libVLC VLM example

[desp]

Hi there,
i am using 2.x libvlc version and want to use vlm functionality to stream "sheduled" streams (udp, rtp protocols). But i end up with strange problems such a blocking in libvlc_vlm_stop_media or in some more certain libvlc_vlm_* functions in my own libvlc_VlmMediaInstanceStatusEnd event callback. What i want is actually just to stop current streaming in any time, or continue streaming another file when current one is finished. I need some decent libvlc_vlm_* usage examples or just advices to find out what i am doing wrong. To clear out my actual problem i provide some code examples:

Registering event handler:

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eventManager = libvlc_vlm_get_event_manager(vlc); libvlc_event_attach(eventManager, libvlc_VlmMediaInstanceStatusEnd, vlcEventHandler, NULL);

My event callback

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void vlcEventHandler(const struct libvlc_event_t * evt, void * data) { printf("stream end?\n"); int ret = libvlc_vlm_stop_media(vlc, "media_name"); PINFO("Returned: %d", ret); // it does not print, prints -1 when media_name is faked one //int ret = libvlc_vlm_set_input(vlc, "media_name", "/home/algirdas/dev/live555/adstreamer/big_buck_bunny_1080p_surround.ts"); blocks here again //PINFO("Return value: %d", ret); //ret = libvlc_vlm_play_media(vlc, "media_name"); blocks here too //PINFO("Return value: %d", ret); }

Streaming (playing)

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libvlc_vlm_play_media(vlc, "media_name");

After *_play_media() call i use

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while (1) { sleep(1); }

Thanks!

[Jean-Baptiste Kempf]

To be honest, I wouldn't be surprised if the libvlc_vlm code to have some internal issues.

[Rémi Denis-Courmont]

Seriously, for scheduling, you may be better off implementing the timer in your application. You can use a normal LibVLC media player object then.

The VLM API is a bitch, if I may say.

[desp]

Seriously, for scheduling, you may be better off implementing the timer in your application. You can use a normal LibVLC media player object then.

Huh? It is not about playback, it is about streaming to network or maybe libvlc_media_player_* module has streaming ability too which i did not notice. Can anyone give just simple streaming without VLM example to start with?

[Rémi Denis-Courmont]

It's the same. You need to set the input path, the sout options, etc.

The only component that, alas, can currently really only be reached through VLM is RTSP VoD.

[desp]

Thanks for your answers. So it depends only on sout i guess, i will try to read docs about it, thanks again. Will write here when i fail again

[desp]

Ok, i got same problem about blocking as i said about from the start. Now all VLM functions are removed. I extracted my other code and tested vlc-only. Wrote my problems in code as comments. There it is:

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#include <vlc/libvlc.h> #include <vlc/libvlc_media.h> #include <vlc/libvlc_media_player.h> #include <vlc/libvlc_events.h> #include <stdio.h> #include <time.h> #include <unistd.h> #define PERROR(x,...) printf("ERROR: (%s) "x"\n", __func__, ##__VA_ARGS__) #define PWARNING(x,...) printf("WARNING: (%s) "x"\n", __func__, ##__VA_ARGS__) #define PINFO(x,...) printf("INFO: (%s) "x"\n", __func__, ##__VA_ARGS__) static int streaming = 1; static libvlc_instance_t *vlc; static libvlc_media_player_t *mediaPlayer; void vlcEventHandler(const struct libvlc_event_t * evt, void * data) { PINFO("stream end? %x", mediaPlayer); libvlc_media_t *m = libvlc_media_new_path(vlc, "movie_next.ts"); // PROBLEM: blocks from here libvlc_media_player_stop(mediaPlayer); libvlc_media_player_set_media(mediaPlayer, m); libvlc_media_player_play(mediaPlayer); PINFO("Does not reach here"); } int main(int argc, char * argv[]) { const char * sout = "--sout #std{access=udp,mux=ts,dst=239.1.1.2}"; const char * const vlcArgs[] = { "-I", "dummy", "--ignore-config", "--extraintf=logger", "--verbose=0", "--sout-all", "--sout", "#std{access=udp,mux=ts,dst=239.1.1.2}", "--sout-keep", "--no-skip-frames", "--no-drop-late-frames", "vlclog.log" }; const char * url = "movie1.ts"; libvlc_event_manager_t *eventManager; // VLC main job vlc = libvlc_new(sizeof(vlcArgs)/sizeof(vlcArgs[0]), (const char * const*)vlcArgs); libvlc_media_t *m = libvlc_media_new_path(vlc, url); libvlc_media_add_option(m, sout); // ANOTHER PROBLEM: this one is not working either, how to add whole sout line by this method? I need it for more dynamic use mediaPlayer = libvlc_media_player_new_from_media(m); libvlc_media_release(m); // events eventManager = libvlc_media_player_event_manager(mediaPlayer); libvlc_event_attach(eventManager, libvlc_MediaPlayerEndReached, vlcEventHandler, NULL); libvlc_media_player_play(mediaPlayer); PINFO("Entering loop"); while (streaming) { sleep(1); } PINFO("Exiting loop.."); }

[Rémi Denis-Courmont]

Controlling LibVLC from its own event callback is going to deadlock. No big surprises there.

[desp]

Oh, i understand now, but... how to avoid it? It seems i need to add more logics here, like set some extra vars and change player's state in some other places but not in event callbacks. Thanks. Btw, can i add sout line with libvlc_media_add_option() or it can be used only when creating vlc instance?

[sherington]

Oh, i understand now, but... how to avoid it?

I simply send all the events I receive via the callback to a background thread. That other thread can serialise all the events and safely call back into libvlc.