g_width = width;
g_height = height;

hr = DirectDrawCreateEx(NULL, (void **)&pDD, IID_IDirectDraw7, NULL);
if (FAILED(hr)) {
TRACE("failed to create directdraw device (hr:0x%x)\n", hr);
return -1;
}

hr = pDD->SetCooperativeLevel(hWnd, DDSCL_NORMAL);

if(FAILED(hr)) {

TRACE("failed to SetCooperativeLevel (hr:0x%x)\n", hr);

return -1;

}

DDSURFACEDESC2 ddsd;

/* creating primary surface (RGB32) */
ZeroMemory( &ddsd, sizeof( ddsd ) );
ddsd.dwSize         = sizeof( ddsd );
ddsd.dwFlags        = DDSD_CAPS;
ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE;

if (hr=pDD->CreateSurface(&ddsd, &lpPrimary, NULL ) != DD_OK)
{
TRACE("failed to create create primary surface (hr:0x%x)\n", hr);
        return -1;
}

/* creating clipper */

hr = pDD->CreateClipper(0, &lpClipper, NULL);

if (hr != DD_OK)

{

TRACE("failed to create create clipper (hr:0x%x)\n", hr);

pDD->Release();

return -1;

}

hr = lpClipper->SetHWnd(0, hWnd);

if (hr != DD_OK)

{

TRACE("failed to clippter sethwnd (hr:0x%x)\n", hr);

lpClipper->Release();

lpPrimary->Release();

pDD->Release();

return -1;

}

hr = lpPrimary->SetClipper(lpClipper);

if (hr != DD_OK)

{

TRACE("failed to set clipper (hr:0x%x)\n", hr);

lpClipper->Release();

lpPrimary->Release();

pDD->Release();

return -1;

}

/* creating yuv420 surface */
ZeroMemory(&ddsd, sizeof(ddsd));
ddsd.dwSize = sizeof(ddsd);
ddsd.dwFlags = DDSD_CAPS | DDSD_WIDTH | DDSD_HEIGHT | DDSD_PIXELFORMAT;
ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
ddsd.dwWidth = width;
ddsd.dwHeight = height;

memcpy(&ddsd.ddpfPixelFormat, &g_ddpfFormats[0], sizeof(DDPIXELFORMAT));

if ((hr=pDD->CreateSurface(&ddsd, &lpYUVBuffer, NULL)) != DD_OK)

{

TRACE("failed to create yuv buffer surface\n");

return -1;

}

...

}

< Primary Surface 로 변환해서 출력 - yuv surface -> primary surface blt >

int draw(RECT *rectTarget, AVFrame *pPicture)

{
HRESULT hr;

int w = g_width;
int h = g_height;

...

DDSURFACEDESC2 ddsd;

ZeroMemory(&ddsd, sizeof(ddsd));

ddsd.dwSize = sizeof(ddsd);

if ((hr=lpYUVBuffer->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL)) == DD_OK)

{

LPBYTE lpSurf = (LPBYTE)ddsd.lpSurface;

LPBYTE ptr = lpSurf;

int t_stride = pPicture->linesize[0];

int i;

for (i=0; i < h; i++) {

memcpy(ptr+i*ddsd.lPitch, pPicture->data[0]+i*t_stride, w);

}

ptr += ddsd.lPitch*h;

for (i=0; i < h/2; i++) {

memcpy(ptr+i*ddsd.lPitch/2, pPicture->data[2]+i*t_stride/2, w/2);

}

ptr += ddsd.lPitch*h/4;

for (i=0; i < h/2; i++) {

memcpy(ptr+i*ddsd.lPitch/2, pPicture->data[1]+i*t_stride/2, w/2);

}

lpYUVBuffer->Unlock(NULL);

}

RECT rectSrc;
rectSrc.top = 0;
rectSrc.left = 0;
rectSrc.right = w;
rectSrc.bottom = h;

hr = lpPrimary->Blt(rectTarget, lpYUVBuffer, &rectSrc, DDBLT_ASYNC, NULL);

}

< ddraw resource release >


void release()
{
if (pDD != NULL)
{
pDD->Release();
pDD = NULL;
}

if (lpPrimary != NULL)
{
lpPrimary->Release();
lpPrimary = NULL;
}

if (lpYUVBuffer != NULL)
{
lpYUVBuffer->Release();
lpYUVBuffer = NULL;
}
}

위 소스에서 AVFrame 은 ffmpeg 에서 사용하는 구조체이고 data[0], data[2], data[1] 는 각각 yuv(yuv420) 값을 가진다.

분리된(non-interleaved) yuv 값을 가진 버퍼를 yuv surface에 memcpy 로 적절하게 복사한 다음 primary surface 로 blt 하면 하드웨어 가속기를 이용한 고속복사를 통해 영상 이미지를 출력할 수 있다.

여기서 primary surface의 픽셀포멧은 RGB32 인데 다른 픽셀포멧의 surface 에다 blt 시켜서 변환시킬수도 있을것같다.