bool directx_videofile_server::open_and_find_parameters(const char *filename)
{
//-------------------------------------------------------------------
// Create COM and DirectX objects needed to access a video stream.
// Initialize COM. This must have a matching uninitialize in
// the destructor.
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Before CoInitialize\n");
#endif
CoInitialize(NULL);
// Create the filter graph manager
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Before manager CoCreateInstance\n");
#endif
CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,
IID_IGraphBuilder, (void **)&_pGraph);
if (_pGraph == NULL) {
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Can't create graph manager\n");
return false;
}
_pGraph->QueryInterface(IID_IMediaControl, (void **)&_pMediaControl);
_pGraph->QueryInterface(IID_IMediaEvent, (void **)&_pEvent);
// Create the Capture Graph Builder.
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Before builder CoCreateInstance\n");
#endif
if (CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC,
IID_ICaptureGraphBuilder2, (void **)&_pBuilder) != S_OK) {
_pBuilder = NULL;
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Can't create graph builder\n");
return false;
}
// Associate the graph with the builder.
_pBuilder->SetFiltergraph(_pGraph);
//-------------------------------------------------------------------
// Construct the sample grabber callback handler that will be used
// to receive image data from the sample grabber.
if ( (_pCallback = new directx_samplegrabber_callback()) == NULL) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Can't create sample grabber callback handler (out of memory?)\n");
return false;
}
//-------------------------------------------------------------------
// Construct the sample grabber that will be used to snatch images from
// the video stream as they go by.
// Create the Sample Grabber.
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Before grabber CoCreateInstance\n");
#endif
CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,
IID_IBaseFilter, reinterpret_cast<void**>(&_pSampleGrabberFilter));
_pSampleGrabberFilter->QueryInterface(IID_ISampleGrabber,
reinterpret_cast<void**>(&_pGrabber));
// Set the media type to video and 8-bit RGB.
AM_MEDIA_TYPE mt;
ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
mt.majortype = MEDIATYPE_Video; // Ask for video media producers
mt.subtype = MEDIASUBTYPE_RGB24; // Ask for 8 bit RGB
_pGrabber->SetMediaType(&mt);
// Set the callback, where '0' means 'use the SampleCB callback'
_pGrabber->SetCallback(_pCallback, 0);
//-------------------------------------------------------------------
// Create a NULL renderer that will be used to discard the video frames
// on the output pin of the sample grabber
IBaseFilter *pNull = NULL;
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Before NULL render CoCreateInstance\n");
#endif
CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER,
IID_IBaseFilter, reinterpret_cast<void**>(&pNull));
//-------------------------------------------------------------------
// Build the filter graph. First add the filters and then connect them.
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Building filter graph...");
#endif
// pSrc is a the file-reading filter.
IBaseFilter *pSrc;
wchar_t longfilename[2048];
mbstowcs(longfilename, filename, 2047);
longfilename[2047] = L'\0';
if (FAILED(_pGraph->AddSourceFilter(longfilename, L"Source", &pSrc))) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Can't create reader for %s\n", filename);
return false;
}
#ifdef DEBUG
fprintf(stderr, "(source)...");
#endif
// Add the sample grabber filter
if (FAILED(_pGraph->AddFilter(_pSampleGrabberFilter, L"SampleGrabber"))) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Can't create grabber filter\n");
return false;
}
#ifdef DEBUG
fprintf(stderr, "(grabber)...");
#endif
// Add the null renderer filter
if (FAILED(_pGraph->AddFilter(pNull, L"NullRenderer"))) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Can't create Null Renderer\n");
return false;
}
#ifdef DEBUG
fprintf(stderr, "(renderer)...");
#endif
// Connect the output of the video reader to the sample grabber input
fprintf(stderr, "XXX DirectShow reading of video files fails on Windows 7\n");
return false;
// XXX The call below hangs on Windows 7 on Russ Taylor's laptop.
ConnectTwoFilters(_pGraph, pSrc, _pSampleGrabberFilter);
#ifdef DEBUG
fprintf(stderr, "(connected reader)...");
#endif
// Connect the output of the sample grabber to the NULL renderer input
#ifdef DEBUG
fprintf(stderr, "(connected grabber)...");
#endif
ConnectTwoFilters(_pGraph, _pSampleGrabberFilter, pNull);
#ifdef DEBUG
fprintf(stderr, "\n");
#endif
//-------------------------------------------------------------------
// We don't need a reference clock for playout because we're going
// to limit playback rate by controlling how fast we pass frames through
// the callback handler. We can't set a playout rate anyway, because
// the NULL renderer won't do this for us. Recall that the frames come
// out of the file reader as fast as it can process them, and only
// block up if the downstream buffers all fill up.
pNull->SetSyncSource(NULL); // Turn off the reference clock.
//-------------------------------------------------------------------
// Find the control that lets you seek in the media (rewind uses this
// to restart at the beginning of the file).
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Locating seek controls\n");
#endif
if (FAILED(_pGraph->QueryInterface(IID_IMediaSeeking, (void **)&_pMediaSeeking))) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Can't create media seeker\n");
pSrc->Release();
pNull->Release();
return false;
}
//-------------------------------------------------------------------
// Find _num_rows and _num_columns, which is the maximum size.
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Determining image size\n");
#endif
_pGrabber->GetConnectedMediaType(&mt);
VIDEOINFOHEADER *pVih;
if (mt.formattype == FORMAT_VideoInfo) {
pVih = reinterpret_cast<VIDEOINFOHEADER*>(mt.pbFormat);
} else if (mt.formattype == FORMAT_VideoInfo2) {
pVih = reinterpret_cast<VIDEOINFOHEADER*>(mt.pbFormat);
} else {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Can't get video header type\n");
fprintf(stderr," (Expected %x or %x, got %x)\n", FORMAT_VideoInfo, FORMAT_VideoInfo2, mt.formattype);
fprintf(stderr," (GetConnectedMediaType is not valid for DirectX headers later than version 7)\n");
fprintf(stderr," (We need to re-implement reading video in some other interface)\n");
return false;
}
// Number of rows and columns. This is different if we are using a target
// rectangle (rcTarget) than if we are not.
if (IsRectEmpty(&pVih->rcTarget)) {
_num_columns = pVih->bmiHeader.biWidth;
_num_rows = pVih->bmiHeader.biHeight;
} else {
_num_columns = pVih->rcTarget.right;
_num_rows = pVih->bmiHeader.biHeight;
printf("XXX directx_videofile_server::open_and_find_parameters(): Warning: may not work correctly with target rectangle\n");
}
printf("Got %dx%d video\n", _num_columns, _num_rows);
// Make sure that the image is not compressed and that we have 8 bits
// per pixel.
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Checking compression\n");
#endif
if (pVih->bmiHeader.biCompression != BI_RGB) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Compression not RGB\n");
switch (pVih->bmiHeader.biCompression) {
case BI_RLE8:
fprintf(stderr," (It is BI_RLE8)\n");
break;
case BI_RLE4:
fprintf(stderr," (It is BI_RLE4)\n");
case BI_BITFIELDS:
fprintf(stderr," (It is BI_BITFIELDS)\n");
break;
default:
fprintf(stderr," (Unknown compression type)\n");
}
return false;
}
int BytesPerPixel = pVih->bmiHeader.biBitCount / 8;
if (BytesPerPixel != 3) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Not 3 bytes per (%d)\n",
pVih->bmiHeader.biBitCount);
return false;
}
// A negative height indicates that the images are stored non-inverted in Y
// Not sure what to do with images that have negative height -- need to
// read the book some more to find out.
if (_num_rows < 0) {
fprintf(stderr,"directx_videofile_server::open_and_find_parameters(): Num Rows is negative (internal error)\n");
return false;
}
// Find the stride to take when moving from one row of video to the
// next. This is rounded up to the nearest DWORD.
_stride = (_num_columns * BytesPerPixel + 3) & ~3;
//-------------------------------------------------------------------
// Release resources that won't be used later and return
#ifdef DEBUG
fprintf(stderr, "directx_videofile_server::open_and_find_parameters(): Releasing resources\n");
#endif
pSrc->Release();
pNull->Release();
return true;
}
