Search Results

Search found 1441 results on 58 pages for 'colour blend'.

Page 41/58 | < Previous Page | 37 38 39 40 41 42 43 44 45 46 47 48  | Next Page >

  • Very basic OpenGL ES 2 error

    - by user16547
    This is an incredibly simple shader, yet I'm having a lot of trouble understanding what's wrong with it. I'm trying to send a float to my fragment shader. Its purpose is to adjust the alpha of the fragment colour. Here is my fragment shader: precision mediump float; uniform sampler2D u_Texture; uniform float u_Alpha; varying vec2 v_TexCoordinate; void main() { gl_FragColor = texture2D(u_Texture, v_TexCoordinate); gl_FragColor.a *= u_Alpha; } and below is my rendering method. I get a 1282 (invalid operation) on the GLES20.glUniform1f(u_Alpha, alpha); line. alpha is 1 (but I tried other values as well) and transparent is true: public void render() { GLES20.glUseProgram(mProgram); if(transparent) { GLES20.glEnable(GLES20.GL_BLEND); GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA); GLES20.glUniform1f(u_Alpha, alpha); } Matrix.setIdentityM(mModelMatrix, 0); Matrix.rotateM(mModelMatrix, 0, angle, 0, 0, 1); Matrix.translateM(mModelMatrix, 0, x, y, z); Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0); Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0); GLES20.glUniformMatrix4fv(u_MVPMatrix, 1, false, mMVPMatrix, 0); GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, vbo[0]); GLES20.glVertexAttribPointer(a_Position, 3, GLES20.GL_FLOAT, false, 12, 0); GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, vbo[1]); GLES20.glVertexAttribPointer(a_TexCoordinate, 2, GLES20.GL_FLOAT, false, 8, 0); //snowTexture start GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]); GLES20.glUniform1i(u_Texture, 0); GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, ibo[0]); GLES20.glDrawElements(GLES20.GL_TRIANGLE_STRIP, indices.capacity(), GLES20.GL_UNSIGNED_BYTE, 0); GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, 0); GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, 0); if(transparent) { GLES20.glDisable(GLES20.GL_BLEND); } GLES20.glUseProgram(0); }

    Read the article

  • Why doesn't the monitor output anything in Linux console mode?

    - by flypen
    I install Linux without graphics support. Previously I used a monitor with 720p support. And it can display normally. Now I change to a monitor with 1080p support. I can see BIOS and GRUB info on monitor, and kernel messages in early stages. However, the monitor says that there is no input immediately, and then I can't see anything again. It seems that it happens after something initializes. Is it related to vesafb? vesafb: mode is 1280x1024x32, linelength=5120, pages=0 vesafb: scrolling: redraw vesafb: Truecolor: size=8:8:8:8, shift=24:16:8:0 mtrr: type mismatch for 7f800000,800000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,400000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,200000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,100000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,80000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,40000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,20000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,10000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,8000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,4000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,2000 old: write-back new: write-combining mtrr: type mismatch for 7f800000,1000 old: write-back new: write-combining vesafb: framebuffer at 0x7f800000, mapped to 0xffffc90011380000, using 5120k, total 5120k Console: switching to colour frame buffer device 160x64 fb0: VESA VGA frame buffer device

    Read the article

  • Windows 7 Blank Screen on Boot / Login

    - by Greg
    I have a new system that's having a few problems... sometimes (seems to be when the PC is cold, i.e. has been switched off for a while, though that could be my imagination) I get a blank blue screen when I boot up. The system boots normally and auto-logs-in. The desktop loads and I'm even able to launch applications, but then everything disappears and the screen goes to the default windows desktop blue colour (not the desktop image, just a plain blue with no mouse cursor). At this point the machine completely locks up - I'm unable to even toggle Num Lock and have to hold in the power button for 5 seconds to kill it. Interestingly if I manage to launch some applications before it goes blank, they will usually crash... sometimes explorer.exe will crash too. When I reboot, the system is fine and stable. I've installed the latest graphics drivers and run memtest86+ for 6 passes (and counting) with no errors. The system specs are: CPU: Intel I7 2.66 @ 3.4GHz RAM: 6GB (3 * 2GB DDR3) HDD: 128GB Crucial M225 SSD Motherboard: Gigabyte EX58-UD3R Gfx: ATI Radeon Sapphire 5870 1GB Note: There are a few similar questions but I haven't found one that matches my symptoms

    Read the article

  • Why is Safari on my computer rendering all of the colors -- not just for images -- incorrectly?

    - by richardhenry
    I’m not just talking about image color profile issues; every single color that the browser renders is incorrect. It’s like it’s in it’s own color space (or something!). Screenshot: http://drp.ly/DJk1O (Opera, Safari, Chrome, Firefox) Spot the odd one out? Open this up in Photoshop or similar and try using the eyedropper to select the colour. Safari renders the same hex color completely differently. That color is set using a background-color declaration in CSS, so it should be identical in all four of those browsers. Here’s the HTML I was using: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>untitled</title> <style type="text/css"> body { background-color: #114742; } </style> </head> <body> </body> </html> Literally every website I’m viewing with my install of Safari is displaying colors incorrectly. The blue of the bar on Facebook is slightly less rich. This doesn’t occur on any other Macs I’ve tried. Any idea what’s happened to my Safari install?

    Read the article

  • RHEL 5.2 installing on ProLiant BL460c - hangs at 'now booting the kernel'

    - by Dr Rocket Mr Socket
    As the title states, I have a problem. This server and the installation disc are also on the other side of the world to me so... So far, I have tried to start the install with the parameters: linux text noapic noacpi no=apic no=acpi which results in the same hang. I have also disabled a PCI ethernet adapter, I am uneasy about disabling the onboard ethernet adapter I do not know if ILO uses this. Anyone have any advice? Much appreciated. EDIT: full output after trying to begin the installation. boot: linux text Loading initrd.img.................. Loading vmlinuz....... Uncompressing Linux...done. Now booting the kernel stays on this for hours EDIT2: adding the 'mem=40960M' (server has 40 gigs of ram) parameter allows it to proceed but the following output directly after 'Now booting the kernal' Memory: sized by int13 0e801h initrd extends beyond end of memory (0x00ef2090 > 0x00000000) disabling initrd Console: 16 point font, 400 scans Console: colour VGA+ 80x25, 1 virtual console (max 63) pcibios_init : BIOS32 Service Directory Structure at 0x000ffee0 pcibios_init : BIOS32 Service Directory entry at 0xf0000

    Read the article

  • Fix Linux-made png file for use on Windows

    - by BGM
    There is a particular icon library that I really like. Now, I have downloaded the package that has the png files inside (I know the ico files are there, but I want the png files). However, about my Windows 7 computer tells me that about 1/3 of the png files are corrupt. I usually use XnView to view the files, and it won't display the "corrupt" files. I've tried other editors and viewers and I get the same issue. Now, the png package was originally designed for Linux to be an OS-icon-package for the entire system, so I figure the png files were built in Linux. So, is there a way I can "fix" the "corrupted" png files for my Windows 7 computer? Maybe when the files were created there was some bit that was off-colour or something? Any clues? [edit] I have read in this thread that the "corruption" could happen during the extraction process. I did all the extraction with 7-zip. It was a zip containing a tar. I will try another extractor, but I don't think it will make any difference.

    Read the article

  • Problems compiling coreutils-8.5 on Solaris 5.10 on Intel platform

    - by PP
    I am having trouble compiling coreutils-8.5 on Solaris 5.10 on the Intel platform using cc. Firstly I had the following error during ./configure: checking whether <wchar.h> uses 'inline' correctly... no configure: error: <wchar.h> cannot be used with this compiler (/tool/sunstudio12.1/bin/cc -xc99=all -g -D_REENTRANT). This seemed similar to the problem in this question. The solution was to edit configure and replace the reference of -xc99=all to -xc99=all,no_lib. This permitted the configure to complete. Then I ran /usr/sfw/bin/gmake and it progressed until I received the following message: Making all in src gmake[2]: Entering directory `/home/peterp/src/coreutils-8.5/src' gmake all-am gmake[3]: Entering directory `/home/peterp/src/coreutils-8.5/src' CCLD chroot Undefined first referenced symbol in file eaccess ../lib/libcoreutils.a(euidaccess.o) ld: fatal: Symbol referencing errors. No output written to chroot What could cause this problem? PS I was only compiling coreutils because I wanted colour ls.

    Read the article

  • Outlook 2007 message formatting - pasted images

    - by Jack
    When you cut and past an image into a message window when composing a new email, the image will display as you would expect and formatting the image appears straight forward, However the pain happens when you click send. The recipient notices that the image will resize with the size of there outlook window. The original image size is ignored and no scrollbars appear. Howe do you stop this behaviour. When said image is pasted, say you want to place a graphic on top of the image such as an arrow. By using the ribbon, selecting the insert tab and choosing shapes, you go ahead and select the arrow shape and plonk it on to of the image, just where you want it, give it a nice colour and then send the email. As the recipient resizes there outlook message window, the image resizes but the shape remains where it was, now who wants that micros*a*ft! So, how do you A) make the shape resize with the image, so the shape stays where I put it in relation to the image, and b) stop the image resizing in the first place.

    Read the article

  • FFmpeg overlay two videos, one input with transparency

    - by Gian B.
    I am trying to create a karaoke from a CD+G file (converted to AVI using FFmpeg) and add a video as a background of the lyrics. Here's a screenshot of a the output from CD+G conversion, for simplicity let's call this lyrics.avi http://imgur.com/wUwHUhV Now a have this video.mp4 file that I'd like to put behind this lyrics.avi Here's a sample of what I'm trying to achieve http://imgur.com/8GuWXtQ I'm sure most of you are familiar with karaoke. I haven't used FFmpeg much and I'm not really sure if what I want to achieve is possible with FFmpeg. Is it possible to overlay two videos, and add a transparency to one of the videos? In this case the colour black? How can I set the offset time of the lyrics.avi? Here's the command the I've tried so far: ffmpeg -i video.mp4 -i lyrics.avi -filter_complex "nullsrc=size=854x480 [base]; [0:v] setpts=PTS-STARTPTS, scale=854x480 [upperleft]; [1:v] setpts=PTS-STARTPTS, scale=854x200 [bottomleft]; [base][upperleft] overlay=shortest=1 [tmp1]; [tmp1][bottomleft] overlay=shortest=1:y=280" -c:v libx264 -y karaoke.mp4

    Read the article

  • how to remove background layer of djvu file

    - by Jon
    Hello, I've downloaded some files from the Internet Archive. They come in different file formats and most of the time I use pdf. However, sometimes the scans are saves in colour instead of b/w. This makes it difficult/impossible to read on a dedicated ebook reader. In that case I downloaded the djvu files as on the PC you can select which layer (color, bw,fore,back) one would like to see. Selecting the bw gives excellent results. However, the ebook reader does not has this option. The question is, how can I remove /extract a layer from the djvu file and save only this layer. So far I've tried the following two approaches: 1) select bw in the djvu viewer on the PC and printed to postscript file. Followed by a ps2pdf conversion. This works, but generates a fairly large pdf file. Sure, I can again upload it to any2djvu but it just seems to much manual work for each file. 2) I tried the shared annotation feature and said (mode bw). This works on the PC as desired but is ignored on the ebook reader as the other layers are still present. Any help or suggestions would be greatly appreciated.

    Read the article

  • Bash shell prompt: where is $RET?

    - by Evgeni Sergeev
    I was reading this https://wiki.archlinux.org/index.php/Color_Bash_Prompt and ended up with the following: # Stores the status of each command in $RET PROMPT_COMMAND='RET=$?;' # A colour. RED_SHELL='\e[0;36m' # Prints "Status 1" if RET is 1, for example. RET_VISUALISE='$(if [[ $RET != 0 ]]; then echo -ne "Status \[$RED_SHELL\]$RET\n" && RET=0; fi;)' # What to print for each prompt. PS1="$RET_VISUALISE\[\e]0;\w\a\]\n\[\e[32m\]\u@\h \t \[\e[33m\]\w\[\e[0m\]\n\$ " This does almost what I want, except when I press Enter,Enter,Enter multiple times after a command that returned status != 0. In this case it prints "Status 1" every time I press Enter. This is what the && RET=0; part was supposed to get rid of. Also, I don't understand why env | grep RET only shows the PS1 contents. What is the scope of $RET ?

    Read the article

  • Windows 7 Blank Screen on Boot / Login

    - by Greg
    I have a new system that's having a few problems... sometimes (seems to be when the PC is cold, i.e. has been switched off for a while, though that could be my imagination) I get a blank blue screen when I boot up. The system boots normally and auto-logs-in. The desktop loads and I'm even able to launch applications, but then everything disappears and the screen goes to the default windows desktop blue colour (not the desktop image, just a plain blue with no mouse cursor). At this point the machine completely locks up - I'm unable to even toggle Num Lock and have to hold in the power button for 5 seconds to kill it. Interestingly if I manage to launch some applications before it goes blank, they will usually crash... sometimes explorer.exe will crash too. When I reboot, the system is fine and stable. I've installed the latest graphics drivers and run memtest86+ for 6 passes (and counting) with no errors. The system specs are: CPU: Intel I7 2.66 @ 3.4GHz RAM: 6GB (3 * 2GB DDR3) HDD: 128GB Crucial M225 SSD Motherboard: Gigabyte EX58-UD3R Gfx: ATI Radeon Sapphire 5870 1GB Note: There are a few similar questions but I haven't found one that matches my symptoms

    Read the article

  • Is it possible to theme Windows 7 like XP?

    - by LonelyPixel
    Everybody seems to mean the window frame colour and a set of desktop background pictures when they're talking about Windows 7 themes. Does anybody remember what themes used to be in Windows XP? You could actually alter the appearance of the window frame, how close buttons and menu popups looked, put a texture on the taskbar, all those funny things. Microsoft themselves have published a number of XP themes over time (Luna on XP, Royal on MCE2005, Zune later on). I don't say that most of those and the numerous third party XP themes were beautiful or even practical. But it was possible to create something nice. In Windows 7 (I suppress the existence of Windows Vista...) such a theme could well be used to increase readability to a level before Aero Glass again. I mean, you cannot really tell whether a Glass window is active or not. I've been tweaking the colours and transparency levels a lot recently but the only safe indicator is the close button: it's red when the window is active, it's colourless otherwise. Then there's the window title. It is always painted black, on however dark a background. Again, regardless of whether the window is active or not. Turning off Aero is not an option in Windows 7 anymore. Classic design looks just ugly there. It already wasn't exactly looking good on XP with the wide start menu. So, can we increase the readability of the Windows 7 UI with themes like in XP or didn't Microsoft learn a thing since the Windows 7 Preview "Vista"?

    Read the article

  • Different font SIZES in a Text Editor, based on Script(Alphabet) type (ie. per Unicode Code-Block)

    - by fred.bear
    Some non-Latin-based scripts(alphabets) have more detail in their glyphs than do the Latin-based-script equivalents, and typically need a larger font to give the same degree of legibility (resolution-wise). Sometimes, both script types need to be present in the same file. Notepad++ allows different font SIZES (and colour, etc) courtesy of syntax-highlighting. This allows me to display larger-fonted non-Latin-based script in a // BIG-FONT comment. Although this has been quite handy for me in some situations, it is quite limited. A Word Processor can handle this scenario, but I'm not interested in that. I want a nice simple(?) plain(?) Text Editor to do it... on a per script-type basis... eg. mixing Latin-1 and Devanagari (and Mandarin, and ... Such a thing may not exits, but Notepad++ has shown that a simple(?) plain(?) Text Editor is capable of it. Does anyone know of such a Text Editor? ...Q. Why not a Word Processor? ...A. Because GCC and Python don't like that format! but UTF-8 is fine.

    Read the article

  • Visual Studio 2010 error: Type universe cannot resolve assembly

    - by dthrasher
    I've loaded a WPF project initially created in Visual Studio 2008 into Visual Studio 2010. The conversion process goes smoothly, but on certain XAML files the VS2010 designer throws several errors related to project references, including this one: System.Reflection.Adds.UnresolvedAssemblyException Type universe cannot resolve assembly: GalaSoft.MvvmLight, Version=3.0.0.31869, Culture=neutral, PublicKeyToken=3e875cdb3903c512. This assembly reference works just fine in the Expression Blend 4 designer, but not in VS2010. I can build and run the solution successfully. My solution targets the .Net Framework 3.5 SP1.

    Read the article

  • How to disable scrolling in ScrollViewer while Ctrl is pressed

    - by zunyite
    I'd like to implement zoom function while Ctrl key is pressed. But the MouseWheel event is not trigger while the mouse is over the ScrollView. Is there any way to do it? ps:SilverLight 4.0 <UserControl x:Class="SilverlightApplication11.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400"> <Grid x:Name="LayoutRoot" Background="White"> <ScrollViewer Background="Gray" MouseWheel="ScrollViewer_MouseWheel" x:Name="scrollViewer"> <Rectangle Width="200" Height="2000" MouseWheel="ScrollViewer_MouseWheel" Fill="AliceBlue" /> </ScrollViewer> </Grid> private void ScrollViewer_MouseWheel(object sender, MouseWheelEventArgs e) { if (Keyboard.Modifiers.HasFlag(ModifierKeys.Control)) { zoom+=0.1; e.Handled = true; } }

    Read the article

  • Resize Clipping Path on window resize in WPF

    - by blobkat
    Hello, I was wondering how to resize a Clipping path dynamically when resizing the window. Right now I'm taking a rectangle in Expression Blend that resizes with the window. Applying this rectangle to a circle as a clipping path makes the rectangle fixed, and it won't resize anymore. I've seen different ways of making clipping paths in XAML, in the Clip="" property as well as style markup. But I haven't succeeded yet in finding a proper XAML solution. Can anyone point me in the right direction? Thanks!

    Read the article

  • WPF: Apply ScrollBar Style to ListBox Template - Error object cannot be added to border

    - by TheMar
    Hi, I thought this may be straightforward question but did not find any definitive answer while searching net or SO. I have created scrollbar style (using standard scroll bard template - Blend 2) I am not sure how to apply this style "MyScrollStyle" to a ListBox Template . I saw on ListBox template they have Scroll Viewer -- which should contain the scrollbar Assuming it is something simple as ---Content Added--- After going through lot of xaml in template edit I kind of understood how to apply style. I am trying to add the scroll view style set in this example -http://blog.xamltemplates.net/wp-content/uploads/2008/12/scrollviewer.zip, to my list view template but it gives error -- System.Windows.Markup.XamlParseException was unhandled Message="'ScrollViewer' object cannot be added to 'Border'. Exception has been thrown by the target of an invocation. Error at object 'System.Windows.Controls.ScrollViewer' in markup file 'MenuModule, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null;component/resources/Resources.xaml' Line 19 Position 26." Source="PresentationFramework" LineNumber=19 LinePosition=26 NameContext="1_T" Any help is appreciated Thank you, The Mar

    Read the article

  • Silverlight - Binding ImageSource to Rectangle Fill

    - by Matt.M
    Blend 4 is telling me this is invalid markup and its not telling me why: <ImageBrush Stretch="Fill" ImageSource="{Binding Avatar, Mode=OneWay}"/> I'm pulling data from a Twitter feed, saving to an ImageSource, and then binding it to an ImageBrush(as seen below) to be used as the Fill for a Rectangle. Here is more context: <Rectangle x:Name="Avatar" RadiusY="9" RadiusX="9" Width="45" Height="45" VerticalAlignment="Center" HorizontalAlignment="Center" > <Rectangle.Fill> <ImageBrush Stretch="Fill" ImageSource="{Binding Avatar, Mode=OneWay}"/> </Rectangle.Fill> </Rectangle> I'm using this inside of a Silverlight UserControl, which is used inside of a Silverlight Application. Any Ideas on what the problem could be?

    Read the article

  • Silverlight: Why can't silverlight see my xaml file referenced in MergedDictionary?

    - by Sergio
    Hi there, I have a silverlight application with a number of styles defined in a seperate xaml file under the directory /Styles. My App.xaml looks like this: <Application.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/Styles/Legend.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </Application.Resources> Legend.xaml has its build action set to Content and 'Do Not Copy' as the copy to output directory setting. The message I'm getting in blend is: An error occurred while finding the resource dictionary "/Styles/Legend.xaml" Thanks in advance!

    Read the article

  • Why does Silverlight 4 Tools only give partial intellisense?

    - by Edward Tanguay
    I finally got Silverlight 4 Toolkit installed , referenced and working after the difficulty of finding the right namespace described in this question. But intellisense doesn't work fully: after I type "tk:", it doesn't pop up the various controls I have available, but if I type a control name out, e.g. DockPanel, then it works, as shown below. It will even give me intellisense after I type tk:DropPanel, which is odd. How can I get intellisense to work in all cases for the Silverlight 4 Toolkit? I can imagine I need another namespace, but this site says that this reference: is now all you need (and will be automatically used by both Visual Studio and Blend)

    Read the article

  • Adjust a Control Template and still respect the Theme of the OS?

    - by bitbonk
    In WPF how do I modifiy the template for a standard control in a way that it will respect the current Theme of the Operating System later on? If I just "edit a copy" of the template in blend, it will just give me the template of the currently running theme. Is this correct? So when I apply the modified template and run the app on different themes it will always look the same. For custom controls and even for data templates the problem is similar. How do I provide a template that respects all possible themes of the OS?

    Read the article

  • Blending transparent textures with depth

    - by l.thee.a
    I am trying to blend textures which have transparent areas: glEnable( GL_TEXTURE_2D ); glBindTexture( GL_TEXTURE_2D, ...); glVertexPointer( 2, GL_FLOAT, 0, ... ); glEnable (GL_BLEND); glBlendFunc (GL_ONE, GL_ONE_MINUS_SRC_ALPHA); glDrawArrays( GL_TRIANGLE_STRIP, 0, 4 ); Unless I add glDisable(GL_DEPTH_TEST), transparent parts of the top textures overwrite everything beneath them (instead of blending). Is there any way to do this without disabling depth? I have tried various blending functions but none of the helped.

    Read the article

  • Conceal packet loss in PCM stream

    - by ZeroDefect
    I am looking to use 'Packet Loss Concealment' to conceal lost PCM frames in an audio stream. Unfortunately, I cannot find a library that is accessible without all the licensing restrictions and code bloat (...up for some suggestions though). I have located some GPL code written by Steve Underwood for the Asterisk project which implements PLC. There are several limitations; although, as Steve suggests in his code, his algorithm can be applied to different streams with a bit of work. Currently, the code works with 8kHz 16-bit signed mono streams. Variations of the code can be found through a simple search of Google Code Search. My hope is that I can adapt the code to work with other streams. Initially, the goal is to adjust the algorithm for 8+ kHz, 16-bit signed, multichannel audio (all in a C++ environment). Eventually, I'm looking to make the code available under the GPL license in hopes that it could be of benefit to others... Attached is the code below with my efforts. The code includes a main function that will "drop" a number of frames with a given probability. Unfortunately, the code does not quite work as expected. I'm receiving EXC_BAD_ACCESS when running in gdb, but I don't get a trace from gdb when using 'bt' command. Clearly, I'm trampimg on memory some where but not sure exactly where. When I comment out the *amdf_pitch* function, the code runs without crashing... int main (int argc, char *argv[]) { std::ifstream fin("C:\\cc32kHz.pcm"); if(!fin.is_open()) { std::cout << "Failed to open input file" << std::endl; return 1; } std::ofstream fout_repaired("C:\\cc32kHz_repaired.pcm"); if(!fout_repaired.is_open()) { std::cout << "Failed to open output repaired file" << std::endl; return 1; } std::ofstream fout_lossy("C:\\cc32kHz_lossy.pcm"); if(!fout_lossy.is_open()) { std::cout << "Failed to open output repaired file" << std::endl; return 1; } audio::PcmConcealer Concealer; Concealer.Init(1, 16, 32000); //Generate random numbers; srand( time(NULL) ); int value = 0; int probability = 5; while(!fin.eof()) { char arr[2]; fin.read(arr, 2); //Generate's random number; value = rand() % 100 + 1; if(value <= probability) { char blank[2] = {0x00, 0x00}; fout_lossy.write(blank, 2); //Fill in data; Concealer.Fill((int16_t *)blank, 1); fout_repaired.write(blank, 2); } else { //Write data to file; fout_repaired.write(arr, 2); fout_lossy.write(arr, 2); Concealer.Receive((int16_t *)arr, 1); } } fin.close(); fout_repaired.close(); fout_lossy.close(); return 0; } PcmConcealer.hpp /* * Code adapted from Steve Underwood of the Asterisk Project. This code inherits * the same licensing restrictions as the Asterisk Project. */ #ifndef __PCMCONCEALER_HPP__ #define __PCMCONCEALER_HPP__ /** 1. What does it do? The packet loss concealment module provides a suitable synthetic fill-in signal, to minimise the audible effect of lost packets in VoIP applications. It is not tied to any particular codec, and could be used with almost any codec which does not specify its own procedure for packet loss concealment. Where a codec specific concealment procedure exists, the algorithm is usually built around knowledge of the characteristics of the particular codec. It will, therefore, generally give better results for that particular codec than this generic concealer will. 2. How does it work? While good packets are being received, the plc_rx() routine keeps a record of the trailing section of the known speech signal. If a packet is missed, plc_fillin() is called to produce a synthetic replacement for the real speech signal. The average mean difference function (AMDF) is applied to the last known good signal, to determine its effective pitch. Based on this, the last pitch period of signal is saved. Essentially, this cycle of speech will be repeated over and over until the real speech resumes. However, several refinements are needed to obtain smooth pleasant sounding results. - The two ends of the stored cycle of speech will not always fit together smoothly. This can cause roughness, or even clicks, at the joins between cycles. To soften this, the 1/4 pitch period of real speech preceeding the cycle to be repeated is blended with the last 1/4 pitch period of the cycle to be repeated, using an overlap-add (OLA) technique (i.e. in total, the last 5/4 pitch periods of real speech are used). - The start of the synthetic speech will not always fit together smoothly with the tail of real speech passed on before the erasure was identified. Ideally, we would like to modify the last 1/4 pitch period of the real speech, to blend it into the synthetic speech. However, it is too late for that. We could have delayed the real speech a little, but that would require more buffer manipulation, and hurt the efficiency of the no-lost-packets case (which we hope is the dominant case). Instead we use a degenerate form of OLA to modify the start of the synthetic data. The last 1/4 pitch period of real speech is time reversed, and OLA is used to blend it with the first 1/4 pitch period of synthetic speech. The result seems quite acceptable. - As we progress into the erasure, the chances of the synthetic signal being anything like correct steadily fall. Therefore, the volume of the synthesized signal is made to decay linearly, such that after 50ms of missing audio it is reduced to silence. - When real speech resumes, an extra 1/4 pitch period of sythetic speech is blended with the start of the real speech. If the erasure is small, this smoothes the transition. If the erasure is long, and the synthetic signal has faded to zero, the blending softens the start up of the real signal, avoiding a kind of "click" or "pop" effect that might occur with a sudden onset. 3. How do I use it? Before audio is processed, call plc_init() to create an instance of the packet loss concealer. For each received audio packet that is acceptable (i.e. not including those being dropped for being too late) call plc_rx() to record the content of the packet. Note this may modify the packet a little after a period of packet loss, to blend real synthetic data smoothly. When a real packet is not available in time, call plc_fillin() to create a sythetic substitute. That's it! */ /*! Minimum allowed pitch (66 Hz) */ #define PLC_PITCH_MIN(SAMPLE_RATE) ((double)(SAMPLE_RATE) / 66.6) /*! Maximum allowed pitch (200 Hz) */ #define PLC_PITCH_MAX(SAMPLE_RATE) ((SAMPLE_RATE) / 200) /*! Maximum pitch OLA window */ //#define PLC_PITCH_OVERLAP_MAX(SAMPLE_RATE) ((PLC_PITCH_MIN(SAMPLE_RATE)) >> 2) /*! The length over which the AMDF function looks for similarity (20 ms) */ #define CORRELATION_SPAN(SAMPLE_RATE) ((20 * (SAMPLE_RATE)) / 1000) /*! History buffer length. The buffer must also be at leat 1.25 times PLC_PITCH_MIN, but that is much smaller than the buffer needs to be for the pitch assessment. */ //#define PLC_HISTORY_LEN(SAMPLE_RATE) ((CORRELATION_SPAN(SAMPLE_RATE)) + (PLC_PITCH_MIN(SAMPLE_RATE))) namespace audio { typedef struct { /*! Consecutive erased samples */ int missing_samples; /*! Current offset into pitch period */ int pitch_offset; /*! Pitch estimate */ int pitch; /*! Buffer for a cycle of speech */ float *pitchbuf;//[PLC_PITCH_MIN]; /*! History buffer */ short *history;//[PLC_HISTORY_LEN]; /*! Current pointer into the history buffer */ int buf_ptr; } plc_state_t; class PcmConcealer { public: PcmConcealer(); ~PcmConcealer(); void Init(int channels, int bit_depth, int sample_rate); //Process a block of received audio samples. int Receive(short amp[], int frames); //Fill-in a block of missing audio samples. int Fill(short amp[], int frames); void Destroy(); private: int amdf_pitch(int min_pitch, int max_pitch, short amp[], int channel_index, int frames); void save_history(plc_state_t *s, short *buf, int channel_index, int frames); void normalise_history(plc_state_t *s); /** Holds the states of each of the channels **/ std::vector< plc_state_t * > ChannelStates; int plc_pitch_min; int plc_pitch_max; int plc_pitch_overlap_max; int correlation_span; int plc_history_len; int channel_count; int sample_rate; bool Initialized; }; } #endif PcmConcealer.cpp /* * Code adapted from Steve Underwood of the Asterisk Project. This code inherits * the same licensing restrictions as the Asterisk Project. */ #include "audio/PcmConcealer.hpp" /* We do a straight line fade to zero volume in 50ms when we are filling in for missing data. */ #define ATTENUATION_INCREMENT 0.0025 /* Attenuation per sample */ #if !defined(INT16_MAX) #define INT16_MAX (32767) #define INT16_MIN (-32767-1) #endif #ifdef WIN32 inline double rint(double x) { return floor(x + 0.5); } #endif inline short fsaturate(double damp) { if (damp > 32767.0) return INT16_MAX; if (damp < -32768.0) return INT16_MIN; return (short)rint(damp); } namespace audio { PcmConcealer::PcmConcealer() : Initialized(false) { } PcmConcealer::~PcmConcealer() { Destroy(); } void PcmConcealer::Init(int channels, int bit_depth, int sample_rate) { if(Initialized) return; if(channels <= 0 || bit_depth != 16) return; Initialized = true; channel_count = channels; this->sample_rate = sample_rate; ////////////// double min = PLC_PITCH_MIN(sample_rate); int imin = (int)min; double max = PLC_PITCH_MAX(sample_rate); int imax = (int)max; plc_pitch_min = imin; plc_pitch_max = imax; plc_pitch_overlap_max = (plc_pitch_min >> 2); correlation_span = CORRELATION_SPAN(sample_rate); plc_history_len = correlation_span + plc_pitch_min; ////////////// for(int i = 0; i < channel_count; i ++) { plc_state_t *t = new plc_state_t; memset(t, 0, sizeof(plc_state_t)); t->pitchbuf = new float[plc_pitch_min]; t->history = new short[plc_history_len]; ChannelStates.push_back(t); } } void PcmConcealer::Destroy() { if(!Initialized) return; while(ChannelStates.size()) { plc_state_t *s = ChannelStates.at(0); if(s) { if(s->history) delete s->history; if(s->pitchbuf) delete s->pitchbuf; memset(s, 0, sizeof(plc_state_t)); delete s; } ChannelStates.erase(ChannelStates.begin()); } ChannelStates.clear(); Initialized = false; } //Process a block of received audio samples. int PcmConcealer::Receive(short amp[], int frames) { if(!Initialized) return 0; int j = 0; for(int k = 0; k < ChannelStates.size(); k++) { int i; int overlap_len; int pitch_overlap; float old_step; float new_step; float old_weight; float new_weight; float gain; plc_state_t *s = ChannelStates.at(k); if (s->missing_samples) { /* Although we have a real signal, we need to smooth it to fit well with the synthetic signal we used for the previous block */ /* The start of the real data is overlapped with the next 1/4 cycle of the synthetic data. */ pitch_overlap = s->pitch >> 2; if (pitch_overlap > frames) pitch_overlap = frames; gain = 1.0 - s->missing_samples * ATTENUATION_INCREMENT; if (gain < 0.0) gain = 0.0; new_step = 1.0/pitch_overlap; old_step = new_step*gain; new_weight = new_step; old_weight = (1.0 - new_step)*gain; for (i = 0; i < pitch_overlap; i++) { int index = (i * channel_count) + j; amp[index] = fsaturate(old_weight * s->pitchbuf[s->pitch_offset] + new_weight * amp[index]); if (++s->pitch_offset >= s->pitch) s->pitch_offset = 0; new_weight += new_step; old_weight -= old_step; if (old_weight < 0.0) old_weight = 0.0; } s->missing_samples = 0; } save_history(s, amp, j, frames); j++; } return frames; } //Fill-in a block of missing audio samples. int PcmConcealer::Fill(short amp[], int frames) { if(!Initialized) return 0; int j =0; for(int k = 0; k < ChannelStates.size(); k++) { short *tmp = new short[plc_pitch_overlap_max]; int i; int pitch_overlap; float old_step; float new_step; float old_weight; float new_weight; float gain; short *orig_amp; int orig_len; orig_amp = amp; orig_len = frames; plc_state_t *s = ChannelStates.at(k); if (s->missing_samples == 0) { // As the gap in real speech starts we need to assess the last known pitch, //and prepare the synthetic data we will use for fill-in normalise_history(s); s->pitch = amdf_pitch(plc_pitch_min, plc_pitch_max, s->history + plc_history_len - correlation_span - plc_pitch_min, j, correlation_span); // We overlap a 1/4 wavelength pitch_overlap = s->pitch >> 2; // Cook up a single cycle of pitch, using a single of the real signal with 1/4 //cycle OLA'ed to make the ends join up nicely // The first 3/4 of the cycle is a simple copy for (i = 0; i < s->pitch - pitch_overlap; i++) s->pitchbuf[i] = s->history[plc_history_len - s->pitch + i]; // The last 1/4 of the cycle is overlapped with the end of the previous cycle new_step = 1.0/pitch_overlap; new_weight = new_step; for ( ; i < s->pitch; i++) { s->pitchbuf[i] = s->history[plc_history_len - s->pitch + i]*(1.0 - new_weight) + s->history[plc_history_len - 2*s->pitch + i]*new_weight; new_weight += new_step; } // We should now be ready to fill in the gap with repeated, decaying cycles // of what is in pitchbuf // We need to OLA the first 1/4 wavelength of the synthetic data, to smooth // it into the previous real data. To avoid the need to introduce a delay // in the stream, reverse the last 1/4 wavelength, and OLA with that. gain = 1.0; new_step = 1.0/pitch_overlap; old_step = new_step; new_weight = new_step; old_weight = 1.0 - new_step; for (i = 0; i < pitch_overlap; i++) { int index = (i * channel_count) + j; amp[index] = fsaturate(old_weight * s->history[plc_history_len - 1 - i] + new_weight * s->pitchbuf[i]); new_weight += new_step; old_weight -= old_step; if (old_weight < 0.0) old_weight = 0.0; } s->pitch_offset = i; } else { gain = 1.0 - s->missing_samples*ATTENUATION_INCREMENT; i = 0; } for ( ; gain > 0.0 && i < frames; i++) { int index = (i * channel_count) + j; amp[index] = s->pitchbuf[s->pitch_offset]*gain; gain -= ATTENUATION_INCREMENT; if (++s->pitch_offset >= s->pitch) s->pitch_offset = 0; } for ( ; i < frames; i++) { int index = (i * channel_count) + j; amp[i] = 0; } s->missing_samples += orig_len; save_history(s, amp, j, frames); delete [] tmp; j++; } return frames; } void PcmConcealer::save_history(plc_state_t *s, short *buf, int channel_index, int frames) { if (frames >= plc_history_len) { /* Just keep the last part of the new data, starting at the beginning of the buffer */ //memcpy(s->history, buf + len - plc_history_len, sizeof(short)*plc_history_len); int frames_to_copy = plc_history_len; for(int i = 0; i < frames_to_copy; i ++) { int index = (channel_count * (i + frames - plc_history_len)) + channel_index; s->history[i] = buf[index]; } s->buf_ptr = 0; return; } if (s->buf_ptr + frames > plc_history_len) { /* Wraps around - must break into two sections */ //memcpy(s->history + s->buf_ptr, buf, sizeof(short)*(plc_history_len - s->buf_ptr)); short *hist_ptr = s->history + s->buf_ptr; int frames_to_copy = plc_history_len - s->buf_ptr; for(int i = 0; i < frames_to_copy; i ++) { int index = (channel_count * i) + channel_index; hist_ptr[i] = buf[index]; } frames -= (plc_history_len - s->buf_ptr); //memcpy(s->history, buf + (plc_history_len - s->buf_ptr), sizeof(short)*len); frames_to_copy = frames; for(int i = 0; i < frames_to_copy; i ++) { int index = (channel_count * (i + (plc_history_len - s->buf_ptr))) + channel_index; s->history[i] = buf[index]; } s->buf_ptr = frames; return; } /* Can use just one section */ //memcpy(s->history + s->buf_ptr, buf, sizeof(short)*len); short *hist_ptr = s->history + s->buf_ptr; int frames_to_copy = frames; for(int i = 0; i < frames_to_copy; i ++) { int index = (channel_count * i) + channel_index; hist_ptr[i] = buf[index]; } s->buf_ptr += frames; } void PcmConcealer::normalise_history(plc_state_t *s) { short *tmp = new short[plc_history_len]; if (s->buf_ptr == 0) return; memcpy(tmp, s->history, sizeof(short)*s->buf_ptr); memcpy(s->history, s->history + s->buf_ptr, sizeof(short)*(plc_history_len - s->buf_ptr)); memcpy(s->history + plc_history_len - s->buf_ptr, tmp, sizeof(short)*s->buf_ptr); s->buf_ptr = 0; delete [] tmp; } int PcmConcealer::amdf_pitch(int min_pitch, int max_pitch, short amp[], int channel_index, int frames) { int i; int j; int acc; int min_acc; int pitch; pitch = min_pitch; min_acc = INT_MAX; for (i = max_pitch; i <= min_pitch; i++) { acc = 0; for (j = 0; j < frames; j++) { int index1 = (channel_count * (i+j)) + channel_index; int index2 = (channel_count * j) + channel_index; //std::cout << "Index 1: " << index1 << ", Index 2: " << index2 << std::endl; acc += abs(amp[index1] - amp[index2]); } if (acc < min_acc) { min_acc = acc; pitch = i; } } std::cout << "Pitch: " << pitch << std::endl; return pitch; } } P.S. - I must confess that digital audio is not my forte...

    Read the article

  • deploying a styles library for plugin developers

    - by bitbonk
    I have an application that my customers can write plugins (that have WPF UIs) for. Now I would like to expose a set of styles as a library that they can use and that will help them with the development of the UIs sO they don't have to reivent the weel. How would I idealy expose those styles without actually having to deploy a lot of xaml files? How is something like this usually done in WPF so it does not break tooling support (blend, vs). How do I expose it and how does the cusomer reference those styles?

    Read the article

< Previous Page | 37 38 39 40 41 42 43 44 45 46 47 48  | Next Page >