How can i get the output to my TMemo

[mathias63]

Hello again i did some code to open up my rtsp stream with ffplay after a button click, that now works good, but i would allso like to have the output written in a tmemo, to read eventually errors when connecting to it. So this is my code so far in a click button event:

RunProgram := TProcess.Create(nil);
RunProgram.CommandLine := ('/bin/ffplay -rtsp_transport tcp -i rtsp://myuser:mypass@192.168.0.50:554');
RunProgram.Execute;
RunProgram.Free;

I have tried some examples that i found on internet, but i dont really get any output, and the app freezes.
If some one could tell me i would be happy...


/Mathias

[jamie]

you need to run the code within a TTHREAD object so you can sit there without locking up the rest of your code.

[mathias63]

you need to run the code within a TTHREAD object so you can sit there without locking up the rest of your code.

Thanks for your answer. I have no clue how or what threads does then, i only made some apps long ago in delphi (maybe 20 years ago). But now try using linux and Lazarus.
But will try google it and see if i can understand how to do this.

[jamie]

https://www.sigmdel.ca/michel/program/fpl/yweather/process_thread_en.html

Look there, scroll down.

Jamie

[n7800]

See also: https://wiki.freepascal.org/Executing_External_Programs#Reading_large_output

[mathias63]

Thanks for tips but still feels a bit hard to understand what i need to do ....if i just could download the most simple project with a form, a Tmemo, and button that starts another app and write the output in a TMemo or similar would help so i can just try change some code for my needs.

[mathias63]

See also: https://wiki.freepascal.org/Executing_External_Programs#Reading_large_output

I was trying this on a new project, but now i have no clue how do i get the output to the TMemo?

[egsuh]

Instead of
     with TStringList.Create do LoadfromStream
in following,

Code: Pascal  [Select][+][-]

1.   // Or the data can be shown on screen
2.   with TStringList.Create do
3.   begin
4.     OutputStream.Position := 0; // Required to make sure all data is copied from the start
5.     LoadFromStream(OutputStream);
6.     writeln(Text);
7.     writeln('--- Number of lines = ', Count, '----');
8.     Free
9.   end;

something like this:

    OutputStream.Position := 0;
    Memo1.Lines.LoadFromStream(OutputStream);

[Thausand]

I have tried some examples that i found on internet, but i dont really get any output, and the app freezes.

Example make wrong use TProcess options (https://www.freepascal.org/docs-html/fcl/process/tprocess.commandline.html read deprecate is for Linux because no work). Make use parameters https://www.freepascal.org/docs-html/fcl/process/tprocess.parameters.html

If some one could tell me i would be happy...

Thanks for tips but still feels a bit hard to understand what i need to do ....if i just could download the most simple project with a form, a Tmemo, and button that starts another app and write the output in a TMemo or similar would help so i can just try change some code for my needs.

Is no simple answer, you see when get there but can make very simple example.

something like this:

No work for ffplay output because output have many begin of line rewrite. Is continue output until finish (or error).

Code: Pascal  [Select][+][-]

1. {$mode objfpc}{$h+}
2. uses
3.   cthreads, sysutils, sockets, ctypes, process, pipes;
4.  
5. // is idea not me
6. function GetLocalIPString: string;
7. const
8.   GDNS_ADDR = '127.0.0.1';
9.   GDNS_PORT = 53;
10. var
11.   sockErr  : cint    = 0;
12.   fail     : boolean = false;
13.   socket   : cint;
14.   IPAddr   : TInetSockAddr;
15.   HostAddr : TSockAddr;
16.   namelen  : cuint32;
17. begin
18.   result := '';
19.  
20.   socket := fpsocket(AF_INET, SOCK_DGRAM, 0);
21.   fail := (socket = -1);
22.  
23.   if not fail then
24.   begin
25.     IPAddr.sin_family      := AF_INET;
26.     IPAddr.sin_port        := htons(GDNS_PORT);
27.     IPAddr.sin_addr.s_addr := StrToHostAddr(GDNS_ADDR).s_addr;
28.  
29.     fail := (fpConnect(socket,@IPAddr,SizeOf(IPAddr)) <> 0);
30.     if not fail then
31.     begin
32.       namelen := SizeOf(HostAddr);
33.       fail := (fpgetsockname(socket, @HostAddr, @namelen) <> 0);
34.       if not fail then
35.       begin
36.         result := NetAddrToStr(HostAddr.sin_addr);
37.         exit;
38.       end;
39.     end
40.   end;
41.  
42.   if fail then
43.   begin
44.     // have error raise
45.     sockerr := socketError;
46.     writeln('error local get IP-Address: ', sockerr);
47.     halt(255);
48.   end;
49. end;
50.  
51. procedure Log(S: string);
52. begin
53.   writeln(S);  // or write memo(.lines)
54. end;
55.  
56. procedure Log(S: string; const A: array of const);
57. begin
58.   Log(Format(S, A));
59. end;
60.  
61. procedure RunFFPlay;
62. var
63.   LocalIP    : string;
64.   FFPlayProc : TProcess;
65.   Answer     : string;
66.   Count      : LongInt;
67. begin
68.   localIP:= GetLocalIPString;
69.   Log('IP-Address = %s',[LocalIP]);
70.  
71.   FFPlayProc:= TProcess.Create(nil);
72.   try
73.     FFPlayProc.Executable:= 'ffplay';
74.     FFPlayProc.Parameters.Add('-i');
75.     FFPlayProc.Parameters.Add('rtsp://' + localIP + ':8090/live');
76.  
77.     FFPlayProc.Options:=[poUsePipes, poStderrToOutPut];
78.     FFPlayProc.Execute;
79.  
80.     // have output FFPlay
81.     Log('start FFPlay loop');
82.     while FFPlayProc.Running or (FFPlayProc.Output.NumBytesAvailable>0) do
83.     begin
84.       if FFPlayProc.Output.NumBytesAvailable>0 then
85.       begin
86.         Count:= FFPlayProc.Output.NumBytesAvailable;
87.         SetLength(Answer,Count);
88.  
89.         Count:= FFPlayProc.Output.Read(Answer[1],Count);
90.         Log(Answer);
91.         Sleep(1);
92.         // can have stop while boolean
93.       end;
94.     end;
95.     Log('stop FFPlay loop');
96.   finally
97.     FFPlayProc.Free;
98.   end;
99. end;
100.  
101. ..
102. .. RunFFPlay;
103. ..
104.  

If want GUI work then make RunFFPlay in TProcess of own.

[Thaddy]

you need to run the code within a TTHREAD object so you can sit there without locking up the rest of your code.

Or use TProcessAsync.

[marcov]

See https://forum.lazarus.freepascal.org/index.php?topic=62855.0

[mathias63]

Thanks for answers...takes some time for me to get used to lazarus, will see if i can fix this in the future.

[mathias63]

Thanks Thausand! i  will try that code tomorrow and see if it works

[Thausand]

Thanks Thausand! i  will try that code tomorrow and see if it works

Make note and change parameters for ffplay because example use parameters for work my configuration.

Link marcov also good because example make process output and store in memo.

[Jurassic Pork]

hello,
have a look here
The example project use TprocessEx  from processutils unit of the fpcupdeluxe project  and displays output in a Tmemo from a command line in RealTime.

Friendly, J.P