C / C++ / MFC

25-Oct-02 8:21

I've tried to load a bitmap sequence using VB.NET and .NET framework. Here's the spec:

(a) class Bitmap("filepath")
(b) 7kB per bitmap (or frame)
(c) 588 bitmaps in sequence - Therefore, preloading the entire sequence is impossible (will consume over 250MB RAM!!)
(d) 15 frames per second

The basic process is as follows:
(a) preload a certain number of bitmap
(b1) start a thread to start rendering pre-loaded bitmap to screen
(b2) at the same time, start another thread to continue loading the rest of the sequence into memory (bitmaps)

However, even at a low 15 frames per second, the buffer is emptied too fast and frames loading (b2) is not able to keep in pace with frames rendering (b1)... But on the other hand, pre-load the entire sequence is just impossible!!? I wonder how they do this in Windows Media Player or Adobe Premier. Premier was able to render my bitmap sequence without any jitter on the same machine!? So, can I conclude that "class Bitmap" constructor from .NET framework is not very efficient in loading bitmap? Should I try CBitmap and build a MFC app to test it out? Or should I build a DirectDraw SDI...?

What can I do? I was considering using Quicktime player (downloaded Quicktime SDK and got the sample working). But this option requires that we go thru the proper licencing process... so screw that...

Thanx!

devvvy25-Oct-02 8:23

devvvy

25-Oct-02 8:23

forgot my email... my email is:

norman_lm_fung@hotmail.com

thanks!

norm

Paul M Watt25-Oct-02 8:44

Paul M Watt

25-Oct-02 8:44

You can preload the images if you would like, even though you have 250 MB loaded into the heap, it will simply be paged, so you will not really be using 250 MB of ram. When the system needs the memory page that contains the next set of images, it will swap the page into memory.

The media players use a compressed form of the images and therefore preload all of the data (images) into memory, then render the frame when it is time to be displayed or at least pre-render it in a cache waiting to be displayed.

What I would suggest for you, if this is a possibility, is to convert your images to an AVI then use one of the media players to display the AVI.

Good Luck

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Anonymous25-Oct-02 12:55

25-Oct-02 12:55

any idea where to get free avi player control? free for commercial distribution?

i am aware of CAnimateCtrl (VC6) and MCIWnd class (prolly also for VC6 only). Will u recommend....? And if I want to go with VB.NET, then is there any free control available?

mapping and unmapping a resource

Paul M Watt25-Oct-02 21:19

Paul M Watt

25-Oct-02 21:19

You could just use the standard windows animation control. There are only about 6-10 functions that are required to use it. That is probably the control that is wrapped in the CAnimateCtrl of MFC.

Otherwise if you need advanced features you could look into the media player or even DirectShow.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Template confusion

Todd Smith25-Oct-02 8:09

Todd Smith

25-Oct-02 8:09

Browsing through the zlib code I'm confused by the template code shown below. How or when would you make use of it? Can you give an example?

class ozstream
{
    public:
        ozstream() : m_fp(0), m_os(0) {
        }

// snip...

        ostream& os() {
            if (m_os == 0) m_os = new ostrstream;
            return *m_os;
        }

        void os_flush() {
            if (m_os && m_os->pcount()>0) {
                ostrstream* oss = new ostrstream;
                oss->fill(m_os->fill());
                oss->flags(m_os->flags());
                oss->precision(m_os->precision());
                oss->width(m_os->width());
                ::gzwrite(m_fp, m_os->str(), m_os->pcount());
                delete[] m_os->str(); delete m_os; m_os = oss;
            }
        }

};

/*
 * Ascii write with the << operator;
 */
template <class T>
inline ostream& operator<<(ozstream& zs, const T& x) {
    zs.os_flush();
    return zs.os() << x;
}

Todd Smith

Re: Template confusion

Navin25-Oct-02 10:30

Navin

25-Oct-02 10:30

It looks like it is simply overloading the << operator for arbitrary template types. Looking at the code, this means the << operator should work for any type T that the ostream operator << overloads.

So you should be able to do something like this:

<br />
ozstream :bob:;<br />
int i;<br />
char ch;<br />
double d;<br />
<br />
:bob: << i;<br />
:bob: << ch;<br />
:bob: << d;<br />

and it will Do The Right Thing. If you try to use << on a weird type that cannot be passed to an ostream, it will give you an error.

Even a broken clock is right twice a day.

Tom Wright25-Oct-02 7:36

Tom Wright

25-Oct-02 7:36

I know that I need to use WNetAddConnection2 to map a network resource but when I use WNetCancelConnection, and then try to map again I get an error 1312. I noticed that I can use WNetUseConnection to make my mapping but how do I disconnect a mapped resource on my pc? Thanks

Tom Wright
Programmer
tawright915@yahoo.com

flexgrid

Anthony988725-Oct-02 7:05

Anthony9887

25-Oct-02 7:05

I'm trying to figure a way to print the flexgrid. Is there away?

Thanks

Don't show all resource icons in explorer?

Anonymous25-Oct-02 6:00

Re: Don't show all resource icons in explorer?

25-Oct-02 6:00

Hi,
when I make a shortcut to my application and choose a different icon, explorer shows me all icons from my resource. I want only 1 or two icons being possible for the explorer, how?

Thanks for your help!

Anonymous25-Oct-02 22:08

25-Oct-02 22:08

sounds like impossible mission?

htmlhelp question

ns25-Oct-02 5:59

25-Oct-02 5:59

I want to launch my help file so I did:

void CTestView::OnHtm() 
{
	// TODO: Add your command handler code here
	HtmlHelp(AfxGetMainWnd()->GetSafeHwnd(), "ice.chm", HH_DISPLAY_TOPIC,0);
}

But nothong happens when I press Help....??? Confused | :confused:

Appreciate your help,
ns

Ravi Bhavnani25-Oct-02 7:02

25-Oct-02 7:02

Try specifying the fully qualified filespec (eg: C:\SomeDir\ice.chm). In general, it's a good idea to always use fully qualified filespecs, since you can never rely on the default directory.

/ravi

Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com

Atlantys25-Oct-02 7:06

Atlantys

25-Oct-02 7:06

Ravi Bhavnani wrote:
use fully qualified filespecs

or just find out the directory that the exe is running in (::GetModuleFileName) and then use relatve paths. Big Grin | :-D

Ravi Bhavnani25-Oct-02 7:13

25-Oct-02 7:13

GetModuleFilename will certainly allow you to determine the app's directory and therefore create a fully qualified filespec. But it's not an alternative, as the word "or" implied!

/ravi

Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com

Atlantys25-Oct-02 8:20

Atlantys

25-Oct-02 8:20

Ravi Bhavnani wrote:
But it's not an alternative, as the word "or" implied!

True enough, but I understood your response to mean "hard-code the fully qualified path" (ie: "C:\mydir\myfile.chm"), instead of a concat-ed string from GetModuleFileName values.

either way, I think the question has been answered. Big Grin | :-D

Ravi Bhavnani25-Oct-02 9:32

25-Oct-02 9:32

Actually "C:\mydir\myfile.chm" is not a valid filespec.

either way, I think the question has been answered
I couldn't agree more. Smile | :)

/ravi

Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com

Bad topic id?

Ravi Bhavnani25-Oct-02 7:05

25-Oct-02 7:05

Maybe topic 0 doesn't exist? Try using HH_DISPLAY_TOC (pass 0 or NULL as the last arg) to see if it displays the TOC.

/ravi

Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com

Re: Bad topic id?

ns25-Oct-02 7:26

25-Oct-02 7:26

Okay. TOC does display my chm. Also the book had neglected to mention one vital step so I was getting only 1 pane. I persisted in comparing their finished project with the one I step-followed, and found the omission. I now have three panes. Onto more explorations...

Appreciate your help,
ns

Re: Bad topic id?

Ravi Bhavnani25-Oct-02 9:33