Re: losing dimensions in metafile - C / C++ / MFC Discussion Boards

WhiteSky

I have a CTreeCtl drived class which implement OnContexMenu();
but i don't know why the popup menu would popup only when i pressed the scrollbar using right button!
Somebody would tell me why?

You may want to consider handling the treeview's NM_RCLICK notification instead of WM_CONTEXTMENU.

See How To Display a Context Menu for CTreeCtrl[^] for details.

Mark

Mark Salsbery
Microsoft MVP - Visual C++

This episode brought to you by the letter Z

I have a word processing app (no source) in which a user can copy bitmaps onto the client area, resize them on the client, and then paste them somewhere else in the client area with their new size (nothing unusual here).

I'm intercepting the paste command msgs of this app (through subclassing, etc.), and for the moment, all I'm trying to do is retrieve the content of the clipboard, duplicate it, and replace the original clipboard content with the duplicate. (not my ultimate objective obviously). However, no matter how I try to retrieve the data and put it back to the clipboard, its apparently being altered, because the bitmap dimensions are destroyed, and when the app pastes the item, its it has the original dimensions (not the user-resized dimensions).

The bitmap is being copied by the app as a metafile, so when I intercept the paste message, I'm retrieving it and putting it back to the clipboard as a metafile. The data can be retrieved from the clipboard as an enhanced metafile or plain metafile, and it makes no difference. I've tried Copy[Enh]MetaFile, Get[Enh]MetaFileBits/Set[Enh]MetaFileBits, Create[Enh]MetaFile/Play[Enh]MetaFile, etc - no matter how I try to copy the clipboard data and just put it back unchanged, everthing *is* unchanged, EXCEPT the dimensions, which always lose the most current dimensions and instead revert to the original dimensions.

I'm confused (not a rare event Smile | :)

). Are you actually changing the metafile before you put it
back on the clipboard?

If so, what methods/APIs are you using to do so?

Mark

Mark Salsbery
Microsoft MVP - Visual C++

This episode brought to you by the letter Z

Mark Salsbery wrote:
I'm confused (not a rare event ). Are you actually changing the metafile before you put it
back on the clipboard?

If so, what methods/APIs are you using to do so?

As I stated, my goal for the moment is just to succeed in copying the data from the clipboard and replacing the content of the clipboard with the copy. However, the metafile's dimensions I put back to the clipboard are screwed up somehow.

Here's one code sample:

HENHMETAFILE henh = (HENHMETAFILE)GetClipboardData(CF_ENHMETAFILE);
int nSize = GetEnhMetaFileBits(henh,0,NULL);
BYTE* data = new BYTE[nSize];
GetEnhMetaFileBits(henh,nSize,data);
EmptyClipboard();
henh = SetEnhMetaFileBits(nSize,data);
SetClipboardData(CF_ENHMETAFILE,henh);

(yeah, its straight SDK.)
The copy that's put back has bitmap dimension info that has been altered. I say that, because if I don't mess with the clipboard at all, (as above) the bitmap is pasted with the dimensions most recently altered by user. With the code above, (which seemingly does nothing but replace the clipboard with a duplicate) when the paste is completed, the image has reverted to some previous dimensions.

In the above, I'm using GetEnhMetaFileBits/SetEnhMetaFileBits. However the same result occurs when just using CopyEnhMetaFile (as well as with yet another method for copying the metafile).

-- modified at 13:00 Monday 9th July, 2007

Force Code wrote:
the bitmap is pasted with the dimensions most recently altered by user.

Probably a dumb question, but are you creating a new metafile created by drawing using the new
dimensions or editing an existing metafile when the user alters something?

Also, what do you mean by "the bitmap is pasted"?

Mark

Mark Salsbery
Microsoft MVP - Visual C++

This episode brought to you by the letter Z

Mark Salsbery wrote:
Probably a dumb question, but are you creating a new metafile created by drawing using the new
dimensions or editing an existing metafile when the user alters something?

Also, what do you mean by "the bitmap is pasted"?

OK, here's the scenario:

A user copies a bitmap from some source to the client area of this application. Then, in the client area, he resizes the bitmap by dragging an edge of it. Then he copies this resized bitmap (ctrl-c) and pastes it somewhere else in the client area (ctrl-v). Once he resized the image, the application converted it from a bitmap to a memory metafile. So, when it is copied with ctrl-c, it is copied as a metafile and then pasted as a metafile.

What I have done is just intercept the paste message right before the image (i.e. the meta file) is pasted. Then, for now, i.e. *strictly for testing purposes*, all I've done is make a duplicate of the clipboard data (i.e. the metafile), and replaced the clipboard data with this duplicate metafile. So basically NOTHING should be changed *AT ALL*. But when the image is pasted, its size has reverted to what it was before the user resized it.

Understand?

Maybe I should have asked to begin with - have you ever copied metafiles from the clipboard.

Here is the complete code I used to intercept the paste msg:

//following excerpt is from a subclassed WndProc in a DLL
//injected into an application's address space:
.
.
.
case CM_PASTE_WP: {
OpenClipboard(hwnd);
if (IsClipboardFormatAvailable(CF_ENHMETAFILE)) {
HENHMETAFILE henh = (HENHMETAFILE)GetClipboardData(CF_ENHMETAFILE);
int nSize = GetEnhMetaFileBits(henh,0,NULL);
BYTE* data = new BYTE[nSize];
GetEnhMetaFileBits(henh,nSize,data);
EmptyClipboard();
henh = SetEnhMetaFileBits(nSize,data);
SetClipboardData(CF_ENHMETAFILE,henh);
}
CloseClipboard();
}
break;

.
.
.

return CallWindowProc(r_obj->WordProcPrev,hwnd,message,wParam,lParam);

}

Force Code wrote:
OK, here's the scenario

Thanks!

I don't see anything in THAT code that changes anything in the metafile.

It seems to me you may want to look in the "Once he resized the image, the application converted
it from a bitmap to a memory metafile" code and/or the PlayEnhMetaFile() code and make sure
everything is consistent with the DCs (resolution/units) and bounding rects.

Mark

Mark Salsbery
Microsoft MVP - Visual C++

This episode brought to you by the letter Z

any chance the app is caching them ?

image processing toolkits | batch image processing | blogging

Chris Losinger wrote:
any chance the app is caching them ?

Not entirely sure what you're implying.

The only state change in the process is that code snippet I supplied where I manipulate the clipboard. Comment that out, and everything is back to normal. The only conclusion I can reach is that what I'm putting back to the clipboard isn't really a copy. I've just been working with metafiles for the last couple of days.

Recently I try to convert mpg file to avi programmly, but it doesn't work , i am a beginner Smile | :)

,the code list below, anyone can give me suggestion? thanks.

hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,
IID_IGraphBuilder, (void **)&pGraph);
IBaseFilter *pSrcFilter = NULL;
hr = pGraph->AddSourceFilter(lpMpgFile, L"Source Filter", &pSrcFilter);
hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC, IID_ICaptureGraphBuilder2, (void **)&pBuilder);
pBuilder->SetFiltergraph(pGraph);
hr = pBuilder->SetOutputFileName(&MEDIASUBTYPE_Avi, lpOutputAviFile, &pMux, NULL);
hr = pGraph->AddFilter(pMux, L"Mux Filter");
IBaseFilter *pMpeg2Splitter= NULL;
hr = CoCreateInstance(CLSID_MPEG2Demultiplexer, 0, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (void **)&pMpeg2Splitter);
hr = pGraph->AddFilter(pMpeg2Splitter, L"Mpeg2 Splitter");
IMpeg2Demultiplexer *pDemux = NULL;
hr = pMpeg2Splitter->QueryInterface(IID_IMpeg2Demultiplexer, (void**)&pDemux);
AM_MEDIA_TYPE pMediaType;
memset(&pMediaType, 0x0, sizeof(pMediaType));
pMediaType.majortype = MEDIATYPE_Video;
pMediaType.subtype = MEDIASUBTYPE_MPEG2_VIDEO;
pMediaType.formattype = FORMAT_MPEG2Video;
pMediaType.bFixedSizeSamples = FALSE;
pMediaType.bTemporalCompression = TRUE;
pMediaType.lSampleSize = 0;
MPEG2VIDEOINFO video_info;
memset(&video_info, 0x0, sizeof(MPEG2VIDEOINFO));
pMediaType.cbFormat = sizeof(MPEG2VIDEOINFO);
pMediaType.pbFormat = (BYTE *)&video_info;

AM_MEDIA_TYPE pMediaAudioType;
memset(&pMediaAudioType, 0x0, sizeof(pMediaAudioType));
pMediaAudioType.majortype = MEDIATYPE_Audio;
pMediaAudioType.subtype = MEDIASUBTYPE_MPEG1Payload;
pMediaAudioType.formattype = FORMAT_WaveFormatEx;
pMediaAudioType.bFixedSizeSamples = FALSE;
pMediaAudioType.bTemporalCompression = FALSE;
pMediaAudioType.lSampleSize = 0;
MPEG1WAVEFORMAT audio_info;
memset(&audio_info, 0x0, sizeof(MPEG1WAVEFORMAT));
pMediaAudioType.cbFormat = sizeof(MPEG1WAVEFORMAT);
pMediaAudioType.pbFormat = (BYTE *)&audio_info;

IPin *pPin0 = NULL;
hr = pDemux->CreateOutputPin(&pMediaType, L"Video Output", &pPin0);
IMPEG2StreamIdMap *pStreamIdMap = NULL;
hr = pPin0->QueryInterface(IID_IMPEG2StreamIdMap, (void **)&pStreamIdMap);
hr = pStreamIdMap->MapStreamId(0xC0, MPEG2_PROGRAM_ELEMENTARY_STREAM, 0, 0);
IPin *pPin1 = NULL;
hr = pDemux->CreateOutputPin(&pMediaAudioType, L"Audio Output", &pPin1);
IMPEG2StreamIdMap *pStreamIdMap1 = NULL;
hr = pPin1->QueryInterface(IID_IMPEG2StreamIdMap, (void **)&pStreamIdMap1);
hr = pStreamIdMap1->MapStreamId(0xE0, MPEG2_PROGRAM_ELEMENTARY_STREAM, 0, 0);

//error occurs in below code
hr = pBuilder->RenderStream(NULL, NULL, pSrcFilter, NULL, pMpeg2Splitter);
hr = pBuilder->RenderStream(NULL, NULL, pMpeg2Splitter, NULL, pMux);
hr = pBuilder->RenderStream(NULL, NULL, pMpeg2Splitter, NULL, pMux);
.......

why doen't it work ?
what error do you get ?

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A few potential problems...

SetOutputFileName() adds the AVI mux filter to the graph - you don't need to add it manually.

I'm not sure why you're using the MPEG2 splitter AND muxer.
Regardless, you'll need an mpeg2 decoder for it to work (I don't think there's one included with
Windows).

I would try simplifying your graph building first. Compare your method to the method shown here:
Building the Recompression Graph[^]

Also testing it in graphedit.exe can help to make sure you're using the correct filters.

MArk

Mark Salsbery
Microsoft MVP - Visual C++

This episode brought to you by the letter Z

Thanks you very much! I get the root of problem by using graphedit.exe: the input mpg file is a mpeg-1 file, so the file source filer outputs mpeg1-stream, but mpeg2demultiplexer requires mpeg2-stream, when it's running, it popup many DCDSPFilter.ax window and show a error message: These filters cannot agree on a connection, verify type compatibility of input pin and output pin. after I change the mpeg2demultiplexer to mpeg1streamsplitter and add the mpeg1 decoder, it runs OK.
But this remains a problem: how can I get the type of mpeg file? I have to identify the file type(mpeg1 or mpeg2) programmly so that I can add the according filter. ???

liur17 wrote:
how can I get the type of mpeg file? I have to identify the file type(mpeg1 or mpeg2) programmly
so that I can add the according filter. ???

2 possible ways I can think of:

1) After the successful AddSourceFilter() call, obtain a IFileSourceFilter interface from the
source filter and use the IFileSourceFilter::GetCurFile() method to get the media type (looking
for MPEG subtypes).

2) Let intelligent connect insert the necessary filters for you.
Use AddSourceFilter() and SetOutputFileName() like you're doing, add the compressor filter you
want for the destination AVI file, and use RenderStream() to connect the filters added by
AddSourceFilter() and SetOutputFileName(), with the intermediate compressor filter.

If you have suitable MPEG filters installed, intelligent connect will insert them for you.
If not, RenderStream() will fail.

A second call to RenderStream() will connect an audio stream to the AVI muxer if it's available
(again, see here[^] for an example.

You can try this in graphedit by manually adding a filesource async filter, setting the input
filename, add a filewriter filter, set the output filename, add an AVI Mux filter, and connect
the filesource to the filewriter filter.

Mark

Mark Salsbery
Microsoft MVP - Visual C++

This episode brought to you by the letter Z

I got it. Thank you for your kind reply.

Do you get any error?

WhiteSky

1. For UI Localization: Is is possible to have VC++.Net 2003 application with resources in .rc file for one language (English) and resouce only dll for another language (Japanese)?
2. What modification in code required to handle the switching between .rc and dll resources @ runtime to display the appropriate UI resources in the corresponding language? (either after changing the locale of the English OS or running the application on Japanese OS)?

Thanks & Regards,
Neeraj

Hi all,

Part of the app I'm developing downloads fairly large files via HTTP. Everything works great, except for when the clients network connection is dropped. I have tried using WSAGetLastError, but it always returns 0. The thread just keeps pulling mystical data, then it just stops after about 300 or so KB. No crash or anything.

do
{
    len = recv( Socket, buffer, sizeof( buffer ), 0 );

    if( ( pos + len ) > contentLength )
        return 0;

    memcpy( body + pos, buffer, len );
    pos += len;

    int error = WSAGetLastError( );

    if( error )
        return 0;

} while( len > 0 );

To simulate a network drop I am turning my modem off.

Has anyone got a solution to this?

Silly me. I just realised that the socket was blocking.

I set it to non-blocking and it works fine.

<br />
class Foo<br />
{<br />
private:<br />
	int (*pf)(int);<br />
<br />
public:<br />
	Foo()<br />
	{<br />
		this->pf = &Foo::cube; // error c2440<br />
	}<br />
<br />
private:<br />
	int cube(int n) {return n*n*n;}<br />
<br />
};<br />

how do i get that statement in the constructor working? any help is greatly appreciated.

eirche wrote:
int (*pf)(int);

Should make this a member function pointer. So it should be...

int (<code>Foo::</code>*pf)(int);

Nibu thomas
A Developer

Code must be written to be read, not by the compiler, but by another human being.

http:\\nibuthomas.wordpress.com

thank you for the quick response. it's working like a charm.

set the cube() member function either static or global...

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