vlc command line transforming to libvlc

[zamek]

Hi All,

I need to stream + display from a webcam on Debian Linux. In vlc I made the command line:

vlc -vvv v4l2:///dev/video0 --file-caching=800 :input-slave=alsa:// :v4l2-standard=0 '--sout=#transcode{vcodec=mp2v,vb=800,scale=1,acodec=none}:duplicate{dst=file{dst=q.ts},dst=display}'

it works well display and stream. And when I try to use it from my client program, It seems to works, display the video, but it doesn't create video file and there is no error on console.

How can I translate vlc command line to libvlc command line?

thx,
Zamek

[zamek]

Some interesting things:

1. if --file-caching=800 :input-slave=alsa:// :v4l2-standard=0 params are in option string, there is video in vlc window but vlc doesn't create stream file and there are absolutly NO error in messages.
2. if these params are not in option string it creates stream file and save correct, but there is NO video in vlc window.

Is there any timing mistake? What is the difference vlc and libvlc? vlc works correct with this params, libvlc doesn' t.
If I try to set an existing video file as source, its working well, only v4l2 webcam doesn' t works.
My webcam is a Pinnacle Dazzle video creator DVC 1000

thx,
Zamek

[sherington]

In vlc I made the command line:

vlc -vvv v4l2:///dev/video0 --file-caching=800 :input-slave=alsa:// :v4l2-standard=0 '--sout=#transcode{vcodec=mp2v,vb=800,scale=1,acodec=none}:duplicate{dst=file{dst=q.ts},dst=display}'

How can I translate vlc command line to libvlc command line?

thx,
Zamek

Maybe this can give you a hint? viewtopic.php?f=32&t=56939&p=251520&hilit=braca#p251520

The syntax is different, for example you change --sout to :sout= when you use libvlc.

[zamek]

yes I use it.

Here is the command line of vlc :

vlc -vvv v4l2:///dev/video0 --file-caching=800 :input-slave=alsa:// :v4l2-standard=0 '--sout=#transcode{vcodec=mp2v,vb=800,scale=1,acodec=none}:duplicate{dst=file{dst=./q.ts},dst=display}'
it works well, show video and creates a stream.

Here is the libvlc command code:

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SwingUtilities.invokeLater(new Runnable() { @Override public void run() { String options = " :file-caching=800 :input-slave=alsa:// :v4l2-standard=0 ':sout=#transcode{vcodec=mp2v,vb=800,scale=1,acodec=none}:duplicate{dst=file{dst=./q.ts},dst=display}'"; mediaPlayer.playMedia("v4l2:///dev/video0", options); } });

it shows video, but not create stream and there is NO error in status messages.

[ps2010]

Hi,

I am facing the similar issue.

I am using this command-line for streaming which works perfectly fine.

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cvlc -vvv v4l2:// :input-slave=alsa:// :v4l2-standard=0 :sout='#transcode{vcodec=h264,vb=0,scale=0,acodec=mp4a,ab=128,channels=2,samplerate=44100}:std{access=http,mux=ts,dst=192.168.5.128:8080}' :no-sout-audio :no-sout-rtp-sap :no-sout-standard-sap :sout-keep

But, when I try to accomplish this using libVLC using the following code,

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const char *args[] = {"--plugin-path=/usr/lib/vlc/plugins"}; const char options[] = {"--input-slave=alsa:// --v4l2-standard=0 --sout='#transcode{vcodec=mp4v,vb=1000,scale=0,acodec=mpga,ab=128,channels=2,samplerate=44100} --std{access=http,mux=ts,dst=192.168.65.129:8080}' --no-sout-audio --no-sout-rtp-sap --no-sout-standard-sap --sout-keep"}; inst = libvlc_new (1, args); m = libvlc_media_new_path (inst, "v4l2://"); libvlc_media_add_option (m, options); mp = libvlc_media_player_new_from_media (m); libvlc_media_player_play (mp);

This plays the webcam capture locally at the server, but does not seem to stream it on to the network. There is no error as well.
But, when I try to capture the stream at the client's side, I get an error in opening the connection.

Please guys... tell me what am I doing wrong!!

[ps2010]

Any help anyone... please!!

[sherington]

Any help anyone... please!!

Well I don't know the full answer, but in general I believe the following to be true:

1. You have to add options one at a time, not all in one go.
2. You don't use "--" syntax, you have to use for example ":sout"

[ps2010]

Well I don't know the full answer, but in general I believe the following to be true:

1. You have to add options one at a time, not all in one go.
2. You don't use "--" syntax, you have to use for example ":sout"

So, I modified the code as follows, hoping this is what you suggested

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const char *args[] = {"--plugin-path=/usr/lib/vlc/plugins"}; const char options1[] = {":input-slave=alsa://"}; const char options2[] = {":v4l2-standard=0"}; const char options3[] = {":transcode{vcodec=mp4v,vb=1000,scale=0,acodec=mpga,ab=128,channels=2,samplerate=44100}"}; const char options4[] = {":sout=#standard{mux=ts,access=http,dst=192.168.65.129:8080}"}; const char options5[] = {":no-sout-audio"}; const char options6[] = {":no-sout-rtp-sap"}; const char options7[] = {":no-sout-standard-sap"}; const char options8[] = {":sout-keep"}; /* Load the VLC engine */ inst = libvlc_new (1, args); /* Create a new item */ m = libvlc_media_new_path (inst, "v4l2://"); libvlc_media_add_option (m, options1); libvlc_media_add_option (m, options2); libvlc_media_add_option (m, options3); libvlc_media_add_option (m, options4); libvlc_media_add_option (m, options5); libvlc_media_add_option (m, options6); libvlc_media_add_option (m, options7); libvlc_media_add_option (m, options8); /* Create a media player playing environement */ mp = libvlc_media_player_new_from_media (m); /* play the media_player */ libvlc_media_player_play (mp);

This doesn't start the media at all at the server.
It throws this error:

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[0x870a4bc] main access out: creating httpd [0x870a4bc] main access out error: socket bind error (Permission denied) [0x870a4bc] main access out error: cannot create socket(s) for HTTP host [0x870a4bc] access_output_http access out error: cannot listen on 192.168.65.129 port 8080 [0x8708ef4] stream_out_standard stream out error: no suitable sout access module for `http/ts://192.168.65.129:8080' [0x86ff12c] main stream output error: stream chain failed for `standard{mux=ts,access=http,dst=192.168.65.129:8080}' [0x86f5fd4] main input error: cannot start stream output instance, aborting

I tried different combinations by uniting transcode and standard option, but no luck.

Please please advise!!

[sherington]

Here's what works for me in Java:

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String[] options = { ":sout=#transcode{vcodec=mp4v,vb=2048,scale=1,acodec=mpga,ab=128,channels=2,samplerate=44100}:duplicate{dst=display,dst=rtp{dst=230.0.0.1,port=5555,mux=ts}}", ":no-sout-rtp-sap", ":no-sout-standard-sap", ":sout-all", ":sout-keep", ":input-slave=alsa://hw:0,0" }; mediaPlayer.playMedia("v4l2:///dev/video0", options);

That array of options gets iterated and each individual option added with libvlc_media_add_option().

I've picked different streaming options to you, but at least it's something that works that you can refer to.

Note that "duplicate" does not seem to work with vlc 1.2.0 from git, but it's ok on vlc 1.1.7.

I can not help you any more than that.

[ps2010]

Here's what works for me in Java:
That array of options gets iterated and each individual option added with libvlc_media_add_option().

I've picked different streaming options to you, but at least it's something that works that you can refer to.

Note that "duplicate" does not seem to work with vlc 1.2.0 from git, but it's ok on vlc 1.1.7.

I can not help you any more than that.

Hi Sherington,

First of all, the libvlc_media_add_option() takes cost char* as the argument and not the array of string as you mentioned.

Still I tried what you suggested and the outcome was same as the beginning.....
The webcam capture was being played at the server but there was no streaming. The client gave error in opening the connection at HTTP port.

[sherington]

First of all, the libvlc_media_add_option() takes cost char* as the argument and not the array of string as you mentioned.

You did read the bit in my previous post where I said it was Java, and where I said I iterated the array calling libvlc_media_player_add_option()? I expected you to be able to adapt that example Java code to your own C code, I did not think that I needed to explain it all in more detail.

Still I tried what you suggested and the outcome was same as the beginning.....

I can't help you. What I posted works - I capture video from a web-cam, I encode it, I display it locally, I stream it across the network, I have another client display the stream. It all works.

[ps2010]

I can't help you. What I posted works - I capture video from a web-cam, I encode it, I display it locally, I stream it across the network, I have another client display the stream. It all works.

Thanks for your help Sherington...
I will try some other methods.... hope something works for me!!

[sherington]

I can't help you. What I posted works - I capture video from a web-cam, I encode it, I display it locally, I stream it across the network, I have another client display the stream. It all works.

Thanks for your help Sherington...
I will try some other methods.... hope something works for me!!

I am not an expert on these options, but I did notice you do your sout/transcode differently to me. Did you try using the exact same options in my example?

[sherington]

I am really not an expert on these things, but this jumps out:

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main access out: creating httpd [0x870a4bc] main access out error: socket bind error (Permission denied) [0x870a4bc] main access out error: cannot create socket(s) for HTTP host [0x870a4bc] access_output_http access out error: cannot listen on 192.168.65.129 port 8080

Is something else already using port 8080?

[dineshlakshmanan]

Hi,

I am exactly looking into this issue now. I want to stream the 6 webcam locally. Can someone tell me in which code I should do the changes in vlc source code. Because I could see in the following location inside vlc source code folder
~/vlc-source/test/libvlc/media_player.c


Should I change in the above file or should I change in the libvlc.c


Kindly someone help me to transform this vlc command line in a source code which is in C language.


Thanks in Advance!!!!
Dinesh