screen recording per command line, i.e. bash-script

rohuezo · Postby **rohuezo** » 21 Feb 2016 20:41

Hi guys,

I'm trying to start the screen recording feature of VLC media player using the command line under MacOS X (10.11.3, El Capitan) using a bash-script. I have accomplished this using the Windows version of VLC media player (2.0.8) and I'm now trying with VLC media player (2.2.2) under MacOSX. I'm using the following bash-script and it works, but not as I wanted/intend to do. Here is my script:

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#!/bin/bash

#Filename parameters
TIMESTAMP=$(date +%Y%m%d-%H%M%S)
EXT="mp4"

# Screen parameters
#screen 1 1280 800
#screen 2 1600x1200
SCREENINDEX="1"
SCREENWIDTH="1280"
SCREENHEIGHT="800"
SCREENTOP="0"
SCREENLEFT="0"

# Transcode parameters
TRANSCODEVENC="x264"
TRANSCODEVCODEC="h264"
TRANSCODESCALE="1"
TRANSCODEFPS="25"
TRANSCODEVB="1024"

# Standard parameters
STANDARDACCESS="file"
STANDARDMUX="mp4"
STANDARDFILENAME="vlc-record-$TIMESTAMP-screen__""$SCREENWIDTH""x""$SCREENHEIGHT""_$TRANSCODEFPS""fps_$TRANSCODEVB""kb.$EXT"
STANDARDPATH="/Users/rohuezo/Movies/vlc-output/$STANDARDFILENAME"

# Command parameters
VLCEXE="/Applications/VLC.app/Contents/MacOS/VLC"
VLCDEVICE="screen://"
#VLCINTF="-I dummy $@"
VLCINTF="-I rc $@ --telnet-host 127.0.0.1 --telnet-port 81"
VLCDEFAULTS=""
VLCSCREEN="--screen-index $SCREENINDEX --screen-width $SCREENWIDTH --screen-height $SCREENHEIGHT --screen-top $SCREENTOP --screen-left $SCREENLEFT" 
VLCSTANDARD=":standard{mux=$STANDARDMUX,access=$STANDARDACCESS{no-overwrite},dst=$STANDARDPATH}"
VLCTRANSCODE=":sout=#transcode{vcodec=$TRANSCODEVCODEC,vb=$TRANSCODEVB,scale=$TRANSCODESCALE,fps=$TRANSCODEFPS,acodec=none}"
 
VLCCOMMAND="$VLCEXE $VLCDEVICE $VLCINTF $VLCDEFAULTS $VLCSCREEN $VLCTRANSCODE$VLCSTANDARD"

echo "Calling: $VLCCOMMAND"

exec $VLCCOMMAND

The variable

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#VLCINTF="-I dummy $@"
VLCINTF="-I rc $@ --telnet-host 127.0.0.1 --telnet-port 81"

, doesn't matter which one, above is the line I believe is not working as I expect it. As in the Windows version I would expect that the remote control interface under MacOSX would start listening on host 127.0.0.1 port 81 and if I telnet to that host and port I could send the

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quit

command which will stop the screen recording. Here is the command line output after executing my script:

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MacBookPro13:ScreenRecordingScripts rohuezo$ ./ScreenRecording.sh 
Calling: /Applications/VLC.app/Contents/MacOS/VLC screen:// -I rc   --telnet-host 127.0.0.1 --telnet-port 81  --screen-index 1 --screen-width 1280 --screen-height 800 --screen-top 0 --screen-left 0 :sout=#transcode{vcodec=h264,vb=1024,scale=1,fps=25,acodec=none}:standard{mux=mp4,access=file{no-overwrite},dst=/Users/rohuezo/Movies/vlc-output/vlc-record-20160221-203010-screen__1280x800_25fps_1024kb.mp4}
VLC media player 2.2.2 Weatherwax (revision 2.2.2-3-gf8c9253)
[0000000100604218] core interface error: no suitable interface module
[000000010022cf78] core libvlc error: interface "oldrc,none" initialization failed
[00000001006041e8] core interface error: no suitable interface module
[000000010022cf78] core libvlc error: interface "(null),none" initialization failed
[0000000100708ca8] [cli] lua interface: Listening on host "*console".
VLC media player 2.2.2 Weatherwax
Command Line Interface initialized. Type `help' for help.
> [00000001008758b8] x264 encoder: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX

[00000001008758b8] x264 encoder: profile High, level 3.2

[00000001008758b8] x264 encoder: final ratefactor: 28,61

[00000001006051e8] stream_out_transcode stream out: input interval 100000 (base 1)
[00000001006051e8] stream_out_transcode stream out: output interval 40000 (base 1)
[00000001008758b8] x264 encoder: using SAR=1/1

[00000001008758b8] x264 encoder: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX

[00000001008758b8] x264 encoder: profile High, level 3.2

The output file is created and the screen recording begins. But the only way to stop it is by pressing

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Ctrl-C

When I do that I get the following output added to the one above:

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^C[0000000100708ca8] [cli] lua interface error: Error loading script /Applications/VLC.app/Contents/MacOS/share/lua/intf/cli.luac: ...kage/macosx/../../../share/lua/intf/modules/host.lua:279: Interrupted.
[00000001008758b8] x264 encoder: frame I:3     Avg QP:16,31  size:253710

[00000001008758b8] x264 encoder: frame P:162   Avg QP:16,61  size:  6617

[00000001008758b8] x264 encoder: frame B:453   Avg QP:15,10  size:   216

[00000001008758b8] x264 encoder: consecutive B-frames:  1,8%  1,3%  0,5% 96,4%

[00000001008758b8] x264 encoder: mb I  I16..4: 35,0% 10,8% 54,2%

[00000001008758b8] x264 encoder: mb P  I16..4:  0,7%  0,4%  0,8%  P16..4:  6,6%  0,6%  0,5%  0,0%  0,0%    skip:90,4%

[00000001008758b8] x264 encoder: mb B  I16..4:  0,1%  0,1%  0,0%  B16..8:  3,6%  0,0%  0,0%  direct: 0,0%  skip:96,2%  L0:31,7% L1:68,2% BI: 0,1%

[00000001008758b8] x264 encoder: final ratefactor: 16,94

[00000001008758b8] x264 encoder: 8x8 transform intra:17,8% inter:48,7%

[00000001008758b8] x264 encoder: coded y,uvDC,uvAC intra: 35,6% 46,5% 41,2% inter: 0,7% 1,3% 0,8%

[00000001008758b8] x264 encoder: i16 v,h,dc,p: 48% 47%  4%  0%

[00000001008758b8] x264 encoder: i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 30% 18% 46%  1%  1%  1%  2%  0%  2%

[00000001008758b8] x264 encoder: i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 32% 30% 12%  2%  5%  4%  7%  3%  5%

[00000001008758b8] x264 encoder: i8c dc,h,v,p: 49% 37% 12%  2%

[00000001008758b8] x264 encoder: Weighted P-Frames: Y:0,0% UV:0,0%

[00000001008758b8] x264 encoder: ref P L0: 87,9%  3,5%  7,1%  1,5%

[00000001008758b8] x264 encoder: ref B L0: 44,9% 54,3%  0,8%

[00000001008758b8] x264 encoder: ref B L1: 96,8%  3,2%

[00000001008758b8] x264 encoder: kb/s:624,85

MacBookPro13:ScreenRecordingScripts rohuezo$

The output file is a correct recording of the screen. My problem is that this way I cannot use scripts to stop the recording when unattended, e.g. overnight integrated tests, etc.

Does anyone know how to set up the remote control under MacOSX for the command line so I can telnet to it to control it? Any help will be greatly appreciated.

Best regards,

rohuezo · Postby **rohuezo** » 22 Feb 2016 21:25

Ok, found the answer/solution to my problem. Here is my bash script which will start a screen recording and will create a unix socket instead of a telnet connection:

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#!/bin/bash

# Filename parameters
TIMESTAMP=$(date +%Y%m%d-%H%M%S)
EXT="mp4"

# Screen parameters
#screen 1 1280 800
#screen 2 1600x1200
SCREENINDEX="1"
SCREENWIDTH="1280"
SCREENHEIGHT="800"
SCREENTOP="0"
SCREENLEFT="0"

# Transcode parameters
TRANSCODEVENC="x264"
TRANSCODEVCODEC="h264"
TRANSCODESCALE="1"
TRANSCODEFPS="25"
TRANSCODEVB="1024"

# Standard parameters
STANDARDACCESS="file"
STANDARDMUX="mp4"
STANDARDFILENAME="vlc-record-$TIMESTAMP-screen__""$SCREENWIDTH""x""$SCREENHEIGHT""_$TRANSCODEFPS""fps_$TRANSCODEVB""kb.$EXT"
STANDARDPATH="/Users/rohuezo/Movies/vlc-output/$STANDARDFILENAME"

# Command parameters
VLCEXE="/Applications/VLC.app/Contents/MacOS/VLC"
VLCDEVICE="screen://"
VLCINTF="-I rc --rc-unix /Users/rohuezo/vlc.sock"
VLCSCREEN="--screen-index $SCREENINDEX --screen-width $SCREENWIDTH --screen-height $SCREENHEIGHT --screen-top $SCREENTOP --screen-left $SCREENLEFT" 
VLCSTANDARD=":standard{mux=$STANDARDMUX,access=$STANDARDACCESS{no-overwrite},dst=$STANDARDPATH}"
VLCTRANSCODE=":sout=#transcode{vcodec=$TRANSCODEVCODEC,vb=$TRANSCODEVB,scale=$TRANSCODESCALE,fps=$TRANSCODEFPS,acodec=none}"
 
VLCCOMMAND="$VLCEXE $VLCDEVICE $VLCINTF $VLCSCREEN $VLCTRANSCODE$VLCSTANDARD"

echo "Calling: $VLCCOMMAND"

exec $VLCCOMMAND

then I have another bash script that sends the quit signal with a pipe command:

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echo quit | nc -U /Users/rohuezo/vlc.sock

ending the recording per script and saving the file specified in the command line.

Important was the line:

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VLCINTF="-I rc --rc-unix /Users/rohuezo/vlc.sock"

For some reason the sockets work instead of telnet. I read on another thread here in the forum that telnet in MacOS X is very "buggy"!

Postby **ajmas** » 25 Feb 2016 21:52

You may even want to look at ssh instead of telnet, if you are executing from a command line. For example, you can do:

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ssh user@host 'remote command to execute'

I can't comment on the health level of the MacOS implementation of telnet, since I haven't used it in a while and instead prefer ssh for remote execution, since it is more secure for credentials.

rohuezo · Postby **rohuezo** » 25 Feb 2016 22:57

Hi ajmas,

do you mean ssh as -I interface? I will try to find out the ssh way of connecting. I always thought telnet was not to secure... Thanks for the tip!

Regards,

Postby **ajmas** » 26 Feb 2016 21:58

What I meant is to 'ssh'ing into the host machines and then run your scripts there. Running ssh as indicated will ssh into the host run the command and then exit. An example, which leverages Applescript (I specified the absolute path, since I have multiple VLC installs and it was getting confused about which instance to use).

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ssh localhost "osascript -e 'tell application \"/Applications/VLC.app\" to quit'"

BTW I don't have enough experience with VLC's telnet interface to provide help there, which is the other reason, beyond security, for suggesting an alternative approach.

Edit: Just played around with the telnet interface and it would appear to be 'shutdown' is the command to send to quit VLC, whereas 'quit' will simply quit the telnet connection. You can see the available commands by typing 'help' in the telnet interface.

rohuezo · Postby **rohuezo** » 27 Feb 2016 19:21

Now I understand what you mean ajmas! Thanks for the tip and the example! I will give it a try.

Concerning telnet, I can't really tell you why the command 'quit' works for me (under Windows!). Here is the little VBScript I use to telnet to VLC listening on 127.0.0.1:81

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<job>
	<script language="VBScript">
		Option Explicit
		On Error Resume Next
 
		Dim WshShell
		set WshShell=CreateObject("WScript.Shell")
		WshShell.run "cmd.exe"
		WScript.Sleep 1000
 
		'Send commands to the window as needed - IP and commands need to be customized
		'Step 1 - Telnet to remote IP
		WshShell.SendKeys "telnet 127.0.0.1 81"
		WshShell.SendKeys ("{Enter}")
		WScript.Sleep 1000
 
		'Step 2 - Stop VLC Recording
		WshShell.SendKeys "quit"
		WshShell.SendKeys ("{Enter}")
		WScript.Sleep 3000
 
		'Step 3 - Exit Command Window
		WshShell.SendKeys " exit" '' <-- Important, empty space before exit!
		WshShell.SendKeys ("{Enter}")
		WScript.Sleep 1000
 
		WScript.Quit	
	</script>
</job>

Here is the output after the telnet command:

Step 1: connects to telnet

Step 2: send 'quit' to stop VLC from recording and terminate the file correctly

Step 3: send ' exit' to exit telnet

Regards,

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screen recording per command line, i.e. bash-script

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