請教關於VirtualDubMod 插件的logo怎麼用

[psac]

Q:
請教關於VirtualDubMod 插件的logo怎麼用

VirtualDubMod的logo只能使用bmp格式的圖片，但是BMP的都有背景色彩，
請問如何將背景色彩去掉
另外下面的 Alpha image怎麼使用？

logo image
謝謝


A:
沒用過這個插件，但是一般來說，在做logo時，是將(255,0,255)作為背景色，從源圖片中摳除。
至於Alpha image，看說明大概是將第二幅圖片（應該是黑白圖片吧）的gray通道作為第一幅圖的alpha通道，將第一張圖片中相應的地方的alpha值進行調整，從而達到調整第一幅圖片透明度的目的。


Q:
關鍵問題是BMP格式的背景色不能被透明啊


A:


兩張圖片的疊加試了一下 還是不能通過透明去掉背景色。
背景色改為（255，0，255）

或者把第二張圖片中第一張圖片需要透明的地方的色彩設為（255，255，255）。
換用這個

附件: logo14.zip

Logo Filter for VirtualDub
(Version 1.4)
[Place this text file in the VirtualDub plugins directory to make it available via the Help button on the filter configuration dialog box. The computer must have a program called Notepad available in its search path.]
This filter provides the ability to overlay a logo contained in a bitmap file. The position of the bitmap may be specified. Selectable alpha blending allows variable merging with the video, and a transparent color may be selected to obtain a free-floating effect. Animated logos can be created by defining a series of bitmaps. Filter preview is supported.

This filter is ideal for unobtrusively placing a logo on the video as is done on many cable TV channels.

Two test bitmaps and an animated bitmap sequence are provided in the zip file.


How to Make a Static Logo
Create a 24-bit-depth windows bitmap file with the desired size and with a transparent color zone if desired. The transparency color may be arbitrarily selected and then configured in the filter configuration.
In the filter configuration dialog box, enter the input file. If the specified bitmap file cannot be found, or if it is not a bitmap file, or if it is of the wrong depth, the output frame will be all black. Set the desired X and Y coordinates, the starting frame and the duration (in frames). Set the desired alpha blend and transparent color.

How to Make an Animated Logo
To make an animated logo, create a series of bitmap files named name0000.bmp, name0001.bmp, name0002.bmp, etc. (you can replace "name" with desired text). Specify the first one as the input file and check the 'Animation sequence' checkbox. Set the duration to be the number of frames to display each bitmap file before moving to the next one. Set the loop count to the number of repetitions desired for the sequence. Set the other parameters as described for static logos.
Note that stepping forward and rewinding will operate correctly, but stepping backward is currently not supported.

A sample sequence is provided that produces a spinning earth. To run it, set the duration to 1, loops to 0, and enable a transparent color of 0/0/0.

Detailed Option Descriptions
The following options are provided:
Input file: Specifies the full pathname of the bitmap file to be used.

Animation sequence: Check this to enable an animated sequence.

X: This option determines the X offset of the start of the bitmap on the video.

Y: This option determines the Y offset of the start of the bitmap on the video.

Starting frame: The frame number on which to begin displaying the logo.

Duration: For a static bitmap, the number of frames for which to display the logo. For animated bitmaps, the number of frames to display each bitmap before moving to the next bitmap. To display a bitmap for the whole clip length, select 0.

Loops: For static logos, this has no effect. For animated logos, the number of repetitions of the bitmap sequence. To loop forever, select 0.

Alpha: This option determines the blending of the bitmap with the video. For full bitmap and no video, use the value 255. As this value is reduced toward 0, more and more of the video is blended in. An alpha of about 100-128 gives a nice unobtrusive overlay.

Fade: These options allow for the logo to be faded in and/or out. For fade-in, the starting frame number of the fade is determined by the logo starting frame. The length of the fade is determined by the In Len value. For fade-out, the ending frame number of the fade is determined by the Out End value. The length of the fade is determined by the Out Len value. If fade-in and fade-out overlap, fade-out overrides. Even if the logo is otherwise enabled such that it would appear beyond the end of a fade-out if the fade-out were not there, the logo will be suppressed after the fade-out. Finally, if you put silly values in the fade boxes, you will get what you deserve.

Enable transparent color: Check this if you have made a transparent color zone in your bitmap. Then select the transparent color in the Red, Green, and Blue edit boxes. Full video shows in the transparent areas. The tolerance box allows you to specify a 'sloppiness' factor fo the match to the transparent color. As long as the difference between each color channel and the corresponding specified transparent color is not greater than the specified tolerance, then the color will be considered to be transparent. For example, if the tolerance is 10 and the specified transparent color is 37:45:10, then a color 39:44:5 will be considered transparent, while a color 39:56:11 will not be transparent (because one color channel's difference exceeds tolerance).

For additional information, version updates, and other filters, please go to the following web site:

Filters for VirtualDub
http://shelob.mordor.net/dgraft/index.html

Donald Graft
(C) Copyright 2000-2003, All Rights Reserved


附上VD的Logo插件在AVS使用中的方法，這個經常要用到

用net1999提供的1.4版logo插件


編輯AVS文本如下:
#######指定VirtualDub插件的目錄########
global VirtualDub_plugin_directory = "C:\VirtualDub\PlugIns"
#######################################
AVISource("file.avi")
##################函數定義#####################
function VD_Logo(clip clip, int "x", int "y", int "alpha", bool "transparent",
\ int "xr", int "xg", int "xb", int "tolerance", string "filename",
\ bool "animate", int "start", int "duration", int "loops",
\ int "fadeinlen", int "fadeoutend", int "fadeoutlen")
{
LoadVirtualdubPlugin(VirtualDub_plugin_directory+"\logo.vdf", "_VD_Logo", 1)
return clip._VD_Logo(default(x,0), default(y,0), default(alpha,128),
\ default(transparent,true)?1:0, default(xr,0), default(xg,0), default(xb,255),
\ default(tolerance,0), default(filename,VirtualDub_plugin_directory+"\demo.bmp"),
\ default(animate,false)?1:0, default(start,0), default(duration,0), default(loops,0),
\ default(fadeinlen,0), default(fadeoutend,200), default(fadeoutlen,0))
################掛上插件,只能在RGB Color Sapce下用###########################
ConvertToRGB()
VD_logo(3, 320, 255, true, 0, 0, 0, 45, "E:\logo.bmp", false, 276, 216, 0, 20, 492, 10)
############################################################

具體的參數說明
VD_Logo(clip clip, int "x", int "y", int "alpha", bool "transparent",
\ int "xr", int "xg", int "xb", int "tolerance", string "filename",
\ bool "animate", int "start", int "duration", int "loops",
\ int "fadeinlen", int "fadeoutend", int "fadeoutlen")


X,Y為圖像出現位置的坐標，alpha為透明度，布爾值的"transparent"設置圖形是否有透明的色彩，即Alpha通道，int "xr", int "xg", int "xb",分別為需要設置透明的色彩的RGB值，如logo圖像背景為黑色，內嵌時想做成透明背景，去掉黑色，則把transparent設成True,RGB的值分別為0,0,0,就可以實現.
tolerance為容差，string "filename"是logo所在路徑及檔案名，布爾值的"animate"設置是否為序列的靜態圖片所組成的動態效果, int "start"開始出現圖像時的Frame Number,int "fadeinlen"為圖像持續的Frame數,int "loops"為循環次數(對序列圖像),int "fadeinlen"是淡入長度(Frame),"fadeoutend"為淡出結束的Frame數，int "fadeoutlen"為淡出的長度(Frame).