Related
I am experiencing a strange problem when trying to use the GMFBridge filter with the output of an Euresys UxH264 card.
I am trying to integrate this card into our solution, that relies on GMFBridge to handle the ability of continuous capture to multiple files, performing muxing and file-splitting without having to stop the capture graph.
This card captures video and audio from analog inputs. It provides a DirectShow filter exposing both a raw stream of the video input and a hardware-encoded H.264 stream. The audio stream is provided as an uncompressed stream only.
When I attempt to directly connect any of the output pins of the Euresys source filters to the input pins of the GMFBridge Sink, they get rejected, with the code VFW_E_NO_ALLOCATOR. (In the past I have successfully connected both H.264 and raw audio streams to the bridge).
Grasping at straws, I plugged in a pair of SampleGrabber filters between the Euresys card filters and the bridge sink filter, and -just like that- the connections between sample grabbers and sink were accepted.
However, I am not getting any packets on the other side of the bridge (the muxing graph). I inspected the running capture graph with GraphStudioNext and somehow the sample grabbers appear detached from my graph, even though I got successful confirmations when I connected them to the source filter!.
Here's the source code creating the graph.
void EuresysSourceBox::BuildGraph() {
HRESULT hRes;
CComPtr<IGraphBuilder> pGraph;
COM_CALL(pGraph.CoCreateInstance(CLSID_FilterGraph));
#ifdef REGISTER_IN_ROT
_rotEntry1 = FilterTools::RegisterGraphInROT(IntPtr(pGraph), "euresys graph");
#endif
// [*Video Source*]
String^ filterName = "Ux H.264 Visual Source";
Guid category = _GUIDToGuid((GUID)AM_KSCATEGORY_CAPTURE);
FilterMonikerList^ videoSourceList = FilterTools::GetFilterMonikersByName(category, filterName);
CComPtr<IBaseFilter> pVideoSource;
int monikerIndex = config->BoardIndex; // a filter instance will be retrieved for every installed board
clr_scoped_ptr<CComPtr<IMoniker>>^ ppVideoSourceMoniker = videoSourceList[monikerIndex];
COM_CALL((*ppVideoSourceMoniker->get())->BindToObject(NULL, NULL, IID_IBaseFilter, (void**)&pVideoSource));
COM_CALL(pGraph->AddFilter(pVideoSource, L"VideoSource"));
// [Video Source]
//
// [*Audio Source*]
filterName = "Ux H.264 Audio Encoder";
FilterMonikerList^ audioSourceList = FilterTools::GetFilterMonikersByName(category, filterName);
CComPtr<IBaseFilter> pAudioSource;
clr_scoped_ptr<CComPtr<IMoniker>>^ ppAudioSourceMoniker = audioSourceList[monikerIndex];
COM_CALL((*ppAudioSourceMoniker->get())->BindToObject(NULL, NULL, IID_IBaseFilter, (void**)&pAudioSource));
COM_CALL(pGraph->AddFilter(pAudioSource, L"AudioSource"));
CComPtr<IPin> pVideoCompressedOutPin(FilterTools::GetPin(pVideoSource, "Encoded"));
CComPtr<IPin> pAudioOutPin(FilterTools::GetPin(pAudioSource, "Audio"));
CComPtr<IBaseFilter> pSampleGrabber;
COM_CALL(pSampleGrabber.CoCreateInstance(CLSID_SampleGrabber));
COM_CALL(pGraph->AddFilter(pSampleGrabber, L"SampleGrabber"));
CComPtr<IPin> pSampleGrabberInPin(FilterTools::GetPin(pSampleGrabber, "Input"));
COM_CALL(pGraph->ConnectDirect(pVideoCompressedOutPin, pSampleGrabberInPin, NULL)); // DOES NOT FAIL!!
CComPtr<IBaseFilter> pSampleGrabber2;
COM_CALL(pSampleGrabber2.CoCreateInstance(CLSID_SampleGrabber));
COM_CALL(pGraph->AddFilter(pSampleGrabber2, L"SampleGrabber2"));
CComPtr<IPin> pSampleGrabber2InPin(FilterTools::GetPin(pSampleGrabber2, "Input"));
COM_CALL(pGraph->ConnectDirect(pAudioOutPin, pSampleGrabber2InPin, NULL)); // DOES NOT FAIL!!
// [Video Source]---
// |-->[*Bridge Sink*]
// [Audio Source]---
CComPtr<IPin> pSampleGrabberOutPin(FilterTools::GetPin(pSampleGrabber, "Output"));
CComPtr<IPin> pSampleGrabber2OutPin(FilterTools::GetPin(pSampleGrabber2, "Output"));
CreateGraphBridge(
IntPtr(pGraph),
IntPtr(pSampleGrabberOutPin),
IntPtr(pSampleGrabber2OutPin)
);
// Root graph to parent object
_ppCaptureGraph.reset(new CComPtr<IGraphBuilder>(pGraph));
}
COM_CALL is my HRESULT checking macro, it will raise a managed exception if the result is other than S_OK. So the connection between pins succeeded, but here is how the graph looks disjointed when it is running:
So, I have three questions:
1) What could VFW_E_NO_ALLOCATOR mean in this instance? (the source filter can be successfully connected to other components such as LAV Video decoder or ffdshow video decoder).
2) Is there a known workaround to circumvent the VFW_E_NO_ALLOCATOR problem?
3) Is it possible that a filter gets disconnected at runtime as it seems to be happening in my case?
I found a reference by Geraint Davies giving a reason as to why the GMFBridge sink filter may be rejecting the connection.
It looks as though the parser is insisting on using its own allocator
-- this is common with parsers where the output samples are merely pointers into the input samples. However, the bridge cannot implement
suspend mode without using its own allocator, so a copy is required.
With this information, I decided to create an ultra simple CTransformFilter filter that simply accepts the allocator offered by the bridge and copies to the output sample whatever comes in from the input sample. I am not 100% sure that what I did was right, but it is working now. I could successfully plug-in the Euresys card as part of my capture infrastructure.
For reference, if anyone experiences something similar, here is the code of the filter I created:
class SampleCopyGeneratorFilter : public CTransformFilter {
protected:
HRESULT CheckInputType(const CMediaType* mtIn) override { return S_OK; }
HRESULT GetMediaType(int iPosition, CMediaType* pMediaType) override;
HRESULT CheckTransform(const CMediaType *mtIn, const CMediaType *mtOut) override { return S_OK; }
HRESULT DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pProp) override;
HRESULT Transform(IMediaSample *pSource, IMediaSample *pDest) override;
public:
SampleCopyGeneratorFilter();
};
//--------------------------------------------------------------------------------------------------------------------
SampleCopyGeneratorFilter::SampleCopyGeneratorFilter()
: CTransformFilter(NAME("SampleCopyGeneratorFilter"), NULL, GUID_NULL)
{
}
HRESULT SampleCopyGeneratorFilter::GetMediaType(int iPosition, CMediaType* pMediaType) {
HRESULT hRes;
ASSERT(m_pInput->IsConnected());
if( iPosition < 0 )
return E_INVALIDARG;
CComPtr<IPin> connectedTo;
COM_CALL(m_pInput->ConnectedTo(&connectedTo));
CComPtr<IEnumMediaTypes> pMTEnumerator;
COM_CALL(connectedTo->EnumMediaTypes(&pMTEnumerator));
AM_MEDIA_TYPE* pIteratedMediaType;
for( int i = 0; i <= iPosition; i++ ) {
if( pMTEnumerator->Next(1, &pIteratedMediaType, NULL) != S_OK )
return VFW_S_NO_MORE_ITEMS;
if( i == iPosition )
*pMediaType = *pIteratedMediaType;
DeleteMediaType(pIteratedMediaType);
}
return S_OK;
}
HRESULT SampleCopyGeneratorFilter::DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pProp) {
HRESULT hRes;
AM_MEDIA_TYPE mt;
COM_CALL(m_pInput->ConnectionMediaType(&mt));
try {
BITMAPINFOHEADER* pBMI = HEADER(mt.pbFormat);
pProp->cbBuffer = DIBSIZE(*pBMI); // format is compressed, uncompressed size should be enough
if( !pProp->cbAlign )
pProp->cbAlign = 1;
pProp->cbPrefix = 0;
pProp->cBuffers = 4;
ALLOCATOR_PROPERTIES actualProperties;
COM_CALL(pAlloc->SetProperties(pProp, &actualProperties));
if( pProp->cbBuffer > actualProperties.cbBuffer )
return E_FAIL;
return S_OK;
} finally{
FreeMediaType(mt);
}
}
HRESULT SampleCopyGeneratorFilter::Transform(IMediaSample *pSource, IMediaSample *pDest) {
HRESULT hRes;
BYTE* pBufferIn;
BYTE* pBufferOut;
long destSize = pDest->GetSize();
long dataLen = pSource->GetActualDataLength();
if( dataLen > destSize )
return VFW_E_BUFFER_OVERFLOW;
COM_CALL(pSource->GetPointer(&pBufferIn));
COM_CALL(pDest->GetPointer(&pBufferOut));
memcpy(pBufferOut, pBufferIn, dataLen);
pDest->SetActualDataLength(dataLen);
pDest->SetSyncPoint(pSource->IsSyncPoint() == S_OK);
return S_OK;
}
Here is how I inserted the filter in the capture graph:
CComPtr<IPin> pAACEncoderOutPin(FilterTools::GetPin(pAACEncoder, "XForm Out"));
CComPtr<IPin> pVideoSourceCompressedOutPin(FilterTools::GetPin(pVideoSource, "Encoded"));
CComPtr<IBaseFilter> pSampleCopier;
pSampleCopier = new SampleCopyGeneratorFilter();
COM_CALL(pGraph->AddFilter(pSampleCopier, L"SampleCopier"));
CComPtr<IPin> pSampleCopierInPin(FilterTools::GetPin(pSampleCopier, "XForm In"));
COM_CALL(pGraph->ConnectDirect(pVideoSourceCompressedOutPin, pSampleCopierInPin, NULL));
CComPtr<IPin> pSampleCopierOutPin(FilterTools::GetPin(pSampleCopier, "XForm Out"));
CreateGraphBridge(
IntPtr(pGraph),
IntPtr(pSampleCopierOutPin),
IntPtr(pAACEncoderOutPin)
);
Now, I still have no idea why inserting the sample grabber instead did not work and resulted in detached graphs. I corroborated this quirk by examining the graphs with Graphedit Plus too. If anyone can offer me an explanation, I would be very grateful indeed.
Hello i am using AM1808 ARM9 microprocessor.
I have an interfacing of GSM dongle.I want to make the GSM dongle connection as well all data transmission as well reception in the background using pthreads.
When i am trying to connect the dongle in background it is continuously blinking green light and i could not get connect to the server.
I can not find the problem.
Here is my code for the datacard initialisation as well as communication routine.
I am initialising the Thread in the Main thread.
int InitializeDataCard(void)
{
static int connect_ret = 0;
pthread_t processing_th;
pthread_create(&processing_th, NULL, Datacard_Connection_Thread, &db_mc_object);
pthread_detach(processing_th);
ShowMessageBox(msgbox_text[136], MB_TASKMODAL);
if(connect_ret)
{
ShowMessageBox(msgbox_text[163], MB_ICONERROR);
return -1;`enter code here`
}
else
{
return 0;
}
}
int ConnectToServer(void)
{
int connect_ret = 0;
Dprintf(__func__,"Trying to connect ....");
DPUUtilsLib_RetrieveParameter(PID_DATACARD_INFO,(UCHAR *)&datacard_info,sizeof(datacard_info));
connect_ret = DataCardConnect(datacard_info);
sleep(3);
//g_do_process = 0;
Dprintf(__func__,"DataCardConnect ret=%d",connect_ret);
return connect_ret;
}
void * Datacard_Connection_Thread(void *tempdata)
{
int ret=0,response = -1,enc_ret=0;
static int g_gsm_response = 0;
dpu_csv_file_param_t fileparam;
dpu_db_export_search_params_t tempparams;
dpu_db_milk_collection_t *livedata,*updatedata;
dpu_db_user_master_t CreatedBy,UpdatedBy;
dpu_db_society_master_t soc_info;
char filename[50]={0};
livedata = (dpu_db_milk_collection_t *)tempdata;
//Connect to the Network
create_connection :
ret = ConnectToServer();
//connected successfully
if(!ret)
{
//Get the SocietyCode from the Database
if(g_data_available)
{
g_data_available=0;
soc_info.SocietyId = g_society_list[g_selected_society].SocietyId;
DPUDBLib_search_society_master(&soc_info);
strncpy(livedata->SocietyCode,soc_info.SocietyCode,5);
Dprintf(__func__,"%04d\n %5.2f\n %5.2f\n %5.2f\n %5.2f\n %5.2f\n %5.2f\n %7.2f\n %7.2f\n %03d\n %c\n %d\n %5.2d\n %s\n %d",
livedata->MemberCode,livedata->Fat,livedata->LRCLR,livedata->SNF,livedata->Solid,
livedata->FatKG,livedata->SNFKG,livedata->Rate,livedata->Amount,
livedata->CanNumber,livedata->EntryMode,livedata->MC_RateChartId,livedata->Water,livedata->SocietyCode,__LINE__);
sprintf(tempparams.FileName,"%s/%s",DATA_TEMP,MT_MILKLIVEFILE);
memcpy(fileparam.FilePath,tempparams.FileName,sizeof(tempparams.FileName));
fileparam.Type = DPU_CSV_EXPORT;
fileparam.FileType = DPU_CSV_MILK_LIVE_DATA_FILE;
//open a csv file
DPUCSVLib_open_csv_file(&fileparam);
memset(&CreatedBy,0,sizeof(dpu_db_user_master_t));
memset(&UpdatedBy,0,sizeof(dpu_db_user_master_t));
strncpy(CreatedBy.Username,TempUser,5);
//write the live data into the file
DPUCSVLib_write_csv_file(&fileparam,livedata,&CreatedBy,&UpdatedBy);
//encrypt the file
enc_ret = DPUEncryptFile(tempparams.FileName,filename);
if(!enc_ret)
{
//send file request to server for the accepting the data
response = SendFileRequest(g_gsm_response,filename,9);
if(!response)
{
//receive the response of the server
response = GetResponceFromServer(g_gsm_response,&response,9);
if(response || g_gsm_response) response = -1;
else
{
//If record is successfully sent to the server then update the FlagGSM flag of the record as well as
//Update the database
g_update_record = 1;
livedata->FlagGSM = 1;
updatedata->MilkCollectionId = livedata->MilkCollectionId;
DPUDBLib_search_milk_collection_entry_by_record(&updatedata);
DPUDBLib_edit_milk_collection_entry(&updatedata,&livedata);
g_update_record = 0;
}
}
//remove the temp file generated
remove(filename);
}
}
}
else
{
//if connection is not successfully done then try to reconnect the server
ShowMessageBox(msgbox_text[156], MB_ICONERROR);
goto create_connection;
}
}
I think there is basic mistake here. By declaring the static variable connect_ret in InitializeDataCard, it does not mean in any way that it is going to be the same variable declared in ConnectToServer. Therefore, the first function will always have the same behaviour...
I think you'll need a global variable (i.e. not defined in a function) and possibily some kind of synchronization, because when you create the thread, then probably it won't be executed immediately, so even if you have a global variable, you can't check against it until you know that it has been correctly set.
I'm using AuthorizationExecuteWithPriveleges to execute bash commands from my App with admin privilege. I have found really weird issue. Here what I'm using
FILE *pipe=nil;
OSStatus err;
AuthorizationRef authorizationRef;
char *command= "/bin/chmod";
char *args[] = {"644","folderPath", nil};
if(err!=0)
{
err = AuthorizationCreate(nil,
kAuthorizationEmptyEnvironment,
kAuthorizationFlagDefaults,
&authorizationRef);
}
NSLog(#"test");
err = AuthorizationExecuteWithPrivileges(authorizationRef,
command,
kAuthorizationFlagDefaults,
args,
&pipe);
After calling this function about 40 times, it's starting respond very slowly. And after it is will just die,and freeze application, and I have no idea what is happening to this.It doesn't show the log "test", and doesn't do anything, after calling about 40 times.
It doesn't matter what Bash command or what arguments you are using. It still does the same thing. What is wrong with this ? The reason I'm using this, because my App needs to run on 10.5 as well.
Please if someone have idea, what can I do. I really appreciate it. I need ASAP. Thanks
Looked at this a bit more, and cooked up the following example, presented without warranty, but which works for me for thousands of invocations of AuthorizationExecuteWithPrivileges without issue:
void DoOtherStuff(AuthorizationRef auth, char* path);
void DoStuff(char* path)
{
AuthorizationItem foo;
foo.name = kAuthorizationRightExecute;
foo.value = NULL;
foo.valueLength = 0;
foo.flags = 0;
AuthorizationRights rights;
rights.count = 1;
rights.items = &foo;
AuthorizationRef authorizationRef;
OSStatus err = errAuthorizationSuccess;
if (errAuthorizationSuccess != (err = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &authorizationRef)))
{
NSLog(#"Error on AuthorizationCreate: %lu", (long)err);
return;
}
for (NSUInteger i = 0; i < 5000; i++)
{
NSLog(#"Doing run: %lu", (long)i+1);
DoOtherStuff(authorizationRef, "/tmp/foo");
}
if (errAuthorizationSuccess != (err = AuthorizationFree(authorizationRef, kAuthorizationFlagDefaults)))
{
NSLog(#"Error on AuthorizationFree: %lu", (long)err);
return;
}
}
void DoOtherStuff(AuthorizationRef authorizationRef, char* path)
{
OSStatus err = errAuthorizationSuccess;
FILE *pipe = NULL;
#try
{
char *args[] = {"644", path, NULL};
if (errAuthorizationSuccess != (err = AuthorizationExecuteWithPrivileges(authorizationRef,
"/bin/chmod", kAuthorizationFlagDefaults, args, &pipe)))
{
NSLog(#"Error on AuthorizationExecuteWithPrivileges: %lu", (long)err);
return;
}
int stat;
wait(&stat);
NSLog(#"Success! Child Process Died!");
}
#finally
{
if (pipe)
fclose(pipe);
}
}
What Chris Suter said is dead on. What happens when you call AuthorizationExecuteWithPrivileges is that it fork()s your process and then exec()s the requested process (chmod in this case) from the child process. The child process won't be reaped until someone calls wait(), but that's hard because we don't get the PID of the child out of AuthorizationExecuteWithPrivileges (it would have been returned by fork()). As he said, if you're sure there aren't other threads spawning processes at the same time (i.e. your thread is the only one creating child processes), then you can just call the non-PID specific version of wait() like I do in this example.
If you don't call wait() then what happens is you accumulate these zombie child processes that are all waiting to be reaped. Eventually the OS says "no more."
I feel kinda bad posting this, since it's just a retread of what Chris Suter said; I've upvoted his answer.
For completeness, here's a reworked version of that example that achieves the goal by ignoring SIGCHLD instead of calling wait. It also is presented without warranty, but works for me.
void DoOtherStuff(AuthorizationRef auth, char* path);
void DoStuff(char* path)
{
AuthorizationItem foo;
foo.name = kAuthorizationRightExecute;
foo.value = NULL;
foo.valueLength = 0;
foo.flags = 0;
AuthorizationRights rights;
rights.count = 1;
rights.items = &foo;
AuthorizationRef authorizationRef;
OSStatus err = errAuthorizationSuccess;
struct sigaction oldAction;
struct sigaction newAction;
newAction.__sigaction_u.__sa_handler = SIG_IGN;
newAction.sa_mask = 0;
newAction.sa_flags = 0;
if(0 != sigaction(SIGCHLD, &newAction, &oldAction))
{
NSLog(#"Couldn't ignore SIGCHLD");
return;
}
#try
{
if (errAuthorizationSuccess != (err = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &authorizationRef)))
{
NSLog(#"Error on AuthorizationCreate: %lu", (long)err);
return;
}
for (NSUInteger i = 0; i < 1000; i++)
{
NSLog(#"Doing run: %lu", (long)i+1);
DoOtherStuff(authorizationRef, "/tmp/foo");
}
if (errAuthorizationSuccess != (err = AuthorizationFree(authorizationRef, kAuthorizationFlagDefaults)))
{
NSLog(#"Error on AuthorizationFree: %lu", (long)err);
return;
}
}
#finally
{
const struct sigaction cOldAction = oldAction;
if(0 != sigaction(SIGCHLD, &cOldAction, NULL))
{
NSLog(#"Couldn't restore the handler for SIGCHLD");
return;
}
}
}
void DoOtherStuff(AuthorizationRef authorizationRef, char* path)
{
OSStatus err = errAuthorizationSuccess;
FILE *pipe = NULL;
#try
{
char *args[] = {"644", path, NULL};
if (errAuthorizationSuccess != (err = AuthorizationExecuteWithPrivileges(authorizationRef,
"/bin/chmod", kAuthorizationFlagDefaults, args, &pipe)))
{
NSLog(#"Error on AuthorizationExecuteWithPrivileges: %lu", (long)err);
return;
}
NSLog(#"Success!");
}
#finally
{
if (pipe)
fclose(pipe);
}
}
What you’re trying to do is not a good idea.
I would guess that you have a bug else where in your code, perhaps in the monitoring of the pipe. We need to see the rest of your code.
If you do pursue this approach, you will need to take care and make sure that you clean up zombie processes which can be awkward when using AuthorizationExecuteWithPrivileges because you don’t get the child process ID. You’ll either need to ignore SIGCHLD, or if you can be certain there are no other threads that are doing things with processes at the same time, you can just issue a call to wait.
You’ve also got to make sure you clean up the pipe as otherwise you’ll run out of file descriptors.
The system is far less forgiving about you leaking file descriptors or processes than it is about leaking memory.
The correct approach for your problem is probably to write a helper tool and then communicate with your helper tool asking it to perform privileged operations on your behalf. That way you’ll only be running your helper tool once. You should be able to read more about this in Apple’s documentation.
You should initialize err (due to the first IF statement), because it's no guaranteed to be 0. However, it probably is, so you are skipping AuthorizationCreate, so the authorized session isn't created.
Basically you are passing authorizationRef uninitialized to AuthorizationExecuteWithPrivileges which might be a problem.
Plus like others, I would put AuthorizationFree(authorizationRef,kAuthorizationFlagDefaults); at the end as well when you do use AuthorizationCreate to free the memory.
Also it's worth noting that AuthorizationExecuteWithPrivileges is deprecated as of OS X v10.7, but I think you know that since you said you are trying to run on 10.5
EDIT: You might want to check the status of err too after running AuthorizationCreate
if ( err != errAuthorizationSuccess ) {
return;
}
... you should check err after AuthorizationExecuteWithPrivileges as well.
I think I might know what's going on here: Try handling the pipe correctly (i.e. don't pass NULL, and make sure you close it). Weird stuff like this also happens with NSTask if you fail to give it a STDIN pipe. This page over at cocoadev.com explains:
An NSTask will break Xcode's debug log entirely if you execute
ANYTHING related with sh or bash (including scripts). printf, NSLog;
all will cease to function as soon as the task has been launched. Even
things like right clicking on an object in the debugger will yield
nothing (straight GDB still prints though). ... I figured out that the
problem lies with standard input, of all things. A quick fix for this
would be to set your standard input up to something random, like a
pipe, and do nothing with it.
This stumped me for hours and hours (albiet with NSTask and not AS). I would be surprised if the odd behavior you're seeing isn't related. Make sure you're not passing NULL, and then make sure that you're cleaning up the file handle that AuthorizationExecuteWithPrivileges creates for you, by calling fclose, etc.
I'm not 100% sure, but the "NSLog stopped working" symptom caught my eye.
I'm messing around with the PushSource sample filter shipped with the DirectShow SDK and I'm having the following problem:
When I call IMediaControl::Run(), it returns S_FALSE which means "the graph is preparing to run, but some filters have not completed the transition to a running state". MSDN suggests to then call IMediaControl::GetState() and wait for the transition to finish.
And so, I call IMediaControl::GetState(INFINITE, ...) which is supposed to solve the problem.
However, to the contrary, it returns VFW_S_STATE_INTERMEDIATE even though I've specified an infinite waiting time.
I've tried all three variations (Bitmap, Bitmap Set and Desktop) and they all behave the same way, which initially lead me to believe there is a bug in there somewhere.
However, then, I tried using IFilterGraph::AddSourceFilter to do the same and it did the same thing, which must mean it's my rendering code that is the problem:
CoInitialize(0);
IGraphBuilder *graph = 0;
assert(S_OK == CoCreateInstance(CLSID_FilterGraph, 0, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void**)&graph));
IBaseFilter *pushSource = 0;
graph->AddSourceFilter(L"sample.bmp", L"Source", &pushSource);
IPin *srcOut = 0;
assert(S_OK == GetPin(pushSource, PINDIR_OUTPUT, &srcOut));
graph->Render(srcOut);
IMediaControl *c = 0;
IMediaEvent *pEvent;
assert(S_OK == graph->QueryInterface(IID_IMediaControl, (void**)&c));
assert(S_OK == graph->QueryInterface(IID_IMediaEvent, (void**)&pEvent));
HRESULT hr = c->Run();
if(hr != S_OK)
{
if(hr == S_FALSE)
{
OAFilterState state;
hr = c->GetState(INFINITE, &state);
assert(hr == S_OK );
}
}
long code;
assert(S_OK == pEvent->WaitForCompletion(INFINITE, &code));
Anyone knows how to fix this?
IBaseFilter *pushSource = 0;
graph->AddSourceFilter(L"sample.bmp", L"Source", &pushSource);
AddSourceFilter adds a default source filter, I don't think it will add your pushsource samplefilter.
I would recommend to add the graph to the ROT, so you can inspect it with graphedit.
And what happens if you don't call GetState()?
hr = pMediaControl->Run();
if(FAILED(hr)) {
/// handle error
}
long evCode=0;
while (evCode == 0)
{
pEvent->WaitForCompletion(1000, &evCode);
/// other code
}
Open GraphEditPlus, add your filter, render its pin and press Run. Then you'll see states of each filter separately, so you'll see what filter didn't run and why.
During the modification of an existing ATL COM object I came across an article from the "The Old New Thing" blog called "The ways people mess up IUnknown::QueryInterface" and there was a discussion in the comments section that started when one of the respondents (Norman Diamond) pointed out that that in one of the article's examples that the cast to void** was incorrect.
However when I try and correct my code to do the casting properly I end up with a memory leak.
The example was as follows:
IShellFolder *psf = some object;
IUnknown *punk = NULL;
psf->QueryInterface(IID_IUnknown, (void**)&punk);
Norman said
punk is not a void*. punk is an IUnknown*.
void** is not a universal pointer type. void* is a universal pointer type, and char* and relatives are grandparented in to be equivalent in that way, but void** is not.
If you want to obey the calling convention and avoid horrible deaths, you have to do this:
IUnknown *punk;
void *punkvoid;
psf->QueryInterface(IID_IUnknown, &punkvoid);
punk = (IUnknown *)punkvoid;
Lots of other MSDN contributors made the same identical mistake.... some people might say that it works in all VC++ implementations to date, but that doesn't make it correct code, and it's still violating the calling convention.
In light of this I went to change my old code - which was as follows:
#include <comdef.h>
...
HRESULT FinalConstruct()
{
if (m_dwROTCookie != 0)
return E_FAIL;
//Check whether there already is an instance of the Object
IUnknownPtr pUnk = NULL;
if (GetActiveObject(CLSID_Object, NULL, &pUnk) == S_OK)
{
TRACE_WARNING("An instance of Object already exists in the current context");
return S_OK;
}
HRESULT hr = QueryInterface(IID_IUnknown, reinterpret_cast<void **>(&pUnk));
hr = RegisterActiveObject(pUnk, CLSID_Object, ACTIVEOBJECT_WEAK, m_dwROTCookie);
if (FAILED(hr))
return hr;
hr = CoLockObjectExternal(pUnk, TRUE, TRUE);
pUnk = NULL;
ATLASSERT(m_dwRef == 2);
return hr;
}
I then changed it as follows:
HRESULT FinalConstruct()
{
if (m_dwROTCookie != 0)
return E_FAIL;
//Check whether there already is an instance of the Object
IUnknownPtr pUnk = NULL;
if (GetActiveObject(CLSID_Object, NULL, &pUnk) == S_OK)
{
TRACE_WARNING("An instance of Object already exists in the current context");
return S_OK;
}
void* pUnkVoid = NULL;
HRESULT hr = QueryInterface(IID_IUnknown, &pUnkVoid);
if (SUCCEEDED(hr)
{
pUnk = reinterpret_cast<IUnknown*>(pUnkVoid);
hr = RegisterActiveObject(pUnk, CLSID_Object, ACTIVEOBJECT_WEAK, m_dwROTCookie);
if (FAILED(hr))
return hr;
hr = CoLockObjectExternal(pUnk, TRUE, TRUE);
pUnk = NULL;
}
ATLASSERT(m_dwRef == 2);
return hr;
However now my application has a memory leak from this the COM Object
You likely have a memory leak because you call GetActiveObject() and QueryInterface() which upon success increment the reference count on the object, but don't call Release() later to decrement the reference count.
Mmm, I think that rather than assigning the void* to pUnk I should be using:
pUnk.Attach(reinterpret_cast<IUnknown*>(pUnkVoid));