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Trouble with transfer function in WIA C#

I have a problem with the below code. I want to scan a document by clicking a button in a WinForms C# application.
I use WIA, Visual studio and the scanner Fujitsu N7100A working with Windows 8. I am following a tutorial online for using WIA.
But the program doesn't run as expected. It seems to break down at the Transfer method.
// Create a DeviceManager instance
var deviceManager = new DeviceManager();
// Create an empty variable to store the scanner instance
DeviceInfo firstScannerAvailable = null;
// Loop through the list of devices to choose the first available
AddLogs(deviceManager.DeviceInfos.Count.ToString(), filename);
foreach (DeviceInfo d in deviceManager.DeviceInfos)
{
if (d.Type == WiaDeviceType.ScannerDeviceType)
{
firstScannerAvailable = d;
}
}
// Connect to the first available scanner
var device = firstScannerAvailable.Connect();
// Select the scanner
var scannerItem = device.Items[0];
// Retrieve a image in JPEG format and store it into a variable
var imageFile = (ImageFile)scannerItem.Transfer(FormatID.wiaFormatPNG);
//Save the image in some path with filename
var path = #"C:\Documents\scan.png";
if (File.Exists(path))
{
File.Delete(path);
}
// Save image !
imageFile.SaveFile(path);
I just have to remove the addition of lines in the file of log.

This is much more of a workaround since i have no idea about your scanner.
I would assume that all scanners has a drive where they store their scanned documents, like mine, So i would suggest that you read all available drives loop through them check for DriveType and VolumeLabel and then read it's files and copy the document where you want
Something like this :
foreach (var item in DriveInfo.GetDrives())
{
//VolumeLabel differs from a scanner to another
if (item.VolumeLabel == "Photo scan" && item.DriveType == DriveType.Removable)
{
foreach (var obj in Directory.GetFiles(item.Name))
{
File.Copy(obj, "[YOUR NEW PATH]");
break;
}
break;
}
}

Finaly a TWAIN application work with this scanner. I will work with that. I don't said why do that work with TWAIN and not with WIA but that the reality. Sorry for this waste of time. Thank you for the answers. Have a nice day.

I am currently solving this very problem. It seems the N7100A driver sets the Pages property of the device to 0, which should mean continous scanning, but the transfer method is unable to handle this value. You must set that property to 1:
var pages = 1;
// Not all devices have this property, but Fujitsu N7100A has.
device.Properties["Pages"]?.set_Value(ref pages);

I think the problem is here
var scannerItem = device.Items[0];
as WIA indexes are NOT zero based so it should be 1 instead
var scannerItem = device.Items[1];

Capturing output from powershell script

I have been working on converting a GUI script from another language to C# in VS2017 for a customer. With help from the folks here I am 95% of the way there, but have run into a couple of snags; just not sure I am doing things in the best way. I'm including just the relevant portions of code below, please let me know if I am not providing enough:
The majority of the code is centered on the wpf form, which collects data for low level technicians to batch deploy a number of Virtual Machines into the VMware environment. This number could easily range into the dozens or even a hundred VMs at once. The information for each VM is specified in the form, then collected in a listview. Once the listview is fully populated it is exported to a csv. Up to this point everything works just fine.
I've next been working on actually launching the powershell/powerCLI script (also working) and capturing output. The log file is opened with a specific reader application the customer uses, which updates in real time, and the captured output is fed to the log. It is important for the technicians to see the output from the code line by line so they can react if there is an issue.
I started with something like this as a test:
string sPSScript = "C:\\Users\\Admin\\Desktop\\TestC#.ps1";
string logFile = "C:\\Users\\Admin\\Desktop\\My.log";
string logReader = "C:\\Users\\Admin\\Documents\\CMTrace.exe";
string standard_output;
System.Diagnostics.Process PSScript = new System.Diagnostics.Process();
PSScript.StartInfo.FileName =
Environment.GetFolderPath(Environment.SpecialFolder.SystemX86) +
"\\WindowsPowerShell\\v1.0\\powershell.exe";
PSScript.StartInfo.Arguments = "-command . '" + sPSScript + "' " +
vCenter.Text;
PSScript.StartInfo.RedirectStandardOutput = true;
PSScript.StartInfo.UseShellExecute = false;
PSScript.Start();
System.Diagnostics.Process LogFile = new System.Diagnostics.Process();
LogFile.StartInfo.FileName = logReader;
LogFile.StartInfo.Arguments = logFile;
LogFile.Start(); while ((standard_output =
PSScript.StandardOutput.ReadLine()) != null)
{
if (standard_output != "")
{
using (StreamWriter file = new StreamWriter(logFile, append: true))
{
file.WriteLine(standard_output);
}
}
}
While this writes to the log file in real time as expected, it creates 100 instances of the logReader application. I understand why, since I am declaring a new StreamWriter object through every pass, but am unsure how better to go about this.
I tried creating the file outside the loop, like this:
StreamWriter file = new StreamWriter(logFile, append: true) { };
System.Diagnostics.Process LogFile = new System.Diagnostics.Process();
LogFile.StartInfo.FileName = logReader;
LogFile.StartInfo.Arguments = logFile;
System.Diagnostics.Process PSScript = new System.Diagnostics.Process();
PSScript.StartInfo.FileName = Environment.GetFolderPath(Environment.SpecialFolder.SystemX86) + "\\WindowsPowerShell\\v1.0\\powershell.exe";
PSScript.StartInfo.Arguments = "-command . '" + sPSScript + "' " + vCenter.Text;
PSScript.StartInfo.RedirectStandardOutput = true;
PSScript.StartInfo.UseShellExecute = false;
LogFile.Start();
PSScript.Start();
System.Threading.Thread.Sleep(1500);
while ((standard_output = PSScript.StandardOutput.ReadLine()) != null)
{
if (standard_output != "")
{
file.WriteLine(standard_output);
}
}
It doesn't create multiple instances, but it also does not update the log file in real time as the previous code does. It only updates once the script runs, and then only partially. The script produces ~1000 lines of output, and I consistently see only about 840 written to the log file.
I thought about doing something like this:
FileStream logFS;
logFS = new FileStream(logFile, FileMode.Append);
but it appears the only options available to me to write to the file are expecting a byte array.
I am sure that I am missing something stupid simple in this, but would appreciate any suggestions on the easiest way to create the log file, open it in the reader, and then update it with the standard output from the powershell script.

why did the previous code writes in real time?
because you are wrapping it with using. And at the end of using block its gonna call dispose which calls .Flush to write to disk
Your second code block calls WriteLine but never called Flush so it writes to the disk whenever the buffer is full. Just add a .Flush call after WriteLine and you will have real time logging

Getting a poster frame(thumbnail) with ffmpeg

I am trying to get a poster frame from a video file, using ffmpeg.
I have been following this tutorial and come up with the following code(which is taken/adapted from the link I gave):
public bool GetVideoThumbnail(string path, string saveThumbnailTo, int seconds)
{
string parameters = string.Format("-i {0} {1} -vcodec mjpeg -ss {2} -vframes 1 -an -f rawvideo", path, saveThumbnailTo, seconds);
if (File.Exists(saveThumbnailTo))
{
return true;
}
else
{
using (Process process = Process.Start(pathToConvertor, parameters))
{
process.WaitForExit();
}
return File.Exists(saveThumbnailTo);
}
}
At the moment this code is successfully creating a file in the correct destination (saveThumbnailTo) only the picture is completely black. I have tried changing the seconds value in the code to ensure that I am not just getting a blank picture from the start of the video. The path refers to where my video is stored, by the way.
I am currently calling the above code like so:
GetVideoThumbnail(videoPath, folderPath + "/poster.jpg", 100)
..and then passing it out to my view to display the picture. I just wonder whether ".jpg" is the extension I should be giving to this file as I am not entirely sure?
Edit: When I run the same command from the command line I get the following errors:
Incompatible pixel format 'yuv420p' for codec 'mjpeg', auto-selecting
format 'yuvj420p'
which appears in yellow, and
[image2 # 02S96AE0] Could not get frame filename number 2 from pattern
'poster.jpg' an_interleaved_write_frame(): Invalid argument
which appears in red.
Could anyone help me with getting this working properly as I am completely unfamiliar with the ffmpeg command line and not sure what I am doing wrong. I have tried removing the vcodec parameter and get the same error message.

Try this:
public bool GetVideoThumbnail(string path, string saveThumbnailTo, int seconds)
{
string parameters = string.Format("-ss {0} -i {1} -f image2 -vframes 1 -y {2}", seconds, path, saveThumbnailTo);
var processInfo = new ProcessStartInfo();
processInfo.FileName = pathToConvertor;
processInfo.Arguments = parameters;
processInfo.CreateNoWindow = true;
processInfo.UseShellExecute = false;
File.Delete(saveThumbnailTo);
using(var process = new Process())
{
process.StartInfo = processInfo;
process.Start();
process.WaitForExit();
}
return File.Exists(saveThumbnailTo);
}
Short explanation:
f image2 : output is image
vframes 1 : take one frame from the input
y : overwrite output file
"processInfo.CreateNoWindow = true" : do not show the ffmpeg window
Try several times with different values for the "seconds" parameter.
Also, make sure the "pathToConvertor" is correct.
This worked for me, with recent build of ffmpeg.exe on a Windows machine.
Let me know how it goes.

C# Problem Reading Console Output to string

i want to launch ffmpeg from my app and retrive all console output that ffmpeg produces. Thing seems obvious, i followed many forum threads/articles like this one but i have problem, though i follow all information included there I seem to end up in dead end.
String that should contain output from ffmpeg is always empty. I've tried to see where is the problem so i made simple c# console application that only lists all execution parameters that are passed to ffmpeg, just to check if problem is caused by ffmpeg itself. In that case everything work as expected.
I also did preview console window of my app. When i launch ffmpeg i see all the output in console but the function that should recieve that output for further processing reports that string was empty. When my param-listing app is launched the only thing I see is the expected report from function that gets output.
So my question is what to do to get ffmpeg output as i intended at first place.
Thanks in advance
MTH

This is a long shot, but have you tried redirecting StandardError too?

Here is a part of my ffmpeg wrapper class, in particular showing how to collect the output and errors from ffmpeg.
I have put the Process in the GetVideoDuration() function just so you can see everything in the one place.
Setup:
My ffmpeg is on the desktop, ffPath is used to point to it.
namespace ChildTools.Tools
{
public class FFMpegWrapper
{
//path to ffmpeg (I HATE!!! MS special folders)
string ffPath = System.Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "\\ffmpeg.exe";
//outputLines receives each line of output, only if they are not zero length
List<string> outputLines = new List<string>();
//In GetVideoDuration I only want the one line of output and in text form.
//To get the whole output just remove the filter I use (my search for 'Duration') and either return the List<>
//Or joint the strings from List<> (you could have used StringBuilder, but I find a List<> handier.
public string GetVideoDuration(FileInfo fi)
{
outputLines.Clear();
//I only use the information flag in this function
string strCommand = string.Concat(" -i \"", fi.FullName, "\"");
//Point ffPath to my ffmpeg
string ffPath = System.Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "\\ffmpeg.exe";
Process processFfmpeg = new Process();
processFfmpeg.StartInfo.Arguments = strCommand;
processFfmpeg.StartInfo.FileName = ffPath;
//I have to say that I struggled for a while with the order that I setup the process.
//But this order below I know to work
processFfmpeg.StartInfo.UseShellExecute = false;
processFfmpeg.StartInfo.RedirectStandardOutput = true;
processFfmpeg.StartInfo.RedirectStandardError = true;
processFfmpeg.StartInfo.CreateNoWindow = true;
processFfmpeg.ErrorDataReceived += processFfmpeg_OutData;
processFfmpeg.OutputDataReceived += processFfmpeg_OutData;
processFfmpeg.EnableRaisingEvents = true;
processFfmpeg.Start();
processFfmpeg.BeginOutputReadLine();
processFfmpeg.BeginErrorReadLine();
processFfmpeg.WaitForExit();
//I filter the lines because I only want 'Duration' this time
string oStr = "";
foreach (string str in outputLines)
{
if (str.Contains("Duration"))
{
oStr = str;
}
}
//return a single string with the duration line
return oStr;
}
private void processFfmpeg_OutData(object sender, DataReceivedEventArgs e)
{
//The data we want is in e.Data, you must be careful of null strings
string strMessage = e.Data;
if outputLines != null && strMessage != null && strMessage.Length > 0)
{
outputLines.Add(string.Concat( strMessage,"\n"));
//Try a Console output here to see all of the output. Particularly
//useful when you are examining the packets and working out timeframes
//Console.WriteLine(strMessage);
}
}
}
}

How to get musicbrainz track information from audio file

Can anyone tell me how to get track information from the MusicBrainz database from an audio file (mp3, wav, wma, ogg, etc...) using audio fingerprinting. I'm using MusicBrainz Sharp library, but any other library is ok.
I've seen that you must use the libofa library, that you can't use MusicBrainz Sharp to get puid from the audio file, but I can't figure out how to use libofa with C#.
Please show some examples and code snippets to help me, because I can't find them anywhere.
Thanks in advance!

The thing is that you can probably use libofa to get a fingerprint of the audio file, but if the file has no PUID available, you will be stuck and will have to use something like genpuid to submit the audio fingerprint to AmpliFIND and wait about a day to get a PUID.
That being said, I tried something similar about two years ago, but kinda lost interest in the project when I failed to write the IDv3 tags, if I remember correctly. However, the source code is available on Bitbucket.
I basically wrapped libofa using a DllImport and also wrapped genpuid (ie. read the output XML) to be able to read the fingerprint and submit the file for fingerprinting if I did not get one from libofa. I also wrote some code that reads information from MusicBrainz using MusicBrainz Sharp.
Well, at least that was what I planned back then, I think. :) I hope this helps you to solve your problem and I'd love to see an update on this.
Edit: I just noticed that I created a bug report for myself, which basically says that I still needed an implementation for my decoder which is probably why I created this question in SO. So I guess I did not implement the genpuid fingerprinter just to be able to do the fingerprint/get the guid, because I did not get the libofa fingerprinter to work correctly.

I did the wrapped genpuid approach suggested above.
private string GetPUID(string fileName)
{
Process p;
ProcessStartInfo si;
string outRow;
string puidReturned;
string gendPuidPath = #"C:\Program Files\genpuid\genpuid.exe";
string gendPuidKey = "your key here";
System.Text.RegularExpressions.Regex puidRex = new System.Text.RegularExpressions.Regex( #"puid: (\S+)" ); // sample: puid: 3c62e009-ec93-1c0f-e078-8829e885df67
System.Text.RegularExpressions.Match m;
if (File.Exists(gendPuidPath))
{
try
{
si = new ProcessStartInfo(gendPuidPath, gendPuidKey + " \"" + fileName + "\"");
si.RedirectStandardOutput = true;
si.UseShellExecute = false;
p = new Process();
p.StartInfo = si;
p.Start();
puidReturned = "";
while ((outRow = p.StandardOutput.ReadLine()) != null)
{
m = puidRex.Match(outRow);
if (m.Success)
puidReturned = m.Groups[1].Value;
Debug.WriteLine(outRow);
}
p.WaitForExit();
p.Close();
return puidReturned;
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
Debug.WriteLine(ex.StackTrace);
throw new Exception("Unexpexted Error obtaining PUID for file: " + fileName, ex);
}
}
else
{
Debug.WriteLine("genpuid.exe not found");
return "";
}
}