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Sugantha wrote: May I know the difference between MPEG4 SD and MPEG4 HD.
Just a guess but "SD" is Standard Definition and "HD" is High Definition?
Doing my part to piss off the religious right.
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Hai,
Thanks for your reply.But I want to know what will be difference in the picturization or resolution or aspect ratio or any other difference between them..
Thanks and Regards
T.Angeline
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Sugantha wrote: Thanks for your reply.But I want to know what will be difference in the picturization or resolution or aspect ratio or any other difference between them..
the difference is more related to the level of compression.
SD=640x480 or 720x480 (approximately...) and there is the interlace and progressive issue, most SD are interlaced, which halves the data on the 30hz cycle and alternates the frame such that 60hz signal is generated. You are never looking at more than half the picture as "new" but since the other half is kept around it looks higher quality than you think it is.
HD is more difficult because you have 720i/p vertical and 1080i/p vertical and you have wide and standard aspects. But we will assume it is the max HD with 1920x1080p
The screen then has about 6.75 times more pixels of detail. Six times detail is a lot of information. BUT, since you also have compression issues.... if you keep the compression the same, you need about 6.75 times the storage space for equal compression level videos on SD and HD. But if you increase the compression on HD you can store a signal in the same space by increasing the compression 6.75 times (approximately -- mpeg is never linear).
so it really comes down to the video source. crappy source expanded big looks worse because the extra 6.75 times resolution you can see more of the errors in the lossy compression (called compression artifacts) and SD has fewer pixels so doesn't show as much compression artifacts. If you have equally compressed signals (equal error rate on lossy compression on a per screen basis), then HD will always win because of the larger amount of detail (more detail, more sharpness, easier on contrast, etc.). But in reality, it is often a combination of different compression and different resolution, and never the two are exactly the same for any given movie. So the answer varies depending on your source and comparison.
To make matters more interesting, HD now encorporates the possibility for 48bit color (16bits R, 16bits G, 16bits B), and SD has no ability to display more than 24bit, so now HD is capable of holding twice the color depth, twice the contrast, etc. Again depending on your source. Comparing 48bit HD video to 24bit SD video is really an apples to orange comparison, if the compression ratio is run in the wrong direction SD really doesn't stand a chance. mmmm I love apples.
HD is simple higher density all around, but it realy still matters what you compressed and how much you compressed it.
_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
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Hai
Thank you for the reply. I am able to get some knowledge about the mpeg4.
Thank you
Thanks and regards
T.Angeline
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Hi have a div tag on an asp page, i want a write a javascript code to place positon the div tag in the center of the displayable screen, I have a scrollable window on my page.
so if scroll down and then clcik on my link the code should show div tag in the center of the screen
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Please post this in the right forum.
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I want to play targa files on device context . gdi+ unable to play
it . how it is possible .
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I don't know anything about it but according to the DirectX 9 documentation[^] there is some support for Targa files.
led mike
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I am trying to find out if there are any algorithms like the ones used in Visio in a class diagram or ER diagram. My basic requirement is that like in Visio, I have shapes and I try and connect them between them by drawing lines programmatically.
However, it would be great if someone can point me to any algorithms out there (no matter the programming language) which does collision detection and other things like automatically adjusting the shapes and lines if another shape is dropped on another shape. I hope I am being clear. Any algorithm written in .NET or any other language would be great or just an algorithm would be much appreciated. Thanks in advance. Really appreciate it. 
Sriram
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Have a look at GraphViz[^], maybe it can help you.
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I have a custom control that i am able to change its opacity. In my client application, i have a picture box that i use to view the video from my web cam.
The problem is that, my custom control has refused to sit on to of the picture box. At design time and at runtime when my web can is shut down i can see it on top of the picture box; but at runtime when the web cam transmits its video to the picture box, the control goes below the picture box.
I want my control to always sit on top, can someone help me.
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Initially, Z-order is determined by the order the controls are
created (assuming they have the same parent). What order do you
create the controls?
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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I have not tried setting the z-order yet.
One thing i would like to stress on is that, when i place the default .net panel on the video viewer(picturebox with realtime image from the webcam) the panel remains on top. But with my custom semi-transparent panel, the video viewer over laps the custom panel.
I have a feeling that there is a/some lines of code im missing out in my custom panel.
I just found out that my semi-transparent panel can not display background images.
This is the code for the semi-transparent panel:
<code>
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Drawing;
namespace VideoCapture_Tutorial
{
public partial class MyControl : Panel
{
private Color brushColor;
public MyControl()
{
InitializeComponent();
}
public MyControl(IContainer container)
{
container.Add(this);
InitializeComponent();
}
protected override CreateParams
CreateParams
{
get
{
CreateParams createParams =
base.CreateParams;
createParams.ExStyle |=
0x00000020; // WS_EX_TRANSPARENT
return createParams;
}
}
protected override void
OnPaintBackground(PaintEventArgs e)
{
//
}
protected override void
OnPaint(PaintEventArgs e)
{
Graphics graphics = e.Graphics;
Rectangle rect = new Rectangle(0, 0,
base.Width - 1, base.Height - 1);
Color brushColor = this.brushColor;
Pen pen = new Pen(Color.Black);
int num = (10 * 0xff) / 100;
SolidBrush brush = new
SolidBrush(Color.FromArgb(num, brushColor));
graphics.FillRectangle(brush, rect);
graphics.DrawRectangle(pen, rect);
pen.Dispose();
brush.Dispose();
graphics.Dispose();
//Invalidate();
}
public Color BrushColor
{
get
{
return this.brushColor;
}
set
{
this.brushColor = value;
base.RecreateHandle();
}
}
//protected override void
}
}
</code>
Thanks for your help. I guess you can still do more it is really urgent.
Thanks
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I have not tried setting the z-order yet.
One thing i would like to stress on is that, when i place the default .net panel on the video viewer(picturebox with realtime image from the webcam) the panel remains on top. But with my custom semi-transparent panel, the video viewer over laps the custom panel.
I have a feeling that there is a/some lines of code im missing out in my custom panel.
This is the code for the semi-transparent panel:
<code>
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Drawing;
namespace VideoCapture_Tutorial
{
public partial class MyControl : Panel
{
private Color brushColor;
public MyControl()
{
InitializeComponent();
}
public MyControl(IContainer container)
{
container.Add(this);
InitializeComponent();
}
protected override CreateParams
CreateParams
{
get
{
CreateParams createParams =
base.CreateParams;
createParams.ExStyle |=
0x00000020; // WS_EX_TRANSPARENT
return createParams;
}
}
protected override void
OnPaintBackground(PaintEventArgs e)
{
//
}
protected override void
OnPaint(PaintEventArgs e)
{
Graphics graphics = e.Graphics;
Rectangle rect = new Rectangle(0, 0,
base.Width - 1, base.Height - 1);
Color brushColor = this.brushColor;
Pen pen = new Pen(Color.Black);
int num = (10 * 0xff) / 100;
SolidBrush brush = new
SolidBrush(Color.FromArgb(num, brushColor));
graphics.FillRectangle(brush, rect);
graphics.DrawRectangle(pen, rect);
pen.Dispose();
brush.Dispose();
graphics.Dispose();
//Invalidate();
}
public Color BrushColor
{
get
{
return this.brushColor;
}
set
{
this.brushColor = value;
base.RecreateHandle();
}
}
//protected override void
}
}
</code>
Thanks for your help. I guess you can still do more it is really urgent.
Thanks
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Orson wrote: I have not tried setting the z-order yet.
But that's what determines what gets drawn on top of what 
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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How do the video frames get drawn on the picture box?
Since video frames are being drawn periodically, you'll also
need to redraw any overlaid controls each time a frame is drawn.
Of course, this will flicker....you'll probably have to deal with
that as well.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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What event do i override for the picture box(video viewer) for repainting the picture box?
How do implement the z-order?
Sorry im asking to many questions, i just came into c# im from a java background.
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Orson wrote: What event do i override for the picture box(video viewer) for repainting the picture box?
The Paint event? I'm still unclear as to how the video is being drawn
on your picture box. What control are you using?
Orson wrote: How do implement the z-order?
You can change the z-order of controls on a form using the
Control.ControlCollection.SetChildIndex Method[^]
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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The code fragment from different layers on my application that previews the video in the picture is displayed below:
<br />
private void lstVideoSources_SelectedIndexChanged(object sender, EventArgs e)<br />
{<br />
Device d = DeviceManager.GetDevice(lstVideoSources.SelectedIndex);<br />
d.ShowWindow(this.video_viewer);<br />
}<br />
<br />
<br />
<br />
public void ShowWindow(global::System.Windows.Forms.Control windowsControl)<br />
{<br />
Init(windowsControl.Height, windowsControl.Width, windowsControl.Handle.ToInt32());<br />
}<br />
<br />
<br />
public void Init(int windowHeight, int windowWidth, int handle)<br />
{<br />
string deviceIndex = Convert.ToString(this.index);<br />
deviceHandle = capCreateCaptureWindowA(ref deviceIndex, WS_VISIBLE | WS_CHILD, 0, 0, windowWidth, windowHeight, handle, 0);<br />
<br />
if (SendMessage(deviceHandle, WM_CAP_DRIVER_CONNECT, this.index, 0) > 0)<br />
{<br />
SendMessage(deviceHandle, WM_CAP_SET_SCALE, -1, 0);<br />
SendMessage(deviceHandle, WM_CAP_SET_PREVIEWRATE, 0x42, 0);<br />
SendMessage(deviceHandle, WM_CAP_SET_PREVIEW, -1, 0);<br />
<br />
SetWindowPos(deviceHandle, 1, 0, 0, windowWidth, windowHeight, 6);<br />
}<br />
}<br />
Im trying out what you said...
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Can i send you the entire code through your mail box please?
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I just noticed something. I tried to change the z-order and position(left,top) on the click event of the picturebox, but each time i click on the picture box while the video is on it, nothing happens. but when i stop the video(i.e when picturebox is now like normal without images) and click on the picturebox the action specified in the click event takes place.
I feel the video is like a different layer on top of the picture box.
Another important note is that the video also works on a panel.
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Orson wrote: I feel the video is like a different layer on top of the picture box
In a way, it is. You won't be able to draw on the top of live video because
every new frame gets drawn on top of whatever you draw there. Changing the z-order
will not help here - VFW still just draws to the screen.
To get around this, you need (ideally) to be able to draw on a video frame before
it is drawn to the screen. This will prevent the flicker associated with redrawing
any overlay over the top of every video frame on the screen.
With VFW, capSetCallbackOnVideoStream() can help.
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://www.codeproject.com/script/Forums/Images/coffee.gif)
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hey guys..anyone knows a good website to download .x models to use with directx 9?
thank you 
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