microsoft.public.win32.programmer.directx.sdk

Re: GraphEdit File Format

Alessandro Angeli [MVP::DigitalMedia] <nob...@nowhere.in.the.net>

[Sorry for the richtext, but I've used it to preserve the code formatting.]

cairn wrote:
> I am reading in a .grf file into a IStorage, and then
> getting the data with an IStream object. I am then using
> the IStream read to get the data in to an array of bytes.
> This is then compacted by getting every other byte and
> placing the result into a CString, but when I view the
> data I cannot see the 'CONNECTIONS' section of the file.
> I get the Filters section and then some binary. Please
> could someone explain a good way to extarct all the data,
> anothe way to get the data from the file so that we can
> do some processing on it.

Most likely you are parsing it wrong. Here is a full sample
parser:

--------- grfdump.cpp -------------------
#include <windows.h>
#include <errno.h>
#include <stdio.h>

#define TRACE(x) x
#define trace_open(x,y)
#define trace_close()
#ifdef UNICODE
# define trace wprintf
# define TRACEWSTR TEXT("s")
#else
# define trace printf
# define TRACEWSTR TEXT("S")
#endif
#define DWRESERVED 0
#define LPRESERVED NULL
#define TRACEHR_STR TEXT("0x%08lX")
#define TRACEHR_REF(hr) (hr)

#define LWS(c) ((c) == L'\n' || (c) == L'\r' || (c) == L'\t' || (c) == L' ')

LPWSTR token(LPWSTR p, LPWSTR* s1, LPWSTR* s2, WCHAR* q)
{
for(; LWS(*p); p++);
if(*q = *p == L'"' ? *p++ : L'\0') {
for(*s1 = p; *p != *q; p++); *s2 = p++;
} else {
for(*s1 = p; !LWS(*p); p++); *s2 = p;
}
return p;

}

HRESULT skip(LPWSTR s1, LPWSTR* p)
{
int n = wcstol(s1,NULL,10);
if(n == 0 && errno == ERANGE) return E_FAIL;
(*p)++; if(n > 0) *p = (LPWSTR)&((LPBYTE)(*p))[n];
return S_OK;

}

int wmain(int argc, LPWSTR argv[])
{
HRESULT hr = S_OK;
IStorage* pGrfFile = NULL;
IStream* pGrfData = NULL;
STATSTG rGrfStat;
int cb;
LPWSTR pb = NULL;
LPWSTR s1, s2, p;
WCHAR q;

TRACE(trace_open(NULL,zFalse));

TRACE(trace(TEXT("*** StgOpenStorage(L\"%") TRACEWSTR TEXT("\")...\n"),argv[1]));
if(S_OK != (hr = StgOpenStorage(argv[1],NULL,STGM_DIRECT|STGM_READ|STGM_SHARE_DENY_WRITE,NUL L,DWRESERVED,&pGrfFile))) goto exit;

TRACE(trace(TEXT("*** OpenStream(L\"ActiveMovieGraph\")...\n")));
if(S_OK != (hr = pGrfFile->OpenStream(L"ActiveMovieGraph",LPRESERVED,STGM_DIRECT|STGM_READ|S TGM_SHARE_EXCLUSIVE,DWRESERVED,&pGrfData))) goto exit;

TRACE(trace(TEXT("*** Stat()...\n")));
if(S_OK != (hr = pGrfData->Stat(&rGrfStat,STATFLAG_NONAME))) goto exit;

cb = (int)rGrfStat.cbSize.QuadPart;
TRACE(trace(TEXT("*** new BYTE[%d]...\n"),cb));
if(NULL == (pb = (LPWSTR)new BYTE[cb])) goto exit;

TRACE(trace(TEXT("*** Read(%d)...\n"),cb));
if(S_OK != (hr = pGrfData->Read(pb,(ULONG)cb,NULL))) goto exit;

p = pb;

p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> version = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));

p = token(p,&s1,&s2,&q);
if(0 == wcsnicmp(s1,L"FILTERS",s2-s1)) {
TRACE(trace(TEXT(">>> FILTERS\n")));
while(TRUE) {
p = token(p,&s1,&s2,&q);
if(0 == wcsnicmp(s1,L"CONNECTIONS",s2-s1)) break;
TRACE(trace(TEXT(">>> %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> name .... = L\"%.*") TRACEWSTR TEXT("\"\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> class_id = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
if(0 == wcsnicmp(s1,L"SOURCE",s2-s1) || 0 == wcsnicmp(s1,L"SINK",s2-s1)) {
TRACE(trace(TEXT(">>> file .... = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> file_name = L\"%.*") TRACEWSTR TEXT("\"\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
}
TRACE(trace(TEXT(">>> length .. = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
if(S_OK != (hr = skip(s1,&p))) goto exit;
}
}
if(0 == wcsnicmp(s1,L"CONNECTIONS",s2-s1)) {
TRACE(trace(TEXT(">>> CONNECTIONS\n")));
while(TRUE) {
p = token(p,&s1,&s2,&q);
if(0 == wcsnicmp(s1,L"CLOCK",s2-s1)) break;
if(0 == wcsnicmp(s1,L"END",s2-s1)) break;

TRACE(trace(TEXT(">>> %.*") TRACEWSTR,s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(" [L\"%.*") TRACEWSTR TEXT("\"]"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(" -> %.*") TRACEWSTR,s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(" [L\"%.*") TRACEWSTR TEXT("\"]\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> sample_size ........ = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> major_type ......... = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> subtype ............ = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> fixed_sample_size .. = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> temporal_compression = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> length(?) .......... = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> format_type ........ = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> length ............. = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
if(S_OK != (hr = skip(s1,&p))) goto exit;
p++; /// where is this L'\0' terminator documented??
}
}
if(0 == wcsnicmp(s1,L"CLOCK",s2-s1)) {
TRACE(trace(TEXT(">>> CLOCK\n")));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> required = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
p = token(p,&s1,&s2,&q);
TRACE(trace(TEXT(">>> clock_id = %.*") TRACEWSTR TEXT("\n"),s2-s1,s1));
}
if(0 == wcsnicmp(s1,L"END",s2-s1)) {
TRACE(trace(TEXT(">>> END\n")));
}

exit:
TRACE(trace(TEXT("*** hr = ") TRACEHR_STR TEXT("\n"),TRACEHR_REF(hr)));
if(pb) delete [] (LPBYTE)pb;
if(pGrfData) pGrfData->Release();
if(pGrfFile) pGrfFile->Release();
TRACE(trace_close());
return hr;

}

-----------------------------------------

// Alessandro Angeli
// MVP :: Digital Media
// a dot angeli at psynet dot net