Uncategorized – Alex Weinberger's blog

If you are running Agent DVR on a slow computer and keep getting errors like OPEN_INPUT: file not found

You can look in the logs and see things like:

Camera 1: DoStart: Reader: Camera 1: OPEN_INPUT:No such file or directory at CoreLogic.Sources.Combined.MediaStream.DoStart()
Camera 1: SourceErrorHandler: CoreLogic.Sources.Combined.MediaStream:Reader: Camera 2: OPEN_INPUT:No such file or directory
Camera 1: SourcePlayingFinished: Playing finished (SourceError)
Camera 1: NextReconnectTarget: Reconnecting in 1s
Connect: creating pipe *pipe GUID*
Connect: Cannot access a closed pipe. at CoreLogic.Extensions.WaitForConnectionEx(NamedPipeServerStream stream, ManualResetEvent cancelEvent) at CoreLogic.Sources.DVR.Connect()

Camera 1: DoStart: Reader: Camera 1: OPEN_INPUT:No such file or directory at CoreLogic.Sources.Combined.MediaStream.DoStart()

Camera 1: SourceErrorHandler: CoreLogic.Sources.Combined.MediaStream:Reader: Camera 2: OPEN_INPUT:No such file or directory

Camera 1: SourcePlayingFinished: Playing finished (SourceError)

Camera 1: NextReconnectTarget: Reconnecting in 1s

Connect: creating pipe *pipe GUID*

Connect: Cannot access a closed pipe. at CoreLogic.Extensions.WaitForConnectionEx(NamedPipeServerStream stream, ManualResetEvent cancelEvent) at CoreLogic.Sources.DVR.Connect()

And the cameras sometimes appear and sometimes don’t, the logs actually give a good hint of what’s going on.

OPEN_INPUT is looking for a pipe, which is only being created later on where it says creating pipe

I tried all kinds of things like using CPU, GPU, using a different version of ffmpeg, lowering the bitrate of the streams, but the problem is a race condition that happens before all that can have any effect. When it finally starts working, it works fine for any quality setting.

OK, how do we fix this? Easy. Before you start make sure the service isn’t running. Run services.msc, look for a service called Agent, which should be one of the first ones, and press stop.

Also look for the file Program files\Agent\CoreLogic.dll and make a backup copy of it.

Now get your favorite .NET decompiler (I used dnSpy which wasn’t great but worked) and open CoreLogic.dll.

Look for the class CoreLogic.Sources.Combined.NamedPipe and look for the public void Start() method. Right click and choose Edit Method (C#). Add the following lines so it looks like this:

public void Start()
{
    this.DVR.Start();
    CoreLogic.Utilities.Logger.LogDebug("Called start, will wait...", null, "Start");
    System.Threading.Thread.Sleep(500);
    CoreLogic.Utilities.Logger.LogDebug("Continuing...", null, "Start");
}

public void Start()

{

this.DVR.Start();

CoreLogic.Utilities.Logger.LogDebug("Called start, will wait...", null, "Start");

System.Threading.Thread.Sleep(500);

CoreLogic.Utilities.Logger.LogDebug("Continuing...", null, "Start");

}

Now press File > Save module, and save it as CoreLogic.dll. This will update the file in-place. Now go back to services.msc and restart the service. It should work after a couple seconds. Your log should look like this now:

(The first time it tries I still get an error, but the next time I see this:)

2:02:15 PM Camera 1: CheckReconnect: Reconnecting
2:02:15 PM Camera 1: EnableDevice: Enabled
2:02:15 PM Start: Called start, will wait...
2:02:15 PM Connect: creating pipe *GUID*
2:02:16 PM PortScanner: checking: *ip address*
2:02:16 PM PortScanner: checking: *ip address*
...
2:02:16 PM Start: Continuing...
2:02:16 PM Camera 1: SetupFormat: Finding Stream Info

2:02:15 PM Camera 1: CheckReconnect: Reconnecting

2:02:15 PM Camera 1: EnableDevice: Enabled

2:02:15 PM Start: Called start, will wait...

2:02:15 PM Connect: creating pipe *GUID*

2:02:16 PM PortScanner: checking: *ip address*

...

2:02:16 PM Start: Continuing...

2:02:16 PM Camera 1: SetupFormat: Finding Stream Info

Notice how the pipe is created right after the wait starts, so 500ms is pretty safe. Enjoy!

I just wanted to share a little snippet that took me a few minutes to write but that is really useful. Let’s say you want to display a list of items separated by a string, or a line break. There are lots of options here: https://stackoverflow.com/questions/34034038/how-to-render-react-components-by-using-map-and-join but they are not very elegant.

How about if you could write something like:

function render({ products }) {
  return Utils.mapWithSeparator(products, <br/>, product =>
    <a href={"/Product/Details?id=" + product.id}>{product.description}</a>
  );
}

function render({ products }) {

return Utils.mapWithSeparator(products, <br/>, product =>

<a href={"/Product/Details?id=" + product.id}>{product.description}</a>

);

}

and get a list of links, separated by line breaks?

Well you can. Here is the code:

    static mapWithSeparator<T>(source: Iterable<T>, 
                               separator: ReactNode, 
                               mapfn: (x: T) => ReactNode) {
        const result: ReactNode[] = [];

        const iter = source[Symbol.iterator]();

        let { value: current, done: done } = iter.next();
        if (done) return result;

        let last = current;
        ({ value: current, done: done } = iter.next());

        let i = isValidElement(separator) ? 0 : undefined;
        while (!done) {
            result.push(mapfn(last));
            if (i !== undefined)
                result.push(cloneElement(separator as ReactElement, { key: "sep_" + i++ }));
            else
                result.push(separator);
            last = current;
            ({ value: current, done: done } = iter.next());
        }
        result.push(mapfn(last));
        return result;
    }

static mapWithSeparator<T>(source: Iterable<T>,

separator: ReactNode,

mapfn: (x: T) => ReactNode) {

const result: ReactNode[] = [];

const iter = source[Symbol.iterator]();

let { value: current, done: done } = iter.next();

if (done) return result;

let last = current;

({ value: current, done: done } = iter.next());

let i = isValidElement(separator) ? 0 : undefined;

while (!done) {

result.push(mapfn(last));

if (i !== undefined)

result.push(cloneElement(separator as ReactElement, { key: "sep_" + i++ }));

else

result.push(separator);

last = current;

({ value: current, done: done } = iter.next());

}

result.push(mapfn(last));

return result;

}

There are simpler ways of writing this but I wanted to understand how iterators work.

Category: Uncategorized

Running Agent DVR on a slow computer

Map react items with separator