Hi,
Long code using C#, which I don't master. I would like to have a small
program, preferable in C/C++, that illustrates the error. Also you are
using a DLL, which can be an old version. I can tell you the color
translator uses same approach (shared profiles) and it works fine. You
can safely share same hProfile on different threads, each thread have to
use a different transform, because the caching mechanism. You need the
library compiled with multithreading capabilities enabled, the toggle is
set by default, but this was not supported on old versions.
- Make sure you are using "modern" code. Latest 2.8 is recommended.
- Make sure you manage properly the shared resources in your part of code.
If anyway you get the error, please report it to me. Try to do a small
program that shows the error. I am glad to get bug reports as this
helps in getting a better product.
Regards
Marti.
On 08/01/2017 20:52, liti1...@vipmail.hu wrote:
> Hi Marti,
> Also forgot to mention, that i use c#.
>
> Try to simplify the codes here.
> This is working solution if use without multi-threading:
> ***
> [DllImport("lcms2.dll")]
> public static extern IntPtr cmsCreateTransform(IntPtr hInputProfile,
> UInt32 InputFormat, IntPtr hOutputProfile, UInt32 OutputFormat, UInt32
> Intent, UInt32 dwFlags);
>
> [DllImport("lcms2.dll")]
> public static extern void cmsDoTransformLineStride(IntPtr
> hTransform, byte[] InputBuffer, byte[] OutputBuffer, UInt32 PixelsPerLine,
> UInt32 LineCount,
> UInt32
> BytesPerLineIn, UInt32 BytesPerLineOut, UInt32 BytesPerPlaneIn, UInt32
> BytesPerPlaneOut);
>
> public static class Profiles
> {
> private static IntPtr __hMonitor = IntPtr.Zero;
> public static IntPtr hMonitor { get { return __hMonitor; } set {
> __hMonitor = value; } }
> // etc.
> }
>
> [HandleProcessCorruptedStateExceptions]
> public BitmapSource LoadSingleFile(string filename)
> {
> var ms = LoadImageFileToMemoryStream(filename);
> BitmapFrame bf = BitmapFrame.Create(ms,
> BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
>
> IntPtr hInput, hMonitor;
> byte[] inputProfile =
> StreamToByteArray(bf.ColorContexts[0].OpenProfileStream()); // Check it
> before, if not available, create one on-the-fly in the actual format
> hInput = cmsOpenProfileFromMem(inputProfile,
> (uint)inputProfile.Length);
>
> // Monitor Profile: opened earlier and located in
> Profiles.hMonitor;
>
> IntPtr hTransform = IntPtr.Zero;
>
> int BytesPerPixelIn = 0;
> int StrideIn = 0;
> int SizeIn = 0;
> byte[] PixelsIn;
> UInt32 TypeIn = 0;
>
> int BytesPerPixelOut = 0;
> int StrideOut = 0;
> int SizeOut = 0;
> byte[] PixelsOut;
> UInt32 TypeOut = 0;
>
> // CHECK INPUT FORMATS
> if (bf.Format == PixelFormats.Bgr24)
> {
> BytesPerPixelIn = BytesPerPixelOut = 3;
> StrideIn = StrideOut = ((bf.PixelWidth * BytesPerPixelIn) +
> (bf.PixelWidth % 4));
> SizeIn = SizeOut = StrideIn * bf.PixelHeight;
> PixelsIn = new byte[SizeIn];
> PixelsOut = new byte[SizeOut];
> TypeIn = TypeOut = LittleCMS.LCMS.TYPE_BGR_8;
>
> bf.CopyPixels(PixelsIn, StrideIn, 0);
> }
> else if (bf.Format == PixelFormats.Cmyk32)
> {
> BytesPerPixelIn = bf.Format.BitsPerPixel / 8; // In this
> case: 4
> BytesPerPixelOut = 3;
> StrideIn = ((bf.PixelWidth * BytesPerPixelIn) +
> (bf.PixelWidth % 4));
> StrideOut = ((bf.PixelWidth * BytesPerPixelOut) +
> (bf.PixelWidth % 4));
> SizeIn = StrideIn * bf.PixelHeight;
> SizeOut = StrideOut * bf.PixelHeight;
> PixelsIn = new byte[SizeIn];
> PixelsOut = new byte[SizeOut];
> TypeIn = LittleCMS.LCMS.TYPE_CMYK_8;
> TypeOut = LittleCMS.LCMS.TYPE_BGR_8;
>
> bf.CopyPixels(PixelsIn, StrideIn, 0);
> }
> // etc., etc., etc....
> else
> {
> // Using FormatConvertedBitmap class and do the first step
> var fcb = new FormatConvertedBitmap(bmp,
> System.Windows.Media.PixelFormats.Bgr24, null, 0));
> }
>
> // Create the transform
> try
> {
> hTransform = cmsCreateTransform(hInput, TypeIn, hMonitor,
> TypeOut, iFlags, dwFlags);
> }
> catch (AccessViolationException)
> {
> return null;
> }
> catch (Exception e)
> {
> return null;
> }
>
> // Do the transform: VERSION 1. simple transform
> try
> {
> cmsDoTransformLineStride(hTransform, PixelsIn, PixelsOut,
> (uint)bf.PixelWidth, (uint)partHeight, (uint)StrideIn, (uint)StrideOut, 0, 0);
> }
> catch (AccessViolationException)
> {
> return null;
> }
> catch (Exception e)
> {
> return null;
> }
>
> // Do the transform: VERSION 2: This is also a single thread
> version, what i can change to use multi-threaded, and works fine.
> try
> {
> int cores = Environment.ProcessorCount; ;
> int partHeight = bf.PixelHeight / cores;
> int lastPlaceIn = 0, lastPlaceOut = 0;
> for (int i = 0; i < cores; i++)
> {
> int tSizeIn = 0;
> int tSizeOut = 0;
> if (i == (cores - 1))
> {
> partHeight = (bf.PixelHeight - (cores - 1) *
> partHeight);
> }
>
> tSizeIn = partHeight * StrideIn;
> tSizeOut = partHeight * StrideOut;
>
> byte[] tPixelsIn = new byte[tSizeIn];
> byte[] tPixelsOut = new byte[tSizeOut];
>
> Array.Copy(PixelsIn, lastPlaceIn, tPixelsIn, 0, tSizeIn);
> lastPlaceIn = ((i + 1) * partHeight * StrideIn);
>
> cmsDoTransformLineStride(hTransform, tPixelsIn,
> tPixelsOut, (uint)bf.PixelWidth, (uint)partHeight, (uint)StrideIn,
> (uint)StrideOut, 0, 0);
>
> if (i == (cores - 1))
> Array.Copy(tPixelsOut, 0, PixelsOut, lastPlaceOut,
> tSizeOut);
> else
> {
> Array.Copy(tPixelsOut, 0, PixelsOut, lastPlaceOut,
> tSizeOut);
> lastPlaceOut = ((i + 1) * partHeight * StrideOut);
> }
> }
> // catch exceptions....
>
> BitmapSource ccb = BitmapSource.Create(bf.PixelWidth,
> bf.PixelHeight, bf.DpiX, bf.DpiY, PixelFormats.Bgr24, null, PixelsOut,
> StrideOut);
> cmsDeleteTransform(hTransform);
> cmsCloseProfile(hInput);
> // cmsCloseProfile(hMonitor); - Not Close Monitor Profile
> because i would like to use it for the next file(s), too.
> return ccb;
> }
> ***
>
> So, when i open only one image and call the LoadSingleFile method, everything
> works nice.
> When i load multiple files and use the LoadSingleFile method in a for loop,
> everything works nice.
> When i load multiple files and put the LoadSingleFiles method in a for loop
> and each of them starts in different thread, everything works nice till the
> files has the same sRGB profiles and 24bit depth.
> If i put e.g. a CMYK image (anything else, but different then the previously
> used format), that is the point where the problem begins....
> The error is about the AccessViolationException during the cmsCreateTransform
> or rarely in the DoTransform / cmsDeleteTransform / cmsDeleteProfile.
> "Attempted to read or write protected memory. This is often an indication
> that other memory is corrupt."
> And best error is when the vshost.exe (during debugging) crashed - without
> any information about the problem.
>
> If i need to use cmsContexts (and the errorhandling) i also have no clues
> about how to declare them in C-Sharp.
>
> Let me know if you need more infos.
>
> Thanks a lot,
> *Tamas*
>
> -- Eredeti üzenet --
> Feladó: Marti Maria @ LittleCMS <marti.ma...@littlecms.com>Címzett:
> <liti1...@vipmail.hu>,
> <lcms-user@lists.sourceforge.net>Elküldve: 2017. január 8. 19:48Tárgy :
> Re: [Lcms-user] Multi-Threading in VS
>
> Hi Tamas,
>
> Could you please detail which errors you get? I'm using multi threading
> without problems, so maybe something is wrong, perhaps In the documentation.
>
> Best regards,
> Marti On 8 Jan 2017, at 18:47, liti1...@vipmail.hu wrote: Dear All,
> I am using lcms2.dll and their standard methods and all of them works fine in
> a single-thread environment. (I was able to use cmsDoTransformLineStride
> multi-threaded when this is the only function which is using multiple
> threads. My question is about e.g. if i would like to use as a batch process
> across multiple/different image files and the whole image process put into
> different threads per files .)
> When i tried to put them in a multi-threaded environment, always get errors.
> I try to understand the cmsContexts and start to experiment with them, but it
> seems something i missed.
> Can anybody provide me a simple sample code of how should i use these
> functions (with dll declaration, too)?
>
> Also, i would be happy if someone provide me a sample about the error
> handling function.
>
> In case both questions, I'm using WPF in VS 2015.
>
> Thanks,
> *Tamas*
>
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>
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